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Sample records for onchocerca volvulus comparison

  1. Histological examination of adult Onchocerca volvulus and comparison with the collagenase technique.

    PubMed

    Büttner, D W; Albiez, E J; von Essen, J; Erichsen, J

    1988-12-01

    The methods used for the assessment of adult Onchocerca volvulus by histology are described. Based on the results of several studies, mainly in Liberia and Burkina Faso, the morphology of the adult filariae in histological sections is represented as far as it is relevant for the evaluation. Especially are described the morphological alterations due to old age of the worms, to chronic hyperreactivity of the human host (sowda) and effects of the macrofilaricidal suramin and of microfilaricidal drugs. Quantitative results are reported on untreated adult O. volvulus from various countries, the changes of the worm population during 12 years of vector control in Burkina Faso and the effects of suramin, diethylcarbamazine, metrifonate, and ivermectin. The data from the histological examinations are compared with those gained from the examination of worms isolated by the collagenase technique in the same studies.

  2. The mitogenome of Onchocerca volvulus from the Brazilian Amazonia focus

    PubMed Central

    Crainey, James L; da Silva, Túllio RR; Encinas, Fernando; Marín, Michel A; Vicente, Ana Carolina P; Luz, Sérgio LB

    2016-01-01

    We report here the first complete mitochondria genome of Onchocerca volvulus from a focus outside of Africa. An O. volvulus mitogenome from the Brazilian Amazonia focus was obtained using a combination of high-throughput and Sanger sequencing technologies. Comparisons made between this mitochondrial genome and publicly available mitochondrial sequences identified 46 variant nucleotide positions and suggested that our Brazilian mitogenome is more closely related to Cameroon-origin mitochondria than West African-origin mitochondria. As well as providing insights into the origins of Latin American onchocerciasis, the Brazilian Amazonia focus mitogenome may also have value as an epidemiological resource. PMID:26814648

  3. The mitogenome of Onchocerca volvulus from the Brazilian Amazonia focus.

    PubMed

    Crainey, James L; Silva, Túllio R R da; Encinas, Fernando; Marín, Michel A; Vicente, Ana Carolina P; Luz, Sérgio L B

    2016-01-01

    We report here the first complete mitochondria genome of Onchocerca volvulus from a focus outside of Africa. An O. volvulus mitogenome from the Brazilian Amazonia focus was obtained using a combination of high-throughput and Sanger sequencing technologies. Comparisons made between this mitochondrial genome and publicly available mitochondrial sequences identified 46 variant nucleotide positions and suggested that our Brazilian mitogenome is more closely related to Cameroon-origin mitochondria than West African-origin mitochondria. As well as providing insights into the origins of Latin American onchocerciasis, the Brazilian Amazonia focus mitogenome may also have value as an epidemiological resource.

  4. Misidentification of Onchocerca volvulus as guinea worm.

    PubMed

    Eberhard, M L; Melemoko, G; Zee, A K; Weisskopf, M G; Ruiz-Tiben, E

    2001-12-01

    Over the past 10 years, the status of human infection with guinea worm (Dracunculus medinensis) in the Central African Republic (CAR) has been difficult to ascertain. It is unclear if indigenous cases are occurring and whether cases are migrating into the CAR from surrounding countries. A team of investigators visited the CAR in July-August 2000, to attempt to ascertain the presence of indigenous transmission. No cases of true guinea-worm infection (i.e. dracunculiasis) were detected, but three cases of human infection with Onchocerca volvulus, each of which had been misidentified as dracunculiasis, were detected. The unusual presentation of skin blisters and extraction of an intact female O. volvulus are described. As a result of this investigation, and the confusion of onchocerciasis being misidentified as dracunculiasis, the presence of endemic transmission of guinea worm in the CAR remains in question.

  5. Comparison of the use of skin scarification and skin biopsies to determine the prevalence and intensity of Onchocerca volvulus infection.

    PubMed

    Newell, E D

    1997-09-01

    Two methods for the detection of Onchocerca volvulus microfilariae in the skin were compared in a population-based survey in Gatete, Murama and Jerama, three 'collines' (administrative units) in Burundi. Of the 513 subjects examined, each by both methods, 131 (25.5%) were found positive by skin scarification and 119 (23.2%) by membrane filtration of the fluid in which two skin snips had been incubated. Whilst the sensitivity of the two methods was similar (90% for scarifications and 82% for skin snips), more microfilariae were found by scarification than by biopsy (with geometric mean numbers of 9.1 and 4.1, respectively). Also, more of the cases with infections of low intensity (i.e. < or = 5 microfilariae detected) were found by scarification than by skin snipping (77.9% v. 60.3%; P = 0.06). The endemicity of onchocerciasis and age- and sex-specific prevalences and intensities of infection could be determined equally well using either method. The shortcomings of past comparisons between scarification and skin-snip methods are discussed. Skin scarification has many advantages for the detection of infected individuals in rural health centres and for use in population-based surveys. It may also be helpful when mixed filarial infections are present (especially where onchocerciasis and loiasis co-occur).

  6. Emergence of Onchocerca volvulus from Skin Mimicking Dracunculiasis medinensis

    PubMed Central

    Eberhard, Mark L.; Ruiz-Tiben, Ernesto; Korkor, Andrew S.; Roy, Sharon L.; Downs, Philip

    2010-01-01

    We describe 11 cases of suspected Dracunculus medinensis infection in which the worm recovered was identified as Onchocerca volvulus. Identification was based on morphology of the examined specimen. PMID:21118947

  7. Onchocerca volvulus: comparison of field collection methods for the preservation of parasite and vector samples for PCR analysis.

    PubMed Central

    Toé, L.; Back, C.; Adjami, A. G.; Tang, J. M.; Unnasch, T. R.

    1997-01-01

    In recent years, methods for the identification of the filarial worm Onchocerca volvulus and its vector, blackflies of the Simulium damnosum complex (S. damnosum sensu lato (s.l.)), based on the amplification of parasite and vector DNA sequences with the polymerase chain reaction (PCR), have been developed. Routine application of these methods requires techniques for sample collection and preservation that are compatible with the limitations of field collection, yet preserve DNA in a form suitable for PCR. Two different methods for sample preservation were evaluated by the field collection teams and the DNA probe laboratory of the Onchocerciasis Control Programme in West Africa. The most successful involved the preservation of material from O. volvulus and its associated vectors in a dried state on microscope slides. Of over 1200 parasite samples preserved in this manner, more than 93% retained DNA yielding positive results in PCR analysis (1208/1291). Vector material (malpighian tubules and ovaries) preserved in the same manner on the same microscope slides also yielded DNA that was suitable for PCR. Images Fig. 2 PMID:9447777

  8. The effects of drugs on Onchocerca volvulus

    PubMed Central

    Duke, B. O. L.

    1968-01-01

    It is important to standardize quantitative methods for assessing the action of drugs on Onchocerca volvulus in man. There are certain disadvantages to making observations on adult worms removed from excised nodules in treated patients, but a great deal of information on drug action can be obtained by making a careful study of the concentrations of microfilariae in multiple weighed skin snips taken before treatment and at intervals after treatment. Before drug trials can be carried out intelligently by this method it is necessary to know the normal length of life of the various stages of the parasite in man. By a variety of experimental methods the life-spans of the adult worms and the microfilariae have been determined, as well as the duration of the prepatent interval. Diethylcarbamazine can be used at doses that are effectively microfilaricidal but have no action on the adult worms. This drug can therefore be used to eliminate any residual microfilariae that remain after treatment with a new drug under trial, thus permitting a more rapid assessment of the latter's action on adult worms. PMID:4881066

  9. The effects of ivermectin on transmission of Onchocerca volvulus.

    PubMed

    Cupp, E W; Bernardo, M J; Kiszewski, A E; Collins, R C; Taylor, H R; Aziz, M A; Greene, B M

    1986-02-14

    Ivermectin, given to onchocerciasis patients as a single oral dose of 200 micrograms per kilogram of body weight, substantially reduced the uptake of Onchocerca volvulus microfilariae by Simulium yahense, an efficient black fly vector of the parasite in the tropical rain forests of West Africa. Three months after treatment, patients given ivermectin infected flies at a significantly lower rate than those who had received diethylcarbamazine or placebo, thereby reducing the number of developing larvae in the vector population. This diminished rate of infectiousness was also evident 6 months after treatment. These results strongly suggest that ivermectin could be effective in interrupting transmission of Onchocerca volvulus for epidemiologically important periods of time.

  10. Onchocerciasis: invasion of deep organs by Onchocerca volvulus.

    PubMed

    Meyers, W M; Neafie, R C; Connor, D H

    1977-07-01

    Autopsies of two patients with onchocerciasis in the Republic of Zaïre are reported. In one patient elephantiasis who died following diethylcarbamazine therapy there were large numbers of microfilariae of Onchocerca volvulus in the kidney, liver, pancreas, and lung. In the second patient, who also had leprosy and hyperinfection strongyloidiasis, we found an encapsulated adult O. volvulus in the wall of the thoracic aorta.

  11. The effects of drugs on Onchocerca volvulus

    PubMed Central

    Duke, B. O. L.

    1968-01-01

    Suramin and Mel W are the only two drugs at present known to be effective against the adult worms of Onchocerca volvulus, but in view of the unpredictable occurrence of fatal arsenical encephalopathy in a small proportion of patients receiving Mel W, suramin remains the preferred macrofilaricide in the treatment of onchocerciasis. It is therefore important to determine the suramin dosage schedules that will produce parasitological cures with minimal concomitant risks of toxic reactions. The criteria by which cures should be judged must also be appreciated. Courses of different duration and employing doses of 1.0 g, 0.5 g and 0.25 g suramin have been investigated for their action on adult worms and microfilariae, for the toxic reactions which they produce on the kidney, and for the level of suramin reached in the serum during treatment. A course of 5 or 6 weekly doses of 1.0 g has been shown to be the optimum for adults. It is sometimes stated without good foundation that different brands of suramin differ in their purity and chemical composition, thus producing inconsistent effects on the parasites and grave risks of toxic manifestations. The three main brands in current use in Africa (Antrypol, Moranyl and Naganol) have therefore been compared in a group of patients, using the same optimum dosage schedule for each preparation and recording the action of the various brands on the parasites, as well as their comparative toxicities and the serum suramin levels achieved. No significant differences between the brands were recorded. PMID:4881068

  12. Experiments on the chemoprophylaxis of Onchocerca volvulus infection.

    PubMed

    Duke, B O

    1968-01-01

    Previous work on monkeys and on human volunteers led to the development of a schedule of diethylcarbamazine dosage suitable for the chemoprophylaxis of loiasis. In several parts of Africa where this chemoprophylaxis is practised against Loa loa, infections with Onchocerca volvulus are also common. Attempts were therefore made to determine whether diethylcarbamazine has any prophylactic action against the latter parasite by making use of chimpanzees exposed to experimental infections, and also by using biopsy techniques to study the fate of infective larvae inoculated into volunteers.Both experimental methods proved more difficult to apply in O. volvulus infections than had been the case with L. loa, but evidence was obtained that diethylcarbamazine is not an effective chemoprophylactic for O. volvulus.Further experiments were then carried out with suramin and with melarsonyl potassium (Mel W). Although both gave some evidence of partial prophylactic activity, their use for this purpose is at present neither practical nor safe.

  13. Experiments on the chemoprophylaxis of Onchocerca volvulus infections

    PubMed Central

    Duke, B. O. L.

    1968-01-01

    Previous work on monkeys and on human volunteers led to the development of a schedule of diethylcarbamazine dosage suitable for the chemoprophylaxis of loiasis. In several parts of Africa where this chemoprophylaxis is practised against Loa loa, infections with Onchocerca volvulus are also common. Attempts were therefore made to determine whether diethylcarbamazine has any prophylactic action against the latter parasite by making use of chimpanzees exposed to experimental infections, and also by using biopsy techniques to study the fate of infective larvae inoculated into volunteers. Both experimental methods proved more difficult to apply in O. volvulus infections than had been the case with L. loa, but evidence was obtained that diethylcarbamazine is not an effective chemoprophylactic for O. volvulus. Further experiments were then carried out with suramin and with melarsonyl potassium (Mel W). Although both gave some evidence of partial prophylactic activity, their use for this purpose is at present neither practical nor safe. ImagesFIG. 1FIG. 2FIG. 3 PMID:4881070

  14. The association of adult Onchocerca volvulus with lymphatic vessels.

    PubMed

    Mackenzie, C D; Huntington, M K; Wanji, S; Lovato, R V; Eversole, R R; Geary, T G

    2010-02-01

    Immunocytochemical examination of onchocercal nodule tissues containing adult Onchocerca volvulus using immuno-markers for blood and lymphatic vessels (vWF, D2-40, podoplanin, Prox-1, and Lyve1) shows a distinct pattern of distribution of these vessels within nodules. Blood vessels were commonly seen associated with organized lymphoid cellular aggregates in the both the outer and inner areas of the nodules. In contrast, the majority of the lymphatic vessel positivity was seen in the central zone in close apposition to the adult parasites, and the remainder usually associated with microfilariae in the outer areas of the nodule. These findings suggest an intimate relationship between adult O. volvulus and lymphatic vessels, including the likely proliferation of lymphatic endothelial cells (lymphangectasia) akin to that seen with other filariae. These findings indicate that adult O. volvulus may migrate via the lymphatic system, and that clinical manifestations of this disease that involve tissue edema may be the result of the location of these worms in the lymphatic system.

  15. The genome of Onchocerca volvulus, agent of river blindness

    PubMed Central

    Cotton, James A.; Bennuru, Sasisekhar; Grote, Alexandra; Harsha, Bhavana; Tracey, Alan; Beech, Robin; Doyle, Stephen R.; Dunn, Matthew; Dunning Hotopp, Julie C.; Holroyd, Nancy; Kikuchi, Taisei; Lambert, Olivia; Mhashilkar, Amruta; Mutowo, Prudence; Nursimulu, Nirvana; Ribeiro, Jose M. C.; Rogers, Matthew B.; Stanley, Eleanor; Swapna, Lakshmipuram S.; Tsai, Isheng J.; Unnasch, Thomas R.; Voronin, Denis; Parkinson, John; Nutman, Thomas B.; Ghedin, Elodie; Berriman, Matthew; Lustigman, Sara

    2017-01-01

    Human onchocerciasis is a serious neglected tropical disease caused by the filarial nematode Onchocerca volvulus that can lead to blindness and chronic disability. Control of the disease relies largely on mass administration of a single drug, and the development of new drugs and vaccines depends on a better knowledge of parasite biology. Here, we describe the chromosomes of O. volvulus and its Wolbachia endosymbiont. We provide the highest-quality sequence assembly for any parasitic nematode to date, giving a glimpse into the evolution of filarial parasite chromosomes and proteomes. This resource was used to investigate gene families with key functions that could be potentially exploited as targets for future drugs. Using metabolic reconstruction of the nematode and its endosymbiont, we identified enzymes that are likely to be essential for O. volvulus viability. In addition, we have generated a list of proteins that could be targeted by Federal-Drug-Agency-approved but repurposed drugs, providing starting points for anti-onchocerciasis drug development. PMID:27869790

  16. The genome of Onchocerca volvulus, agent of river blindness.

    PubMed

    Cotton, James A; Bennuru, Sasisekhar; Grote, Alexandra; Harsha, Bhavana; Tracey, Alan; Beech, Robin; Doyle, Stephen R; Dunn, Matthew; Hotopp, Julie C Dunning; Holroyd, Nancy; Kikuchi, Taisei; Lambert, Olivia; Mhashilkar, Amruta; Mutowo, Prudence; Nursimulu, Nirvana; Ribeiro, Jose M C; Rogers, Matthew B; Stanley, Eleanor; Swapna, Lakshmipuram S; Tsai, Isheng J; Unnasch, Thomas R; Voronin, Denis; Parkinson, John; Nutman, Thomas B; Ghedin, Elodie; Berriman, Matthew; Lustigman, Sara

    2016-11-21

    Human onchocerciasis is a serious neglected tropical disease caused by the filarial nematode Onchocerca volvulus that can lead to blindness and chronic disability. Control of the disease relies largely on mass administration of a single drug, and the development of new drugs and vaccines depends on a better knowledge of parasite biology. Here, we describe the chromosomes of O. volvulus and its Wolbachia endosymbiont. We provide the highest-quality sequence assembly for any parasitic nematode to date, giving a glimpse into the evolution of filarial parasite chromosomes and proteomes. This resource was used to investigate gene families with key functions that could be potentially exploited as targets for future drugs. Using metabolic reconstruction of the nematode and its endosymbiont, we identified enzymes that are likely to be essential for O. volvulus viability. In addition, we have generated a list of proteins that could be targeted by Federal-Drug-Agency-approved but repurposed drugs, providing starting points for anti-onchocerciasis drug development.

  17. Genomic diversity in Onchocerca volvulus and its Wolbachia endosymbiont.

    PubMed

    Choi, Young-Jun; Tyagi, Rahul; McNulty, Samantha N; Rosa, Bruce A; Ozersky, Philip; Martin, John; Hallsworth-Pepin, Kymberlie; Unnasch, Thomas R; Norice, Carmelle T; Nutman, Thomas B; Weil, Gary J; Fischer, Peter U; Mitreva, Makedonka

    2016-11-21

    Ongoing elimination efforts have altered the global distribution of Onchocerca volvulus, the agent of river blindness, and further population restructuring is expected as efforts continue. Therefore, a better understanding of population genetic processes and their effect on biogeography is needed to support elimination goals. We describe O. volvulus genome variation in 27 isolates from the early 1990s (before widespread mass treatment) from four distinct locales: Ecuador, Uganda, the West African forest and the West African savanna. We observed genetic substructuring between Ecuador and West Africa and between the West African forest and savanna bioclimes, with evidence of unidirectional gene flow from savanna to forest strains. We identified forest:savanna-discriminatory genomic regions and report a set of ancestry informative loci that can be used to differentiate between forest, savanna and admixed isolates, which has not previously been possible. We observed mito-nuclear discordance possibly stemming from incomplete lineage sorting. The catalogue of the nuclear, mitochondrial and endosymbiont DNA variants generated in this study will support future basic and translational onchocerciasis research, with particular relevance for ongoing control programmes, and boost efforts to characterize drug, vaccine and diagnostic targets.

  18. Genetic Selection of Low Fertile Onchocerca volvulus by Ivermectin Treatment

    PubMed Central

    Bourguinat, Catherine; Pion, Sébastien D. S.; Kamgno, Joseph; Gardon, Jacques

    2007-01-01

    Background Onchocerca volvulus is the causative agent of onchocerciasis, or “river blindness”. Ivermectin has been used for mass treatment of onchocerciasis for up to 18 years, and recently there have been reports of poor parasitological responses to the drug. Should ivermectin resistance be developing, it would have a genetic basis. We monitored genetic changes in parasites obtained from the same patients before use of ivermectin and following different levels of ivermectin exposure. Methods and Findings O. volvulus adult worms were obtained from 73 patients before exposure to ivermectin and in the same patients following three years of annual or three-monthly treatment at 150 µg/kg or 800 µg/kg. Genotype frequencies were determined in β-tubulin, a gene previously found to be linked to ivermectin selection and resistance in parasitic nematodes. Such frequencies were also determined in two other genes, heat shock protein 60 and acidic ribosomal protein, not known to be linked to ivermectin effects. In addition, we investigated the relationship between β-tubulin genotype and female parasite fertility. We found a significant selection for β-tubulin heterozygotes in female worms. There was no significant selection for the two other genes. Quarterly ivermectin treatment over three years reduced the frequency of the β-tubulin “aa” homozygotes from 68.6% to 25.6%, while the “ab” heterozygotes increased from 20.9% to 69.2% in the female parasites. The female worms that were homozygous at the β-tubulin locus were more fertile than the heterozygous female worms before treatment (67% versus 37%; p = 0.003) and twelve months after the last dose of ivermectin in the groups treated annually (60% versus 17%; p<0.001). Differences in fertility between heterozygous and homozygous worms were less apparent three months after the last treatment in the groups treated three-monthly. Conclusions The results indicate that ivermectin is causing genetic selection on

  19. Interruption of Onchocerca volvulus transmission in Northern Venezuela.

    PubMed

    Convit, Jacinto; Schuler, Harland; Borges, Rafael; Olivero, Vimerca; Domínguez-Vázquez, Alfredo; Frontado, Hortencia; Grillet, María E

    2013-10-07

    Onchocerciasis is caused by Onchocerca volvulus and transmitted by Simulium species (black flies). In the Americas, the infection has been previously described in 13 discrete regional foci distributed among six countries (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela) where more than 370,000 people are currently considered at risk. Since 2001, disease control in Venezuela has relied on the mass drug administration to the at-risk communities. This report provides empirical evidence of interruption of Onchocerca volvulus transmission by Simulium metallicum in 510 endemic communities from two Northern foci of Venezuela, after 10-12 years of 6-monthly Mectizan (ivermectin) treatment to all the eligible residents. In-depth entomologic and epidemiologic surveys were serially conducted from 2001-2012 in selected (sentinel and extra-sentinel) communities from the North-central (NC) and North-east (NE) onchocerciasis foci of Venezuela in order to monitor the impact of ivermectin treatment. From 2007-2009, entomological indicators in both foci confirmed that 0 out of 112,637 S. metallicum females examined by PCR contained L3 infection in insect heads. The upper bound of the 95% confidence intervals of the infective rate of the vector reached values below 1% by 2009 (NC) and 2012 (NE). Additionally, after 14 (NC) and 22 (NE) rounds of treatment, the seasonal transmission potential (±UL CIs) of S. metallicum was under the critical threshold of 20 L3 per person per season. Serological analysis in school children < 15 years-old demonstrated that 0 out of 6,590 individuals were harboring antibodies to Ov-16. Finally, epidemiological surveys made during 2010 (NC) and 2012 (NE) showed no evidence of microfilariae in the skin and eyes of the population. These results meet the WHO criteria for absence of parasite transmission and disease morbidity in these endemic areas which represent 91% of the population previously at-risk in the country. Consequently, the two

  20. Interruption of Onchocerca volvulus transmission in Northern Venezuela

    PubMed Central

    2013-01-01

    Background Onchocerciasis is caused by Onchocerca volvulus and transmitted by Simulium species (black flies). In the Americas, the infection has been previously described in 13 discrete regional foci distributed among six countries (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela) where more than 370,000 people are currently considered at risk. Since 2001, disease control in Venezuela has relied on the mass drug administration to the at-risk communities. This report provides empirical evidence of interruption of Onchocerca volvulus transmission by Simulium metallicum in 510 endemic communities from two Northern foci of Venezuela, after 10–12 years of 6-monthly Mectizan® (ivermectin) treatment to all the eligible residents. Methods In-depth entomologic and epidemiologic surveys were serially conducted from 2001–2012 in selected (sentinel and extra-sentinel) communities from the North-central (NC) and North-east (NE) onchocerciasis foci of Venezuela in order to monitor the impact of ivermectin treatment. Results From 2007–2009, entomological indicators in both foci confirmed that 0 out of 112,637 S. metallicum females examined by PCR contained L3 infection in insect heads. The upper bound of the 95% confidence intervals of the infective rate of the vector reached values below 1% by 2009 (NC) and 2012 (NE). Additionally, after 14 (NC) and 22 (NE) rounds of treatment, the seasonal transmission potential (±UL CIs) of S. metallicum was under the critical threshold of 20 L3 per person per season. Serological analysis in school children < 15 years-old demonstrated that 0 out of 6,590 individuals were harboring antibodies to Ov-16. Finally, epidemiological surveys made during 2010 (NC) and 2012 (NE) showed no evidence of microfilariae in the skin and eyes of the population. Conclusions These results meet the WHO criteria for absence of parasite transmission and disease morbidity in these endemic areas which represent 91% of the population previously at

  1. Comparison of the effects of a single dose and of four six-monthly doses of ivermectin on adult Onchocerca volvulus.

    PubMed

    Duke, B O; Zea-Flores, G; Castro, J; Cupp, E W; Munoz, B

    1991-07-01

    Adult Onchocerca volvulus worms, extracted from nodules of Guatemalans by collagenase digestion, were examined whole and by histological techniques. One group of persons received a single 150 micrograms/kg dose of ivermectin; two other groups (one with older and one with younger nodules) received four similar doses of ivermectin at 6-month intervals. For each group, there were comparable untreated controls. All nodules were removed six months after the last dose. After a single dose, the only significant difference from the controls was in the decreased proportion of female worms producing live microfilariae. After four doses, there were significant increases in the proportions of moribund/dead female worms and of live uninseminated females, when compared with the corresponding controls. There were also fewer male worms present, but this difference was not significant. Six months after the conclusion of the 4-dose regimen, the proportion of female worms producing live microfilariae was significantly lower than in the groups that had received a single dose.

  2. Suramin and the time it takes to kill Onchocerca volvulus.

    PubMed

    Duke, B O

    1991-12-01

    The paper records the numbers of 1-2 mm shotty papules developing in the author's skin after 2-day courses of diethylcarbamazine (DEC) repeated every 16 days before, during and after a 7.1 G suramin course for cutaneous onchocerciasis. Assuming, from biopsy evidence, that each papule represented a dead Onchocerca volvulus microfilaria (mf), the number of mfs reaching the skin every 16 days did not begin to fall until 96 days after the first full dose of suramin; and only reached zero by day 224. The histopathology of nodules excised from Cameroonian patients before, and at intervals of 56-335 days after, the start of a 7.1 G suramin course, revealed changes in the worms that correlated over time with the disappearance of mfs from the skin. Suramin sterilized and killed the male worms between days 77 and 105 and, in the females, it adversely affected the staining and subsequent development of small morulae from about day 56. It was estimated that new embryogenesis ceased about 56-77 days after the first full dose; development of the last viable embryos to mfs was complete by about 136 days; and the last mfs, perhaps having reduced vitality, emerged from the females by 160 days and reached the skin within 16-32 days.

  3. Insights Into Onchocerca volvulus Population Biology Through Multilocus Immunophenotyping.

    PubMed

    Norice-Tra, Carmelle T; Ribeiro, José; Bennuru, Sasisekhar; Fay, Michael P; Tyagi, Rahul; Mitreva, Makedonka; Nutman, Thomas B

    2017-09-15

    We have developed a serologically based immunophenotyping approach to study Onchocerca volvulus (Ov) population diversity. Using genomic sequence data and polymerase chain reaction-based genotyping, we identified nonsynonymous single-nucleotide polymorphisms (SNPs) in the genes of 16 major immunogenic Ov proteins: Ov-CHI-1/Ov-CHI-2, Ov16, Ov-FAR-1, Ov-CPI-1, Ov-B20, Ov-ASP-1, Ov-TMY-1, OvSOD1, OvGST1, Ov-CAL-1, M3/M4, Ov-RAL-1, Ov-RAL-2, Ov-ALT-1, Ov-FBA-1, and Ov-B8. We assessed the immunoreactivity of onchocerciasis patient sera (n = 152) from the Americas, West Africa, Central Africa, and East Africa against peptides derived from 10 of these proteins containing SNPs. Statistically significant variation in immunoreactivity among the regions was seen in SNP-containing peptides derived from 8 of 10 proteins tested: OVOC1192(1-15), OVOC9988(28-42), OVOC9225(320-334), OVOC7453(22-36), OVOC11517(14-28), OVOC3177(283-297), OVOC7911(594-608), and OVOC12628(174-188). Our data show that differences in immunoreactivity to variant antigenic peptides may be used to characterize Ov populations, thereby elucidating features of Ov population biology previously inaccessible because of the limited availability of parasite material. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  4. Immune recognition of Onchocerca volvulus proteins in the human host and animal models of onchocerciasis.

    PubMed

    Manchang, T K; Ajonina-Ekoti, I; Ndjonka, D; Eisenbarth, A; Achukwi, M D; Renz, A; Brattig, N W; Liebau, E; Breloer, M

    2015-05-01

    Onchocerca volvulus is a tissue-dwelling, vector-borne nematode parasite of humans and is the causative agent of onchocerciasis or river blindness. Natural infections of BALB/c mice with Litomosoides sigmodontis and of cattle with Onchocerca ochengi were used as models to study the immune responses to O. volvulus-derived recombinant proteins (OvALT-2, OvNLT-1, Ov103 and Ov7). The humoral immune response of O. volvulus-infected humans against OvALT-2, OvNLT-1 and Ov7 revealed pronounced immunoglobulin G (IgG) titres which were, however, significantly lower than against the lysate of O. volvulus adult female worms. Sera derived from patients displaying the hyperreactive form of onchocerciasis showed a uniform trend of higher IgG reactivity both to the single proteins and the O. volvulus lysate. Sera derived from L. sigmodontis-infected mice and from calves exposed to O. ochengi transmission in a hyperendemic area also contained IgM and IgG1 specific for O. volvulus-derived recombinant proteins. These results strongly suggest that L. sigmodontis-specific and O. ochengi-specific immunoglobulins elicited during natural infection of mice and cattle cross-reacted with O. volvulus-derived recombinant antigens. Monitoring O. ochengi-infected calves over a 26-month period, provided a comprehensive kinetic of the humoral response to infection that was strictly correlated with parasite load and occurrence of microfilariae.

  5. The nematode parasite Onchocerca volvulus generates the transforming growth factor-beta (TGF-beta).

    PubMed

    Korten, Simone; Büttner, Dietrich W; Schmetz, Christel; Hoerauf, Achim; Mand, Sabine; Brattig, Norbert

    2009-09-01

    Transforming growth factor-beta (TGF-beta) is a highly conserved cytokine that has a well-known regulatory role in immunity, but also in organ development of most animal species including helminths. Homologous tgf-b genes and mRNA have been detected in the filaria Brugia malayi. The in situ protein expression is unknown for filariae. Therefore, we examined several filariae for the expression and localization of latent (stable) TGF-beta in adult and larval stages. A specific goat anti-human latency associated protein (LAP, TGF-beta 1) antibody, purified by affinity chromatography, was used for light and electron microscopic immunohistochemistry. Adult Onchocerca volvulus, Onchocerca gibsoni, Onchocerca ochengi, Onchocerca armillata, Onchocerca fasciata, Onchocerca flexuosa, Wuchereria bancrofti, Dirofilaria sp., B. malayi, and infective larvae of W. bancrofti reacted with the antibody. Labeling of worm tissues varied between negative and all degrees of positive reactions. Latent TGF-beta was strongly expressed adjacent to the cell membranes of the hypodermis, epithelia, and muscles and adjacent to many nuclei in all organs. TGF-beta was well expressed in worms without Wolbachia endobacteria eliminated by doxycycline treatment. Pleomorphic neoplasms in O. volvulus were also labeled. We conclude that latent TGF-beta protein is expressed by filariae independently of Wolbachia, possibly regulating worm tissue homeostasis.

  6. Phenotypic Evidence of Emerging Ivermectin Resistance in Onchocerca volvulus

    PubMed Central

    Osei-Atweneboana, Mike Y.; Awadzi, Kwablah; Attah, Simon K.; Boakye, Daniel A.; Gyapong, John O.; Prichard, Roger K.

    2011-01-01

    Background Ivermectin (IVM) has been used in Ghana for over two decades for onchocerciasis control. In recent years there have been reports of persistent microfilaridermias despite multiple treatments. This has necessitated a reexamination of its microfilaricidal and suppressive effects on reproduction in the adult female Onchocerca volvulus. In an initial study, we demonstrated the continued potent microfilaricidal effect of IVM. However, we also found communities in which the skin microfilarial repopulation rates at days 90 and 180 were much higher than expected. In this follow up study we have investigated the reproductive response of female worms to multiple treatments with IVM. Methods and Findings The parasitological responses to IVM in two hundred and sixty-eight microfilaridermic subjects from nine communities that had received 10 to 19 annual doses of IVM treatment and one pre-study IVM-naïve community were followed. Skin snips were taken 364 days after the initial IVM treatment during the study to determine the microfilaria (mf) recovery rate. Nodules were excised and skin snips taken 90 days following a second study IVM treatment. Nodule and worm density and the reproductive status of female worms were determined. On the basis of skin mf repopulation and skin mf recovery rates we defined three categories of response—good, intermediate and poor—and also determined that approximately 25% of subjects in the study carried adult female worms that responded suboptimally to IVM. Stratification of the female worms by morphological age and microfilarial content showed that almost 90% of the worms were older or middle aged and that most of the mf were produced by the middle aged and older worms previously exposed to multiple treatments with little contribution from young worms derived from ongoing transmission. Conclusions The results confirm that in some communities adult female worms were non-responsive or resistant to the anti-fecundity effects of multiple

  7. Molecular cloning of an Onchocerca volvulus extracellular Cu-Zn superoxide dismutase.

    PubMed Central

    James, E R; McLean, D C; Perler, F

    1994-01-01

    Onchocerca volvulus, a human parasitic nematode, is the third leading cause of preventable blindness worldwide. This study describes the molecular cloning of a novel superoxide dismutase (SOD) from the parasite. This putative O. volvulus extracellular SOD (OvEcSOD) is 628 nucleotides (nt) long, including a 22-nt 5' spliced leader (SL1) and a portion encoding an N-terminal hydrophobic 42-amino-acid signal peptide. The remainder of the cDNA shares 71% identity with an O. volvulus cytosolic SOD sequence and is 3 nt longer. All residues involved in metal ion binding, active site formation, folding, and dimer formation in SODs are conserved. Data indicate the OvEcSOD and O. volvulus cytosolic SOD are separate gene products and that the OvEcSOD appears to possess the characteristics of a membrane-bound or secreted enzyme which may be involved in the parasite defense against phagocyte-generated reactive oxygen species. Images PMID:8300230

  8. Tolerance to diethylcarbamazine-medicated salt in individuals infected with Onchocerca volvulus.

    PubMed

    Meyrowitsch, D W; Simonsen, P E; Magnussen, P

    2000-01-01

    The tolerance of Onchocerca volvulus-infected individuals to diethylcarbamazine (DEC)-medicated salt (0.33% w/w) was assessed in 1996 in Tanzania in a double-blind placebo-controlled hospital-based trial involving 4 groups, each of 10 adult males. Groups I and II had O. volvulus microfilariae (mf) only, group III had both O. volvulus and Wuchereria bancrofti mf, and group IV had W. bancrofti mf only. Groups I, III and IV received DEC-medicated salt, whereas group II was a control to group I and received normal cooking salt. Medication was given for 10 days. The most pronounced adverse reactions in groups I and III were mild-to-moderate itching and rash, beginning after 3-4 days and lasting for the remaining medication period. The reactions did not interfere with normal daily activities. By 20 days after the end of medication, adverse reactions had disappeared in all individuals. The low daily dose of DEC had no significant effect on the O. volvulus pre-medication mf geometric mean intensities (GMIs). In contrast, the medication significantly reduced the pre-medication W. bancrofti mf GMIs. The prospects for using DEC-medicated salt for control of bancroftian filariasis in areas where incidental infections with O. volvulus occur are discussed.

  9. Comparative Analysis of Glycosylated and Nonglycosylated Filarial Homologues of the 20-Kilodalton Retinol Binding Protein from Onchocerca volvulus (Ov20)

    PubMed Central

    Nirmalan, Niroshini; Cordeiro, N. J. V.; Kläger, Sabine L.; Bradley, Janette E.; Allen, Judith E.

    1999-01-01

    Ov20 is a structurally novel 20-kDa retinol binding protein secreted by Onchocerca volvulus. Immunological and biological investigation of this protein has been hampered by the inability to maintain O. volvulus in a laboratory setting. In an effort to find a system more amenable to laboratory investigation, we have cloned, sequenced, and expressed cDNA encoding homologues of Ov20 from two closely related filarial species, Brugia malayi (Bm20) and Acanthocheilonema viteae (Av20). Sequence comparisons have highlighted differences in glycosylation of the homologues. We present here an analysis of mouse immune responses to Ov20, Bm20, and Av20. The results suggest a strong genetic restriction in response to native Bm20 that is overcome when recombinant, nonnative material is used. Reactivity of human filarial sera to the three recombinant proteins confirmed previous specificity studies with Ov20 but highlighted important differences in the reactivity patterns of the O. volvulus and B. malayi homologues that may be due to differences in glycosylation patterns. Ov20 is a dominant antigen in infected individuals, while Bm20 is not. The availability of the B. malayi homologue enabled us to use defined murine reagents and inbred strains for genetic analysis of responsiveness in a way that is not possible for Ov20. However, the close sequence similarity between Ov20 and Av20 suggests that the A. viteae model may be more suited to the investigation of the biological functions of Ov20. PMID:10569745

  10. Many transcribed regions of the Onchocerca volvulus genome contain the spliced leader sequence of Caenorhabditis elegans.

    PubMed Central

    Zeng, W L; Alarcon, C M; Donelson, J E

    1990-01-01

    Genomic DNAs of the related parasitic nematodes Onchocerca volvulus and Dirofilariae immitis, and a cDNA library of O. volvulus, were examined for the presence of the 22-nucleotide spliced leader (SL) found at the 5' ends of 10 to 15% of the mRNAs in the free-living nematode Caenorhabditis elegans. As in C. elegans, genes for the SL RNA are linked to the repetitive 5S rRNA genes of O. volvulus and D. immitis, but unlike C. elegans, they are in the same orientation as the 5S rRNA genes within the repeat unit. In O. volvulus the SL sequence is also encoded at more than 30 additional genomic locations and occurs at interior sites within many transcripts. Sequence determinations of four different cDNAs of O. volvulus, each containing an internal copy of the SL within a conserved 25mer, and one corresponding genomic DNA clone indicate that this sequence is not trans spliced onto these RNAs, but is encoded within the genes. The RNAs of two of these cDNAs appear to be developmentally regulated, since they occur in adult O. volvulus but were not detected in the infective L3 stage larvae. In contrast, actin mRNAs are present at all developmental stages, and at least one actin mRNA species contains a trans-spliced 5' SL. The internal locations of the SL in various transcripts and its perfect sequence conservation among parasitic and free-living nematodes argues that it serves specific, and perhaps multiple, functions for these organisms. Images PMID:1692960

  11. Elimination of Onchocerca volvulus Transmission in the Huehuetenango Focus of Guatemala

    PubMed Central

    Cruz-Ortiz, Nancy; Gonzalez, Rodrigo J.; Lindblade, Kim A.; Richards, Frank O.; Sauerbrey, Mauricio; Zea-Flores, Guillermo; Dominguez, Alfredo; Oliva, Orlando; Catú, Eduardo; Rizzo, Nidia

    2012-01-01

    In Latin America, onchocerciasis is targeted for elimination by 2012 through twice-yearly mass treatment of the eligible population with ivermectin. In Guatemala, two of the four historical endemic foci have demonstrated elimination of transmission, following World Health Organization guidelines. Using established guidelines ophthalmological, serological, and entomological evaluations were conducted in 2007-8 to determine the transmission status of onchocerciasis in the Huehuetenango focus. The prevalence of Onchocerca volvulus microfilariae in the anterior segment of the eye in 365 residents was 0% (95% confidence interval [CI] 0–0.8%), the prevalence of infection of O. volvulus in Simulium ochraceum among 8252 flies collected between November 2007 and April 2008 was 0% (95% CI 0–0.02%), and the prevalence of antibodies to a recombinant O. volvulus antigen in 3118 school age children was 0% (95% CI 0–0.1%). These results showed transmission interruption; thus, in 2009 mass treatment was halted and posttreatment surveillance began. To verify for potential recrudescence an entomological evaluation (from December 2010 to April 2011) was conducted during the 2nd and 3rd year of posttreatment surveillance. A total of 4587 S. ochraceum were collected, and the prevalence of infection of O. volvulus was 0% (95% CI 0–0.04%). Transmission of onchocerciasis in the Huehuetenango focus has been eliminated. PMID:22970346

  12. Successful Interruption of Transmission of Onchocerca volvulus in the Escuintla-Guatemala Focus, Guatemala

    PubMed Central

    Gonzalez, Rodrigo J.; Cruz-Ortiz, Nancy; Rizzo, Nidia; Richards, Jane; Zea-Flores, Guillermo; Domínguez, Alfredo; Sauerbrey, Mauricio; Catú, Eduardo; Oliva, Orlando; Richards, Frank O.; Lindblade, Kim A.

    2009-01-01

    Background Elimination of onchocerciasis (river blindness) through mass administration of ivermectin in the six countries in Latin America where it is endemic is considered feasible due to the relatively small size and geographic isolation of endemic foci. We evaluated whether transmission of onchocerciasis has been interrupted in the endemic focus of Escuintla-Guatemala in Guatemala, based on World Health Organization criteria for the certification of elimination of onchocerciasis. Methodology/Principal Findings We conducted evaluations of ocular morbidity and past exposure to Onchocerca volvulus in the human population, while potential vectors (Simulium ochraceum) were captured and tested for O. volvulus DNA; all of the evaluations were carried out in potentially endemic communities (PEC; those with a history of actual or suspected transmission or those currently under semiannual mass treatment with ivermectin) within the focus. The prevalence of microfilariae in the anterior segment of the eye in 329 individuals (≥7 years old, resident in the PEC for at least 5 years) was 0% (one-sided 95% confidence interval [CI] 0–0.9%). The prevalence of antibodies to a recombinant O. volvulus antigen (Ov-16) in 6,432 school children (aged 6 to 12 years old) was 0% (one-sided 95% IC 0–0.05%). Out of a total of 14,099 S. ochraceum tested for O. volvulus DNA, none was positive (95% CI 0–0.01%). The seasonal transmission potential was, therefore, 0 infective stage larvae per person per season. Conclusions/Significance Based on these evaluations, transmission of onchocerciasis in the Escuintla-Guatemala focus has been successfully interrupted. Although this is the second onchocerciasis focus in Latin America to have demonstrated interruption of transmission, it is the first focus with a well-documented history of intense transmission to have eliminated O. volvulus. PMID:19333366

  13. [Effects of diethylcarbamazine and ivermectin on the mobilization of microfilariae of Onchocerca volvulus].

    PubMed

    Basset, D; Bouree, P; Basset, A; Lariviere, M

    1989-06-01

    Microfilaria of Onchocerca volvulus are localized in superficial dermis. However, they are sometimes noticed in the blood and urines, when there is an important infestation. Diethylcarbamazine (DEC) bring on an increase of microfilaria, successively in the blood and after, in the urines. This study of 30 patients, treated in double blind by placebo, DEC and ivermectin, a new molecule with spectacular action on this filariasis, allowed to compare effect of each one on apparition of microfilariae in the blood and urines. Ivermectin bring on very important increase of microfilaremia without microfilaruria, unlike diethylcarbamazine. This establishment bring to discuss very different physiologic mechanisms between them. It should have an incidence on diagnosis and treatment of this dangerous parasite.

  14. A Recombinant Positive Control for Serology Diagnostic Tests Supporting Elimination of Onchocerca volvulus

    PubMed Central

    Golden, Allison; Stevens, Eric J.; Yokobe, Lindsay; Faulx, Dunia; Kalnoky, Michael; Peck, Roger; Valdez, Melissa; Steel, Cathy; Karabou, Potochoziou; Banla, Méba; Soboslay, Peter T.; Adade, Kangi; Tekle, Afework H.; Cama, Vitaliano A.; Fischer, Peter U.; Nutman, Thomas B.; Unnasch, Thomas R.; de los Santos, Tala; Domingo, Gonzalo J.

    2016-01-01

    Background Serological assays for human IgG4 to the Onchocerca volvulus antigen Ov16 have been used to confirm elimination of onchocerciasis in much of the Americas and parts of Africa. A standardized source of positive control antibody (human anti-Ov16 IgG4) will ensure the quality of surveillance data using these tests. Methodology/Principal Findings A recombinant human IgG4 antibody to Ov16 was identified by screening against a synthetic human Fab phage display library and converted into human IgG4. This antibody was developed into different positive control formulations for enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic test (RDT) platforms. Variation in ELISA results and utility as a positive control of the antibody were assessed from multiple laboratories. Temperature and humidity conditions were collected across seven surveillance activities from 2011–2014 to inform stability requirements for RDTs and positive controls. The feasibility of the dried positive control for RDT was evaluated during onchocerciasis surveillance activity in Togo, in 2014. When the anti-Ov16 IgG4 antibody was used as a standard dilution in horseradish peroxidase (HRP) and alkaline phosphatase (AP) ELISAs, the detection limits were approximately 1ng/mL by HRP ELISA and 10ng/mL by AP ELISA. Positive control dilutions and spiked dried blood spots (DBS) produced similar ELISA results. Used as a simple plate normalization control, the positive control antibody may improve ELISA data comparison in the context of inter-laboratory variation. The aggregate temperature and humidity monitor data informed temperature parameters under which the dried positive control was tested and are applicable inputs for testing of diagnostics tools intended for sub-Saharan Africa. As a packaged positive control for Ov16 RDTs, stability of the antibody was demonstrated for over six months at relevant temperatures in the laboratory and for over 15 weeks under field conditions. Conclusions The

  15. [The epidemiological significance of neo-natal parasitism with microfilariae of Onchocerca volvulus (author's transl)].

    PubMed

    Prost, A; Gorim de Ponsay, E

    1979-12-01

    Between April 1977 and June 1978, 214 babies born of 210 mothers infected with Onchocerciasis, were examined at the maternity of Po Hospital (Upper Volta). In four of them (1.9%) dermal microfilariae of Onchocerca volvulus were found during the first week after birth. In two other cases microfilariae were seen in the tissue of the umbilical cord. All specimens from placentas and amniotic fluid gave negative results. The infected babies were reexamined monthly monthly from 2 to 18 months, depending on the cases. One child remained positive until the 6th month follow-up. The base-line examination of 5.757 children less than 2 years old from different villages in the WHO Onchocerciasis Control Programme in the Volta River Basin Area showed that 1% of children less than one year old and 2% of children of 12 to 23 months old were carriers of dermal microfilariae. These results indicate that in meso- or hyperendemic areas children less than one year old and carriers of microfilariae of Onchocerca volbulus may have been infected in utero. The existence of such cases, in an area of vector control, does not prove a residual vector borne transmission.

  16. Criteria for the differentiation between young and old Onchocerca volvulus filariae.

    PubMed

    Specht, Sabine; Brattig, Norbert; Büttner, Marcelle; Büttner, Dietrich W

    2009-11-01

    Drugs exist that show long-lasting inhibition of embryogenesis and microfilaria production or macrofilaricidal activity against Onchocerca volvulus. Therefore, the patients have to be followed-up for several years. Clinical drug trials have to be performed in areas with ongoing transmission to assess the efficacy on younger worms. In addition, future vaccine trials may also require demonstrating efficacy against establishment of new worms. For the evaluation of the efficacy, it is necessary to differentiate between older worms, which were exposed to the drug, and younger worms newly acquired after drug treatment or vaccination. Here, we describe criteria for the differentiation between young and old filariae based on histological studies of worms with a known age from travellers, or from children, or patients living in areas with interrupted transmission in Burkina Faso, Ghana or Uganda. Older worms were larger and presented degenerated tissues. Gomori's iron stain showed that the worms accumulated more iron with increasing age, first in the gut and later in other organs. Using an antibody against O. volvulus lysosomal aspartic protease, the gut of young worms was stained only weakly; whereas, it was stronger labelled in older worms, accompanied by additional staining of hypodermis and epithelia. Using morphological and immunohistological criteria, it was possible to differentiate young (1-3 years old) from older females and to identify young males.

  17. Effect of single-dose ivermectin on Onchocerca volvulus: a systematic review and meta-analysis.

    PubMed

    Basáñez, María-Gloria; Pion, Sébastien D S; Boakes, Eve; Filipe, João A N; Churcher, Thomas S; Boussinesq, Michel

    2008-05-01

    The broad-spectrum antiparasitic drug ivermectin was licensed for use against onchocerciasis in 1987, yet the mechanisms by which it exerts a fast decrease and long-lasting suppression of Onchocerca volvulus microfilaridermia, and inhibition of microfilarial release by female worms remain largely unknown. A better understanding of the effects of ivermectin on O volvulus microfilariae and macrofilariae is crucial to improve our ability to predict the long-term effect of treatment. We did a systematic review of individual and population-based ivermectin trials to investigate the temporal dynamics of the drug's microfilaricidal and embryostatic efficacy after administration of a single, standard dose (150 microg/kg). Meta-analyses on data from 26 microfilarial and 15 macrofilarial studies were linked by a mathematical model describing the dynamics of potentially fertile female parasites to skin microfilariae. The model predicts that after treatment, microfilaridermia would be reduced by half after 24 h, by 85% after 72 h, by 94% after 1 week, and by 98-99% after 1-2 months, the latter also corresponding to the time when the fraction of females harbouring live microfilariae is at its lowest (reduced by around 70% from its original value). Our results provide a baseline microfilarial skin repopulation curve against which to compare studies done after long-term treatment.

  18. Absence of sperm from the seminal receptacle of female Onchocerca volvulus following multiple doses of ivermectin.

    PubMed

    Chavasse, D C; Post, R J; Davies, J B; Whitworth, J A

    1993-09-01

    It is already known that multiple doses of ivermectin have a profound effect on embryonic development in Onchocerca volvulus and that this appears to operate mainly at the single cell stage. To investigate this further, we examined adult female O. volvulus originating from patients treated either with placebo or one, four or five doses of ivermectin. The reproductive organs were dissected out of the worm and examined for evidence of oogenesis and for the quantity of sperm and oocytes in the seminal receptacles. A single dose of ivermectin had no measurable effect on oogenesis or on the amount of sperm and oocytes compared to placebo. However after multiple doses of ivermectin a significantly lower proportion of seminal receptacles contained sperm and there was a significantly higher proportion of ovaries with impaired oogenesis compared to placebo. It is concluded that the reduction in the number of multicellular embryonic stages from worms exposed to multiple doses of ivermectin is due, at least in part, to a major reduction in the effective insemination of female worms and to a minor impairment of oogenesis.

  19. The embryogenesis of Onchocerca volvulus over the first year after a single dose of ivermectin.

    PubMed

    Duke, B O; Zea-Flores, G; Muñoz, B

    1991-09-01

    Adult Onchocerca volvulus, extracted from nodules before, and at intervals of two weeks to 12 months after, a single 150 micrograms/kg dose of ivermectin, were examined longitudinally and by sequential transverse sections. The mean number of male worms per nodule fell, and the proportion of nodules with no male worm rose, within two weeks of ivermectin and remained so for 12 months. In female worms, at intervals after ivermectin, the percentages of the length of the lower genital tracts occupied by embryos at each stage of development, or by degenerating ova, embryos and microfilariae (mfs), were recorded: (a) in un(re-)inseminated worms whose original embryogenesis was continuing and in those in which it was completed; and (b) in worms, reinseminated post-ivermectin, in which a new embryogenesis had begun. The results indicated that: (a) the time needed for the zygotes of O. volvulus to develop to mfs is 8-12 weeks; (b) nearly 40 percent of females had not resumed mf production by 12 months after treatment; (c) many intrauterine mfs had not degenerated within the first two weeks of ivermectin; (d) some of the last embryos to mature to mfs did not degenerate but accumulated temporarily in the anterior uteri 8-16 weeks after ivermectin.

  20. Efficiency of Simulium sanctipauli as a vector of Onchocerca volvulus in the forest zone of Ghana.

    PubMed

    Kutin, K; Kruppa, T F; Brenya, R; Garms, R

    2004-06-01

    The role of Simulium sanctipauli Vajime & Dunbar (Diptera: Simuliidae) as a vector of Onchocerca volvulus (Leuckart) (Spirurida: Onchocercidae) in the forest zone of central Ghana was studied in the Upper Denkyira district, where onchocerciasis is hyperendemic. Simulium sanctipauli was found to be a highly efficient vector, with a mean of 377 infective (L3) larvae in the heads of 1000 parous and 122 in the heads of 1000 biting flies. The overall infection rate of 44% of the parous flies with L1, L2 and L3 stages of O. volvulus (identity confirmed by polymerase chain reaction) demonstrates marked anthropophily. Female flies dispersed over a wide area and can transmit onchocerciasis up to at least 10 km away from their breeding sites. Annual community-directed treatments with ivermectin did not have a noticeable effect on the infection rates and parasitic loads of fly populations, which were as high 2 months after as 3 months before the distribution of ivermectin. This failure can be attributed to poor coverage, with treatment taken by only 24.4% of the population of the six study villages.

  1. Neoplastic change in Onchocerca volvulus and its relation to ivermectin treatment.

    PubMed

    Duke, B O L; Marty, A M; Peett, D L; Gardo, J; Pion, S D S; Kamgno, J; Boussinesq, M

    2002-11-01

    A pleomorphic neoplasm (PN) is described from sections of Onchocerca volvulus worms in nodules excised from Cameroonian patients. PN is confined to older, non-fecund, female worms, and those classed as moribund/dead. It is mainly composed of small, roundish, basophilic cells of diverse sizes, often forming a 'rosette' pattern around amorphous eosinophilic centres. The cells have a high nuclear/cytoplasmic ratio and up to 2-3 mitoses/high-power field; some become grossly enlarged, highly polymorphic and contain large, irregular blocks of chromatin. The eukaryotic PN cells first appear posteriorly in the pseudocoelom, probably from ovarian cells; they spread anteriorly, invading or compressing the uteri. Ivermectin treatment increased the prevalence PN from 3.7% of 1422 female worms in 637 patients before treatment to 17.5% of 1134 worms in 511 patients after 3 years treatment. Ivermectin at 400-800 microg/kg annually, or at 150 microg/kg or 400-800 microg/kg 3-monthly, over 3 years, did not increase the PN prevalence significantly, as compared with standard doses of 150 microg/kg annually. In other small series of African patients, PN prevalence increased in worms 2, 4, 6 and 10 months after ivermectin treatment; but there was no increase after treatment with amocarzine, albendazole or diethylcarbamazine and suramin. PN may partly account for the increased macrofilaricidal action of ivermectin on female O. volvulus in patients treated for 3 years at 3-monthly intervals.

  2. A controlled prospective trial of the prophylactic effect of a single dose of ivermectin against Onchocerca volvulus.

    PubMed

    Boussinesq, M; Chippaux, J P

    2001-09-01

    A clinical trial was conducted in Cameroon in order to evaluate in humans the possible effect of a single dose of ivermectin (150 micrograms per kg) on the pre-adult stages of Onchocerca volvulus. The incidence of the skin microfilariae was measured in two groups of patients who initially had negative biopsies, and who were subsequently treated, immediately after the seasonal peak of transmission of O. volvulus, either with a combination of ivermectin + ferrous sulphate, or with ferrous sulphate alone. One year after the treatment, i.e. 14 months after the start of the transmission period, the proportion of patients with positive skin biopsies, and their mean microfilarial loads, did not differ significantly between the two groups. Thus a single dose of ivermectin does not seem to have any perceptible prophylactic effect against O. volvulus.

  3. Interruption of Transmission of Onchocerca volvulus in the Southern Chiapas Focus, México

    PubMed Central

    Rodríguez-Pérez, Mario A.; Domínguez-Vázquez, Alfredo; Unnasch, Thomas R.; Hassan, Hassan K.; Arredondo-Jiménez, Juan I.; Orozco-Algarra, María Eugenia; Rodríguez-Morales, Kristel B.; Rodríguez-Luna, Isabel C.; Prado-Velasco, Francisco Gibert

    2013-01-01

    Background The Southern Chiapas focus of onchocerciasis in Southern Mexico represents one of the major onchocerciasis foci in Latin America. All 559 endemic communities of this focus have undergone semi-annual mass treatment with ivermectin since 1998. In 50 communities of this focus, ivermectin frequency shifted from twice to four times a year in 2003; an additional 113 communities were added to the quarterly treatment regimen in 2009 to achieve a rapid suppression of transmission. Methodology/Principal findings In-depth epidemiologic and entomologic assessments were performed in six sentinel communities (which had undergone 2 rounds of ivermectin treatment per year) and three extra-sentinel communities (which had undergone 4 rounds of ivermectin treatment per year). None of the 67,924 Simulium ochraceum s.l. collected from this focus during the dry season of 2011 were found to contain parasite DNA when tested by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), resulting in an upper bound of the 95% confidence interval (95%-ULCI) of the infective rate in the vectors of 0.06/2,000 flies examined. Serological assays testing for Onchocerca volvulus exposure conducted on 4,230 children 5 years of age and under (of a total population of 10,280 in this age group) revealed that 2/4,230 individuals were exposed to O. volvulus (0.05%; one sided 95% confidence interval = 0.08%). Conclusions/Significance The in-depth epidemiological and entomological findings from the Southern Chiapas focus meet the criteria for interruption of transmission developed by the international community. PMID:23556018

  4. The effects of diethylcarbamazine, mebendazole and levamisole on Onchocerca volvulus in vivo and in vitro.

    PubMed

    Rivas-Alcala, R; Mackenzie, C D; Gomez-Rojo, E; Greene, B M; Taylor, H R

    1984-06-01

    The effects of mebendazole, levamisole, diethylcarbamazine citrate (DEC-C), and the combination of mebendazole and levamisole, on adult Onchocerca volvulus and on the in utero development of microfilariae was studied in nodules excised from patients in Southern Mexico. Adult worms isolated from patients treated with mebendazole showed a reduction in mobility and contained 40 times fewer developing microfilarial forms than did worms from untreated patients. Most of the developmental forms found in adult worms from mebendazole-treated patients were either oocytes or early morulae, with more mature forms being scarce or morphologically abnormal. Treatment with levamisole had a similar effect on embryogenesis, however it was much less marked. The number and distribution of developing forms in worms from patients treated with DEC-C was similar to that found in the control groups. The effect of the same three drugs on microfilariae in vitro was also tested. DEC-C at concentrations of 0.5 microgram - 2000 micrograms/ml did not have any obvious effect on motility or morphology of the worms provided the pH was maintained at physiological levels; levamisole also had no effect in vitro. Mebendazole induced the death of microfilariae when used at concentrations greater than 100 micrograms/ml, however these levels are greater than those found in the blood of patients under treatment. The optimal conditions for short-term maintenance of O. volvulus microfilariae in culture, are discussed. It is apparent from these studies that mebendazole has an effect on the maturation of microfilariae in utero and may also, at high concentrations, have a direct effect on mature microfilariae.

  5. The effect of drug treatment on the pattern of emergence of Onchocerca volvulus microfilariae from skin snips.

    PubMed

    Kale, O O

    1981-06-01

    A controlled study was carried out to determine the effect of some known anti-filarial drugs on the pattern of emergence of Onchocerca volvulus microfilariae from skin snips into saline. The results show that before treatment, 81.7 to 92.1% of microfilariae emerge in all the groups within 24 hours. The differences between the groups were not significant. After treatment with oral diethylcarbamazine, metrifonate and topical diethylcarbamazine (DEC) the percentage of microfilariae emerging from the snips dropped significantly to 48.4, 56.0 and 60.1 respectively, whereas no significant change occurred following treatment with levamisole (88.1%) and yeast tablets (89.1%). A pair-wise comparison of the post-treatment microfilarial emergence in all the groups showed statistically significant differences when (i) oral DEC is compared to levamisole, topical DEC and yeast, (ii) metrifonate is compared to levamisole and yeast and (iii) topical DEC is compared to yeast. It is suggested that microfilariae which fail to emerge from snips after treatment are those that have been killed or paralysed by the action of the drugs. The study has thus established that drug action in vivo is one of the factors which affects the proportion of microfilariae which emerge from skin snips and provides an additional parameter for measuring the antimicrofilarial potential of drugs in clinical chemotherapeutic trials.

  6. Immunoglobulin G subclass responses of children during infection with Onchocerca volvulus.

    PubMed Central

    Gbakima, A A; Nutman, T B; Bradley, J E; McReynolds, L A; Winget, M D; Hong, Y; Scott, A L

    1996-01-01

    To characterize the patterns of immunoglobulin G (IgG) subclass and IgE reactivity during the early stages of onchocerciasis, sera were collected from 224 children (age groups, 2 to 5, 6 to 10, and 11 to 15 years) residing in a region of Sierra Leone where Onchocerca volvulus is endemic, and these samples were tested by enzyme-linked immunosorbent assay for their reactivity to adult antigens (OvAg) and against four recombinant proteins (OV11, OV27, OV29, and OV16). Over 88% of the samples contained detectable levels of anti-OvAg IgG. In samples from microfilaria (MF)-positive children, IgG4 responses were significantly elevated and constituted on average 39, 35 and 28% of the total IgG responses for the age groups of 2 to 5, 6 to 10, and 11 to 15 years, respectively. For MF-negative individuals, the mean contributions of IgG4 to the total IgG response were 11% (2 to 5 years), 27% (6 to 10 years), and 56% (11 to 15 years). OvAg-specific IgE was detectable in the sera from both MF-negative and MF-positive individuals. To increase the specificity of the response, recombinant antigens OV11, OV27, and OV29 were tested individually or as a cocktail. Nearly 50% of the MF-negative children and 85% of the MF-positive children had detectable levels of IgG against at least one of the recombinant antigens. Only a small portion of the IgG against the recombinant peptides was IgG4. The prevalence of IgG against OV16 in samples from MF-negative children was 51%, and that for MF-positive children was 75%. The general profile of the humoral immune responses mounted by both MF-positive and a large percentage of the MF-negative children during the initial phases of infection with O. volvulus is similar to the profile reported for adults harboring chronic O. volvulus infections. These results suggest that very quickly after infection, the interactions between parasite and host result in an immunological environment that may contribute to the maintenance of a long-term, chronic

  7. Identification of three immunodominant motifs with atypical isotype profile scattered over the Onchocerca volvulus proteome

    PubMed Central

    Van Dorst, Bieke; Stuyver, Lieven J.

    2017-01-01

    Understanding the immune response upon infection with the filarial nematode Onchocerca volvulus and the mechanisms that evolved in this parasite to evade immune mediated elimination is essential to expand the toolbox available for diagnostics, therapeutics and vaccines development. Using high-density peptide microarrays we scanned the proteome-wide linear epitope repertoire in Cameroonian onchocerciasis patients and healthy controls from Southern Africa which led to the identification of 249 immunodominant antigenic peptides. Motif analysis learned that 3 immunodominant motifs, encompassing 3 linear epitopes, are present in 70, 43, and 31 of these peptides, respectively and appear to be scattered over the entire proteome in seemingly non-related proteins. These linear epitopes are shown to have an atypical isotype profile dominated by IgG1, IgG3, IgE and IgM, in contrast to the commonly observed IgG4 response in chronic active helminth infections. The identification of these linear epitope motifs may lead to novel diagnostic development but further evaluation of cross-reactivity against common co-infecting human nematode infections will be needed. PMID:28125577

  8. Lack of Active Onchocerca volvulus Transmission in the Northern Chiapas Focus of Mexico

    PubMed Central

    Rodríguez-Pérez, Mario A.; Unnasch, Thomas R.; Domínguez-Vázquez, Alfredo; Morales-Castro, Alba L.; Richards, Frank; Peña-Flores, Graciela P.; Orozco-Algarra, María Eugenia; Prado-Velasco, Gibert

    2010-01-01

    The northern Chiapas onchocerciasis focus has undergone 11 years of ivermectin mass treatment. No evidence of microfilariae in the cornea and/or anterior chamber of the eye or in skin snips was seen in residents examined in 2006 in two sentinel communities (upper limit of the 95% confidence interval [UL 95% CI] = 0.5% and 0.3%, respectively). In children 10 and under, 0 of 305 were found to harbor antibodies to Ov16, a marker of parasite exposure; 0 of 4,400 Simulium ochraceum s.l. collected in 2005 contained parasite DNA, giving an UL 95% CI for the infective rate of 0.9/2,000, and an UL 95% CI of the seasonal transmission potential of 1.2 L3/person. These data, assumed to be representative of the focus as a whole, suggest that there is no ongoing transmission of Onchocerca volvulus in the northern Chiapas focus. Community-wide treatments with ivermectin were halted in 2008, and a post-treatment surveillance phase was initiated. PMID:20595471

  9. The effect of repeated doses of ivermectin on adult female Onchocerca volvulus in Sierra Leone.

    PubMed

    Chavasse, D C; Post, R J; Lemoh, P A; Whitworth, J A

    1992-12-01

    The effects of single and multiple doses of ivermectin on mortality and morphology were assessed in over 700 female Onchocerca volvulus worms and the effects on embryogenesis were assessed in 490. Nodules were surgically removed from Sierra Leoneans recruited from a double-blind placebo controlled study of ivermectin given at six-monthly intervals. Nodules were digested in collagenase to isolate whole adult worms. After four or five doses of ivermectin there were significant increases in the numbers of discoloured and calcified worms and possibly a trend towards increased mortality, but this was not seen consistently. There was no evidence of a prophylactic effect of the drug. Worms were then homogenised and embryograms constructed. A single dose of ivermectin produced large numbers of degenerating intrauterine microfilariae, but embryonic development occurred normally. After multiple doses we observed almost complete cessation of embryogenesis, with a highly significant decrease in the numbers of viable multicellular embryonic stages, while oocytes appeared to be produced normally. Development is probably impeded at the single cell stage, possibly because of reduced fertilization. In planning the future role of ivermectin as a control measure for onchocerciasis it is crucial to determine if these effects on embryogenesis are reversible.

  10. How long do the effects of ivermectin on adult Onchocerca volvulus persist?

    PubMed

    Kläger, S; Whitworth, J A; Post, R J; Chavasse, D C; Downham, M D

    1993-12-01

    The persistence of the effects of ivermectin on the viability, morphology and reproductivity of adult Onchocerca volvulus was examined eighteen months after treatment with a single or five six-monthly doses of ivermectin and compared with untreated controls. Treated nodules were removed from patients participating in a randomised controlled trial of ivermectin in Sierra Leone. Adult filariae, 545 females and 348 males, were isolated by collagenase digestion. The nodules were significantly smaller, contained fewer young worms and supported lower microfilarial production in those treated with five doses of ivermectin. The productivity index, a measure of the reproductive potential of a worm population, was still reduced by 83% eighteen months after five doses and by 63% after a single dose compared to controls. These results show that worms recover their fertility even after multiple doses of ivermectin, but do so slowly compared to standard dosage intervals. In addition ivermectin may have a partial chemoprophylactic effect which contributes to the maintenance of low microfilarial production in conditions of on-going transmission.

  11. Viability of adult Onchocerca volvulus after six 2-weekly doses of ivermectin.

    PubMed

    Duke, B O; Pacqué, M C; Muñoz, B; Greene, B M; Taylor, H R

    1991-01-01

    Ivermectin is a safe, effective microfilaricide and microfilarial suppressant for Onchocerca volvulus; but in single doses of 100-200 micrograms/kg body weight it has no macrofilaricidal action. The present trial aimed to determine whether 6 doses of 100 micrograms/kg ivermectin, given at 2-week intervals, would kill the adult worms. Eighty-two nodules from 28 otherwise healthy adult male Liberian patients treated with this ivermectin schedule, and 102 nodules from a similar group of 25 control patients, were removed four months after the last dose of ivermectin. They were coded and assessed in a masked fashion either by routine histology or by examination of whole worms extracted from the nodules after collagenase digestion. The drug had no visible effect on adult male worms. More adult female worms were assessed as moribund or dead in the ivermectin-treated group than in the control group (for the collagenase digests P = 0.09; for the histological assessment P = 0.47). The data suggest that repeated dosage with ivermectin may lead to a slow attrition of some female worms and this possibility should be investigated in patients receiving regular doses every 3, 6 or 12 months as part of onchocerciasis control programmes.

  12. The effects of high-dose ivermectin regimens on Onchocerca volvulus in onchocerciasis patients.

    PubMed

    Awadzi, K; Attah, S K; Addy, E T; Opoku, N O; Quartey, B T

    1999-01-01

    Ivermectin, at the standard dose of 150 micrograms/kg bodyweight, does not kill the adult worms of Onchocerca volvulus and does not disrupt embryogenesis or spermatogenesis. Repeated standard doses, if maintained, arrest microfilarial production but result in only a mild-to-modest macrofilaricidal effect. We investigated whether high doses would effectively kill the adult worms, and whether cessation of microfilarial production could be reproduced by an equivalent, single, high dose. One hundred men participated in a double-blind placebo-controlled trial and received increasing doses of ivermectin from 150 micrograms/kg to 1600 micrograms/kg bodyweight. Nodules were excised at day 180 and examined by histopathology. Total doses of ivermectin up to 1600 micrograms/kg were not significantly more effective than 150 micrograms/kg. Moreover, they did not reproduce the marked inhibitory effects of the repeat standard-dose regimens on embryogenesis, nor the modest effect on adult worm viability, at comparable total doses. These effects may be functions of multiplicities of dosages rather than of the total dose. Our findings also suggest that repeated high-dose regimens are unlikely to be more effective than a similar number of 150 micrograms/kg doses. This deficiency of ivermectin requires that the search for macrofilaricides remains a top priority.

  13. Interruption of Onchocerca volvulus Transmission in the Abu Hamed Focus, Sudan

    PubMed Central

    Higazi, Tarig B.; Zarroug, Isam M. A.; Mohamed, Hanan A.; ElMubark, Wigdan A.; Deran, Tong Chor M.; Aziz, Nabil; Katabarwa, Moses; Hassan, Hassan K.; Unnasch, Thomas R.; Mackenzie, Charles D.; Richards, Frank; Hashim, Kamal

    2013-01-01

    Abu Hamed, Sudan, the northernmost location of onchocerciasis in the world, began community-directed treatment with ivermectin (CDTI) in 1998, with annual treatments enhanced to semiannual in 2007. We assessed the status of the parasite transmission in 2011 entomologically, parasitologically, and serologically. O-150 pool screening showed no parasite DNA in 17,537 black flies collected in 2011 (95% confidence interval upper limit [95% CI UL] = 0.023). Skin microfilariae, nodules, and signs of skin disease were absent in 536 individuals in seven local communities. Similarly, no evidence of Onchocerca volvulus Ov16 antibodies was found in 6,756 school children ≤ 10 years (95% CI UL = 0.03%). Because this assessment of the focus meets the 2001 World Health Organization (WHO) criteria for interrupted transmission, treatment was halted in 2012, and a post-treatment surveillance period was initiated in anticipation of declaration of disease elimination in this area. We provide the first evidence in East Africa that long-term CDTI alone can interrupt transmission of onchocerciasis. PMID:23690554

  14. Identification of three immunodominant motifs with atypical isotype profile scattered over the Onchocerca volvulus proteome.

    PubMed

    Lagatie, Ole; Van Dorst, Bieke; Stuyver, Lieven J

    2017-01-01

    Understanding the immune response upon infection with the filarial nematode Onchocerca volvulus and the mechanisms that evolved in this parasite to evade immune mediated elimination is essential to expand the toolbox available for diagnostics, therapeutics and vaccines development. Using high-density peptide microarrays we scanned the proteome-wide linear epitope repertoire in Cameroonian onchocerciasis patients and healthy controls from Southern Africa which led to the identification of 249 immunodominant antigenic peptides. Motif analysis learned that 3 immunodominant motifs, encompassing 3 linear epitopes, are present in 70, 43, and 31 of these peptides, respectively and appear to be scattered over the entire proteome in seemingly non-related proteins. These linear epitopes are shown to have an atypical isotype profile dominated by IgG1, IgG3, IgE and IgM, in contrast to the commonly observed IgG4 response in chronic active helminth infections. The identification of these linear epitope motifs may lead to novel diagnostic development but further evaluation of cross-reactivity against common co-infecting human nematode infections will be needed.

  15. Viability of adult Onchocerca volvulus after six 2-weekly doses of ivermectin.

    PubMed Central

    Duke, B. O.; Pacqué, M. C.; Muñoz, B.; Greene, B. M.; Taylor, H. R.

    1991-01-01

    Ivermectin is a safe, effective microfilaricide and microfilarial suppressant for Onchocerca volvulus; but in single doses of 100-200 micrograms/kg body weight it has no macrofilaricidal action. The present trial aimed to determine whether 6 doses of 100 micrograms/kg ivermectin, given at 2-week intervals, would kill the adult worms. Eighty-two nodules from 28 otherwise healthy adult male Liberian patients treated with this ivermectin schedule, and 102 nodules from a similar group of 25 control patients, were removed four months after the last dose of ivermectin. They were coded and assessed in a masked fashion either by routine histology or by examination of whole worms extracted from the nodules after collagenase digestion. The drug had no visible effect on adult male worms. More adult female worms were assessed as moribund or dead in the ivermectin-treated group than in the control group (for the collagenase digests P = 0.09; for the histological assessment P = 0.47). The data suggest that repeated dosage with ivermectin may lead to a slow attrition of some female worms and this possibility should be investigated in patients receiving regular doses every 3, 6 or 12 months as part of onchocerciasis control programmes. PMID:1860146

  16. The Onchocerca volvulus micro- and macrofilarial responses in onchocerciasis patients to increased dosage of diethylcarbamazine.

    PubMed

    Langham, M E; Beltranena, F

    1985-09-01

    The response of 45 severely infected onchocerciasis patients to relatively high doses of diethylcarbamazine citrate (DEC-C) has been determined. The treatment comprised two sequential phases; the first phase comprised the topical applications of a DEC-C lotion and of the anti-inflammatory steroid betamethasone. The second phase comprised the daily oral administration of high doses of DEC-C (30 mg/kg body wt) for seven days. Onchocerca volvulus microfilarial (o.v.mf.) counts in skin snips of the 45 patients decreased by 96 +/- 1.5% after 5 days of treatment with topical DEC-C lotion. Following the administration of oral DEC, the average O.v.mf. counts in the skin snips at days 51, 97, and 143 remained decreased by 85 to 93%. The mean O.v.mf. counts in 10 nodules excised from 5 treated patients at day 77 had decreased by 93% compared to the mean O.v.mf. counts in 11 nodules taken from 5 untreated patients with similar initial O.v.mf. infection. No visual loss resulted from the treatment.

  17. Onchocerca volvulus-specific antibody and cytokine responses in onchocerciasis patients after 16 years of repeated ivermectin therapy

    PubMed Central

    Mai, C S; Hamm, D M; Banla, M; Agossou, A; Schulz-Key, H; Heuschkel, C; Soboslay, P T

    2007-01-01

    The recommended control option against onchocerciasis is repeated ivermectin treatment, which will need to be implemented for decades, and it remains unknown how repeated ivermectin therapy might affect immunity against Onchocerca volvulus in the long term. O. volvulus-specific antibody reactivity and cellular cytokine production were investigated in onchocerciasis patients receiving ivermectin (150 µg/kg) annually for 16 years. In treated patients, the T helper type 2 (Th2) cytokine interleukin (IL)-5 and T regulatory IL-10 in response to O. volvulus antigen (OvAg) and bacteria-derived Streptolysin O (SL-O) diminished to levels found in infection-free endemic controls; also, cellular release of Th1-type interferon (IFN)-γ at 16 years post initial ivermectin treatment (p.i.t.) approached control levels. In ivermectin-treated onchocerciasis patients, IL-5 production in responses to the mitogen phytohaemagglutinin (PHA) decreased, but IL-10 in response PHA increased, and neither attained the cytokine production levels of endemic controls. At 16 years p.i.t., O. volvulus-specific IgG1 and IgG4 subclass reactivity still persisted at higher levels in onchocerciasis patients than in O. volvulus exposed but microfilariae-free endemic controls. In addition, cytokine responses remained depressed in onchocerciasis patients infected concurrently with Mansonella perstans and Necator americanus or Entamoeba histolytica/dispar. Thus, long-term ivermectin therapy of onchocerciasis may not suffice to re-establish fully a balanced Th1 and Th2 immune responsiveness in O. volvulus microfilariae-negative individuals. Such deficient reconstitution of immune competence may be due to an as yet continuing and uncontrolled reinfection with O. volvulus, but parasite co-infections can also bias and may prevent the development of such immunity. PMID:17302900

  18. No depletion of Wolbachia from Onchocerca volvulus after a short course of rifampin and/or azithromycin.

    PubMed

    Richards, Frank O; Amann, Josef; Arana, Byron; Punkosdy, George; Klein, Robert; Blanco, Carlos; Lopez, Beatriz; Mendoza, Carlos; Domínguez, Alfredo; Guarner, Jeannette; Maguire, James H; Eberhard, Mark

    2007-11-01

    Endosymbionic Wolbachia bacteria inside adult Onchocerca volvulus worms (causing river blindness) are necessary for female worm fertility. We evaluated whether rifampin and/or azithromycin used in a five-day course could kill Wolbachia. In an open-label trial in Guatemala, 73 patients with 134 palpable onchocercal nodules were randomized into four treatment groups: rifampin, azithromycin, a combination of the two drugs, and controls (multivitamins). After five days of antibiotic treatment, all participants received a single dose of ivermectin on day 6. Nine months after treatment, the nodules were removed and the worms were examined. Skin snips to determine microfilariae were obtained at baseline and nine months. There were no significant differences between any of the treatment groups in the condition of the worms in the nodules, the presence of Wolbachia surface protein, or the number of microfilariae in skin. Short courses with these antibiotics will not clear Wolbachia from O. volvulus.

  19. Epidemiology of concomitant infections due to Loa loa, Mansonella perstans, and Onchocerca volvulus in rain forest villages of Cameroon.

    PubMed

    Wanji, S; Tendongfor, N; Esum, M; Ndindeng, S; Enyong, P

    2003-02-01

    An epidemiological survey was conducted in 16 remote villages of the rain forest of southern Cameroon to ascertain the prevalence and intensity of three species of filariae: Loa loa, Onchocerca volvulus, and Mansonella perstans. We examined 1458 individuals for blood-dwelling microfilariae and 1255 of these were also for the presence of palpable nodules. All the villages surveyed were found highly endemic for onchocerciasis and mansonellosis with prevalence ranging from 28.44% to 87.17% for O. volvulus and 52.48% to 100% for M. perstans. The intensities of infection were also found high for M. perstans with arithmetic means of microfilaremia ranging from 280.94 to 4947.57 mf/ml. The loiasis prevalence was relatively low with value from 2.22% to 19.23%. Males were found more infected than females for the three species of filariae, and the prevalence and intensities of microfilaremia vary differently in males and females at different ages. The three species of filariae displayed different degrees of association in the inhabitants with a low prevalence of co-occurrence between L. loa/O. volvulus and between L. loa/M. perstans. In contrast, there was a high prevalence of co-occurrence between M. perstans and O. volvulus. The implications of the co-occurrence of the three species of filariae in the populations of these remote villages on the intervention programs based on mass treatment with mectizan are discussed.

  20. Prevalence of Antibodies to Onchocerca volvulus in Residents of Oaxaca, Mexico, Treated for 10 Years with Ivermectin

    PubMed Central

    Gómez-Priego, Alberto; Mendoza, Raymundo; de-la-Rosa, Jorge-Luis

    2005-01-01

    Studies to determine the prevalence of antibodies to Onchocerca volvulus, prior to and after actions carried out to interrupt transmission, are scarce in Mexico. Here we report the prevalence of immunoglobulin G (IgG) and IgG4 antibodies in an enzyme-linked immunosorbent assay (ELISA) against a crude extract of O. volvulus adult worm in serum samples from persons under noninterrupted biannual treatment with ivermectin in areas of onchocercosis endemicity in Mexico. To perform the prevalence studies, the ELISA procedures were first evaluated. Serological studies were performed with serum samples from skin microfilaria carriers from Guatemala and from people microfilariodermic negative living in the same area as the Guatemalan patients. Sensitivity values for IgG or IgG4 detection were 71 and 86%, while specificities were 92 and 100%, respectively. No anti-O. volvulus antibodies were found in samples from nonendemic controls from Mexico, but 3 of 71 samples from residents in the onchocercosis area of Oaxaca, Mexico, and who have been under ivermectin treatment during the last 10 years were only positive to IgG. Notwithstanding that the IgG4 isotype was not detected and a low (4.2%) anti-O. volvulus IgG antibody prevalence was found, a seroepidemiological follow-up must be performed in order to confirm interruption of onchocercosis transmission in the area of Oaxaca, Mexico, in which onchocercosis is endemic. PMID:15642982

  1. Thioredoxin peroxidase from Onchocerca volvulus: a major hydrogen peroxide detoxifying enzyme in filarial parasites.

    PubMed

    Lu, W; Egerton, G L; Bianco, A E; Williams, S A

    1998-03-15

    Random screening of an Onchocerca volvulus third-stage (L3) cDNA library identified a highly abundant cDNA encoding a newly discovered antioxidant enzyme, thioredoxin peroxidase (TPx), a member of the peroxidoxin superfamily. This TPx cDNA (Ov-tpx-2) encodes a polypeptide of 199 amino acid residues with a calculated molecular weight of 21,890 Da. The Ov-tpx-2 cDNA represents roughly 2.5% of the total cDNAs from the L3 cDNA library. The gene was expressed in Escherichia coli and the protein product was shown to have antioxidant activity. Antiserum raised against Ov-TPX-2 recognized a native protein from extracts of both the L3 and adult-stages with a molecular weight of 22 kD. The localization and stage-specificity of Ov-TPX-2 protein was analyzed by immunocytochemistry and immunoelectron microscopy using monospecific antibodies. Expression was detected in late first-stage larvae during development in the vector and increased in intensity during differentiation to the infective L3-stage. The antigen was also detected in post-infective larvae and adult worms. In larvae, Ov-TPX-2 protein was predominantly localized to the hypodermis and cuticle, with additional sites in the hypodermal chords and multivesicular bodies. In adult worms, the primary sites of expression were the uterine epithelium and intestine, with additional labeling of the body wall and cuticle. Developing embryos and microfilariae in utero were bathed in Ov-TPX-2 protein discharged from epithelial cells. These results suggest that Ov-TPX-2 may protect the parasites from being damaged by host-generated oxidative stress and that Ov-TPX-2 protein provides the H2O2-detoxifying activity predicted but not previously identified in filarial parasites. Its highly upregulated expression in infective larvae may aid in parasite establishment following transmission to the definitive host.

  2. Factors influencing the passage of Onchocerca volvulus microfilariae into the urine.

    PubMed

    Duke, B O; Moore, P J; Vincelette, J

    1975-12-01

    The effect of various substances on the output of Onchocerca volvulus microfilariae in the urine was investigated in volunteers infected with the Cameroon forest and Sudan-savanna strains of the parasite. Output of microfilariae in the urine tended to be higher during periods of normal activity than during sleep. During waking hours, the rate of output remained generally steady, but in some patients occasional showers of microfilariae appeared in the urine, possibly associated with the intake of food and drink. Drinking 1.2-2.5 litres water produced a shower of microfilariae in the urine of some subjects. This began within an hour of drinking and its onset preceeded that of the diuresis. Thiazide diuretics, acting on the convoluted tubules, produced no increase in microfilaruria. In savanna subjects intravenous injection of DT TAB vaccine caused pyrexia, and simultaneously large numbers of microfilariae appeared in the urine. There was no associated diuresis, and no increase in the concentration of microfilariae in the venous blood. In forest subjects DT TAB caused no increase in microfilaruria. In all subjects 25-50 mg diethylcarbamazine (DEC) caused large numbers of microfilariae to appear in the urine on day 0, within a few hours of the first dose; and there was an increased output of urine over the first 24 hours. Microfilaruria declined sharply on day 1 of treatment, but in subjects developing a high microfilaraemia, it rose again on day 2, and declined more slowly thereafter. Betamethazone, given in conjunction with DEC, appeared to slow the rate of destruction of microfilariae in the skin and lymph glands, and to prolong the duration of microfilaraemia and microfilaruria. The findings suggest that there is a reservoir of microfilariae in the glomerular capillaries, which fills slowly by accumulating microfilariae from the circulating blood. The microfilariae probably enter the urine by penetrating the glomerular capillary.

  3. The effects of drugs on Onchocerca volvulus. 4. Trials of melarsonyl potassium.

    PubMed

    Duke, B O

    1970-01-01

    The effects of the arsenical drug melarsonyl potassium on Onchocerca volvulus were investigated in patients in Cameroon infected with the Cameroon forest and Sudan savanna strains of the parasite. Two intramuscular dosage schedules were tested: the first comprised 4 consecutive daily doses of 200 mg repeated once after a 10-14 day interval, i.e., 2 (4x200 mg). The second was a single dose schedule at 7.1 mg/kg-10 mg/kg, with a maximum of 500 mg.In most trials the drug had no immediate action on microfilarial concentrations. Only after the 2(4x200 mg) melarsonyl course against the Sudan savanna strain was a slight microfilaricidal action detected.The 2(4x200 mg) course of melarsonyl apparently killed or sterilized most or all of the adult female worms in the patients tested, leaving the residual population of microfilariae to decline gradually, from natural mortality, over the ensuing 2 years. These residual microfilariae could be killed with diethylcarbamazine.Single doses of melarsonyl at 7.1 mg/kg-10 mg/kg were somewhat less effective in killing or sterilizing adult worms, but it is suggested that if doses at the higher end of this range were to be repeated annually patients could be rendered free from microfilariae by the end of 3 years.It is emphasized that the risks of arsenical encephalopathy should at present preclude the use of melarsonyl potassium in the treatment of onchocerciasis, but that if this danger could be avoided the drug might prove to be of considerable use for mass therapy in control campaigns.

  4. Oligonucleotide Based Magnetic Bead Capture of Onchocerca volvulus DNA for PCR Pool Screening of Vector Black Flies

    PubMed Central

    Gopal, Hemavathi; Hassan, Hassan K.; Rodríguez-Pérez, Mario A.; Toé, Laurent D.; Lustigman, Sara; Unnasch, Thomas R.

    2012-01-01

    Background Entomological surveys of Simulium vectors are an important component in the criteria used to determine if Onchocerca volvulus transmission has been interrupted and if focal elimination of the parasite has been achieved. However, because infection in the vector population is quite rare in areas where control has succeeded, large numbers of flies need to be examined to certify transmission interruption. Currently, this is accomplished through PCR pool screening of large numbers of flies. The efficiency of this process is limited by the size of the pools that may be screened, which is in turn determined by the constraints imposed by the biochemistry of the assay. The current method of DNA purification from pools of vector black flies relies upon silica adsorption. This method can be applied to screen pools containing a maximum of 50 individuals (from the Latin American vectors) or 100 individuals (from the African vectors). Methodology/Principal Findings We have evaluated an alternative method of DNA purification for pool screening of black flies which relies upon oligonucleotide capture of Onchocerca volvulus genomic DNA from homogenates prepared from pools of Latin American and African vectors. The oligonucleotide capture assay was shown to reliably detect one O. volvulus infective larva in pools containing 200 African or Latin American flies, representing a two-four fold improvement over the conventional assay. The capture assay requires an equivalent amount of technical time to conduct as the conventional assay, resulting in a two-four fold reduction in labor costs per insect assayed and reduces reagent costs to $3.81 per pool of 200 flies, or less than $0.02 per insect assayed. Conclusions/Significance The oligonucleotide capture assay represents a substantial improvement in the procedure used to detect parasite prevalence in the vector population, a major metric employed in the process of certifying the elimination of onchocerciasis. PMID:22724041

  5. Immunohistological studies on neoplasms of female and male Onchocerca volvulus: filarial origin and absence of Wolbachia from tumor cells.

    PubMed

    Brattig, N W; Hoerauf, A; Fischer, P U; Liebau, E; Bandi, C; Debrah, A; Büttner, M; Büttner, D W

    2010-04-01

    Up to 5% of untreated female Onchocerca volvulus filariae develop potentially fatal pleomorphic neoplasms, whose incidence is increased following ivermectin treatment. We studied the occurrence of 8 filarial proteins and of Wolbachia endobacteria in the tumor cells. Onchocercomas from patients, untreated and treated with antibiotics and anthelminthics, were examined by immunohistology. Neoplasms were diagnosed in 112 of 3587 female and in 2 of 1570 male O. volvulus. The following proteins and other compounds of O. volvulus were expressed in the cells of the neoplasms: glutathione S-transferase 1, lysosomal aspartic protease, cAMP-dependent protein kinase, alpha-enolase, aspartate aminotransferase, ankyrin E1, tropomyosin, heat shock protein 60, transforming growth factor-beta, and prostaglandin E(2). These findings prove the filarial origin of the neoplasms and confirm the pleomorphism of the tumor cells. Signs indicating malignancy of the neoplasms are described. Wolbachia were observed in the hypodermis, oocytes, and embryos of tumor-harbouring filariae using antibodies against Wolbachia surface protein, Wolbachia HtrA-type serine protease, and Wolbachia aspartate aminotransferase. In contrast, Wolbachia were not found in the cells of the neoplasms. Further, neoplasm-containing worms were not observed after more than 10 months after the start of sufficient treatment with doxycycline or doxycycline plus ivermectin.

  6. Immunohistological studies on neoplasms of female and male Onchocerca volvulus: filarial origin and absence of Wolbachia from tumor cells

    PubMed Central

    BRATTIG, N. W.; HOERAUF, A.; FISCHER, P. U.; LIEBAU, E.; BANDI, C.; DEBRAH, A.; BÜTTNER, M.; BÜTTNER, D. W.

    2010-01-01

    SUMMARY Up to 5% of untreated female Onchocerca volvulus filariae develop potentially fatal pleomorphic neoplasms, whose incidence is increased following ivermectin treatment. We studied the occurrence of 8 filarial proteins and of Wolbachia endobacteria in the tumor cells. Onchocercomas from patients, untreated and treated with antibiotics and anthelminthics, were examined by immunohistology. Neoplasms were diagnosed in 112 of 3587 female and in 2 of 1570 male O. volvulus. The following proteins and other compounds of O. volvulus were expressed in the cells of the neoplasms: glutathione S-transferase 1, lysosomal aspartic protease, cAMP-dependent protein kinase, alpha-enolase, aspartate aminotransferase, ankyrin E1, tropomyosin, heat shock protein 60, transforming growth factor-beta, and prostaglandin E2. These findings prove the filarial origin of the neoplasms and confirm the pleomorphism of the tumor cells. Signs indicating malignancy of the neoplasms are described. Wolbachia were observed in the hypodermis, oocytes, and embryos of tumor-harbouring filariae using antibodies against Wolbachia surface protein, Wolbachia HtrA-type serine protease, and Wolbachia aspartate aminotransferase. In contrast, Wolbachia were not found in the cells of the neoplasms. Further, neoplasm-containing worms were not observed after more than 10 months after the start of sufficient treatment with doxycycline or doxycycline plus ivermectin. PMID:20199697

  7. The mitochondrial heat shock protein 60 (HSP60) is up-regulated in Onchocerca volvulus after the depletion of Wolbachia.

    PubMed

    Pfarr, K M; Heider, U; Schmetz, C; Büttner, D W; Hoerauf, A

    2008-04-01

    Wolbachia, a genus of endosymbiotic bacteria of filarial worms, represent novel targets for anti-filarial therapy. The efficacy of compounds against Wolbachia has been evaluated using antiserum raised against the 60 kDa heat shock protein (HSP60) which binds specifically to this protein in both Wolbachia and mitochondria. It has been shown that Wolbachia stains (using such specific probes) stronger than the mitochondria in untreated Onchocerca volvulus, whereas after the depletion of Wolbachia (with drugs) staining of the mitochondria is increased. Herein, immunogold electron microscopy showed that specific anti-HSP60 serum specifically labelled Wolbachia and filarial mitochondria, and that both have distinct localization patterns, thus allowing them to be differentiated. Immunohistochemistry of O. volvulus showed that HSP60 staining is increased in the mitochondria after Wolbachia depletion in the hypodermis, epithelia, muscles, oocytes, embryos, and developing spermatozoa. This could have been the result of the antiserum preferentially binding to the Wolbachia when they are present or due to increased expression of the protein in the absence of the bacteria. To address this, mRNA levels of filarial hsp60 in O. volvulus were measured. After the depletion of Wolbachia, the transcription of hsp60 was significantly greater (7.7 fold) compared with untreated worms. We hypothesize that the increased expression of HSP60 in the absence of Wolbachia is due to a disruption of the homeostasis of the endosymbiosis.

  8. Immunological crossreactivity between a cloned antigen of Onchocerca volvulus and a component of the retinal pigment epithelium

    PubMed Central

    1991-01-01

    Onchocerciasis (river blindness) is a major blinding disease in Africa, Central America, and South America. Loss of vision can be due to corneal change, optic atrophy, or chorioretinal disease. It has been suggested that autoimmunological reactions resulting from crossreactivity between parasite antigens and components of eye tissues contribute to development of ocular pathology. Using sera collected from onchocerciasis patients as a screening reagent, a cDNA clone (Ov39) has been isolated from a lambda gt11 expression library of Onchocerca volvulus. This antigen exhibits immunological crossreactivity with a component of retinal pigment epithelium cells (RPE). Antiserum raised against this recombinant peptide immunoprecipitates a 22,000 Mr antigen of adult O. volvulus and recognizes a 44,000 Mr component of bovine RPE by Western blotting. A 44,000 Mr antigen of cultured human RPE metabolically labeled with 35S- methionine can be immunoprecipitated with the same antiserum. An antigen of the same size is recognized by a rabbit antiserum raised against whole O. volvulus extract. Immunocytochemical studies on cryostat sections of the bovine eye using the antirecombinant sera localizes this antigen to the RPE. PMID:2056276

  9. Neutrophil granule proteins: evidence for the participation in the host reaction to skin microfilariae of Onchocerca volvulus after diethylcarbamazine administration.

    PubMed

    Gutiérrez-Peña, E J; Knab, J; Büttner, D W

    1996-10-01

    The participation of neutrophil granulocytes in the cellular reaction to skin microfilariae of Onchocerca volvulus was studied by immunohistochemistry. Skin biopsies were obtained from adult Liberian and Ugandan patients with generalized onchocerciasis after exposure to topically applied diethylcarbamazine (DEC) and from untreated patients. After DEC many damaged microfilariae were observed either in dermal infiltrates or in epidermal microabscesses consisting both of neutrophils and eosinophils. Infiltrates and microabscesses contained some intact granulocytes and many neutrophils releasing myeloperoxidase, elastase, lactoferrin, defensin, lysozyme, alpha 1-antitrypsin and alpha 1-antichymotrypsin. Eosinophils discharged peroxidase and cationic proteins. Released granule proteins and remnants of disrupted granulocytes were found on the surface and in close proximity of damaged microfilariae in dermal infiltrates and epidermal microabscesses. In larger microabscesses neutrophils were predominant. These observations show that neutrophils and not only eosinophils recruit, accumulate, localize around and release their helminthotoxic granule proteins such as myeloperoxidase onto or closely around skin microfilariae of O. volvulus after topical DEC administration. The association between these processes and the damage of the microfilariae indicated that neutrophils together with eosinophils attack and damage microfilariae of O. volvulus after DEC treatment in the skin.

  10. Onchocerca volvulus. Monoclonal anti-idiotype antibody as antigen signal for the microfilaricidal cytotoxicity of diethylcarbamazine-treated platelets.

    PubMed

    Cesbron, J Y; Hayasaki, M; Joseph, M; Lutsch, C; Grzych, J M; Capron, A

    1988-07-01

    Over the past 35 yr, diethylcarbamazine (DEC) has been the most widely used agent for the treatment of filarial diseases, particularly in onchocerciasis. The microfilaricidal action of DEC has been recently shown to be mediated by blood platelets with the additional triggering of a filarial excretory Ag (FEA). This FEA could be detected by using mAb in the serum of infected patients. By using one mAb (IA2(23] directed against Onchocerca volvulus and recognizing circulating Ag (Ab1), we purified by affinity chromatography the target molecule of IA2(23) (an O. volvulus glycoprotein recognized by IA2(23) mAb). This compound had a dose-dependent effect on the cytotoxic action of DEC-treated platelets. We subsequently produced an anti-idiotype mAb to Ab1 (Ab2), and considered the possibility of replacing the O. volvulus glycoprotein recognized by IA2(23) mAb by Ab2. Ab2 was selected according to its ability to inhibit the binding of radioiodinated Ab1 to the filarial target Ag. It induced the production of anti-O. volvulus antibodies (Ab3) in rats. At a constant concentration of DEC platelets, the addition of increasing amounts of Ab2 led to a dose-dependent cytotoxic effect against parasite larvae. Experiments performed with Ab2 on detergent solubilized surface proteins of platelets identified four bands of Mr 18, 26, 43.5, and 100 kDa, supporting the idea of the presence of binding sites on the platelets for a FEA required for the microfilaricidal cytotoxicity of DEC-treated platelets.

  11. Differential cytokine and antibody responses to adult and larval stages of Onchocerca volvulus consistent with the development of concomitant immunity.

    PubMed

    MacDonald, Angus J; Turaga, Prasad S D; Harmon-Brown, Carolyn; Tierney, Tracy J; Bennett, Kristine E; McCarthy, Maggie C; Simonek, Scott C; Enyong, Peter A; Moukatte, Daniel W; Lustigman, Sara

    2002-06-01

    The possibility of concomitant immunity and its potential mechanisms in Onchocerca volvulus infection were examined by analyzing cytokine and antibody responses to infective larval (third-stage larvae [L3] and molting L3 [mL3]), adult female worm (F-OvAg), and skin microfilaria (Smf) antigens in infected individuals in a region of hyperendemicity in Cameroon as a function of age. Peripheral blood mononuclear cell interleukin 5 (IL-5) responses to F-OvAg and Smf declined significantly with age (equivalent to years of exposure to O. volvulus). In contrast, IL-5 secretion in response to L3 and mL3 remained elevated with increasing age. Gamma interferon responses to L3, mL3, and F-OvAg were low or suppressed and unrelated to age, except for responses to Smf in older subjects. IL-10 levels were uniformly elevated, regardless of age, in response to L3, mL3, and F-OvAg but not to Smf, for which levels declined with age. A total of 49 to 60% of subjects had granulocyte-macrophage colony-stimulating factor responses to all O. volvulus antigens unrelated to age. Analysis of levels of stage-specific immunoglobulin G3 (IgG3) and IgE revealed a striking, age-dependent dissociation between antibody responses to larval antigens (L3 and a recombinant L3-specific protein, O. volvulus ALT-1) which were significantly increased or maintained with age and antibody responses to F-OvAg, which decreased. Levels of IgG1 to L3 and F-OvAg were elevated regardless of age, and levels of IgG4 increased significantly with age, although not to O. volvulus ALT-1, which may have unique L3-specific epitopes. Immunofluorescence staining of whole larvae showed that total anti-L3 immunoglobulin levels also increased with the age of the serum donor. The separate and distinct cytokine and antibody responses to adult and infective larval stages of O. volvulus which are age related are consistent with the acquisition of concomitant immunity in infected individuals.

  12. Genotypic analysis of β-tubulin in Onchocerca volvulus from communities and individuals showing poor parasitological response to ivermectin treatment

    PubMed Central

    Osei-Atweneboana, Mike Y.; Boakye, Daniel A.; Awadzi, Kwablah; Gyapong, John O.; Prichard, Roger K.

    2012-01-01

    Ivermectin (IVM) has been in operational use for the control of onchocerciasis for two decades and remains the only drug of choice. To investigate the parasitological responses and genetic profile of Onchocerca volvulus, we carried out a 21 month epidemiological study to determine the response of the parasite to IVM in 10 Ghanaian endemic communities. Onchocerca nodules were surgically removed from patients in three IVM response categories (good, intermediate and poor) and one IVM naïve community. DNA from adult worms was analyzed to determine any association between genotype and IVM response phenotypic. Embryogramme analysis showed significantly higher reproductive activity in worms from poor response communities, which had up to 41% of females with live stretched microfilaria (mf) in utero, despite IVM treatment, compared with good response communities, which had no intra-uterine stretched mf. β-tubulin isotype 1 gene has been shown to be linked to IVM selection in O. volvulus and also known to be associated with IVM resistance in veterinary nematodes. We have genotyped the full length genomic DNA sequence of the β-tubulin gene from 127 adult worms obtained from the four community categories. We found SNPs at 24 sites over the entire 3696 bp. Eight of the SNPs occurred at significantly higher (p < 0.05) frequencies in the poor response communities compared with the good response communities and the IVM naïve community. Phenotypic and genotypic analyses show that IVM resistance has been selected and the genotype (1183GG/1188CC/1308TT/1545GG) was strongly associated with the resistance phenotype. Since the region in the β-tubulin gene where these four SNPs occur is within 362 bp, it is feasible to develop a genetic marker for the early detection of IVM resistance. PMID:24533268

  13. Modulation of human T cell responses and macrophage functions by onchocystatin, a secreted protein of the filarial nematode Onchocerca volvulus.

    PubMed

    Schönemeyer, A; Lucius, R; Sonnenburg, B; Brattig, N; Sabat, R; Schilling, K; Bradley, J; Hartmann, S

    2001-09-15

    Immune responses of individuals infected with filarial nematodes are characterized by a marked cellular hyporesponsiveness and a shift of the cytokine balance toward a Th2/Th3 response. This modulation of cellular immune responses is considered as an important mechanism to avoid inflammatory immune responses that could eliminate the parasites. We investigated the immunomodulatory potential of a secreted cysteine protease inhibitor (onchocystatin) of the human pathogenic filaria Onchocerca volvulus. Recombinant onchocystatin (rOv17), a biologically active cysteine protease inhibitor that inhibited among others the human cysteine proteases cathepsins L and S, suppressed the polyclonally stimulated and the Ag-driven proliferation of human PBMC. Stimulated as well as unstimulated PBMC in the presence of rOv17 produced significantly more IL-10, which was paralleled in some situations by a decrease of IL-12p40 and preceded by an increase of TNF-alpha. At the same time, rOv17 reduced the expression of HLA-DR proteins and of the costimulatory molecule CD86 on human monocytes. Neutralization of IL-10 by specific Abs restored the expression of HLA-DR and CD86, whereas the proliferative block remained unaffected. Depletion of monocytes from the PBMC reversed the rOv17-induced cellular hyporeactivity, indicating monocytes to be the target cells of immunomodulation. Therefore, onchocystatin has the potential to contribute to a state of cellular hyporesponsiveness and is a possible pathogenicity factor essential for the persistence of O. volvulus within its human host.

  14. Ivermectin uptake and distribution in the plasma and tissue of Sudanese and Mexican patients infected with Onchocerca volvulus.

    PubMed

    Elkassaby, M H

    1991-06-01

    Ten Sudanese patients with Onchocerca volvulus infection were treated with a single oral dose of 150 micrograms/kg of ivermectin. Plasma samples were collected before treatment, 0.5, 1, 3, 4, 6, 12 hours and 1, 2, 3, 7, and 30 days. Four patients were selected for nodulectomies and skin biopsies at 6, 18 and 30 hours and 3 days post treatment. Using these samples O. volvulus worm fragments were dissected free of host nodular tissues for ivermectin extraction. Ivermectin was present in the nodular tissue at 6 hr and persisted for 3 days. It was also detected in an individual worm tissue extract at a concentration similar to the nodule, but in subcutaneous fascial tissue higher concentrations were sometimes found. Ivermectin was detected by radioimmunoassay in the plasma of all patients at 1 hr and peak concentrations were reached in an average of 5.6 hr. The drug persisted at detectable levels for 7 days in 70% of the studied patients. Plasma samples were also collected from 16 treated Mexican onchocerciasis patients before ivermectin treatment and 4 hr treatment and from six individuals who served as controls. The Mexican patients had concentrations of ivermectin in their plasma similar to those in the Sudanese patients.

  15. Stage-Specific Transcriptome and Proteome Analyses of the Filarial Parasite Onchocerca volvulus and Its Wolbachia Endosymbiont

    PubMed Central

    Bennuru, Sasisekhar; Cotton, James A.; Ribeiro, Jose M. C.; Grote, Alexandra; Harsha, Bhavana; Holroyd, Nancy; Mhashilkar, Amruta; Molina, Douglas M.; Randall, Arlo Z.; Shandling, Adam D.; Unnasch, Thomas R.; Ghedin, Elodie; Berriman, Matthew

    2016-01-01

    ABSTRACT Onchocerciasis (river blindness) is a neglected tropical disease that has been successfully targeted by mass drug treatment programs in the Americas and small parts of Africa. Achieving the long-term goal of elimination of onchocerciasis, however, requires additional tools, including drugs, vaccines, and biomarkers of infection. Here, we describe the transcriptome and proteome profiles of the major vector and the human host stages (L1, L2, L3, molting L3, L4, adult male, and adult female) of Onchocerca volvulus along with the proteome of each parasitic stage and of its Wolbachia endosymbiont (wOv). In so doing, we have identified stage-specific pathways important to the parasite’s adaptation to its human host during its early development. Further, we generated a protein array that, when screened with well-characterized human samples, identified novel diagnostic biomarkers of O. volvulus infection and new potential vaccine candidates. This immunomic approach not only demonstrates the power of this postgenomic discovery platform but also provides additional tools for onchocerciasis control programs. PMID:27881553

  16. Quantitative aspects of the infection of Simulium ochraceum by Onchocerca volvulus: the relation of skin microfilarial density to vector infection.

    PubMed

    Campbell, C C; Collins, R C; Huong, A Y; Marroquin, H F

    1980-12-01

    In Guatemala, 16 wild Simulium ochraceum were permitted to feed on a 15" x 15" grid on the back of each of 13 persons infected with Onchocerca volvulus. Based on 6 skin biopsies, the mean microfilarial density (mfd) in these study participants ranged from 1.256 mf/mg of skin to 111.824 mf/mg. The files were dissected 6 to 10 hours after feeding and the number of microfilariae in the blood meal and escaping the midgut into the thoracic musculature were counted. A nearly linear relationship was found between the mean skin mfd and the mean microfilarial uptake by S. ochraceum (rs = 0.868). An even stronger relation existed between the mean mfd and the mean number of microfilariae escaping the midgut (rs = 0.915). Because the approximate 1:1 relationship observed between the number of microfilariae escaping the midgut and the subsequent number of infective (L3) larvae has been previously demonstrated, it can be concluded that a similar linear relationship exists between microfilarial skin densities and the number of L3 larvae available for transmission of O. volvulus by the Guatemalan vector.

  17. Rapid suppression of Onchocerca volvulus transmission in two communities of the Southern Chiapas focus, Mexico, achieved by quarterly treatments with Mectizan.

    PubMed

    Rodríguez-Pérez, Mario A; Lutzow-Steiner, Miguel A; Segura-Cabrera, Aldo; Lizarazo-Ortega, Cristian; Domínguez-Vázquez, Alfredo; Sauerbrey, Mauricio; Richards, Frank; Unnasch, Thomas R; Hassan, Hassan K; Hernández-Hernández, Raymundo

    2008-08-01

    The impact of quarterly Mectizan (ivermectin) treatments on transmission, microfiladermia, and ocular lesions was evaluated in two formerly hyperendemic communities (Las Golondrinas and Las Nubes II) located in the main endemic focus for onchocerciasis in Southern Chiapas, Mexico. The data suggest that Onchocerca volvulus transmission has been suppressed after elimination of microfiladermia in these two communities. Increasing the frequency of Mectizan treatment to four times per year appears to have resulted in the rapid suppression of transmission in communities with residual transmission.

  18. Comparative analysis of macrophage migration inhibitory factors (MIFs) from the parasitic nematode Onchocerca volvulus and the free-living nematode Caenorhabditis elegans.

    PubMed

    Ajonina-Ekoti, Irene; Kurosinski, Marc Andre; Younis, Abuelhassan Elshazly; Ndjonka, Dieudonne; Tanyi, Manchang Kingsley; Achukwi, Mbunkah; Eisenbarth, Albert; Ajonina, Caroline; Lüersen, Kai; Breloer, Minka; Brattig, Norbert W; Liebau, Eva

    2013-09-01

    The macrophage migration inhibitory factors (MIFs) from the filarial parasite Onchocerca volvulus (OvMIF) were compared to the MIFs from the free-living nematode Caenorhabditis elegans (CeMIF) with respect to molecular, biochemical and immunological properties. Except for CeMIF-4, all other MIFs demonstrated tautomerase activity. Surprisingly, OvMIF-1 displayed oxidoreductase activity. The strongest immunostaining for OvMIF-1 was observed in the outer cellular covering of the adult worm body, the syncytial hypodermis; moderate immunostaining was observed in the uterine wall. The generation of a strong humoral immune response towards OvMIF-1 and reduced reactivity to OvMIF-2 was indicated by high IgG levels in patients infected with O. volvulus and cows infected with the closely related Onchocerca ochengi, both MIFs revealing identical amino acid sequences. Using Litomosoides sigmodontis-infected mice, a laboratory model for filarial infection, MIFs derived from the tissue-dwelling O. volvulus, the rodent gut-dwelling Strongyloides ratti and from free-living C. elegans were recognized, suggesting that L. sigmodontis MIF-specific IgM and IgG1 were produced during L. sigmodontis infection of mice and cross-reacted with all MIF proteins tested. Thus, MIF apparently functions as a target of B cell response during nematode infection, but in the natural Onchocerca-specific human and bovine infection, the induced antibodies can discriminate between MIFs derived from parasitic or free-living nematodes.

  19. Dynamics of Onchocerca volvulus microfilarial densities after ivermectin treatment in an ivermectin-naïve and a multiply treated population from Cameroon.

    PubMed

    Pion, Sébastien D S; Nana-Djeunga, Hugues C; Kamgno, Joseph; Tendongfor, Nicholas; Wanji, Samuel; Njiokou, Flobert; Prichard, Roger K; Boussinesq, Michel

    2013-01-01

    Ivermectin has been the keystone of onchocerciasis control for the last 25 years. Sub-optimal responses to the drug have been reported in Ghanaian communities under long-term treatment. We assessed, in two Cameroonian foci, whether the microfilaricidal and/or embryostatic effects of ivermectin on Onchocerca volvulus have been altered after several years of drug pressure. We compared the dynamics of O. volvulus skin microfilarial densities after ivermectin treatment in two cohorts with contrasting exposure to this drug: one received repeated treatment for 13 years whereas the other had no history of large-scale treatments (referred to as controls). Microfilarial densities were assessed 15, 80 and 180 days after ivermectin in 122 multiply treated and 127 ivermectin-naïve individuals. Comparisons were adjusted for individual factors related to microfilarial density: age and number of nodules. Two weeks post ivermectin, microfilarial density dropped equally (98% reduction) in the ivermectin-naïve and multiply treated groups. Between 15 and 180 days post ivermectin, the proportion of individuals with skin microfilariae doubled (from 30.8% to 67.8%) in controls and quadrupled (from 19.8% to 76.9%) in multiply treated individuals but the mean densities remained low in both sites. In fact, between 15 and 80 days, the repopulation rate was significantly higher in the multiply treated individuals than in the controls but no such difference was demonstrated when extending the follow-up to 180 days. The repopulation rate by microfilariae was associated with host factors: negatively with age and positively with the number of nodules. These observations may indicate that the worms from the multi-treated area recover mf productivity earlier but would be less productive than the worms from the ivermectin-naïve area between 80 and 180 days after ivermectin. Moreover, they do not support the operation of a strong cumulative effect of repeated treatments on the fecundity of female

  20. The secretory omega-class glutathione transferase OvGST3 from the human pathogenic parasite Onchocerca volvulus.

    PubMed

    Liebau, Eva; Höppner, Jana; Mühlmeister, Mareike; Burmeister, Cora; Lüersen, Kai; Perbandt, Markus; Schmetz, Christel; Büttner, Dietrich; Brattig, Norbert

    2008-07-01

    Onchocerciasis or river blindness, caused by the filarial nematode Onchocerca volvulus, is the second leading cause of blindness due to infectious diseases. The protective role of the omega-class glutathione transferase 3 from O. volvulus (OvGST3) against intracellular and environmental reactive oxygen species has been described previously. In the present study, we continue our investigation of the highly stress-responsive OvGST3. Alternative splicing of two exons and one intron retention generates five different transcript isoforms that possess a spliced leader at their 5'-end, indicating that the mechanism of mature mRNA production involves alternative-, cis- and trans-splicing processes. Interestingly, the first two exons of the ovgst3 gene encode a signal peptide before sequence identity to other omega-class glutathione transferases begins. Only the recombinant expression of the isoform that encodes the longest deduced amino acid sequence (OvGST3/5) was successful, with the purified enzyme displaying modest thiol oxidoreductase activity. Significant IgG1 and IgG4 responses against recombinantly expressed OvGST3/5 were detected in sera from patients with the generalized as well as the chronic hyperreactive form of onchocerciasis, indicating exposure of the secreted protein to the human host's immune system and its immunogenicity. Immunohistological localization studies performed at light and electron microscopy levels support the extracellular localization of the protein. Intensive labeling of the OvGST3 was observed in the egg shell at the morula stage of the embryo, indicating extremely defined, stage-specific expression for a short transient period only.

  1. Deposition of eosinophil granule major basic protein onto microfilariae of Onchocerca volvulus in the skin of patients treated with diethylcarbamazine.

    PubMed

    Kephart, G M; Gleich, G J; Connor, D H; Gibson, D W; Ackerman, S J

    1984-01-01

    We investigated the association between eosinophil degranulation, as evidenced by the deposition of granule major basic protein (MBP), and the killing of microfilariae of Onchocerca volvulus in vivo following treatment with diethylcarbamazine (DEC). Utilizing an immunofluorescence procedure for the cellular and extracellular localization of eosinophil MBP in formalin-fixed, paraffin-embedded tissues, we studied skin biopsies from onchocerciasis patients before and during treatment with topically or orally administered DEC. Before DEC, there was little or no inflammatory response in either dermis or epidermis and microfilariae were essentially intact. Immunofluorescent staining for MBP revealed some filamentous fluorescence associated with dermal collagen fibers, very few eosinophils, and no fluorescence in association with intact microfilariae. In contrast, during treatment with DEC, immunofluorescent staining for MBP revealed extensive eosinophil infiltrates in both dermis and epidermis with numerous intraepidermal eosinophil abscesses containing degenerating microfilariae. An intense extracellular immunofluorescence for MBP surrounded degenerating microfilariae in the dermis and epidermis in both the presence and absence of eosinophil infiltrates as early as 4.5 hours after starting therapy. Many intact nondegenerating microfilariae were also present, but they did not show immunofluorescent staining for MBP nor a surrounding inflammatory infiltrate. The results show that immediately following administration of DEC, eosinophils localize and degranulate around microfilariae in the skin and release granule MBP onto or in close proximity to the parasite's surface. Because of the striking association between eosinophil localization, degranulation, and deposition of MBP onto microfilarial surfaces, and the degeneration of microfilariae in the skin, these observations support the hypothesis that the eosinophil, through helminthotoxic granule proteins such as MBP

  2. Vaccines to combat river blindness: expression, selection and formulation of vaccines against infection with Onchocerca volvulus in a mouse model

    PubMed Central

    Hess, Jessica A.; Zhan, Bin; Bonne-Année, Sandra; Deckman, Jessica M.; Bottazzi, Maria Elena; Hotez, Peter J.; Klei, Thomas R.; Lustigman, Sara; Abraham, David

    2014-01-01

    Human onchocerciasis is a neglected tropical disease caused by Onchocerca volvulus and an important cause of blindness and chronic disability in the developing world. Although mass drug administration of ivermectin has had a profound effect on control of the disease, additional tools are critically needed including the need for a vaccine against onchocerciasis. The objectives of the present study were to: (i) select antigens with known vaccine pedigrees as components of a vaccine; (ii) produce the selected vaccine antigens under controlled conditions, using two expression systems and in one laboratory and (iii) evaluate their vaccine efficacy using a single immunization protocol in mice. In addition, we tested the hypothesis that joining protective antigens as a fusion protein or in combination, into a multivalent vaccine, would improve the ability of the vaccine to induce protective immunity. Out of eight vaccine candidates tested in this study, Ov-103, Ov-RAL-2 and Ov-CPI-2M were shown to reproducibly induce protective immunity when administered individually, as fusion proteins or in combination. Although there was no increase in the level of protective immunity induced by combining the antigens into one vaccine, these antigens remain strong candidates for inclusion in a vaccine to control onchocerciasis in humans. PMID:24907553

  3. Vaccines to combat river blindness: expression, selection and formulation of vaccines against infection with Onchocerca volvulus in a mouse model.

    PubMed

    Hess, Jessica A; Zhan, Bin; Bonne-Année, Sandra; Deckman, Jessica M; Bottazzi, Maria Elena; Hotez, Peter J; Klei, Thomas R; Lustigman, Sara; Abraham, David

    2014-08-01

    Human onchocerciasis is a neglected tropical disease caused by Onchocerca volvulus and an important cause of blindness and chronic disability in the developing world. Although mass drug administration of ivermectin has had a profound effect on control of the disease, additional tools are critically needed including the need for a vaccine against onchocerciasis. The objectives of the present study were to: (i) select antigens with known vaccine pedigrees as components of a vaccine; (ii) produce the selected vaccine antigens under controlled conditions, using two expression systems and in one laboratory and (iii) evaluate their vaccine efficacy using a single immunisation protocol in mice. In addition, we tested the hypothesis that joining protective antigens as a fusion protein or in combination, into a multivalent vaccine, would improve the ability of the vaccine to induce protective immunity. Out of eight vaccine candidates tested in this study, Ov-103, Ov-RAL-2 and Ov-CPI-2M were shown to reproducibly induce protective immunity when administered individually, as fusion proteins or in combination. Although there was no increase in the level of protective immunity induced by combining the antigens into one vaccine, these antigens remain strong candidates for inclusion in a vaccine to control onchocerciasis in humans. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  4. Ongoing Transmission of Onchocerca volvulus after 25 Years of Annual Ivermectin Mass Treatments in the Vina du Nord River Valley, in North Cameroon

    PubMed Central

    Eisenbarth, Albert; Achukwi, Mbunkah Daniel; Renz, Alfons

    2016-01-01

    Background Recent reports of transmission interruption of Onchocerca volvulus, the causing agent of river blindness, in former endemic foci in the Americas, and more recently in West and East Africa, raise the question whether elimination of this debilitating disease is underway after long-term treatment of the population at risk with ivermectin. The situation in Central Africa has not yet been clearly assessed. Methods and findings Entomologic data from two former endemic river basins in North Cameroon were generated over a period of 43 and 48 months to follow-up transmission levels in areas under prolonged ivermectin control. Moreover, epidemiologic parameters of animal-borne Onchocerca spp. transmitted by the same local black fly vectors of the Simulium damnosum complex were recorded and their impact on O. volvulus transmission success evaluated. With mitochondrial DNA markers we unambiguously confirmed the presence of infective O. volvulus larvae in vectors from the Sudan savannah region (mean Annual Transmission Potential 2009–2012: 98, range 47–221), but not from the Adamawa highland region. Transmission rates of O. ochengi, a parasite of Zebu cattle, were high in both foci. Conclusions/significance The high cattle livestock density in conjunction with the high transmission rates of the bovine filaria O. ochengi prevents the transmission of O. volvulus on the Adamawa plateau, whereas transmission in a former hyperendemic focus was markedly reduced, but not completely interrupted after 25 years of ivermectin control. This study may be helpful to gauge the impact of the presence of animal-filariae for O. volvulus transmission in terms of the growing human and livestock populations in sub-Saharan countries. PMID:26926855

  5. Ivermectin effect on microfilariae of Onchocerca volvulus after a single oral dose in humans.

    PubMed

    Soboslay, P T; Newland, H S; White, A T; Erttmann, K D; Albiez, E J; Taylor, H R; Williams, P N; Greene, B M

    1987-03-01

    Ivermectin is a broad spectrum anti-helminthic agent which is currently being tested for use in human onchocerciasis. Its activity is believed to result from its effect on GABA-mediated neurotransmission. We examined the effects of ivermectin on motility of microfilariae of O. volvulus following administration to humans. When ivermectin was given in dosages of 100, 150 and 200 mcg/kg on day 1 there was a clear reduction in motility of microfilariae obtained on day 3 when compared to microfilariae from the placebo group. The mean motility scores in microfilariae from ivermectin recipients were 3.1, 2.3, and 2.2 at 0, 12, and 24 hours of incubation compared to 3.3, 2.9, and 2.5, respectively, in microfilariae from placebo recipients (p less than 0.003, p less than 0.005, and p less than 0.012, respectively). Examination of the effect according to dose suggested a dose-response relationship. Microfilariae in the anterior chamber of the eye 2 days after a single oral dose of ivermectin showed abnormal and reduced winding and coiling. Microfilariae in 50% of ivermectin recipients showed abnormal motility compared to no such effects in subjects examined concurrently who received oral DEC, DEC lotion or placebo. These observations indicate that ivermectin has an effect on motility of microfilariae of O. volvulus following administration to humans.

  6. Design, synthesis, and biological activities of closantel analogues: structural promiscuity and its impact on Onchocerca volvulus.

    PubMed

    Garner, Amanda L; Gloeckner, Christian; Tricoche, Nancy; Zakhari, Joseph S; Samje, Moses; Cho-Ngwa, Fidelis; Lustigman, Sara; Janda, Kim D

    2011-06-09

    Onchocerciasis, or river blindness, is a neglected tropical disease that affects more than 37 million people worldwide, primarily in Africa and Central and South America. We have disclosed evidence that the larval-stage-specific chitinase, OvCHT1, may be a potential biological target for affecting nematode development. On the basis of screening efforts, closantel, a known anthelmintic drug, was discovered as a potent and highly specific OvCHT1 inhibitor. Originally, closantel's anthelmintic mode of action was believed to rely solely on its role as a proton ionophore; thus, the impact of each of its biological activities on O. volvulus L3 molting was investigated. Structure-activity relationship studies on an active closantel fragment are detailed, and remarkably, by use of a simple salicylanilide scaffold, compounds acting only as protonophores or chitinase inhibitors were identified. From these data, unexpected synergistic protonophore and chitinase inhibition activities have also been found to be critical for molting in O. volvulus L3 larvae.

  7. Biting behaviour of Simulium damnosum complex and Onchocerca volvulus infection along the Osun River, Southwest Nigeria

    PubMed Central

    2010-01-01

    Background Studies on biting behaviours and infectivity status of insect vectors are pre-requisites in understanding the epidemiology of the vector- borne diseases and planning effective control measures. A longitudinal study was carried out to investigate the transmission index of Simulium damnosum complex species along Osun River, South Western Nigeria. Adult flies were collected on human attractants from 07:00 to 18:00 hours for two consecutive days from February 2008 to June 2009 at three communities: Osun Eleja, Osun Ogbere and Osun Budepo. The infectivity rate was determined by dissection and Polymerase Chain Reaction amplification (PCR) of 0-150 genes of Onchocerca parasite using the pool screening technique. Results The results indicated that the majority of the flies collected at the three sampling points were nulliparous as they accounted for 53.90%, 57.86% and 59.58% of the flies dissected at Osun Budepo, Osun Ogbere and Osun Eleja, respectively. The parous rate was higher during the dry season than the wet season but the difference was not statistically significant (p < 0.05). The biting activity of the parous flies showed two peaks at Osun Budepo and three peaks at Osun Eleja and Osun Ogbere. Of the 1,472 flies dissected and 1,235 flies screened by molecular method, none was infected with Onchocerca parasite at the three sampling points however the annual biting rates at the three communities were higher than 1,000 considered as tolerable value for a person living in an onchocerciasis zone by Word Health Organization. Conclusion The study has provided the baseline data for further study on onchocerciasis transmission dynamics and the need to intercept man- simuliid vector contact at the study area. PMID:20929573

  8. Rapid Suppression of Onchocerca volvulus Transmission in Two Communities of the Southern Chiapas Focus, Mexico, Achieved by Quarterly Treatments with Mectizan

    PubMed Central

    Rodríguez-Pérez, Mario A.; Lutzow-Steiner, Miguel A.; Segura-Cabrera, Aldo; Lizarazo-Ortega, Cristian; Domínguez-Vázquez, Alfredo; Sauerbrey, Mauricio; Richards, Frank; Unnasch, Thomas R.; Hassan, Hassan K.; Hernández-Hernández, Raymundo

    2008-01-01

    The impact of quarterly Mectizan (ivermectin) treatments on transmission, microfiladermia, and ocular lesions was evaluated in two formerly hyperendemic communities (Las Golondrinas and Las Nubes II) located in the main endemic focus for onchocerciasis in Southern Chiapas, Mexico. The data suggest that Onchocerca volvulus transmission has been suppressed after elimination of microfiladermia in these two communities. Increasing the frequency of Mectizan treatment to four times per year appears to have resulted in the rapid suppression of transmission in communities with residual transmission. PMID:18689630

  9. Onchocerca volvulus and O. lienalis: the microfilaricidal activity of moxidectin compared with that of ivermectin in vitro and in vivo.

    PubMed

    Tagboto, S K; Townson, S

    1996-10-01

    The activity of the veterinary drug moxidectin against Onchocerca volvulus and On. lienalis microfilariae (mf), both in vitro and in experimentally infected CBA/Ca mice, was compared with that of ivermectin. The in-vitro results demonstrated that both compounds (at a concentration of 10(-7) M) significantly reduced the mf motility index (MI) throughout the 7-day culture period and that this reduction was similar for the two compounds. Mice were treated with moxidectin and ivermectin by subcutaneous injection (sc) or orally (po); the two routes were equally efficacious. When mice infected with On. lienalis were treated with one of the drugs at 3.2, 1.6, 0.8, 0.4 or 0.2 micrograms/kg.day on days 3-7 post-infection, with necropsy on day 18, moxidectin cleared more mf than ivermectin at all of the doses examined. In mice treated with a single dose (on day 3 post-infection), 150 or 15 micrograms/kg moxidectin completely cleared the mf whereas 1.5 micrograms/kg produced a 90%-96% reduction in mf recoveries. Following ivermectin treatment at the same doses, mf were virtually cleared at 150 micrograms/kg, with a 98% reduction at 15 micrograms/kg but no significant effect at 1.5 micrograms/kg. When mice with On. volvulus infections were treated with a single dose of moxidectin at 15 or 1.5 micrograms/kg, there were reductions in mf recoveries of 96% and 23%, respectively, compared with only a 48% reduction with 15 micrograms ivermectin/kg and a 2% increase with 1.5 micrograms ivermectin/kg. In order to examine the persistence and activity of each drug, mice were treated with a single dose of 150 micrograms/kg up to 28 days before infection. Moxidectin was found to be more efficacious (with subsequent 99.9% reduction in mf when given 28 days pre-infection and a 100% reduction when give 16 or 4 days before or 3 days after infection) than ivermectin (giving reductions of 57.1%, 66.7%, 100% and 100%, respectively). The further evaluation of moxidectin and its potential

  10. Dynamics of Onchocerca volvulus Microfilarial Densities after Ivermectin Treatment in an Ivermectin-naïve and a Multiply Treated Population from Cameroon

    PubMed Central

    Pion, Sébastien D. S.; Nana-Djeunga, Hugues C.; Kamgno, Joseph; Tendongfor, Nicholas; Wanji, Samuel; Njiokou, Flobert; Prichard, Roger K.; Boussinesq, Michel

    2013-01-01

    Background/Objective Ivermectin has been the keystone of onchocerciasis control for the last 25 years. Sub-optimal responses to the drug have been reported in Ghanaian communities under long-term treatment. We assessed, in two Cameroonian foci, whether the microfilaricidal and/or embryostatic effects of ivermectin on Onchocerca volvulus have been altered after several years of drug pressure. Methods We compared the dynamics of O. volvulus skin microfilarial densities after ivermectin treatment in two cohorts with contrasting exposure to this drug: one received repeated treatment for 13 years whereas the other had no history of large-scale treatments (referred to as controls). Microfilarial densities were assessed 15, 80 and 180 days after ivermectin in 122 multiply treated and 127 ivermectin-naïve individuals. Comparisons were adjusted for individual factors related to microfilarial density: age and number of nodules. Findings Two weeks post ivermectin, microfilarial density dropped equally (98% reduction) in the ivermectin-naïve and multiply treated groups. Between 15 and 180 days post ivermectin, the proportion of individuals with skin microfilariae doubled (from 30.8% to 67.8%) in controls and quadrupled (from 19.8% to 76.9%) in multiply treated individuals but the mean densities remained low in both sites. In fact, between 15 and 80 days, the repopulation rate was significantly higher in the multiply treated individuals than in the controls but no such difference was demonstrated when extending the follow-up to 180 days. The repopulation rate by microfilariae was associated with host factors: negatively with age and positively with the number of nodules. Conclusion These observations may indicate that the worms from the multi-treated area recover mf productivity earlier but would be less productive than the worms from the ivermectin-naïve area between 80 and 180 days after ivermectin. Moreover, they do not support the operation of a strong cumulative effect

  11. The populatin dynamics of Onchocerca volvulus microfilariae during treatment with suramin and diethylcarbamazine.

    PubMed

    Duke, B O; Vincelette, J; Moore, P J

    1976-06-01

    During treatment with suramin the numbers of O. volvulus microfilariae in the blood, urine, sputum, and anterior chambers of the eye fell before those in the skin. When diethylcarbamazine (DEC) was given after suramin, increased numbers of microfilariae appeared in the blood, urine, cerebrospinal fluid (CSF) and sputum, but the increase in the blood was less marked, and of shorter duration, than in similar patients receiving DEC without previous suramin. Microfilariae are thought to enter the urine, sputum and CSF directly from the blood by penetrating the capillary walls in the glomeruli, pulmonary alveoli, and choroid plexuses. Those in the aqueous humour do not appear to come directly from the bloodstream. The total numbers of microfilariae in the skin of some heavily infected onchocerciasis patients are estimated, as are the total numbers moving into the blood-stream under the influence of DEC and the proportion which escape into the urine, sputum and CSF. It is concluded that the majority of the microfilariae which appear in the blood during DEC therapy must be destroyed in the body, probably in the liver.

  12. DNA vaccine encoding the moonlighting protein Onchocerca volvulus glyceraldehyde-3-phosphate dehydrogenase (Ov-GAPDH) leads to partial protection in a mouse model of human filariasis.

    PubMed

    Steisslinger, Vera; Korten, Simone; Brattig, Norbert W; Erttmann, Klaus D

    2015-10-26

    River blindness, caused by the filarial parasite Onchocerca volvulus, is a major socio-economic and public health problem in Sub-Saharan Africa. In January 2015, The Onchocerciasis Vaccine for Africa (TOVA) Initiative has been launched with the aim of providing new tools to complement mass drug administration (MDA) of ivermectin, thereby promoting elimination of onchocerciasis in Africa. In this context we here present Onchocerca volvulus glyceraldehyde-3-phosphate dehydrogenase (Ov-GAPDH) as a possible DNA vaccine candidate. We report that in a laboratory model for filariasis, immunization with Ov-GAPDH led to a significant reduction of adult worm load and microfilaraemia in BALB/c mice after challenge infection with the filarial parasite Litomosoides sigmodontis. Mice were either vaccinated with Ov-GAPDH.DNA plasmid (Ov-pGAPDH.DNA) alone or in combination with recombinantly expressed Ov-GAPDH protein (Ov-rGAPDH). During the following challenge infection of immunized and control mice with L. sigmodontis, those formulations which included the DNA plasmid, led to a significant reduction of adult worm loads (up to 57% median reduction) and microfilaraemia (up to 94% reduction) in immunized animals. In a further experiment, immunization with a mixture of four overlapping, synthetic Ov-GAPDH peptides (Ov-GAPDHpept), with alum as adjuvant, did not significantly reduce worm loads. Our results indicate that DNA vaccination with Ov-GAPDH has protective potential against filarial challenge infection in the mouse model. This suggests a transfer of the approach into the cattle Onchocerca ochengi model, where it is possible to investigate the effects of this vaccination in the context of a natural host-parasite relationship.

  13. Significant heterogeneity in Wolbachia copy number within and between populations of Onchocerca volvulus.

    PubMed

    Armoo, Samuel; Doyle, Stephen R; Osei-Atweneboana, Mike Y; Grant, Warwick N

    2017-04-18

    Wolbachia are intracellular bacteria found in arthropods and several filarial nematode species. The filarial Wolbachia have been proposed to be involved in the immunopathology associated with onchocerciasis. Higher Wolbachia-to-nematode ratios have been reported in the savannah-ecotype compared to the forest-ecotype, and have been interpreted as consistent with a correlation between Wolbachia density and disease severity. However, factors such as geographic stratification and ivermectin drug exposure can lead to significant genetic heterogeneity in the nematode host populations, so we investigated whether Wolbachia copy number variation is also associated with these underlying factors. Genomic DNA was prepared from single adult nematodes representing forest and savannah ecotypes sampled from Togo, Ghana, Côte d'Ivoire and Mali. A qPCR assay was developed to measure the number of Wolbachia genome(s) per nematode genome. Next-generation sequencing (NGS) was also used to measure relative Wolbachia copy number, and independently verify the qPCR assay. Significant variation was observed within the forest (range: 0.02 to 452.99; median: 10.58) and savannah (range: 0.01 to 1106.25; median: 9.10) ecotypes, however, no significant difference between ecotypes (P = 0.645) was observed; rather, strongly significant Wolbachia variation was observed within and between the nine study communities analysed (P = 0.021), independent of ecotype. Analysis of ivermectin-treated and untreated nematodes by qPCR showed no correlation (P = 0.869); however, an additional analysis of a subset of the nematodes by qPCR and NGS revealed a correlation between response to ivermectin treatment and Wolbachia copy number (P = 0.020). This study demonstrates that extensive within and between population variation exists in the Wolbachia content of individual adult O. volvulus. The origin and functional significance of such variation (up to ~ 100,000-fold between worms; ~10 to 100

  14. A Randomized, Single-Ascending-Dose, Ivermectin-Controlled, Double-Blind Study of Moxidectin in Onchocerca volvulus Infection

    PubMed Central

    Opoku, Nicholas O.; Attah, Simon K.; Lazdins-Helds, Janis; Kuesel, Annette C.

    2014-01-01

    Background Control of onchocerciasis as a public health problem in Africa relies on annual mass ivermectin distribution. New tools are needed to achieve elimination of infection. This study determined in a small number of Onchocerca volvulus infected individuals whether moxidectin, a veterinary anthelminthic, is safe enough to administer it in a future large study to further characterize moxidectin's safety and efficacy. Effects on the parasite were also assessed. Methodology/Principal Findings Men and women from a forest area in South-eastern Ghana without ivermectin mass distribution received a single oral dose of 2 mg (N = 44), 4 mg (N = 45) or 8 mg (N = 38) moxidectin or 150 µg/kg ivermectin (N = 45) with 18 months follow up. All ivermectin and 97%–100% of moxidectin treated participants had Mazzotti reactions. Statistically significantly higher percentages of participants treated with 8 mg moxidectin than participants treated with ivermectin experienced pruritus (87% vs. 56%), rash (63% vs. 42%), increased pulse rate (61% vs. 36%) and decreased mean arterial pressure upon 2 minutes standing still after ≥5 minutes supine relative to pre-treatment (61% vs. 27%). These reactions resolved without treatment. In the 8 mg moxidectin and ivermectin arms, the mean±SD number of microfilariae/mg skin were 22.9±21.1 and 21.2±16.4 pre-treatment and 0.0±0.0 and 1.1±4.2 at nadir reached 1 and 3 months after treatment, respectively. At 6 months, values were 0.0±0.0 and 1.6±4.5, at 12 months 0.4±0.9 and 3.4±4.4 and at 18 months 1.8±3.3 and 4.0±4.8, respectively, in the 8 mg moxidectin and ivermectin arm. The reduction from pre-treatment values was significantly higher after 8 mg moxidectin than after ivermectin treatment throughout follow up (p<0.01). Conclusions/Significance The 8 mg dose of moxidectin was safe enough to initiate the large study. Provided its results confirm those from this study, availability of moxidectin to control

  15. A randomized, single-ascending-dose, ivermectin-controlled, double-blind study of moxidectin in Onchocerca volvulus infection.

    PubMed

    Awadzi, Kwablah; Opoku, Nicholas O; Attah, Simon K; Lazdins-Helds, Janis; Kuesel, Annette C

    2014-06-01

    Control of onchocerciasis as a public health problem in Africa relies on annual mass ivermectin distribution. New tools are needed to achieve elimination of infection. This study determined in a small number of Onchocerca volvulus infected individuals whether moxidectin, a veterinary anthelminthic, is safe enough to administer it in a future large study to further characterize moxidectin's safety and efficacy. Effects on the parasite were also assessed. Men and women from a forest area in South-eastern Ghana without ivermectin mass distribution received a single oral dose of 2 mg (N = 44), 4 mg (N = 45) or 8 mg (N = 38) moxidectin or 150 µg/kg ivermectin (N = 45) with 18 months follow up. All ivermectin and 97%-100% of moxidectin treated participants had Mazzotti reactions. Statistically significantly higher percentages of participants treated with 8 mg moxidectin than participants treated with ivermectin experienced pruritus (87% vs. 56%), rash (63% vs. 42%), increased pulse rate (61% vs. 36%) and decreased mean arterial pressure upon 2 minutes standing still after ≥5 minutes supine relative to pre-treatment (61% vs. 27%). These reactions resolved without treatment. In the 8 mg moxidectin and ivermectin arms, the mean±SD number of microfilariae/mg skin were 22.9±21.1 and 21.2±16.4 pre-treatment and 0.0±0.0 and 1.1±4.2 at nadir reached 1 and 3 months after treatment, respectively. At 6 months, values were 0.0±0.0 and 1.6±4.5, at 12 months 0.4±0.9 and 3.4±4.4 and at 18 months 1.8±3.3 and 4.0±4.8, respectively, in the 8 mg moxidectin and ivermectin arm. The reduction from pre-treatment values was significantly higher after 8 mg moxidectin than after ivermectin treatment throughout follow up (p<0.01). The 8 mg dose of moxidectin was safe enough to initiate the large study. Provided its results confirm those from this study, availability of moxidectin to control programmes could help them achieve onchocerciasis elimination objectives

  16. Modelling Neglected Tropical Diseases diagnostics: the sensitivity of skin snips for Onchocerca volvulus in near elimination and surveillance settings.

    PubMed

    Bottomley, Christian; Isham, Valerie; Vivas-Martínez, Sarai; Kuesel, Annette C; Attah, Simon K; Opoku, Nicholas O; Lustigman, Sara; Walker, Martin; Basáñez, Maria-Gloria

    2016-06-14

    The African Programme for Onchocerciasis Control has proposed provisional thresholds for the prevalence of microfilariae in humans and of L3 larvae in blackflies, below which mass drug administration (MDA) with ivermectin can be stopped and surveillance started. Skin snips are currently the gold standard test for detecting patent Onchocerca volvulus infection, and the World Health Organization recommends their use to monitor progress of treatment programmes (but not to verify elimination). However, if they are used (in transition and in parallel to Ov-16 serology), sampling protocols should be designed to demonstrate that programmatic goals have been reached. The sensitivity of skin snips is key to the design of such protocols. We develop a mathematical model for the number of microfilariae in a skin snip and parameterise it using data from Guatemala, Venezuela, Ghana and Cameroon collected before the start of ivermectin treatment programmes. We use the model to estimate sensitivity as a function of time since last treatment, number of snips taken, microfilarial aggregation and female worm fertility after exposure to 10 annual rounds of ivermectin treatment. The sensitivity of the skin snip method increases with time after treatment, with most of the increase occurring between 0 and 5 years. One year after the last treatment, the sensitivity of two skin snips taken from an individual infected with a single fertile female worm is 31 % if there is no permanent effect of multiple ivermectin treatments on fertility; 18 % if there is a 7 % reduction per treatment, and 0.6 % if there is a 35 % reduction. At 5 years, the corresponding sensitivities are 76 %, 62 % and 4.7 %. The sensitivity improves significantly if 4 skin snips are taken: in the absence of a permanent effect of ivermectin, the sensitivity of 4 skin snips is 53 % 1 year and 94 % 5 years after the last treatment. Our model supports the timelines proposed by APOC for post-MDA follow-up and

  17. An immunohistochemical analysis of onchocercal nodules: evidence for an interaction between macrophage MRP8/MRP14 and adult Onchocerca volvulus.

    PubMed Central

    Edgeworth, J D; Abiose, A; Jones, B R

    1993-01-01

    of microfilariae (MF) within the same nodules. Since MRP8/MRP14 was seen on the adult worm in the absence of a leucocytic infiltrate, it may have an early role to play in the immune response to Onchocerca volvulus. Images Fig. 2 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8467568

  18. Discrimination between Onchocerca volvulus and O. ochengi filarial larvae in Simulium damnosum (s.l.) and their distribution throughout central Ghana using a versatile high-resolution speciation assay.

    PubMed

    Doyle, Stephen R; Armoo, Samuel; Renz, Alfons; Taylor, Mark J; Osei-Atweneboana, Mike Yaw; Grant, Warwick N

    2016-10-10

    Genetic surveillance of the human filarial parasite, Onchocerca volvulus, from onchocerciasis endemic regions will ideally focus on genotyping individual infective larval stages collected from their intermediate host, Simuliid blackflies. However, blackflies also transmit other Onchocerca species, including the cattle parasite O. ochengi, which are difficult to distinguish from the human parasite based on morphological characteristics alone. This study describes a versatile approach to discriminate between O. volvulus and O. ochengi that is demonstrated using parasite infective larvae dissected from blackflies. A speciation assay was designed based on genetic differentiation between O. volvulus and O. ochengi mitochondrial genome sequences that can be performed in high-throughput high-resolution melt (HRM)- or lower throughput conventional restriction fragment length polymorphism (RFLP) analyses. This assay was validated on 185 Onchocerca larvae dissected from blackflies captured from 14 communities in Ghana throughout 2011-2013. The frequency of O. ochengi was approximately 67 % of all larvae analysed, which is significantly higher than previously reported in this region. Furthermore, the species distribution was not uniform throughout the study region, with 25 %, 47 % and 93 % of O. volvulus being found in the western-most (Black Volta, Tain and Tombe), the central (Pru) and eastern-most (Daka) river basins, respectively. This tool provides a simple and cost-effective approach to determine the identity and distribution of two Onchocerca species, and will be valuable for future genetic studies that focus on parasites collected from blackflies. The results presented highlight the need to discriminate Onchocerca species in transmission studies, as the frequency of each species varied significantly between the communities studied.

  19. Nested PCR to detect and distinguish the sympatric filarial species Onchocerca volvulus, Mansonella ozzardi and Mansonella perstans in the Amazon Region.

    PubMed

    Tang, Thuy-Huong Ta; López-Vélez, Rogelio; Lanza, Marta; Shelley, Anthony John; Rubio, Jose Miguel; Luz, Sérgio Luiz Bessa

    2010-09-01

    We present filaria-nested polymerase chain reaction (PCR), which is based on amplification of first internal transcribed spacer rDNA to distinguish three parasitic filarial species (Onchocerca volvulus, Mansonella ozzardi and Mansonella perstans) that can be found in the Amazon Region. Nested PCR-based identifications yielded the same results as those utilizing morphological characters. Nested PCR is highly sensitive and specific and it detects low-level infections in both humans and vectors. No cross-amplifications were observed with various other blood parasites and no false-positive results were obtained with the nested PCR. The method works efficiently with whole-blood, blood-spot and skin biopsy samples. Our method may thus be suitable for assessing the efficacy of filaria control programmes in Amazonia by recording parasite infections in both the human host and the vector. By specifically differentiating the major sympatric species of filaria, this technique could also enhance epidemiological research in the region.

  20. Recombinant Ov-ASP-1, a Th1-biased protein adjuvant derived from the helminth Onchocerca volvulus, can directly bind and activate antigen-presenting cells.

    PubMed

    He, Yuxian; Barker, Sophie J; MacDonald, Angus J; Yu, Yu; Cao, Long; Li, Jingjing; Parhar, Ranjit; Heck, Susanne; Hartmann, Susanne; Golenbock, Douglas T; Jiang, Shibo; Libri, Nathan A; Semper, Amanda E; Rosenberg, William M; Lustigman, Sara

    2009-04-01

    We previously reported that rOv-ASP-1, a recombinant Onchocerca volvulus activation associated protein-1, was a potent adjuvant for recombinant protein or synthetic peptide-based Ags. In this study, we further evaluated the adjuvanticity of rOv-ASP-1 and explored its mechanism of action. Consistently, recombinant full-length spike protein of SARS-CoV or its receptor-binding domain in the presence of rOv-ASP-1 could effectively induce a mixed but Th1-skewed immune response in immunized mice. It appears that rOv-ASP-1 primarily bound to the APCs among human PBMCs and triggered Th1-biased proinflammatory cytokine production probably via the activation of monocyte-derived dendritic cells and the TLR, TLR2, and TLR4, thus suggesting that rOv-ASP-1 is a novel potent innate adjuvant.

  1. Detection of Onchocerca volvulus in Skin Snips by Microscopy and Real-Time Polymerase Chain Reaction: Implications for Monitoring and Evaluation Activities.

    PubMed

    Thiele, Elizabeth A; Cama, Vitaliano A; Lakwo, Thomson; Mekasha, Sindeaw; Abanyie, Francisca; Sleshi, Markos; Kebede, Amha; Cantey, Paul T

    2016-04-01

    Microscopic evaluation of skin biopsies is the monitoring and evaluation (M and E) method currently used by multiple onchocerciasis elimination programs in Africa. However, as repeated mass drug administration suppresses microfilarial loads, the sensitivity and programmatic utility of skin snip microscopy is expected to decrease. Using a pan-filarial real-time polymerase chain reaction with melt curve analysis (qPCR-MCA), we evaluated 1) the use of a single-step molecular assay for detecting and identifying Onchocerca volvulus microfilariae in residual skin snips and 2) the sensitivity of skin snip microscopy relative to qPCR-MCA. Skin snips were collected and examined with routine microscopy in hyperendemic regions of Uganda and Ethiopia (N= 500 each) and "residual" skin snips (tissue remaining after induced microfilarial emergence) were tested with qPCR-MCA. qPCR-MCA detected Onchocerca DNA in 223 residual snips: 139 of 147 microscopy(+) and 84 among microscopy(-) snips, suggesting overall sensitivity of microscopy was 62.3% (139/223) relative to qPCR-MCA (75.6% in Uganda and 28.6% in Ethiopia). These findings demonstrate the insufficient sensitivity of skin snip microscopy for reliable programmatic monitoring. Molecular tools such as qPCR-MCA can augment sensitivity and provide diagnostic confirmation of skin biopsies and will be useful for evaluation or validation of new onchocerciasis M and E tools. © The American Society of Tropical Medicine and Hygiene.

  2. Quantitative studies on the transmission of Onchocerca volvulus by Simulium damnosum s.l. in the Tukuyu Valley, South West Tanzania.

    PubMed

    Pedersen, E M; Maegga, B T

    1985-12-01

    A survey of the Simulium breeding and the transmission of Onchocerca volvulus was carried out in and around the Tukuyu valley, S.W. Tanzania, S. damnosum s.l. was found breeding in the midstretches of the main rivers in the valley and their bigger tributaries, and also in the boundary river to Malawi and the most northerly of the three rivers draining the Livingstone Mts. to Lake Nyasa (L. Malawi). A total of 19,500 S. damnosum s.l. females was caught and 13,200 dissected. The annual biting rate varied between 2,000 and 23,800. 7.6% of all the flies were infected with O. volvulus and 1.5% carried infective larvae in the head capsule, on average 2.7 per fly. The transmission was mainly in the dry season and the annual transmission potential varied between 0 and 1,120. The entomological data showed many similarities to those from the Mahenge Mts., Tanzania, and correlation of places with comparable transmission potentials suggests a similarity in the relationship parasite-human host between the West African rain forest and the two Tanzanian foci.

  3. The intake and transmissibility of Onchocerca volvulus microfilariae by Simulium damnosum fed on patients treated with Diethylcarbamazine, suramin or Mel W.

    PubMed

    Duke, B O

    1968-01-01

    The best hope for the control of transmission of Onchocerca volvulus over much of Africa lies in combining larvicidal measures directed against the Simulium vectors with chemotherapeutic measures designed to reduce the reservoir of transmissible microfilariae in man.There are few drugs effective against O. volvulus. Diethylcarbamazine kills the microfilariae but has virtually no effect on the adult worms. Suramin kills adult worms and many, but not all, of the microfilariae. Mel W kills adult worms but has little or no action on microfilariae. All these drugs suffer at present from disadvantages of toxicity, which tend to limit their use on a mass scale in the field. Nevertheless, before they, or indeed any new drugs with similar actions on the parasites, can be used intelligently for the control of onchocerciasis transmission, it is necessary to have accurate quantitative information on the effect that each of them has on the microfilarial population available for intake by Simulium, as well as on their actions on the developmental potential of those microfilariae ingested by the flies.The present paper describes the effects of treatment with various courses of diethylcarbamazine, suramin or Mel W on the numbers of microfilariae ingested by groups of S. damnosum and on the numbers of infective larvae developing therefrom.

  4. The intake and transmissibility of Onchocerca volvulus microfilariae by Similium damnosum fed on patients treated with diethylcarbamazine, suramin or Mel W

    PubMed Central

    Duke, B. O. L.

    1968-01-01

    The best hope for the control of transmission of Onchocerca volvulus over much of Africa lies in combining larvicidal measures directed against the Simulium vectors with chemotherapeutic measures designed to reduce the reservoir of transmissible microfilariae in man. There are few drugs effective against O. volvulus. Diethylcarbamazine kills the microfilariae but has virtually no effect on the adult worms. Suramin kills adult worms and many, but not all, of the microfilariae. Mel W kills adult worms but has little or no action on microfilariae. All these drugs suffer at present from disadvantages of toxicity, which tend to limit their use on a mass scale in the field. Nevertheless, before they, or indeed any new drugs with similar actions on the parasites, can be used intelligently for the control of onchocerciasis transmission, it is necessary to have accurate quantitative information on the effect that each of them has on the microfilarial population available for intake by Simulium, as well as on their actions on the developmental potential of those microfilariae ingested by the flies. The present paper describes the effects of treatment with various courses of diethylcarbamazine, suramin or Mel W on the numbers of microfilariae ingested by groups of S. damnosum and on the numbers of infective larvae developing therefrom. PMID:4881069

  5. Reproductive Status of Onchocerca volvulus after Ivermectin Treatment in an Ivermectin-Naïve and a Frequently Treated Population from Cameroon

    PubMed Central

    Bopda, Jean; Kengne-Ouafo, Jonas A.; Njiokou, Flobert; Prichard, Roger K.; Wanji, Samuel; Kamgno, Joseph; Boussinesq, Michel

    2014-01-01

    Background For two decades, onchocerciasis control has been based on mass treatment with ivermectin (IVM), repeated annually or six-monthly. This drug kills Onchocerca volvulus microfilariae (mf) present in the skin and the eyes (microfilaricidal effect) and prevents for 3–4 months the release of new mf by adult female worms (embryostatic effect). In some Ghanaian communities, the long-term use of IVM was associated with a more rapid than expected skin repopulation by mf after treatment. Here, we assessed whether the embryostatic effect of IVM on O. volvulus has been altered following frequent treatment in Cameroonian patients. Methodology Onchocercal nodules were surgically removed just before (D0) and 80 days (D80) after a standard dose of IVM in two cohorts with different treatment histories: a group who had received repeated doses of IVM over 13 years, and a control group with no history of large-scale treatments. Excised nodules were digested with collagenase to isolate adult worms. Embryograms were prepared with females for the evaluation of their reproductive capacities. Principal Findings Oocyte production was not affected by IVM. The mean number of intermediate embryos (morulae and coiled mf) decreased similarly in the two groups between D0 and D80. In contrast, an accumulation of stretched mf, either viable or degenerating, was observed at D80. However, it was observed that the increase in number of degenerating mf between D0 and D80 was much lower in the frequently treated group than in the control one (Incidence Rate Ratio: 0.25; 95% CI: 0.10–0.63; p = 0.003), which may indicate a reduced sequestration of mf in the worms from the frequently treated group. Conclusion/Significance IVM still had an embryostatic effect on O. volvulus, but the effect was reduced in the frequently treated cohort compared with the control population. PMID:24762816

  6. Macrofilaricidal Activity after Doxycycline Only Treatment of Onchocerca volvulus in an Area of Loa loa Co-Endemicity: A Randomized Controlled Trial

    PubMed Central

    Turner, Joseph D.; Tendongfor, Nicholas; Esum, Mathias; Johnston, Kelly L.; Langley, R. Stuart; Ford, Louise; Faragher, Brian; Specht, Sabine; Mand, Sabine; Hoerauf, Achim; Enyong, Peter; Wanji, Samuel; Taylor, Mark J.

    2010-01-01

    Background The risk of severe adverse events following treatment of onchocerciasis with ivermectin in areas co-endemic with loiasis currently compromises the development of control programmes and the treatment of co-infected individuals. We therefore assessed whether doxycycline treatment could be used without subsequent ivermectin administration to effectively deliver sustained effects on Onchocerca volvulus microfilaridermia and adult viability. Furthermore we assessed the safety of doxycycline treatment prior to ivermectin administration in a subset of onchocerciasis individuals co-infected with low to moderate intensities of Loa loa microfilaraemia. Methods A double-blind, randomized, field trial was conducted of 6 weeks of doxycycline (200 mg/day) alone, doxycycline in combination with ivermectin (150 µg/kg) at +4 months or placebo matching doxycycline + ivermectin at +4 months in 150 individuals infected with Onchocerca volvulus. A further 22 individuals infected with O. volvulus and low to moderate intensities of Loa loa infection were administered with a course of 6 weeks doxycycline with ivermectin at +4 months. Treatment efficacy was determined at 4, 12 and 21 months after the start of doxycycline treatment together with the frequency and severity of adverse events. Results One hundred and four (60.5%) participants completed all treatment allocations and follow up assessments over the 21-month trial period. At 12 months, doxycycline/ivermectin treated individuals had lower levels of microfilaridermia and higher frequency of amicrofilaridermia compared with ivermectin or doxycycline only groups. At 21 months, microfilaridermia in doxycycline/ivermectin and doxycycline only groups was significantly reduced compared to the ivermectin only group. 89% of the doxycycline/ivermectin group and 67% of the doxycycline only group were amicrofilaridermic, compared with 21% in the ivermectin only group. O. volvulus from doxycycline groups were depleted of Wolbachia

  7. Ov-ASP-1, the Onchocerca volvulus homologue of the activation associated secreted protein family is immunostimulatory and can induce protective anti-larval immunity.

    PubMed

    MacDonald, A J; Tawe, W; Leon, O; Cao, L; Liu, J; Oksov, Y; Abraham, D; Lustigman, S

    2004-01-01

    Vaccination of mice with a recombinant protein, Ov-ASP-1, the Onchocerca volvulus homologue of the activation associated secreted gene family stimulated very high titres of both IgG1 and IgG2a without adjuvant. rOv-ASP-1 was also immuno-reactive with IgG isotypes from both O. volvulus-infected (INF) and putatively immune (PI) humans, with higher IgG4 in the former group. The protein also stimulated IFN-gamma secretion by PBMC from INF and PI and IL-5 only in INF. Using a mouse diffusion chamber model, vaccination with rOv-ASP-1 resulted in partial but significant protection against challenge with infective third-stage larvae (L3) but only when formulated with Freund's complete adjuvant (FCA) or alum. Protection was Th1-dependent (highly elevated IgG2a) with FCA and contingent on a strongly Th2-skewed (IgG1) response with alum. IgE responses to rOv-ASP-1 with or without adjuvant were weak or absent. When immunization using rOv-ASP-1 in adjuvant failed to induce adequate Th1 (FCA) or Th2 (alum) responses, protection efficacy was compromised. The recombinant protein appears to stimulate a mixed Th1/Th2 response but the outcome in terms of protective immunity is the result of a subtle interplay of its intrinsic and adjuvant-augmented properties. Ov-ASP-1 is potentially secreted based on its localization in the secretory granules of L3.

  8. Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

    PubMed Central

    Nana-Djeunga, Hugues C.; Kengne-Ouafo, Jonas A.; Pion, Sébastien D. S.; Bopda, Jean; Kamgno, Joseph; Wanji, Samuel; Che, Hua; Kuesel, Annette C.; Walker, Martin; Basáñez, Maria-Gloria; Boakye, Daniel A.; Osei-Atweneboana, Mike Y.; Boussinesq, Michel; Prichard, Roger K.; Grant, Warwick N.

    2017-01-01

    Background Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana—exposed to more than a decade of regular ivermectin treatment—have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread. Methodology/Principal findings Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR. Conclusions/Significance This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different

  9. Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity.

    PubMed

    Doyle, Stephen R; Bourguinat, Catherine; Nana-Djeunga, Hugues C; Kengne-Ouafo, Jonas A; Pion, Sébastien D S; Bopda, Jean; Kamgno, Joseph; Wanji, Samuel; Che, Hua; Kuesel, Annette C; Walker, Martin; Basáñez, Maria-Gloria; Boakye, Daniel A; Osei-Atweneboana, Mike Y; Boussinesq, Michel; Prichard, Roger K; Grant, Warwick N

    2017-07-01

    Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread. Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR. This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different parasite populations. Furthermore, we propose that genetic drift

  10. One Hundred Years After Its Discovery in Guatemala by Rodolfo Robles, Onchocerca volvulus Transmission Has Been Eliminated from the Central Endemic Zone.

    PubMed

    Richards, Frank; Rizzo, Nidia; Diaz Espinoza, Carlos Enrique; Monroy, Zoraida Morales; Crovella Valdez, Carol Guillermina; de Cabrera, Renata Mendizabal; de Leon, Oscar; Zea-Flores, Guillermo; Sauerbrey, Mauricio; Morales, Alba Lucia; Rios, Dalila; Unnasch, Thomas R; Hassan, Hassan K; Klein, Robert; Eberhard, Mark; Cupp, Ed; Domínguez, Alfredo

    2015-12-01

    We report the elimination of Onchocerca volvulus transmission from the Central Endemic Zone (CEZ) of onchocerciasis in Guatemala, the largest focus of this disease in the Americas and the first to be discovered in this hemisphere by Rodolfo Robles Valverde in 1915. Mass drug administration (MDA) with ivermectin was launched in 1988, with semiannual MDA coverage reaching at least 85% of the eligible population in > 95% of treatment rounds during the 12-year period, 2000-2011. Serial parasitological testing to monitor MDA impact in sentinel villages showed a decrease in microfilaria skin prevalence from 70% to 0%, and polymerase chain reaction (PCR)-based entomological assessments of the principal vector Simulium ochraceum s.l. showed transmission interruption by 2007. These assessments, together with a 2010 serological survey in children 9-69 months of age that showed Ov16 IgG4 antibody prevalence to be < 0.1%, meeting World Health Organization (WHO) guidelines for stopping MDA, and treatment was halted after 2011. After 3 years an entomological assessment showed no evidence of vector infection or recrudescence of transmission. In 2015, 100 years after the discovery of its presence, the Ministry of Health of Guatemala declared onchocerciasis transmission as having been eliminated from the CEZ. © The American Society of Tropical Medicine and Hygiene.

  11. Transforming growth factor-beta expression by host cells is elicited locally by the filarial nematode Onchocerca volvulus in hyporeactive patients independently from Wolbachia.

    PubMed

    Korten, Simone; Kaifi, Jussuf T; Büttner, Dietrich W; Hoerauf, Achim

    2010-07-01

    Transforming growth factor-beta (TGF-beta) is a key cytokine in immune regulation, cell differentiation, development, wound healing, and tissue remodelling. It mediates immunosuppression in filarial infections facilitating parasite persistence, while attenuating immunopathology, which is induced by migrating microfilariae. Immunosuppression rises with parasite burden, but it remains unknown whether filariae elicit local release of immunosuppressive cytokines. Therefore, using immunohistology, we investigated the expression of stable, released latent TGF-beta1 in subcutaneous nodules from highly infected, hyporeactive onchocerciasis patients, harbouring adult Onchocerca volvulus. Since many cell types produce TGF-beta, we elucidated the cellular source, distribution and dependency on the worms' sex, productivity and vitality. We found TGF-beta1 to be abundantly expressed by T cells, plasma/B cells, macrophages, mast cells, fibrocytes, and vascular endothelial cells, particularly in onchocercomas with productive or previously productive females, damaged, dead and resorbed adult worms or microfilariae. We conclude TGF-beta to be antigen induced by the filariae since expression was scarce around subcutaneous arthropods or cholesterol crystals in onchocercomas. Enhanced expression after ivermectin or endobacteria-depleting doxycycline treatment indicates induction to depend on filariae and not on Wolbachia endobacteria. TGF-beta(+) cells were reduced in HIV co-infection. This finding of local and sustained TGF-beta induction by vital and dead filariae, untreated and after treatment, adds new aspects to immunomodulation by helminths.

  12. The effects of drugs on Onchocerca volvulus. 1. Methods of assessment, population dynamics of the parasite and the effects of diethylcarbamazine.

    PubMed

    Duke, B O

    1968-01-01

    It is important to standardize quantitative methods for assessing the action of drugs on Onchocerca volvulus in man. There are certain disadvantages to making observations on adult worms removed from excised nodules in treated patients, but a great deal of information on drug action can be obtained by making a careful study of the concentrations of microfilariae in multiple weighed skin snips taken before treatment and at intervals after treatment.Before drug trials can be carried out intelligently by this method it is necessary to know the normal length of life of the various stages of the parasite in man. By a variety of experimental methods the life-spans of the adult worms and the microfilariae have been determined, as well as the duration of the prepatent interval.Diethylcarbamazine can be used at doses that are effectively microfilaricidal but have no action on the adult worms. This drug can therefore be used to eliminate any residual microfilariae that remain after treatment with a new drug under trial, thus permitting a more rapid assessment of the latter's action on adult worms.

  13. One Hundred Years After Its Discovery in Guatemala by Rodolfo Robles, Onchocerca volvulus Transmission Has Been Eliminated from the Central Endemic Zone

    PubMed Central

    Richards, Frank; Rizzo, Nidia; Espinoza, Carlos Enrique Diaz; Monroy, Zoraida Morales; Valdez, Carol Guillermina Crovella; de Cabrera, Renata Mendizabal; de Leon, Oscar; Zea-Flores, Guillermo; Sauerbrey, Mauricio; Morales, Alba Lucia; Rios, Dalila; Unnasch, Thomas R.; Hassan, Hassan K.; Klein, Robert; Eberhard, Mark; Cupp, Ed; Domínguez, Alfredo

    2015-01-01

    We report the elimination of Onchocerca volvulus transmission from the Central Endemic Zone (CEZ) of onchocerciasis in Guatemala, the largest focus of this disease in the Americas and the first to be discovered in this hemisphere by Rodolfo Robles Valverde in 1915. Mass drug administration (MDA) with ivermectin was launched in 1988, with semiannual MDA coverage reaching at least 85% of the eligible population in > 95% of treatment rounds during the 12-year period, 2000–2011. Serial parasitological testing to monitor MDA impact in sentinel villages showed a decrease in microfilaria skin prevalence from 70% to 0%, and polymerase chain reaction (PCR)-based entomological assessments of the principal vector Simulium ochraceum s.l. showed transmission interruption by 2007. These assessments, together with a 2010 serological survey in children 9–69 months of age that showed Ov16 IgG4 antibody prevalence to be < 0.1%, meeting World Health Organization (WHO) guidelines for stopping MDA, and treatment was halted after 2011. After 3 years an entomological assessment showed no evidence of vector infection or recrudescence of transmission. In 2015, 100 years after the discovery of its presence, the Ministry of Health of Guatemala declared onchocerciasis transmission as having been eliminated from the CEZ. PMID:26503275

  14. A computational analysis of the binding mode of closantel as inhibitor of the Onchocerca volvulus chitinase: insights on macrofilaricidal drug design

    NASA Astrophysics Data System (ADS)

    Segura-Cabrera, Aldo; Bocanegra-García, Virgilio; Lizarazo-Ortega, Cristian; Guo, Xianwu; Correa-Basurto, José; Rodríguez-Pérez, Mario A.

    2011-12-01

    Onchocerciasis is a leading cause of blindness with at least 37 million people infected and more than 120 million people at risk of contracting the disease; most (99%) of this population, threatened by infection, live in Africa. The drug of choice for mass treatment is the microfilaricidal Mectizan® (ivermectin); it does not kill the adult stages of the parasite at the standard dose which is a single annual dose aimed at disease control. However, multiple treatments a year with ivermectin have effects on adult worms. The discovery of new therapeutic targets and drugs directed towards the killing of the adult parasites are thus urgently needed. The chitinase of filarial nematodes is a new drug target due to its essential function in the metabolism and molting of the parasite. Closantel is a potent and specific inhibitor of chitinase of Onchocerca volvulus (OvCHT1) and other filarial chitinases. However, the binding mode and specificity of closantel towards OvCHT1 remain unknown. In the absence of a crystallographic structure of OvCHT1, we developed a homology model of OvCHT1 using the currently available X-ray structures of human chitinases as templates. Energy minimization and molecular dynamics (MD) simulation of the model led to a high quality of 3D structure of OvCHIT1. A flexible docking study using closantel as the ligand on the binding site of OvCHIT1 and human chitinases was performed and demonstrated the differences in the closantel binding mode between OvCHIT1 and human chitinase. Furthermore, molecular dynamics simulations and free-energy calculation were employed to determine and compare the detailed binding mode of closantel with OvCHT1 and the structure of human chitinase. This comparative study allowed identification of structural features and properties responsible for differences in the computationally predicted closantel binding modes. The homology model and the closantel binding mode reported herein might help guide the rational development of

  15. A computational analysis of the binding mode of closantel as inhibitor of the Onchocerca volvulus chitinase: insights on macrofilaricidal drug design.

    PubMed

    Segura-Cabrera, Aldo; Bocanegra-García, Virgilio; Lizarazo-Ortega, Cristian; Guo, Xianwu; Correa-Basurto, José; Rodríguez-Pérez, Mario A

    2011-12-01

    Onchocerciasis is a leading cause of blindness with at least 37 million people infected and more than 120 million people at risk of contracting the disease; most (99%) of this population, threatened by infection, live in Africa. The drug of choice for mass treatment is the microfilaricidal Mectizan(®) (ivermectin); it does not kill the adult stages of the parasite at the standard dose which is a single annual dose aimed at disease control. However, multiple treatments a year with ivermectin have effects on adult worms. The discovery of new therapeutic targets and drugs directed towards the killing of the adult parasites are thus urgently needed. The chitinase of filarial nematodes is a new drug target due to its essential function in the metabolism and molting of the parasite. Closantel is a potent and specific inhibitor of chitinase of Onchocerca volvulus (OvCHT1) and other filarial chitinases. However, the binding mode and specificity of closantel towards OvCHT1 remain unknown. In the absence of a crystallographic structure of OvCHT1, we developed a homology model of OvCHT1 using the currently available X-ray structures of human chitinases as templates. Energy minimization and molecular dynamics (MD) simulation of the model led to a high quality of 3D structure of OvCHIT1. A flexible docking study using closantel as the ligand on the binding site of OvCHIT1 and human chitinases was performed and demonstrated the differences in the closantel binding mode between OvCHIT1 and human chitinase. Furthermore, molecular dynamics simulations and free-energy calculation were employed to determine and compare the detailed binding mode of closantel with OvCHT1 and the structure of human chitinase. This comparative study allowed identification of structural features and properties responsible for differences in the computationally predicted closantel binding modes. The homology model and the closantel binding mode reported herein might help guide the rational development of

  16. The Immunomodulatory Role of Adjuvants in Vaccines Formulated with the Recombinant Antigens Ov-103 and Ov-RAL-2 against Onchocerca volvulus in Mice.

    PubMed

    Hess, Jessica A; Zhan, Bin; Torigian, April R; Patton, John B; Petrovsky, Nikolai; Zhan, Tingting; Bottazzi, Maria Elena; Hotez, Peter J; Klei, Thomas R; Lustigman, Sara; Abraham, David

    2016-07-01

    In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administration, although there is concern based on several factors that onchocerciasis cannot be eliminated solely through this approach. A vaccine against Onchocerca volvulus would provide a critical tool for the ultimate elimination of this infection. Previous studies have demonstrated that immunization of mice with Ov-103 and Ov-RAL-2, when formulated with alum, induced protective immunity. It was hypothesized that the levels of protective immunity induced with the two recombinant antigens formulated with alum would be improved by formulation with other adjuvants known to enhance different types of antigen-specific immune responses. Immunizing mice with Ov-103 and Ov-RAL-2 in conjunction with alum, Advax 2 and MF59 induced significant levels of larval killing and host protection. The immune response was biased towards Th2 with all three of the adjuvants, with IgG1 the dominant antibody. Improved larval killing and host protection was observed in mice immunized with co-administered Ov-103 and Ov-RAL-2 in conjunction with each of the three adjuvants as compared to single immunizations. Antigen-specific antibody titers were significantly increased in mice immunized concurrently with the two antigens. Based on chemokine levels, it appears that neutrophils and eosinophils participate in the protective immune response induced by Ov-103, and macrophages and neutrophils participate in immunity induced by Ov-RAL-2. The mechanism of protective immunity induced by Ov-103 and Ov-RAL-2, with the adjuvants alum, Advax 2 and MF59, appears to be multifactorial with roles for cytokines, chemokines, antibody and specific effector cells. The vaccines developed in this study have the potential of reducing the morbidity associated with onchocerciasis in humans.

  17. Importance of migrants infected with Onchocerca volvulus in west African river valleys protected by 14 to 15 years of Simulium control.

    PubMed

    De Sole, G; Remme, J

    1991-06-01

    A study was done to determine the importance of human migration from non-controlled endemic onchocerciasis foci to the river valleys that have been protected for the past 14 to 15 years by the vector control operations of the Onchocerciasis Control Programme in West Africa. The aim of the study was to assess the contribution of migrants to the prevalence and intensity of infection in villages from 5 major river valleys and their potential role in causing relapse of transmission once the vector is allowed to return. In Burkina Faso the migrant population varied from 0.0% to 18.1% of the village population, and averaged 4.9%. Migrants accounted only for 0.6% of the population in Ghanaian and Ivorian villages along the Black Volta river. The prevalence of infection was significantly higher in migrants (8.2%) than in non migrants (1.1%) in the surveyed villages in Burkina Faso, and 1.5% of migrants had infections with more than 16 microfilariae per snip as against 0.2% of non migrants. Nearly all infected migrants came from the south of the Côte d'Ivoire. The study shows that human migration has caused the importation of Onchocerca volvulus from non-controlled areas. However, the epidemiological importance of this phenomenon is limited because of the very small number of infected migrants per village while two-third of the infected migrants are believed to be infected with the less pathogenic forest strain of the parasite. Because migration patterns changes geographically and over time similar studies will be continued on a regular basis.

  18. Contribution of migrant coffee labourers infected with Onchocerca volvulus to the maintenance of the microfilarial reservoir in an ivermectin-treated area of Mexico

    PubMed Central

    Rodríguez-Pérez, Mario A; Cabrera, Aldo Segura; Ortega, Cristian Lizarazo; Basáñez, María-Gloria; Davies, John B

    2007-01-01

    Background Since 1991, in Mexico, ivermectin has been administered twice a year to all residents in the onchocerciasis endemic foci which are mainly located in the coffee growing areas. However, the presence of a potentially infected itinerant seasonal labour force which is not treated regularly could jeopardise the attainment of the 85% coverage which is the present target for elimination of the disease. Methods The prevalence and intensity of Onchocerca volvulus microfilariae (mf), as well as their transmission from humans to vectors, were assessed during the coffee planting-clearing and harvesting seasons of 1997–1998, and 1998–1999 in two localities (I and II) of Southern Chiapas, Mexico, which regularly receive an influx of untreated migrant coffee labourers. Results Localities I and II had, respectively, an average of 391 (± 32) and 358 (± 14) resident inhabitants, and 70 (± 52) and 498 (± 289) temporary labourers. The ratio of migrants to residents ranged from 0.1:1 in locality I to 2.4:1 in locality II. The proportion of infected Simulium ochraceum s.l. parous flies was significantly lower in locality I than in locality II, and significantly higher during the stay of the migrants than before their arrival or after their departure. Parity and infection were higher in May-July than in November-February (in contrast with the latter being typically considered as the peak onchocerciasis transmission season by S. ochraceum s.l.). Conclusion The presence of significant numbers of untreated and potentially infected migrants may contribute to ongoing transmission, and their incorporation into ivermectin programmes should be beneficial for the attainment of the elimination goals of the regional initiative. However, the possibility that the results also reflect transmission patterns for the area cannot be excluded and these should be analyzed further. PMID:18088423

  19. The Immunomodulatory Role of Adjuvants in Vaccines Formulated with the Recombinant Antigens Ov-103 and Ov-RAL-2 against Onchocerca volvulus in Mice

    PubMed Central

    Hess, Jessica A.; Zhan, Bin; Torigian, April R.; Patton, John B.; Petrovsky, Nikolai; Zhan, Tingting; Bottazzi, Maria Elena; Hotez, Peter J.; Klei, Thomas R.; Lustigman, Sara; Abraham, David

    2016-01-01

    Background In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administration, although there is concern based on several factors that onchocerciasis cannot be eliminated solely through this approach. A vaccine against Onchocerca volvulus would provide a critical tool for the ultimate elimination of this infection. Previous studies have demonstrated that immunization of mice with Ov-103 and Ov-RAL-2, when formulated with alum, induced protective immunity. It was hypothesized that the levels of protective immunity induced with the two recombinant antigens formulated with alum would be improved by formulation with other adjuvants known to enhance different types of antigen-specific immune responses. Methodology/ Principal Findings Immunizing mice with Ov-103 and Ov-RAL-2 in conjunction with alum, Advax 2 and MF59 induced significant levels of larval killing and host protection. The immune response was biased towards Th2 with all three of the adjuvants, with IgG1 the dominant antibody. Improved larval killing and host protection was observed in mice immunized with co-administered Ov-103 and Ov-RAL-2 in conjunction with each of the three adjuvants as compared to single immunizations. Antigen–specific antibody titers were significantly increased in mice immunized concurrently with the two antigens. Based on chemokine levels, it appears that neutrophils and eosinophils participate in the protective immune response induced by Ov-103, and macrophages and neutrophils participate in immunity induced by Ov-RAL-2. Conclusions/Significance The mechanism of protective immunity induced by Ov-103 and Ov-RAL-2, with the adjuvants alum, Advax 2 and MF59, appears to be multifactorial with roles for cytokines, chemokines, antibody and specific effector cells. The vaccines developed in this study have the potential of reducing the morbidity associated with onchocerciasis in humans. PMID:27387453

  20. Extended Result Reading Window in Lateral Flow Tests Detecting Exposure to Onchocerca volvulus: A New Technology to Improve Epidemiological Surveillance Tools

    PubMed Central

    Golden, Allison; Steel, Cathy; Yokobe, Lindsay; Jackson, Emily; Barney, Rebecca; Kubofcik, Joseph; Peck, Roger; Unnasch, Thomas R.; Nutman, Thomas B.; de los Santos, Tala; Domingo, Gonzalo J.

    2013-01-01

    Onchocerciasis is a neglected tropical disease caused by infection with the parasite Onchocerca volvulus (Ov). An estimated 180 million people are at risk for Ov infection, and 37 million people are infected, mostly in Africa. A lateral flow-based assay to detect human IgG4 antibodies to the Ov-specific antigen Ov-16 was developed as a rapid tool to detect exposure to Ov. The test, when performed on 449 sera specimens from patients with microfiladermia and Ov-negative patients, has a sensitivity of 89.1% (95% confidence interval: 86.2%–92.0%), and specificity of 97% (95% confidence interval: 95.4%–98.6%). Because the intended use of the test is for surveillance, it is highly desirable to have a stable, long-lasting result. An extended read window is thus desirable for a high-volume, busy workflow and facilitates post-surveillance quality assurance. The main restriction on achieving an extended read window for this assay was the erythrocyte lysis that can alter the signal-to-noise ratio, especially in those with low IgG4 levels (weak positives). We describe a test housing that incorporates a user-independent feature driven by assay fluid and an expanding wick that detaches the blood separation membrane from the nitrocellulose used in the assay, but before hemolysis occurs. We demonstrated material functionality at extreme operational conditions (37°C, 80% relative humidity) and a read window of a minimum of 70 days. The fluid-driven assay device performs equally as well with whole blood as with plasma, as demonstrated with 100 spiked clinical specimens (with a correlation coefficient of 0.96). We show a novel, inexpensive, and simple approach to actuating the detachment of the blood separation membrane from the nitrocellulose test with no impact on the performance characteristics of the test. PMID:23935960

  1. Immunity to onchocerciasis: cells from putatively immune individuals produce enhanced levels of interleukin-5, gamma interferon, and granulocyte-macrophage colony-stimulating factor in response to Onchocerca volvulus larval and male worm antigens.

    PubMed

    Turaga, P S; Tierney, T J; Bennett, K E; McCarthy, M C; Simonek, S C; Enyong, P A; Moukatte, D W; Lustigman, S

    2000-04-01

    Antigen-specific interleukin-5 (IL-5), gamma interferon (IFN-gamma), and granulocyte-macrophage colony-stimulating factor (GM-CSF) responses in individuals living in an area of hyperendemicity for onchocerciasis in Cameroon were examined. The responses against antigens prepared from Onchocerca volvulus third-stage larvae (L3), molting L3 (mL3), and crude extract from adult males (M-OvAg) were compared to the responses against antigens from adult female worms and skin microfilariae. Cytokine responses for the putatively immune individuals (PI) and the infected individuals (INF) were compared. A differential cytokine profile of IL-5 (Th2 phenotype) and IFN-gamma (Th1 phenotype) was found in these individuals in response to the antigens. In both the PI and the INF, Th2 responses against all the antigens tested were dominant. However, in the PI group as a whole, there was an enhanced Th2 response against the larval antigens and the adult male and adult female antigens, and a Th1 response in a subgroup of the PI (27 to 54.5%) against L3, mL3, and M-OvAg antigens was present. While the PI produced significantly higher levels of GM-CSF against L3, mL3, and M-OvAg antigens than the INF, there was no difference in the GM-CSF responses of the groups against the other antigens. The present study indicated that, in comparison to the INF, the PI have distinct larva-specific and adult male-specific cytokine responses, thus supporting the premise that immunological studies of the PI would lead to the identification of immune mechanisms and the target genes that play a role in protective immunity.

  2. Effects of high doses of diethylcarbamazine on adult Onchocerca volvulus examined by the collagenase technique and by histology.

    PubMed

    Albiez, E J; Walter, G; Kaiser, A; Newland, H S; White, A T; Greene, B M; Taylor, H R; Büttner, D W

    1988-06-01

    Thirty adult male nodule carriers from a hyperendemic onchocerciasis area in the Liberian rain forest were treated with high doses of diethylcarbamazine (30 mg/kg/d) over one week. Another ten patients received placebo tablets and served as a control. All detectable nodules were removed from half of the patients at two months and from the remaining patients at ten months after chemotherapy. The adult worms in the nodules were examined for pathological alterations by the collagenase technique including embryogram, and by histology. No macrofilaricidal effect was observed at either time, and no significant reduction of microfilariae in the uteri of the female worms or in the tissue of the nodules was seen. Two months after the therapy there was a significant increase of degenerated stretched intrauterine microfilariae but this effect was no longer observed after ten months. No pathological effect was seen on the intrauterine coiled microfilariae. On the contrary, their number had significantly increased after ten months which could mean a stimulation of the embryogenesis. No effect on spermatogenesis was observed. Both techniques, the collagenase digestion and the histological examination of the nodules, provided similar results to demonstrate that there was no marked long lasting effect on O. volvulus after a treatment with high doses of diethylcarbamazine.

  3. Doxycycline Leads to Sterility and Enhanced Killing of Female Onchocerca volvulus Worms in an Area With Persistent Microfilaridermia After Repeated Ivermectin Treatment: A Randomized, Placebo-Controlled, Double-Blind Trial

    PubMed Central

    Debrah, Alexander Yaw; Specht, Sabine; Klarmann-Schulz, Ute; Batsa, Linda; Mand, Sabine; Marfo-Debrekyei, Yeboah; Fimmers, Rolf; Dubben, Bettina; Kwarteng, Alexander; Osei-Atweneboana, Mike; Boakye, Daniel; Ricchiuto, Arcangelo; Büttner, Marcelle; Adjei, Ohene; Mackenzie, Charles D.; Hoerauf, Achim

    2015-01-01

    Background. Ivermectin (IVM) has been the drug of choice for the treatment of onchocerciasis. However, there have been reports of persistent microfilaridermia in individuals from an endemic area in Ghana after many rounds of IVM, raising concerns of suboptimal response or even the emergence of drug resistance. Because it is considered risky to continue relying only on IVM to combat this phenomenon, we assessed the effect of targeting the Onchocerca volvulus Wolbachia endosymbionts with doxycycline for these individuals with suboptimal response. Methods. One hundred sixty-seven patients, most of them with multiple rounds of IVM, were recruited in areas with IVM suboptimal response and treated with 100 mg/day doxycycline for 6 weeks. Three and 12 months after doxycycline treatment, patients took part in standard IVM treatment. Results. At 20 months after treatment, 80% of living female worms from the placebo group were Wolbachia positive, whereas only 5.1% in the doxycycline-treated group contained bacteria. Consistent with interruption of embryogenesis, none of the nodules removed from doxycycline-treated patients contained microfilariae, and 97% of those patients were without microfilaridermia, in contrast to placebo patients who remained at pretreatment levels (P < .001). Moreover, a significantly enhanced number of dead worms were observed after doxycycline. Conclusions. Targeting the Wolbachia in O. volvulus is effective in clearing microfilariae in the skin of onchocerciasis patients with persistent microfilaridermia and in enhanced killing of adult worms after repeated standard IVM treatment. Strategies can now be developed that include doxycycline to control onchocerciasis in areas where infections persist despite the frequent use of IVM. Clinical Trials Registration. ISRCTN 66649839. PMID:25948064

  4. Detection of Onchocerca volvulus infection in low prevalence areas: a comparison of three diagnostic methods.

    PubMed

    Boatin, B A; Toé, L; Alley, E S; Nagelkerke, N J D; Borsboom, G; Habbema, J D F

    2002-12-01

    The standard assay for onchocerciasis diagnosis is microscopical detection of microfilariae in skin snips. Skin snipping is painful, requires appropriate sterilization of equipment, and may fail to diagnose light infections. Two alternatives are a polymerase chain reaction (PCR) test which detects parasite DNA in pieces or scrapings of skin and a test based on allergic reactions to topical application of diethylcarbamazine (DEC). We compared these 2 diagnostics with standard skin snip microscopy in 313 individuals from 2 villages in Guinea, with low prevalence after over 10 years of control by the Onchocerciasis Control Programme. Lower and upper bounds on sensitivities and specificities of these 3 tests were estimated. In addition, these parameters were estimated using 5 different statistical models. Where prevalence was low, PCR and the DEC patch test appeared to be more sensitive than skin snipping which has low sensitivity. As the DEC test is non-invasive, simple and cheap, it may provide a good alternative to skin snipping alone for surveillance in low prevalence areas.

  5. Induction of protection against divergent H5N1 influenza viruses using a recombinant fusion protein linking influenza M2e to Onchocerca volvulus activation associated protein-1 (ASP-1) adjuvant.

    PubMed

    Zhao, Guangyu; Du, Lanying; Xiao, Wenjun; Sun, Shihui; Lin, Yongping; Chen, Min; Kou, Zhihua; He, Yuxian; Lustigman, Sara; Jiang, Shibo; Zheng, Bo-Jian; Zhou, Yusen

    2010-10-18

    Our previous studies have shown the adjuvanticity of an Onchocerca volvulus recombinant protein, Ov-ASP-1 (ASP-1), when administered in an aqueous formulation with bystander vaccine antigens or commercial vaccines. In this study, we reported a novel formulation that took advantage of the protein nature of the ASP-1 adjuvant by creating recombinant fusion protein vaccines linking the highly conserved extracellular domain of M2 protein (M2e) consensus sequence of H5N1 influenza viruses with the ASP-1 adjuvant. Two recombinant fusion proteins designated M2e-ASP-1 and M2e3-ASP-1 were studied, in which ASP-1 was fused with one or three tandem copies of the M2e antigen. Our results show that these novel recombinant influenza vaccines, particularly M2e3-ASP-1, induced strong anti-M2e-specific humoral and cellular immune responses in the established mouse model. Furthermore, M2e3-ASP-1 was able to provide significant cross-clade protection against divergent H5N1 viruses. Consequently, this study has demonstrated a potential novel vaccine formulation that could provide a complementary prophylactic strategy in preventing the threat of future influenza outbreak resulting from rapid evolution of the H5N1 virus and co-circulation of multiple antigenic variants in various regions.

  6. Determination of sample sizes for the estimation of Onchocerca volvulus (Filarioidea: Onchocercidae) infection rates in biting populations of Simulium ochraceum s.l. (Diptera: Simuliidae) and its application to ivermectin control programs.

    PubMed

    Basáñez, M G; Rodríguez-Pérez, M A; Reyes-Villanueva, F; Collins, R C; Rodríguez, M H

    1998-09-01

    Monthly samples of biting Simulium ochraceum s.l. Walker were collected before and after ivermectin treatment in southern Mexico and analyzed for Onchocerca volvulus Leuckart infection rates, infection intensity, and the characteristics of larval distribution among parous flies. The variance over mean ratio (VMR) indicated that in all cases this distribution departed from Poisson and was strongly aggregated (VMR > 1). The negative binomial was found to be an adequate model with a small value of the aggregation parameter k, but the degree of larval overdispersion increased as the mean larval load decreased, invalidating the use of a common kc value. A linear relationship between k and the mean (mu) was established, k(mu) = k1 mu, which permitted exploration of the relationship between the observed proportion of infected flies, p, and the estimated mean larval burden per fly, m (all larval stages in parous flies). This would allow mean numbers of larvae per parous fly to be predicted from presence-absence data (e.g., from infection rates provided by polymerase chain reaction methods applied to pools of flies), assuming that k1 is a known parameter. Given that both p and m are naturally low in S. ochraceum, their relationship was practically linear within the range of observed values. Predictions were tested with the Mexican data from which the clumping parameter was estimated as well as for Guatemalan data for which this information was not available. Results showed a highly satisfactory degree of agreement between predictions and observations. The sample sizes required to estimate mean larval loads from prevalence data for fixed levels of precision (defined as the ratio between SE[m] and m) were calculated for realistic S. ochraceum infection rates (those found in published pre- and postcontrol field surveys as well as in this work). For the special case in which the relationship between k and the mean is linear and goes through the origin, k(mu) = k1 mu, the number

  7. Whence river blindness? The domestication of mammals and host-parasite co-evolution in the nematode genus Onchocerca.

    PubMed

    Lefoulon, Emilie; Giannelli, Alessio; Makepeace, Benjamin L; Mutafchiev, Yasen; Townson, Simon; Uni, Shigehiko; Verocai, Guilherme G; Otranto, Domenico; Martin, Coralie

    2017-03-24

    The genus Onchocerca includes 34 described species and represents one of the largest genera of the filarial nematodes within the family Onchocercidae. Representative members of this genus are mainly parasites of ungulates, with some exceptions such as Onchocerca lupi and Onchocerca volvulus, infecting carnivores and/or humans. For a long time, the evolutionary relationships amongst onchocercids remained poorly studied, as the systematics of this genus was impaired by the high morphological variability of species included in the taxon. Although some molecular phylogenies were developed, these studies were mainly focused on bovine Onchocerca spp. and O. volvulus, including assessments of Wolbachia endosymbionts. In the present study, we analysed 13 Onchocerca spp. from a larger host spectrum using a panel of seven different genes. Analysis of the coxI marker supports its usefulness for the identification of species within the genus. The evolutionary history of the genus has been herein revised by multi-gene phylogenies, presenting three strongly supported clades of Onchocerca spp. Analyses of co-evolutionary scenarios between Onchocerca and their vertebrate hosts underline the effect of domestication on Onchocerca speciation. Our study indicates that a host switch event occurred between Bovidae, Canidae and humans. Cophylogenetic analyses between Onchocerca and the endosymbiotic bacterium Wolbachia indicate the strongest co-evolutionary pattern ever registered within the filarial nematodes. Finally, this dataset indicates that the clade composed by O. lupi, Onchocerca gutturosa, Onchocerca lienalis, Onchocerca ochengi and O. volvulus derived from recent speciation.

  8. Immune recognition of excretory and secretory products of the filarial nematode Onchocerca ochengi in cattle and human sera.

    PubMed

    Djafsia, B; Ndjonka, D; Dikti, J V; van Hoorn, S; Manchang, K; Brattig, N; Liebau, E

    2015-09-11

    Excretory-secretory (ES) products of nematodes and other helminths are the first molecules to interact with cell surfaces and soluble proteins within the host. In the present study, ES products of the filarial nematode Onchocerca ochengi were investigated as a model for Onchocerca volvulus, the causative agent of river blindness. These products were collected from adult and larval stages in vitro over a period of 7 days, to compare their immunological recognition in cattle and human sera, infected with species of Onchocerca. From the 156 sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) ES products or extracts, protein bands showed different patterns between female and male products. A comparison of antibody recognition of the different ES products by sera from infected cattle and humans, when analysed by enzyme-linked immunosorbent assay (ELISA), revealed a relatively higher reactivity of the female somatic extract to human and cattle sera compared to ES products of both genders. Nevertheless, similar reactivity of the O. ochengi male and female ES products to human and cattle sera was noticed. As a result, the interaction of ES products with the surface of the host and immune system often led to host responses, including the generation of antibodies. The O. ochengi ES products are therefore good sources of potential immunogenic proteins. The identification of these ES products is in progress, with the aim of developing vaccine candidates against human onchocerciasis.

  9. [Gastric volvulus].

    PubMed

    Solórzano, J; Acosta, D; Morales, H; Vásquez, F; Mora, G; Chávez, M; Andrade, D; Joutteaux, R; Sánchez, I; García, D; Valenzuela, E

    2006-10-01

    Gastric volvulus is a rare condition in pediatric population in which there is an abnormal rotation of one part of the stomach around itself. It's a surgical emergency. We report a six year old female admitted in the emergency due to upper abdominal distention, nausea without vomiting, physical exam revealed upper abdominal distention and abdominal tenderness, no bowel sounds. Laparotomy was performed and a gastric volvulus with occlusive vascular involvement was found. In the post operative period she required a second laparotomy due to adhesions in small bowel.

  10. Onchocerca armillata contains the endosymbiotic bacterium Wolbachia and elicits a limited inflammatory response

    PubMed Central

    Neary, Joseph M.; Trees, Alexander J.; Ekale, David D.; Tanya, Vincent N.; Hetzel, Udo; Makepeace, Benjamin L.

    2010-01-01

    Human onchocerciasis, also known as River Blindness, is a debilitating disease caused by the filarial nematode Onchocerca volvulus. Many, but not all, filarial nematodes carry within their tissues endosymbiotic, Rickettsia-like bacteria of the genus Wolbachia. Onchocerca spp. infections in cattle offer the most relevant, analogous host–parasite model system. West African cattle are commonly co-infected with four Onchocerca spp.; two of these are Wolbachia-positive (Onchocerca gutturosa and Onchocerca ochengi), and the remainder are of unknown Wolbachia status (Onchocerca dukei and Onchocerca armillata). Previous studies have suggested that worm survival is dependent on this bacterium. O. armillata, an abundant parasite of African cattle that has received little attention, is a primitive species that may lack Wolbachia. The objectives of this study were to determine if O. armillata carries Wolbachia and to provide preliminary descriptions of the host inflammatory cell environment around the adult worms. The findings may support or refute the hypothesis that a prime contribution of Wolbachia is to permit long-term survival and reproduction of certain Onchocerca spp. (including O. volvulus in humans). O. armillata adult worms were found in the aorta of 90.7% of cattle (n = 54) slaughtered at an abattoir in Ngaoundéré, Adamawa Region, Cameroon. The presence of Wolbachia in O. armillata was confirmed by a specific anti-Wolbachia surface protein antibody detected using a peroxidase conjugate (immunohistochemistry) and PCR for detection of Wolbachia-specific sequences within DNA extracts from frozen worms. Tissue sections stained with haematoxylin and eosin showed the host cell response to be dominated by macrophages and fibroblasts. This is unusual compared with nodule-dwelling Wolbachia-positive Onchocerca spp., where the host response is typically characterised by granulocytes, and suggests that the mechanisms for worm survival employed by this species (which is

  11. Onchocerca armillata contains the endosymbiotic bacterium Wolbachia and elicits a limited inflammatory response.

    PubMed

    Neary, Joseph M; Trees, Alexander J; Ekale, David D; Tanya, Vincent N; Hetzel, Udo; Makepeace, Benjamin L

    2010-12-15

    Human onchocerciasis, also known as River Blindness, is a debilitating disease caused by the filarial nematode Onchocerca volvulus. Many, but not all, filarial nematodes carry within their tissues endosymbiotic, Rickettsia-like bacteria of the genus Wolbachia. Onchocerca spp. infections in cattle offer the most relevant, analogous host-parasite model system. West African cattle are commonly co-infected with four Onchocerca spp.; two of these are Wolbachia-positive (Onchocerca gutturosa and Onchocerca ochengi), and the remainder are of unknown Wolbachia status (Onchocerca dukei and Onchocerca armillata). Previous studies have suggested that worm survival is dependent on this bacterium. O. armillata, an abundant parasite of African cattle that has received little attention, is a primitive species that may lack Wolbachia. The objectives of this study were to determine if O. armillata carries Wolbachia and to provide preliminary descriptions of the host inflammatory cell environment around the adult worms. The findings may support or refute the hypothesis that a prime contribution of Wolbachia is to permit long-term survival and reproduction of certain Onchocerca spp. (including O. volvulus in humans). O. armillata adult worms were found in the aorta of 90.7% of cattle (n=54) slaughtered at an abattoir in Ngaoundéré, Adamawa Region, Cameroon. The presence of Wolbachia in O. armillata was confirmed by a specific anti-Wolbachia surface protein antibody detected using a peroxidase conjugate (immunohistochemistry) and PCR for detection of Wolbachia-specific sequences within DNA extracts from frozen worms. Tissue sections stained with haematoxylin and eosin showed the host cell response to be dominated by macrophages and fibroblasts. This is unusual compared with nodule-dwelling Wolbachia-positive Onchocerca spp., where the host response is typically characterised by granulocytes, and suggests that the mechanisms for worm survival employed by this species (which is

  12. Onchocerca volvulus: The Road from Basic Biology to a Vaccine.

    PubMed

    Lustigman, Sara; Makepeace, Benjamin L; Klei, Thomas R; Babayan, Simon A; Hotez, Peter; Abraham, David; Bottazzi, Maria Elena

    2017-09-22

    Human onchocerciasis - commonly known as river blindness - is one of the most devastating yet neglected tropical diseases, leaving many millions in sub-Saharan Africa blind and/or with chronic disabilities. Attempts to eliminate onchocerciasis, primarily through the mass drug administration of ivermectin, remains challenging and has been heightened by the recent news that drug-resistant parasites are developing in some populations after years of drug treatment. Needed, and needed now, in the fight to eliminate onchocerciasis are new tools, such as preventive and therapeutic vaccines. This review summarizes the progress made to advance the onchocerciasis vaccine from the research laboratory into the clinic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Dual Protonophore–Chitinase Inhibitors Dramatically Affect O. volvulus Molting

    PubMed Central

    2015-01-01

    The L3-stage-specific chitinase OvCHT1 has been implicated in the development of Onchocerca volvulus, the causative agent of onchocerciasis. Closantel, a known anthelmintic drug, was previously discovered as a potent and specific OvCHT1 inhibitor. As closantel is also a known protonophore, we performed a simple scaffold modulation to map out the structural features that are relevant for its individual or dual biochemical roles. Furthermore, we present that either OvCHT1 inhibition or protonophoric activity was capable of affecting O. volvulus L3 molting and that the presence of both activities in a single molecule yielded more potent inhibition of the nematode’s developmental process. PMID:24918716

  14. Dual protonophore-chitinase inhibitors dramatically affect O. volvulus molting.

    PubMed

    Gooyit, Major; Tricoche, Nancy; Lustigman, Sara; Janda, Kim D

    2014-07-10

    The L3-stage-specific chitinase OvCHT1 has been implicated in the development of Onchocerca volvulus, the causative agent of onchocerciasis. Closantel, a known anthelmintic drug, was previously discovered as a potent and specific OvCHT1 inhibitor. As closantel is also a known protonophore, we performed a simple scaffold modulation to map out the structural features that are relevant for its individual or dual biochemical roles. Furthermore, we present that either OvCHT1 inhibition or protonophoric activity was capable of affecting O. volvulus L3 molting and that the presence of both activities in a single molecule yielded more potent inhibition of the nematode's developmental process.

  15. Molecular phylogeny of the filaria genus Onchocerca with special emphasis on Afrotropical human and bovine parasites.

    PubMed

    Krueger, A; Fischer, P; Morales-Hojas, R

    2007-01-01

    Filarial parasites of the genus Onchocerca are found in a broad spectrum of ungulate hosts. One species, O. volvulus, is a human parasite that can cause severe disease (onchocerciasis or 'river blindness'). The phylogenetic relationships and the bionomics of many of the nearly 30 known species remain dubious. Here, the phylogeny of 11 species representing most major lineages of the genus is investigated by analysing DNA sequences from three mitochondrial genes (ND5, 12S and 16S rRNA) and portions of the intergenic spacer of the nuclear 5s rRNA. Special emphasis is given to a clade containing a yet unassigned specimen from Uganda (O. sp. 'Siisa'), which appears to be intermediate between O. volvulus and O. ochengi. While the latter can be differentiated by the O-150 tandem repeat commonly used for molecular diagnostics, O. volvulus and O. sp.'Siisa' cannot be differentiated by this marker. In addition, a worm specimen from an African bushbuck appears to be closely related to the bovine O. dukei and represents the basal taxon of the human/bovine clade. At the base of the genus, our data suggest O. flexuosa (red deer), O. ramachandrini (warthog) and O. armillata (cow) to be the representatives of ancient lineages. The results provide better insight into the evolution and zoogeography of Onchocerca. They also have epidemiological and taxonomic implications by providing a framework for more accurate molecular diagnosis of filarial larvae in vectors.

  16. The Emergence of Zoonotic Onchocerca lupi Infection in the United States – A Case-Series

    PubMed Central

    Cantey, Paul T.; Weeks, Jessica; Edwards, Morven; Rao, Suchitra; Ostovar, G. Amin; Dehority, Walter; Alzona, Maria; Swoboda, Sara; Christiaens, Brooke; Ballan, Wassim; Hartley, John; Terranella, Andrew; Weatherhead, Jill; Dunn, James J.; Marx, Douglas P.; Hicks, M. John; Rauch, Ronald A.; Smith, Christiana; Dishop, Megan K.; Handler, Michael H.; Dudley, Roy W. R.; Chundu, Kote; Hobohm, Dan; Feiz-Erfan, Iman; Hakes, Joseph; Berry, Ryan S.; Stepensaski, Shelly; Greenfield, Benjamin; Shroeder, Laura; Bishop, Henry; de Almeida, Marcos; Mathison, Blaine; Eberhard, Mark

    2016-01-01

    This case-series describes the 6 human infections with Onchocerca lupi, a parasite known to infect cats and dogs, that have been identified in the United States since 2013. Unlike cases reported outside the country, the American patients have not had subconjunctival nodules but have manifested more invasive disease (eg, spinal, orbital, and subdermal nodules). Diagnosis remains challenging in the absence of a serologic test. Treatment should be guided by what is done for Onchocerca volvulus as there are no data for O. lupi. Available evidence suggests that there may be transmission in southwestern United States, but the risk of transmission to humans is not known. Research is needed to better define the burden of disease in the United States and develop appropriately-targeted prevention strategies. PMID:26611778

  17. The Emergence of Zoonotic Onchocerca lupi Infection in the United States--A Case-Series.

    PubMed

    Cantey, Paul T; Weeks, Jessica; Edwards, Morven; Rao, Suchitra; Ostovar, G Amin; Dehority, Walter; Alzona, Maria; Swoboda, Sara; Christiaens, Brooke; Ballan, Wassim; Hartley, John; Terranella, Andrew; Weatherhead, Jill; Dunn, James J; Marx, Douglas P; Hicks, M John; Rauch, Ronald A; Smith, Christiana; Dishop, Megan K; Handler, Michael H; Dudley, Roy W R; Chundu, Kote; Hobohm, Dan; Feiz-Erfan, Iman; Hakes, Joseph; Berry, Ryan S; Stepensaski, Shelly; Greenfield, Benjamin; Shroeder, Laura; Bishop, Henry; de Almeida, Marcos; Mathison, Blaine; Eberhard, Mark

    2016-03-15

    This case-series describes the 6 human infections with Onchocerca lupi, a parasite known to infect cats and dogs, that have been identified in the United States since 2013. Unlike cases reported outside the country, the American patients have not had subconjunctival nodules but have manifested more invasive disease (eg, spinal, orbital, and subdermal nodules). Diagnosis remains challenging in the absence of a serologic test. Treatment should be guided by what is done for Onchocerca volvulus as there are no data for O. lupi. Available evidence suggests that there may be transmission in southwestern United States, but the risk of transmission to humans is not known. Research is needed to better define the burden of disease in the United States and develop appropriately-targeted prevention strategies.

  18. Detection and comparison of nitric oxide in clinically healthy horses and those with naturally acquired strangulating large colon volvulus

    PubMed Central

    2005-01-01

    Abstract The objective of the study was to determine whether nitric oxide (NO) is present in clinically healthy horses (control) under basal conditions, and if it increases secondary to naturally acquired strangulating large colon volvulus (affected). Eleven affected horses and 10 controls were studied. Jugular venous blood, abdominal fluid, and urine were collected. The NO concentrations were standardized to the creatinine concentration in the respective samples. A biopsy specimen collected from the large colon pelvic flexure at surgery was divided into subsections for processing for inducible nitric synthase (iNOS) and nitrotyrosine (NT) immunohistochemical staining and reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemical staining. There were no significant differences in plasma, abdominal fluid, or urine NO concentrations between affected and control horses. There was a significant decrease in submucosal arteriolar and venular endothelium, submucosal plexus, mucosal leukocyte, mucosal and musclaris vasculature, and myenteric plexus NADPH diaphorase staining in affected versus control horses. There was a significant increase in iNOS staining in mucosal leukocytes and vasculature in affected versus control horses. Other than a greater number of positively stained mucosal leukocytes in affected horses, there were no significant differences between affected and control horses for NT staining. The presence of NADPH diaphorase staining in the endothelium and submucosal neurons suggests endothelial and neuronal NOS are present under basal conditions in the large colon of horses. Increased iNOS and NT staining in mucosal leukocytes of affected horses suggests involvement of the NO pathway in large colon volvulus. The reasons for the lack of a significant difference in plasma, abdominal fluid, and urine NO concentrations between affected and control horses are unknown. PMID:15971674

  19. Volvulus of the Caecum

    PubMed Central

    Chamberlain, Geoffrey

    1960-01-01

    Three cases of volvulus of the caecum are presented and their symptoms and treatment are discussed. It is suggested that this condition may be commoner than is thought and would be diagnosed more frequently if considered in the differential diagnosis. ImagesFig. 1Fig. 2Fig. 3 PMID:13809057

  20. Spontaneous transverse colon volvulus

    PubMed Central

    Sana, Landolsi; Ali, Gassara; Kallel, Helmi; Amine, Baklouti; Ahmed, Saadaoui; Mohamed Ali, Elouer; Wajdi, Chaeib; Saber, Mannaï

    2013-01-01

    We report a case of spontaneous transverse colon volvulus in a young healthy woman. It constitutes an unusual case since it occurred in a young healthy woman with a subacute onset and no aetiological factor has been found. Its diagnosis is still challenging. Prompt recognition with emergency intervention constitutes the key to successful outcome. PMID:23785565

  1. Spontaneous transverse colon volvulus.

    PubMed

    Sana, Landolsi; Ali, Gassara; Kallel, Helmi; Amine, Baklouti; Ahmed, Saadaoui; Ali, Elouer Mohamed; Wajdi, Chaeib; Saber, Mannaï

    2013-01-01

    We report a case of spontaneous transverse colon volvulus in a young healthy woman. It constitutes an unusual case since it occurred in a young healthy woman with a subacute onset and no aetiological factor has been found. Its diagnosis is still challenging. Prompt recognition with emergency intervention constitutes the key to successful outcome.

  2. Exploiting the Polypharmacology of ß-Carbolines to Disrupt O. volvulus Molting

    PubMed Central

    2015-01-01

    Onchocerciasis is an infection caused by the filarial worm Onchocerca volvulus, which can eventually result in blindness. The lack of an effective macrofilaricide and the possible development of ivermectin-resistant strains of O. volvulus necessitate the need for alternative treatment strategies. We have shown that targeting the L3-stage-specific chitinase OvCHT1 impairs the shedding of the filarial cuticle. In our continued efforts to discover OvCHT1 inhibitors, we identified the β-carboline alkaloid scaffolding as a chitinase inhibitor that is capable of penetrating the worm cuticle. Herein, we disclose the rich polypharmacology of the β-carboline class of compounds as an approach to abrogate the molting of the parasite and thus the initiation of infection in the human host. PMID:25815157

  3. Sigmoid volvulus complicating pregnancy: a case report.

    PubMed

    Atamanalp, Sabri Selcuk; Kisaoglu, Abdullah; Ozogul, Bunyami; Kantarci, Mecit; Disci, Esra; Bulut, O Hakan; Aksungur, Nurhak; Atamanalp, Refik Selim

    2015-02-01

    Sigmoid volvulus during pregnancy is a rare complication, and as of 2012, fewer than 100 cases had been reported. In this report, we present a 30 year-old pregnant woman with sigmoid volvulus, and we discuss this rare entity.

  4. Human ocular filariasis: further evidence on the zoonotic role of Onchocerca lupi

    PubMed Central

    2012-01-01

    Background Among ocular vector-borne pathogens, Onchocerca volvulus, the agent of the so-called “river blindness”, affects about 37 million people globally. Other Onchocerca spp. have been sporadically reported as zoonotic agents. Cases of canine onchocerciasis caused by Onchocerca lupi are on the rise in the United States and Europe. Its zoonotic role has been suspected but only recently ascertained in a single case from Turkey. The present study provides further evidence on the occurrence of O. lupi infesting human eyes in two patients from Turkey (case 1) and Tunisia (case 2). The importance of obtaining a correct sample collection and preparation of nematodes infesting human eyes is highlighted. Methods In both cases the parasites were identified with morpho-anatomical characters at the gross examination, histological analysis and anatomical description and also molecularly in case 1. Results The nematode from the first case was obviously O. lupi based on their morphology at the gross examination, histological analysis and anatomical description. In the second case, although the diagnostic cuticular characters were not completely developed, other features were congruent with the identification of O. lupi. Furthermore, the morphological identification was also molecularly confirmed in the Turkish case. Conclusions The results of this study suggest that O. lupi infestation is not an occasional finding but it should be considered in the differential diagnosis of other zoonotic helminths causing eye infestation in humans (e.g., D. immitis and Dirofilaria repens). Both cases came from areas where no cases of canine onchocerciasis were previously reported in the literature, suggesting that an in depth appraisal of the infestation in canine populations is necessary. Physicians and ophthalmologists are advised on how to preserve nematode samples recovered surgically, to allow a definitive, correct etiological diagnosis. PMID:22541132

  5. Detection, purification and characterisation of a secretory alkaline phosphatase from Onchocerca species.

    PubMed

    Cho-Ngwa, Fidelis; Mbua, Eric Ngalle; Nchamukong, Kingsley G; Titanji, Vincent P K

    2007-12-01

    An Onchocerca secretory alkaline phosphatase (E.C. 3.1.3.1) of molecular weight 90 kDa when in crude extract, but which dimerises to about 180 kDa upon purification, was detected, purified and characterised. The enzyme was found to be secreted by both O. ochengi and O. volvulus worms. It was shown to be of Onchocerca origin by Western blotting with bovine onchocerciasis sera and by its time-dependent release in cultures. The O. ochengi enzyme was purified to near homogeneity by a combination of polyethylene glycol precipitation, DEAE-cellulose chromatography and preparative electrophoresis. About 0.96 mg of the active enzyme was purified from 48.4 mg of the crude parasite-released products, giving a purification fold of 71.45 and a yield of 8.7%. The purified enzyme exhibited a typical Michaelis-Menten kinetics with optimum activity on p-nitrophenylphosphate (p-NPP) at pH 10.2. Its apparent K(m) for p-NPP was 0.56+/-0.03 mM and it required Mg(2+) and dithiothreitol (DTT) for stability throughout its purification. Sodium dodecyl sulphate at 2% (w/v) did not inhibit the enzyme activity, but apparently stabilised it during freezing. Inorganic phosphate inhibited the enzyme competitively with an apparent inhibition constant (K(i)) of 3.33+/-0.04 mM, whereas l-phenylalanine inhibited it in a mixed way with a K(i) of 3.18+/-0.03 mM. While contributing to the understanding of metabolism in Onchocerca, the present apparently unique enzyme which is likely to serve in the nutrition of the parasite could be further characterised as a macrofilaricide target or diagnostic marker in onchocerciasis.

  6. Autoantibody induced by experimental Onchocerca infection. Effect of different routes of administration of microfilariae and of treatment with diethylcarbamazine citrate and ivermectin.

    PubMed

    Donnelly, J J; Xi, M S; Haldar, J P; Hill, D E; Lok, J B; Khatami, M; Rockey, J H

    1988-05-01

    Hartley guinea pigs were injected with microfilariae (Mf) of Onchocerca lienalis as a model for acute inflammatory responses to Mf in human Onchocerca volvulus infection. IgG autoantibody reactive with a 3 M KCl extract of guinea pig cornea was detected by ELISA in the serum of guinea pigs injected with O. lienalis Mf three or more times sub-conjunctivally, or two or more times subcutaneously. Administration of the microfilaricides diethylcarbamazine citrate and ivermectin did not alter the proportion of animals expressing autoantibody or the mean autoantibody titer. The severity of acute corneal inflammatory reactions to Mf was similar in animals with and without circulating autoantibody. Although autoantibody responses did not correlate with acute corneal inflammatory reactions to dead Mf, the ability of Mf to induce formation of an antibody reactive with a component of autologous cornea suggests that autoimmune mechanisms might participate in chronic onchocercal lesions in the cornea, eg, sclerosing keratitis.

  7. Stage-specific Proteomes from Onchocerca ochengi, Sister Species of the Human River Blindness Parasite, Uncover Adaptations to a Nodular Lifestyle*

    PubMed Central

    Armstrong, Stuart D.; Xia, Dong; Bah, Germanus S.; Krishna, Ritesh; Ngangyung, Henrietta F.; LaCourse, E. James; McSorley, Henry J.; Kengne-Ouafo, Jonas A.; Chounna-Ndongmo, Patrick W.; Wanji, Samuel; Enyong, Peter A.; Taylor, David W.; Blaxter, Mark L.; Wastling, Jonathan M.; Tanya, Vincent N.; Makepeace, Benjamin L.

    2016-01-01

    Despite 40 years of control efforts, onchocerciasis (river blindness) remains one of the most important neglected tropical diseases, with 17 million people affected. The etiological agent, Onchocerca volvulus, is a filarial nematode with a complex lifecycle involving several distinct stages in the definitive host and blackfly vector. The challenges of obtaining sufficient material have prevented high-throughput studies and the development of novel strategies for disease control and diagnosis. Here, we utilize the closest relative of O. volvulus, the bovine parasite Onchocerca ochengi, to compare stage-specific proteomes and host-parasite interactions within the secretome. We identified a total of 4260 unique O. ochengi proteins from adult males and females, infective larvae, intrauterine microfilariae, and fluid from intradermal nodules. In addition, 135 proteins were detected from the obligate Wolbachia symbiont. Observed protein families that were enriched in all whole body extracts relative to the complete search database included immunoglobulin-domain proteins, whereas redox and detoxification enzymes and proteins involved in intracellular transport displayed stage-specific overrepresentation. Unexpectedly, the larval stages exhibited enrichment for several mitochondrial-related protein families, including members of peptidase family M16 and proteins which mediate mitochondrial fission and fusion. Quantification of proteins across the lifecycle using the Hi-3 approach supported these qualitative analyses. In nodule fluid, we identified 94 O. ochengi secreted proteins, including homologs of transforming growth factor-β and a second member of a novel 6-ShK toxin domain family, which was originally described from a model filarial nematode (Litomosoides sigmodontis). Strikingly, the 498 bovine proteins identified in nodule fluid were strongly dominated by antimicrobial proteins, especially cathelicidins. This first high-throughput analysis of an Onchocerca spp

  8. Lymphatic Vascularisation and Involvement of Lyve-1+ Macrophages in the Human Onchocerca Nodule

    PubMed Central

    Attout, Tarik; Hoerauf, Achim; Dénécé, Gaëlle; Debrah, Alexander Yaw; Marfo-Debrekyei, Yeboah; Boussinesq, Michel; Wanji, Samuel; Martinez, Valérie; Mand, Sabine; Adjei, Ohene; Bain, Odile

    2009-01-01

    Onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is a parasitic disease leading to debilitating skin disease and blindness, with major economic and social consequences. The pathology of onchocerciasis is principally considered to be a consequence of long-standing host inflammatory responses. In onchocerciasis a subcutaneous nodule is formed around the female worms, the core of which is a dense infiltrate of inflammatory cells in which microfilariae are released. It has been established that the formation of nodules is associated with angiogenesis. In this study, we show using specific markers of endothelium (CD31) and lymphatic endothelial cells (Lyve-1, Podoplanin) that not only angiogenesis but also lymphangiogenesis occurs within the nodule. 7% of the microfilariae could be found within the lymphatics, but none within blood vessels in these nodules, suggesting a possible route of migration for the larvae. The neovascularisation was associated with a particular pattern of angio/lymphangiogenic factors in nodules of onchocerciasis patients, characterized by the expression of CXCL12, CXCR4, VEGF-C, Angiopoietin-1 and Angiopoietin-2. Interestingly, a proportion of macrophages were found to be positive for Lyve-1 and some were integrated into the endothelium of the lymphatic vessels, revealing their plasticity in the nodular micro-environment. These results indicate that lymphatic as well as blood vascularization is induced around O. volvulus worms, either by the parasite itself, e.g. by the release of angiogenic and lymphangiogenic factors, or by consecutive host immune responses. PMID:20011036

  9. Lymphatic vascularisation and involvement of Lyve-1+ macrophages in the human onchocerca nodule.

    PubMed

    Attout, Tarik; Hoerauf, Achim; Dénécé, Gaëlle; Debrah, Alexander Yaw; Marfo-Debrekyei, Yeboah; Boussinesq, Michel; Wanji, Samuel; Martinez, Valérie; Mand, Sabine; Adjei, Ohene; Bain, Odile; Specht, Sabine; Martin, Coralie

    2009-12-09

    Onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is a parasitic disease leading to debilitating skin disease and blindness, with major economic and social consequences. The pathology of onchocerciasis is principally considered to be a consequence of long-standing host inflammatory responses. In onchocerciasis a subcutaneous nodule is formed around the female worms, the core of which is a dense infiltrate of inflammatory cells in which microfilariae are released. It has been established that the formation of nodules is associated with angiogenesis. In this study, we show using specific markers of endothelium (CD31) and lymphatic endothelial cells (Lyve-1, Podoplanin) that not only angiogenesis but also lymphangiogenesis occurs within the nodule. 7% of the microfilariae could be found within the lymphatics, but none within blood vessels in these nodules, suggesting a possible route of migration for the larvae. The neovascularisation was associated with a particular pattern of angio/lymphangiogenic factors in nodules of onchocerciasis patients, characterized by the expression of CXCL12, CXCR4, VEGF-C, Angiopoietin-1 and Angiopoietin-2. Interestingly, a proportion of macrophages were found to be positive for Lyve-1 and some were integrated into the endothelium of the lymphatic vessels, revealing their plasticity in the nodular micro-environment. These results indicate that lymphatic as well as blood vascularization is induced around O. volvulus worms, either by the parasite itself, e.g. by the release of angiogenic and lymphangiogenic factors, or by consecutive host immune responses.

  10. Sigmoid Volvulus Complicating Postpartum Period

    PubMed Central

    Blake, Erin; Gonzalez, Eduardo; Pieracci, Frederic

    2017-01-01

    Background. Sigmoid volvulus is a rare complication of pregnancy and the puerperium. Case. A 19-year-old patient, gravida 1 para 0 at 41 0/7 weeks of gestation, admitted for late-term induction of labor underwent an uncomplicated primary low transverse cesarean delivery for arrest of descent. Her postoperative period was complicated by sudden onset of abdominal pain and the ultimate diagnosis of sigmoid volvulus. Conclusion. Prompt surgical evaluation of an acute abdomen in the postpartum period is essential; delayed diagnosis and treatment can lead to significant maternal morbidity and mortality. PMID:28251004

  11. Anti-Onchocerca activity and phytochemical analysis of an essential oil from Cyperus articulatus L.

    PubMed

    Metuge, Jonathan Alunge; Nyongbela, Kennedy D; Mbah, James A; Samje, Moses; Fotso, Ghislain; Babiaka, Smith B; Cho-Ngwa, Fidelis

    2014-07-07

    The lack of a safe and effective adult worm drug and the emergence of resistant animal parasite strains to the only recommended drug, the microfilaricide, ivermectin put many at risk of the devastating effects of the onchocerciasis. The present study was undertaken to investigate the acclaimed anti-Onchocerca activity of the roots/rhizomes of Cyperus articulatus in the traditional treatment of onchocerciasis in North Western Cameroon and to assess the plant as a new source of potential filaricidal lead compounds. Crude extracts were prepared from the dried plant parts using hexane, methylene chloride and methanol. The antifilarial activity was evaluated in vitro on microfilariae (Mfs) and adult worms of the bovine derived Onchocerca ochengi, a close relative of Onchocerca volvulus. The viabilities of microfilariae and adult male worms were determined based on motility reduction, while for the adult female worms the viability was based on the standard MTT/formazan assay. Cytotoxicity of the active extract was assessed on monkey kidney epithelial cells in vitro and the selectivity indices (SI) were determined. Acute toxicity of the promising extract was investigated in mice. Chemical composition of the active extract was unraveled by GC/MS analysis. Only the hexane extract, an essential oil exhibited anti-Onchocerca activity. The oil killed both the microfilariae and adult worms of O. ochengi in a dose manner dependently, with IC50s of 23.4 μg/ml on the Mfs, 23.4 μg/ml on adult male worms and 31.25 μg/ml on the adult female worms. Selectivity indices were 4, 4, and 2.99 for Mfs, adult males and adult females, respectively. At a single limit dose of 2000 mg/kg body weight, none of 6 mice that received the essential oil by gavage died. GC/MS analysis revealed the presence of terpenoids, hydrocarbons and fatty acids or fatty acid derivatives as components of the oil. The essential oil from the roots/rhizomes of Cyperus articulatus is active against O. ochengi

  12. Undiagnosed hypothyroidism presenting with sigmoid volvulus

    PubMed Central

    Meytes, Vadim; Schulberg, Steven P.; Morin, Nicholas; Glinik, Galina

    2016-01-01

    The incidence of hypothyroidism presenting with sigmoid volvulus, a phenomenon known as myxedema pseudovolvulus, is exceedingly rare. A male in his late thirties presented to our institution with a chief complaint of abdominal pain. The patient underwent CT scan, which was consistent with massive colonic dilatation with sigmoid volvulus. He was taken to the operating room for exploration and was found to have sigmoid volvulus and underwent a segmental resection. Postoperatively, the patient was newly diagnosed with severe hypothyroidism. PMID:27106615

  13. Effect of single-dose ivermectin therapy on human Onchocerca volvulus infection with onchocercal ocular involvement.

    PubMed Central

    Newland, H S; White, A T; Greene, B M; D'Anna, S A; Keyvan-Larijani, E; Aziz, M A; Williams, P N; Taylor, H R

    1988-01-01

    Ivermectin has shown promise as a potentially safe and effective microfilaricidal drug for the treatment of onchocerciasis. Several limited studies have shown it to have fewer side effects, especially ocular complications, than the currently available drug, diethylcarbamazine. The detailed ocular findings in 200 moderately to heavily infected Liberians who were enrolled in a safety and dose-finding study are presented. They received either 0, 100, 150, or 200 micrograms/kg of ivermectin and were followed up for 12 months. In clinical studies so far carried out ivermectin in a dose of 100, 150, or 200 micrograms/kg has not been associated with any major adverse reactions nor were there any sight-threatening effects even in the presence of severe ocular disease. Each of these doses significantly reduced the ocular microfilaria load for at least 12 months when compared with either the placebo (p less than 0.05) or pretreatment values (p less than 0.001). However, the 100 and 150 micrograms/kg doses caused fewer minor side effects than the higher dose. These results confirm that ivermectin in a single oral dose may be a safe and effective microfilaricidal drug for the treatment of onchocerciasis and that it appears to be free of major ocular side effects. Images PMID:3046657

  14. Effect of single-dose ivermectin therapy on human Onchocerca volvulus infection with onchocercal ocular involvement.

    PubMed

    Newland, H S; White, A T; Greene, B M; D'Anna, S A; Keyvan-Larijani, E; Aziz, M A; Williams, P N; Taylor, H R

    1988-08-01

    Ivermectin has shown promise as a potentially safe and effective microfilaricidal drug for the treatment of onchocerciasis. Several limited studies have shown it to have fewer side effects, especially ocular complications, than the currently available drug, diethylcarbamazine. The detailed ocular findings in 200 moderately to heavily infected Liberians who were enrolled in a safety and dose-finding study are presented. They received either 0, 100, 150, or 200 micrograms/kg of ivermectin and were followed up for 12 months. In clinical studies so far carried out ivermectin in a dose of 100, 150, or 200 micrograms/kg has not been associated with any major adverse reactions nor were there any sight-threatening effects even in the presence of severe ocular disease. Each of these doses significantly reduced the ocular microfilaria load for at least 12 months when compared with either the placebo (p less than 0.05) or pretreatment values (p less than 0.001). However, the 100 and 150 micrograms/kg doses caused fewer minor side effects than the higher dose. These results confirm that ivermectin in a single oral dose may be a safe and effective microfilaricidal drug for the treatment of onchocerciasis and that it appears to be free of major ocular side effects.

  15. Interruption of Transmission of Onchocerca volvulus in the Oaxaca Focus, Mexico

    PubMed Central

    Rodríguez-Pérez, Mario A.; Unnasch, Thomas R.; Domínguez-Vázquez, Alfredo; Morales-Castro, Alba L.; Peña-Flores, Graciela P.; Orozco-Algarra, María E.; Arredondo-Jiménez, Juan I.; Richards, Frank; Vásquez-Rodríguez, Miguel A.; Rendón, Vidal García

    2010-01-01

    All endemic communities of the Oaxaca focus of onchocerciasis in southern Mexico have been treated annually or semi-annually with ivermectin since 1994. In-depth epidemiologic assessments were performed in communities during 2007 and 2008. None of the 52,632 Simulium ochraceum s.l. collected in four sentinel communities was found to contain parasite DNA when tested by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), resulting in an upper bound of the infection rate in the vectors of 0.07/2,000. The prevalence of microfilariae (mf) in the cornea and/or anterior chamber of the eye was also zero (0 of 1,039 residents examined; 95%-UL = 0.35%). Similarly, all 1,164 individuals examined by skin biopsy were mf negative (95%-UL = 0.31%), and sera collected from 3,569 children from 25 communities did not harbor Ov16 IgG4-antibodies (95%-UL = 0.09%). These meet the criteria for absence of morbidity and parasite transmission in the Oaxaca focus. As a result mass treatments with ivermectin were halted in 2009. PMID:20595472

  16. Model-Based Geostatistical Mapping of the Prevalence of Onchocerca volvulus in West Africa

    PubMed Central

    O’Hanlon, Simon J.; Slater, Hannah C.; Cheke, Robert A.; Boatin, Boakye A.; Coffeng, Luc E.; Pion, Sébastien D. S.; Boussinesq, Michel; Zouré, Honorat G. M.; Stolk, Wilma A.; Basáñez, María-Gloria

    2016-01-01

    Background The initial endemicity (pre-control prevalence) of onchocerciasis has been shown to be an important determinant of the feasibility of elimination by mass ivermectin distribution. We present the first geostatistical map of microfilarial prevalence in the former Onchocerciasis Control Programme in West Africa (OCP) before commencement of antivectorial and antiparasitic interventions. Methods and Findings Pre-control microfilarial prevalence data from 737 villages across the 11 constituent countries in the OCP epidemiological database were used as ground-truth data. These 737 data points, plus a set of statistically selected environmental covariates, were used in a Bayesian model-based geostatistical (B-MBG) approach to generate a continuous surface (at pixel resolution of 5 km x 5km) of microfilarial prevalence in West Africa prior to the commencement of the OCP. Uncertainty in model predictions was measured using a suite of validation statistics, performed on bootstrap samples of held-out validation data. The mean Pearson’s correlation between observed and estimated prevalence at validation locations was 0.693; the mean prediction error (average difference between observed and estimated values) was 0.77%, and the mean absolute prediction error (average magnitude of difference between observed and estimated values) was 12.2%. Within OCP boundaries, 17.8 million people were deemed to have been at risk, 7.55 million to have been infected, and mean microfilarial prevalence to have been 45% (range: 2–90%) in 1975. Conclusions and Significance This is the first map of initial onchocerciasis prevalence in West Africa using B-MBG. Important environmental predictors of infection prevalence were identified and used in a model out-performing those without spatial random effects or environmental covariates. Results may be compared with recent epidemiological mapping efforts to find areas of persisting transmission. These methods may be extended to areas where data are sparse, and may be used to help inform the feasibility of elimination with current and novel tools. PMID:26771545

  17. Interruption of transmission of Onchocerca volvulus in the Oaxaca focus, Mexico.

    PubMed

    Rodríguez-Pérez, Mario A; Unnasch, Thomas R; Domínguez-Vázquez, Alfredo; Morales-Castro, Alba L; Peña-Flores, Graciela P; Orozco-Algarra, María E; Arredondo-Jiménez, Juan I; Richards, Frank; Vásquez-Rodríguez, Miguel A; Rendón, Vidal García

    2010-07-01

    All endemic communities of the Oaxaca focus of onchocerciasis in southern Mexico have been treated annually or semi-annually with ivermectin since 1994. In-depth epidemiologic assessments were performed in communities during 2007 and 2008. None of the 52,632 Simulium ochraceum s.l. collected in four sentinel communities was found to contain parasite DNA when tested by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), resulting in an upper bound of the infection rate in the vectors of 0.07/2,000. The prevalence of microfilariae (mf) in the cornea and/or anterior chamber of the eye was also zero (0 of 1,039 residents examined; 95%-UL = 0.35%). Similarly, all 1,164 individuals examined by skin biopsy were mf negative (95%-UL = 0.31%), and sera collected from 3,569 children from 25 communities did not harbor Ov16 IgG4-antibodies (95%-UL = 0.09%). These meet the criteria for absence of morbidity and parasite transmission in the Oaxaca focus. As a result mass treatments with ivermectin were halted in 2009.

  18. Effect of diethylcarbamazine on the concentration of Onchocerca volvulus microfilariae in hydrocoele fluid and urine.

    PubMed

    Kale, O O

    1979-06-01

    The effect of graded doses of diethylcarbamazine on the concentration of microfilariae in the hydrocoele fluid, urine and skin of patients suffering from onchocerciasis was studied. The results showed that a significant number of microfilariae migrated into hydrocoele fluid and urine immediately after the drug was given and thereafter returned to pre-treatment levels rather more quickly in the former than the latter. The increase was found to be roughly directly proportional to the intensity of infection in the skin. By contrast the skin concentration of microfilariae fell sharply after treatment and remained significantly lower than pre-treatment levels for over four weeks. The potential use to which these observations could be put with respect to clinical screening of drugs in onchocerciasis is discussed.

  19. Chronic mesenteric volvulus in a dog

    PubMed Central

    Spevakow, Andrea B.; Nibblett, Belle Marie D.; Carr, Anthony P.; Linn, Kathleen A.

    2010-01-01

    A chronic, partial mesenteric volvulus was found on laparotomy of an adult Bernese mountain dog with a 4-month history of intermittent vomiting, diarrhea, and weight loss. The dog had elevated cholestatic and hepatocellular leakage enzymes, increased bile acids, azotemia, isosthenuria, and a hypokalemic, hypochloremic, metabolic alkalosis. The dog recovered fully following reduction of the volvulus. PMID:20357947

  20. An interesting rare case of double volvulus.

    PubMed

    Chittal, R; Harris, D; Patel, A; Goodyear, S; Parkianathan, V

    2011-02-23

    A 71-year-old female presented with recurrent sigmoid volvulus. In the current admission, her symptoms were not settling on conservative measures and subsequently went on to have laparotomy. During laparotomy, along with the sigmoid volvulus, there was associated gallbladder torsion. About 500 cases of gallbladder volvulus have been published in literature, however, in our literature search, the authors did not find any similar published case presenting with volvulus involving the gallbladder and the sigmoid colon at the same time. This patient went onto have cholecystectomy and sigmoid colectomy and had a good postoperative recovery and was discharged on the tenth postoperative day. At 6-week postoperative follow-up, she was doing well with no specific concerns.

  1. Cytoprotective agents in experimental small bowel volvulus.

    PubMed

    Goldman, C D; Rudloff, M A; Ternberg, J L

    1987-03-01

    An accepted experimental model for midgut volvulus was used to produce small bowel strangulation obstruction of 48 hours duration in Sprague-Dawley rats. A 93% perioperative mortality rate resulted after release of the volvulus. Treatment with three cytoprotective agents at the time of volvulus release resulted in the following mortality rates: superoxide dismutase, 89%; ibuprofen, 50%; prostaglandin E1 (PGE1, 11%. The predominant cause of death in all treatment groups was bowel infarction, with a smaller number succumbing to either sepsis or circulatory collapse. Concomitant administration of ephedrine or indomethacin to suppress prostaglandin E1's splanchnic vasodilatory activity did not cause any increase in mortality. A trial of aspirin, to simulate PGE's antiplatelet actions, showed no reduction in mortality when compared with detorsion alone. Prostaglandin E1 and, to a lesser extent, ibuprofen, appear to have cytoprotective effects during reperfusion of bowel compromised by volvulus, independent of their influence on the mesenteric vasculature and thrombogenesis.

  2. Serum Potassium Levels in Sigmoid Volvulus

    PubMed Central

    Atamanalp, S. Selcuk; Keles, M. Sait; Aydinli, Bulent

    2009-01-01

    Objective: This study aimed to determine the serum potassium concentrations in patients with sigmoid volvulus (SV), which is a rare large bowel obstruction. Materials and Methods: The records of 86 patients with SV were reviewed retrospectively, while the records of 41 patients diagnosed with obstructive rectosigmoid cancer (ORC) were considered as the control group and as such, served as a source for comparison. Results: The analysis revealed a mean serum potassium concentration of 3.9 ± 0.6 mEq/L for the patients with SV, while the mean potassium concentration was 3.9 ± 0.5 mEq/L for the patients diagnosed with ORC (t:0.1, P>0.05). The number of hypokalemic and hyperkalemic patients identified in this study sample were 11 versus 5 patients and 1 versus 0 patients, respectively for the SV and ORC groups (x2 = 0.1 and 0.5, respectively with a P>0.05). Conclusions: No cause-and-effect relationship was observed between the serum potassium concentrations and SV. The serum potassium concentration is not pathognomonic for SV. PMID:25610090

  3. Intestinal obstruction from midgut volvulus after laparoscopic appendectomy.

    PubMed

    Cuadra, S A; Khalife, M E; Char, D J; Wax, M R; Halpern, D

    2002-01-01

    We present the case of a 30-year-old man who developed a small bowel obstruction from an acute midgut volvulus 8 days after undergoing a laparoscopic appendectomy. There was no evidence of congenital malrotation or midgut volvulus on the initial computed tomography (CT) scan or at laparoscopy. Subsequently, a midgut volvulus developed in the absence of congenital malrotation.

  4. Wandering spleen with volvulus of pancreas.

    PubMed

    Karaosmanoglu, Ali Devrim; Onur, Mehmet Ruhi; Karcaaltıncaba, Musturay

    2015-07-01

    Abnormal location of the spleen, which is called wandering spleen, results from laxity or absence of the splenic pedicle. In the presence of an elongated splenic pedicle, torsion of the spleen or neighboring organs may occur, which results in acute or chronic abdominal pain. In this case report, we present imaging findings of a wandering spleen that manifested with volvulus of the pancreas.

  5. Malrotation and volvulus associated with heterotaxy syndrome

    PubMed Central

    Mahalik, Santosh K.; Khanna, Sanat; Menon, Prema

    2012-01-01

    A 2-year-old boy with heterotaxy syndrome with associated polysplenia, ventricular septal defect, and malrotation of gut with volvulus is presented. There was delay in diagnosis due to the unusual plain abdominal radiography findings. At laparotomy, the midgut was also found to be enclosed in a thin transparent cocoon. PMID:22869985

  6. Rare case of pediatric cecal volvulus

    PubMed Central

    Mansoor, Khizer; Al Hamidi, Sa'ad; Khan, Abdul Mannan; Samujh, Ram

    2009-01-01

    An 11-year-old female child presented with abdominal pain, vomiting and constipation. An exploratory laparotomy revealed a cecal volvulus due to a congenital band and malfixation of the cecum. This was treated by excision of the band, derotation and decompression of cecum though an appendiceal stump suction. PMID:20376252

  7. Difficulties in diagnosing an intermittent mesenteroaxial gastric volvulus

    PubMed Central

    Kang, David J.; D'Alessio, Matthew; Pan, Andrew S.; Jaffe, Victor A.

    2013-01-01

    Mesenteroaxial volvulus is a form of gastric volvulus that rotates around the short axis of the stomach. Mesenteroaxial volvulus typically presents secondary to an anatomical defect with symptoms that include epigastric pain, retching, dysphagia and early satiety. Our patient presented with episodic abdominal pain, nausea and vomiting for 2 years. Previous imaging was unremarkable but an esophagogastroduodenoscopy done when the patient most recently presented with abdominal pain revealed a mesenteroaxial volvulus. He underwent a laparoscopic gastrostomy-tube gastropexy and has not had any recurrence of his symptoms to date. This case illustrates the difficulties in diagnosing an intermittent volvulus as untimely imaging of a temporarily unfolded volvulus can delay diagnosis and treatment. PMID:24964322

  8. Findings of cecal volvulus at CT.

    PubMed

    Rosenblat, Juliana M; Rozenblit, Alla M; Wolf, Ellen L; DuBrow, Ronelle A; Den, Elana I; Levsky, Jeffrey M

    2010-07-01

    To assess the diagnostic performance of computed tomographic (CT) and radiographic (as seen on CT topograms) signs of cecal volvulus. In this institutional review board-approved, HIPAA-compliant retrospective study, the CT and CT topogram findings in 11 patients (one man, 10 women; age range, 26-100 years) with surgically confirmed cecal volvulus and 12 control patients were reviewed. The control subjects had suspicious radiographs, had undergone CT within 24 hours of radiography, and had received a clinical diagnosis other than cecal volvulus. Three radiologists independently evaluated the CT topograms for cecal distention, the coffee bean sign, cecal apex location, and distal colon decompression. CT images were analyzed for cecal distention, cecal apex location, distal colon decompression, and presence or absence of the whirl, ileocecal twist, transition point(s), the X-marks-the-spot, and the split wall. Sensitivity, specificity, and predictive values were computed. Baseline statistical values for the cecal volvulus and control groups were analyzed by using a two-tailed Z test to compare proportions with a threshold confidence interval of 95%. CT findings of bowel ischemia (free air or fluid, pneumatosis intestinalis, portal venous gas, mesenteric stranding) were correlated with pathology report findings. On CT topograms, greater than 10-cm cecal distention, coffee bean sign, and left upper quadrant cecal apex had sensitivities of 45% (five of 11 patients), 27% (three of 11 patients), and 45% (five of 11 patients), respectively, and specificities of 100% (12 of 12 control subjects), 92% (11 of 12 control subjects), and 100% (12 of 12 control subjects), respectively. Distal colon decompression had sensitivities and specificities of 91% (10 of 11 patients) and 83% (10 of 12 control subject), respectively, on topograms and of 91% (10 of 11 patients) and 92% (11 of 12 patients), respectively, on CT images. On cross-sectional CT images, greater than 10-cm cecal

  9. Gastric Volvulus Following Left Pneumonectomy in an Adolescent Patient

    PubMed Central

    Farber, Benjamin A.; Lim, Irene Isabel P.; Murphy, Jennifer M.; Price, Anita P.; Abramson, Sara J.; La Quaglia, Michael P.

    2015-01-01

    Gastric volvulus is a rare post-pneumonectomy complication. Although it has been described previously, published cases are limited to an older patient population. We report the youngest case of postpneumonectomy gastric volvulus to date, occurring in an 18-year-old male with a history of inflammatory myofibroblastic pseudotumor who underwent left intrapericardial pneumonectomy, and presented 13 years later with chronic intermittent mesenteroaxial gastric volvulus. While postpneumonectomy gastric volvulus is a rare occurrence, it should remain in the differential diagnosis in postoperative thoracic surgical patients presenting with chest pain. PMID:26504742

  10. Seasonal Variation in Biting Rates of Simulium damnosum sensu lato, Vector of Onchocerca volvulus, in Two Sudanese Foci

    PubMed Central

    Zarroug, Isam M. A.; Hashim, Kamal; Elaagip, Arwa H.; Samy, Abdallah M.; Frah, Ehab A.; ElMubarak, Wigdan A.; Mohamed, Hanan A.; Deran, Tong Chor M.; Aziz, Nabil; Higazi, Tarig B.

    2016-01-01

    Background The abundance of onchocerciasis vectors affects the epidemiology of disease in Sudan, therefore, studies of vector dynamics are crucial for onchocerciasis control/elimination programs. This study aims to compare the relative abundance, monthly biting-rates (MBR) and hourly-based distribution of onchocerciasis vectors in Abu-Hamed and Galabat foci. These seasonally-based factors can be used to structure vector control efforts to reduce fly-biting rates as a component of onchocerciasis elimination programs. Methods A cross-sectional study was conducted in four endemic villages in Abu-Hamed and Galabat foci during two non-consecutive years (2007–2008 and 2009–2010). Both adults and aquatic stages of the potential onchocerciasis vector Simulium damnosum sensu lato were collected following standard procedures during wet and dry seasons. Adult flies were collected using human landing capture for 5 days/month. The data was recorded on handheld data collection sheets to calculate the relative abundance, MBR, and hourly-based distribution associated with climatic factors. The data analysis was carried out using ANOVA and Spearman rank correlation tests. Results Data on vector surveillance revealed higher relative abundance of S. damnosum s.l. in Abu- Hamed (39,934 flies) than Galabat (8,202 flies). In Abu-Hamed, vector populations increased in January-April then declined in June-July until they disappeared in August-October. Highest black fly density and MBR were found in March 2007 (N = 9,444, MBR = 58,552.8 bites/person/month), and March 2010 (N = 2,603, MBR = 16,138.6 bites/person/month) while none of flies were collected in August-October (MBR = 0 bites/person/month). In Galabat, vectors increased in September-December, then decreased in February-June. The highest vector density and MBR were recorded in September 2007 (N = 1,138, MBR = 6,828 bites/person/month) and September 2010 (N = 1,163, MBR = 6,978 bites/person/month), whereas, none appeared in collection from April to June. There was a significant difference in mean monthly density of S. damnosum s.l. across the two foci in 2007–2008 (df = 3, F = 3.91, P = 0.011). Minimum temperature showed significant correlation with adult flies counts in four areas sampled; the adult counts were increased in Nady village (rs = 0.799) and were decreased in Kalasecal (rs = - 0.676), Gumaiza (rs = - 0.585), and Hilat Khateir (rs = - 0.496). Maximum temperature showed positive correlation with black fly counts only in Galabat focus. Precipitation was significantly correlated with adult flies counts in Nady village, Abu-Hamed, but no significance was found in the rest of the sampled villages in both foci. Hourly-based distribution of black flies showed a unimodal pattern in Abu-Hamed with one peak (10:00–18:00), while a bimodal pattern with two peaks (07:00–10:00) and (14:00–18:00) was exhibited in Galabat. Conclusion Transmission of onchocerciasis in both foci showed marked differences in seasonality, which may be attributed to ecology, microclimate and proximity of breeding sites to collection sites. The seasonal shifts between the two foci might be related to variations in climate zones. This information on black fly vector seasonality, ecology, distribution and biting activity has obvious implications in monitoring transmission levels to guide the national and regional onchocerciasis elimination programs in Sudan. PMID:26943668

  11. Seasonal Variation in Biting Rates of Simulium damnosum sensu lato, Vector of Onchocerca volvulus, in Two Sudanese Foci.

    PubMed

    Zarroug, Isam M A; Hashim, Kamal; Elaagip, Arwa H; Samy, Abdallah M; Frah, Ehab A; ElMubarak, Wigdan A; Mohamed, Hanan A; Deran, Tong Chor M; Aziz, Nabil; Higazi, Tarig B

    2016-01-01

    The abundance of onchocerciasis vectors affects the epidemiology of disease in Sudan, therefore, studies of vector dynamics are crucial for onchocerciasis control/elimination programs. This study aims to compare the relative abundance, monthly biting-rates (MBR) and hourly-based distribution of onchocerciasis vectors in Abu-Hamed and Galabat foci. These seasonally-based factors can be used to structure vector control efforts to reduce fly-biting rates as a component of onchocerciasis elimination programs. A cross-sectional study was conducted in four endemic villages in Abu-Hamed and Galabat foci during two non-consecutive years (2007-2008 and 2009-2010). Both adults and aquatic stages of the potential onchocerciasis vector Simulium damnosum sensu lato were collected following standard procedures during wet and dry seasons. Adult flies were collected using human landing capture for 5 days/month. The data was recorded on handheld data collection sheets to calculate the relative abundance, MBR, and hourly-based distribution associated with climatic factors. The data analysis was carried out using ANOVA and Spearman rank correlation tests. Data on vector surveillance revealed higher relative abundance of S. damnosum s.l. in Abu- Hamed (39,934 flies) than Galabat (8,202 flies). In Abu-Hamed, vector populations increased in January-April then declined in June-July until they disappeared in August-October. Highest black fly density and MBR were found in March 2007 (N = 9,444, MBR = 58,552.8 bites/person/month), and March 2010 (N = 2,603, MBR = 16,138.6 bites/person/month) while none of flies were collected in August-October (MBR = 0 bites/person/month). In Galabat, vectors increased in September-December, then decreased in February-June. The highest vector density and MBR were recorded in September 2007 (N = 1,138, MBR = 6,828 bites/person/month) and September 2010 (N = 1,163, MBR = 6,978 bites/person/month), whereas, none appeared in collection from April to June. There was a significant difference in mean monthly density of S. damnosum s.l. across the two foci in 2007-2008 (df = 3, F = 3.91, P = 0.011). Minimum temperature showed significant correlation with adult flies counts in four areas sampled; the adult counts were increased in Nady village (rs = 0.799) and were decreased in Kalasecal (rs = -0.676), Gumaiza (rs = -0.585), and Hilat Khateir (rs = -0.496). Maximum temperature showed positive correlation with black fly counts only in Galabat focus. Precipitation was significantly correlated with adult flies counts in Nady village, Abu-Hamed, but no significance was found in the rest of the sampled villages in both foci. Hourly-based distribution of black flies showed a unimodal pattern in Abu-Hamed with one peak (10:00-18:00), while a bimodal pattern with two peaks (07:00-10:00) and (14:00-18:00) was exhibited in Galabat. Transmission of onchocerciasis in both foci showed marked differences in seasonality, which may be attributed to ecology, microclimate and proximity of breeding sites to collection sites. The seasonal shifts between the two foci might be related to variations in climate zones. This information on black fly vector seasonality, ecology, distribution and biting activity has obvious implications in monitoring transmission levels to guide the national and regional onchocerciasis elimination programs in Sudan.

  12. Small bowel volvulus diagnosed by the CT "whirl sign".

    PubMed

    de Korte, Niels; Grutters, Cornelis T; Snellen, Jacob P

    2008-08-01

    A 24-year-old man presented to the emergency department with acute onset, colicky, abdominal pain. A CT scan showed the "whirl sign" diagnostic of small bowel volvulus. Diagnosis of a small bowel volvulus can be challenging, and CT scan is the imaging modality of choice.

  13. In vitro radiolabel uptake viability assay for Onchocerca microfilariae

    SciTech Connect

    Callahan, H.L.; Wakeman, J.M.; Crouch, R.K.; James, E.R.

    1989-02-01

    A radiolabel uptake viability assay for Onchocerca cervicalis using (/sup 3/H)2-deoxy-D-glucose in Hanks' balanced salt solution, pH 7.5, at 30 C is described and compared to the traditional visual motility assay. A correlation of r = 0.92 between the assays was found, with the radiolabel uptake method apparently a more sensitive indicator of microfilarial viability.

  14. Colon cancer presented with sigmoid volvulus: A case report

    PubMed Central

    Aras, Abbas; Kızıltan, Remzi; Batur, Abdussamet; Çelik, Sebahattin; Yılmaz, Özkan; Kotan, Çetin

    2015-01-01

    Introduction Sigmoid volvulus is the most prevalent type of colonic volvulus. Colon cancer is seen less where sigmoid volvulus is common, so it is rare to see that colon cancer is synchronous with sigmoid volvulus. Presentation of case We would like to present a case of sigmoid volvulus caused by colon cancer in a male patient aged 80 who was referred to the hospital with toxaemic shock presentation. Discussion Sigmoid cancer can be presented as sigmoid volvulus to the emergency department. In intestinal obstruction early diagnosis is of crucial importance. Computarized tomography is a diagnosis tool that should be preferred both in the diagnosis of obstruction and in detecting its cause, localisation, degree and complications. Conclusion When surgery is performed due to the urgent colonic obstruction in colonic volvulus diagnosed patients, a colon tumour should be considered in the same column loops or in the distal colon. We believe that CT is the method that should be preferred in large-bowel obstruction suspected patients. PMID:26519810

  15. First description of Onchocerca jakutensis (Nematoda: Filarioidea) in red deer (Cervus elaphus) in Switzerland.

    PubMed

    Bosch, Felix; Manzanell, Ralph; Mathis, Alexander

    2016-08-01

    Twenty-seven species of the genus Onchocerca (Nematoda; Filarioidea) can cause a vector-borne parasitic disease called onchocercosis. Most Onchocerca species infect wild and domestic ungulates or the dog, and one species causes river blindness in humans mainly in tropical Africa. The European red deer (Cervus e. elaphus) is host to four species, which are transmitted by blackflies (simuliids) or biting midges (ceratopogonids). Two species, Onchocerca flexuosa and Onchocerca jakutensis, produce subcutaneous nodules, whereas Onchocerca skrjabini and Onchocerca garmsi live free in the hypodermal serous membranes. During the hunting season, September 2013, red deer (n = 25), roe deer (Capreolus c. capreolus, n = 6) and chamois (Rupicapra r. rupicapra, n = 7), all shot in the Grisons Region (Switzerland) were investigated for the presence of subcutaneous nodules which were enzymatically digested, and the contained Onchocerca worms were identified to species by light and scanning electron microscopy as well as by PCR/sequencing. In addition, microfilariae from skin samples were collected and genetically characterized. Neither nodules nor microfilariae were discovered in the roe deer and chamois. Adult worms were found in 24% of red deer, and all of them were identified as O. jakutensis. Two morphologically different microfilariae were obtained from five red deer, and genetic analysis of a skin sample of one red deer indicated the presence of another Onchocerca species. This is the first report of O. jakutensis in Switzerland with a prevalence in red deer similar to that in neighbouring Germany.

  16. Delayed diaphragmatic rupture presenting with acute gastric volvulus

    PubMed Central

    Macleod, R; Hollowood, A

    2014-01-01

    Gastric volvulus is a rare complication of diaphragmatic rupture. We report the case of an 82-year-old man who presented following an out-of-hospital cardiac arrest. Chest radiography and thoracic computed tomography revealed an acute gastric volvulus and a chronic diaphragmatic hernia containing transverse colon and abdominal viscera. He had complained of retching and associated epigastric pain prior to collapse, and had sustained a motorcycle accident approximately 60 years earlier. Insertion of a nasogastric tube was unsuccessful (completing Borchardt’s diagnostic triad) and his condition prevented both operative and endoscopic reduction of his volvulus. He died soon afterwards. PMID:25245717

  17. [Gallbladder volvulus: Diagnostic and surgical challenges].

    PubMed

    Abadía-Barnó, Pedro; Coll-Sastre, Magdalena; Picón-Serrano, Carmen; Sanjuanbenito-Dehesa, Alfonso; Cabañas-Montero, Jacobo

    2016-12-09

    The gallbladder volvulus is defined as the rotation of the gallbladder on its mesentery along the axis of the cystic duct and cystic artery. It is an extremely rare surgical disease and definitive diagnosis is usually made during surgery. A 78 year old woman presented with upper right quadrant abdominal pain, with no comorbidities and no other accompanying symptoms. Analysis revealed haemodynamic instability and leukocytosis. Computed tomography of abdomen showed an acute cholecystitis. During emergency right hypochondrium laparotomy, the gallbladder was found to be twisted counterclockwise with huge gangrenous gallbladder distal. Open cholecystectomy was performed and after the surgery, the patient was discharged in a few days. Gallbladder volvulus, or gallbladder torsion, is a rare condition and should be considered when clinical and imaging findings of complicated cholecystitis are present. The performance of urgent laparoscopic surgery would be first option to avoid perforation, peritonitis and haemodynamic instability. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  18. Volvulus of the liver with intrathoracic herniation

    PubMed Central

    Thomson, PM; Bohra, A

    2014-01-01

    Introduction We present a rare case of a liver volvulus, stomach and transverse colon herniating through the diaphragm. This scenario has not been reported previously. We discuss the presentation and management of this interesting case. Case history A 65-year-old woman with a history of sarcoidosis and recurrent pericardial effusions, treated previously with a subxiphoid pericardial oval window fenestration, presented with acute upper abdominal pain radiating to the chest. High contrast computed tomography showed a volvulus of the liver with consequent venous congestion, and herniation of the liver, stomach and transverse colon through an anterior diaphragmatic defect. With liver perfusion threatened, an urgent laparoscopic repair was performed. The stomach and transverse colon were reduced, and the twisted left lobe of the liver was unrotated and reduced into the abdominal cavity. A double-sided synthetic mesh was used to repair the defect. The patient made an uneventful recovery. Conclusions This is a novel complication of a patient presenting with abdominal pain with a previous history of pericardial window fenestration. A laparoscopic reduction and repair can be performed safely with excellent postoperative results. PMID:25245721

  19. Pancreatic Volvulus with Wandering Spleen and Gastric Volvulus: An Unusual Triad for Acute Abdomen in a Surgical Emergency

    PubMed Central

    Gorsi, Ujjwal; Bhatia, Anmol; Gupta, Rajesh; Bharathi, Saranga; Khandelwal, Niranjan

    2014-01-01

    Wandering spleen is a rare clinical condition which occurs due to laxity or absence of the normal intraperitoneal ligaments that hold the spleen in place. Gastric volvulus and wandering spleen share a common etiology of absence or laxity of intraperitoneal ligaments. The occurrence of simultaneous pancreatic volvulus has never been described before in adolescence. Herein, we report a case having wandering spleen with torsion, and gastric and distal pancreatic volvulus, an unusual triad in acute abdomen in an emergency setting, which has never been described before to the best of our knowledge. PMID:24976284

  20. Pancreatic volvulus with wandering spleen and gastric volvulus: an unusual triad for acute abdomen in a surgical emergency.

    PubMed

    Gorsi, Ujjwal; Bhatia, Anmol; Gupta, Rajesh; Bharathi, Saranga; Khandelwal, Niranjan

    2014-01-01

    Wandering spleen is a rare clinical condition which occurs due to laxity or absence of the normal intraperitoneal ligaments that hold the spleen in place. Gastric volvulus and wandering spleen share a common etiology of absence or laxity of intraperitoneal ligaments. The occurrence of simultaneous pancreatic volvulus has never been described before in adolescence. Herein, we report a case having wandering spleen with torsion, and gastric and distal pancreatic volvulus, an unusual triad in acute abdomen in an emergency setting, which has never been described before to the best of our knowledge.

  1. Jejunoileal perforation and volvulus caused by multiple magnet ingestion.

    PubMed

    Arslan, Serkan; Basuguy, Erol; Zeytun, Hikmet; Okur, Mehmet Hanifi; Aydogdu, Bahattin; Arslan, Mehmet Serif

    2015-03-01

    Foreign body ingestion is a common problem in children, but magnet ingestion is relatively rare. However, when it occurs, it tends to have a high rate of complications. This is a case report of a 3-year-old child who swallowed multiple magnetic toys, subsequently developing jejunoileal perforation and volvulus. This case report indicates that it is best to surgically remove multiple ingested magnets without delay to avoid intestinal perforation, fistula, and other complications such as volvulus.

  2. Image diagnosis of zoonotic onchocercosis by Onchocerca lupi.

    PubMed

    Franchini, Delia; Giannelli, Alessio; Di Paola, Giancarlo; Cortes, Helder; Cardoso, Luís; Lia, Riccardo Paolo; Campbell, Bronwyn Evelyn; Dantas-Torres, Filipe; Lenoci, Diana; Assad, Eyad Abu; Ricciardi, Mario; Valastro, Carmela; Cavaliere, Leonardo; Di Bello, Antonio; Otranto, Domenico

    2014-06-16

    Onchocerca lupi, a zoonotic nematode infecting the eyes of carnivores, has been increasingly reported in dogs from Europe and the USA. In order to improve the current status of knowledge on this neglected filarioid, diagnostic imaging tools (i.e., ultrasound scan, computed tomography and magnetic resonance imaging) are herein used to diagnose canine onchocercosis in two dogs, which scored positive for O. lupi microfilariae at the skin snip test and to assess the anatomical location of the nematode within the ocular apparatus. Results indicate that ultrasound tools are useful to address the diagnosis of O. lupi in dogs and to evaluate the localization of nodules or cysts containing the adult nematode.

  3. The management of gastric volvulus in elderly patients.

    PubMed

    Zuiki, Toru; Hosoya, Yoshinori; Lefor, Alan Kawarai; Tanaka, Hiroyuki; Komatsubara, Toshihide; Miyahara, Yuzo; Sanada, Yukihiro; Ohki, Jun; Sekiguchi, Chuji; Sata, Naohiro

    2016-01-01

    Gastric volvulus is torsion of the stomach and requires immediate treatment. The optimal treatment strategy for patients with gastric volvulus is not established, because of significant variations in the cause and clinical course of this condition. We describe our experience with six elderly patients with gastric volvulus caused by different conditions using various approaches. This includes two patients managed with endoscopic reduction, followed by endoscopic or laparoscopic gastropexy. Endoscopy is a necessary first step to determine the optimal treatment strategy, and endoscopic reduction is often effective. The indications for surgical repair of gastric volvulus depend on the patient's overall condition, and several options are available. In some elderly patients with severe comorbidities, major surgery may have an unacceptably high risk. We propose a novel treatment strategy for gastric volvulus in the elderly and a review of the literature. Early endoscopy is necessary in patients with gastric volvulus. Endoscopic or laparoscopic gastropexy may be adequate therapy in selected elderly patients. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  4. Endoscopic management of sigmoid volvulus in children

    PubMed Central

    Parolini, Filippo; Orizio, Paolo; Bulotta, Anna Lavinia; Garcia Magne, Miguel; Boroni, Giovanni; Cengia, Gianpaolo; Torri, Fabio; Alberti, Daniele

    2016-01-01

    Sigmoid volvulus (SV) is extremely uncommon in children and is usually associated with a long-standing history of constipation or pseudo-obstruction. An early diagnosis and management are crucial in order to prevent the appearance of hemorrhagic infarction of the twisted loop, avoiding further complications such as necrosis, perforation and sepsis. In patients with no evidence of peritonitis or ischemic bowel, treatment starts with resuscitation and detorsion of the SV, accomplished by means of sigmoidoscopy and concomitant rectal tube placement. The bowel is then prepared and surgery is undertaken electively during the same hospitalization. We report a detailed review of the literature focusing on technical details, risks and benefits of endoscopic management of SV in childhood. PMID:27358669

  5. Primary small bowel volvulus: cause and management.

    PubMed

    Duke, J H; Yar, M S

    1977-06-01

    Most reports of patients with primary small bowel volvulus have indicated that the ingestion of a high-bulk vegetable diet in some way contributes to the development of this condition. During a recent 13-month period at Nangarhar University Hospital at Jalalabad, Afghanistan, the frequency of occurrence among 26 patients was found to be related to abrupt changes in dietary intake. The first and last months of the study were Ramadan, the annual period in which Mohammedans abstain from all oral intake during daylight hours and take a single large meal after dark. During these two isolated months, there was a ten fold and nine fold increase, respectively, in the incidence of the condition. Early diagnosis and surgical intervention offer the only possibility for minimizing an otherwise excessive mortality.

  6. Recurrent Sigmoid Volvulus Associated With Eventration of Diaphragm in a Twenty-Six-Year-Old Man

    PubMed Central

    Prabhu, Shailesh Mukund; Venkatesan, Bhuvaneswari; Shetty, Gurucharan; Narula, Mahender Kaur; Chauhan, Udit; Udiya, Alok Kumar

    2015-01-01

    Recurrent sigmoid volvulus is a clinical entity characterized by recurrent episodes of partial or complete sigmoid volvulus. Although it is commonly seen in the elderly, it can be occasionally seen in younger patients. Patients with recurrent partial sigmoid volvulus are relatively asymptomatic or present with mild abdominal pain. Early diagnosis and treatment is essential to prevent conversion to acute gangrenous volvulus. We present a case of recurrent partial sigmoid volvulus in association with eventration of diaphragm in a 26-year-old man. PMID:25901269

  7. Occurrence of small intestinal volvulus in a terrier puppy-a case report

    PubMed Central

    Golshahi, Hannaneh; Tavasoly, Abbas; Namjoo, Abdolrasol; Bahmani, Mahmoud

    2014-01-01

    Volvulus is the torsion of an organ around its root. In dogs, volvulus of the stomach is well known, but volvulus of the small intestine is rare. A dead 3-month-old female terrier puppy was presented for postmortem examination. According to owner statements, the puppy was depressed, lethargic and had abdominal pain, abdominal distension, severe diarrhea and vomiting a few hours before death. With gross and histopathologic studies, the death of this puppy was indorsed to small intestinal volvulus, subsequent infarction, peritonitis and likely acute toxaemia and/or septicaemia. The present case is going to be the first recorded case of small intestinal volvulus in dog in Iran.

  8. Absolute constipation caused by sigmoid volvulus in a young man

    PubMed Central

    Nuevo, Sergio Pozo; Macías Robles, María Dolores; Sevillano, Ramón Delgado; Pérez-Gallarza, Susana Serrano

    2013-01-01

    We describe a challenging case of sigmoid volvulus where a previously unrecognised anatomical condition, rather than the patient's age, was the main predisposing factor. A man in his thirties presented to the emergency department with a 3-day history of constipation and acute abdominal pain. Initial assessment and studies were inconclusive, but a CT scan revealed torsion of the large bowelSigmoid volvulus is a frequent cause of bowel obstruction that can be missed if appropriate imaging is not available. Clinical presentation and blood analysis can be similar to the findings in acute abdomen caused by other more common causes. PMID:23744852

  9. [Intestinal volvulus. Case report and a literature review].

    PubMed

    Santín-Rivero, Jorge; Núñez-García, Edgar; Aguirre-García, Manuel; Hagerman-Ruiz-Galindo, Gonzalo; de la Vega-González, Francisco; Moctezuma-Velasco, Carla Rubi

    2015-01-01

    Small bowel volvulus is a rare cause of intestinal obstruction in adult patients. This disease is more common in children and its aetiology and management is different to that in adults. A 30 year-old male with sarcoidosis presents with acute abdomen and clinical data of intestinal obstruction. Small bowel volvulus is diagnosed by a contrast abdominal tomography and an exploratory laparotomy is performed with devolvulation and no intestinal resection. In the days following surgery, he developed a recurrent small bowel volvulus, which was again managed with surgery, but without intestinal resection. Medical treatment for sarcoidosis was started, and with his clinical progress being satisfactory,he was discharged to home. Making an early and correct diagnosis of small bowel volvulus prevents large intestinal resections. Many surgical procedures have been described with a high rate of complications. Therefore, conservative surgical management (no intestinal resection) is recommended as the best treatment with the lowest morbidity and mortality rate. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  10. Aggregation of equine platelets by Onchocerca cervicalis collagen.

    PubMed Central

    McConnell, L. A.; Leid, R. W.

    1983-01-01

    The arachidonic acid pathway plays an important role in many inflammatory reactions. Current evidence suggests that platelets can play a central part in host inflammation. Since microfilariae are mobilized into the bloodstream following diethylcarbamazine (DEC) treatment, we have studied the effects of Onchocerca cervicalis cuticle preparations on equine platelet aggregation. The authors have found that O cervicalis cuticular preparations can induce platelet aggregation in vitro. Furthermore, this activity was abrogated by treatment with collagenase and not hyaluronidase, elastase, or alpha-chymotrypsin. When this evidence is viewed collectively with the evidence for in vivo parasite cuticular damage following DEC treatment, it becomes entirely plausible that the cuticular damage may indeed reveal a platelet-reactive surface, thus permitting platelet-parasite binding to occur. This binding would result in platelet aggregation and the generation and release of platelet-derived arachidonate metabolites. These metabolites may play a very critical role in the development of the described pathologic sequelae observed following DEC treatment. Field studies using cyclooxygenase and lipoxygenase inhibitors might therefore be very efficacious in decreasing the frequency of side effects due to DEC or other potentially effective drug regimens. PMID:6299106

  11. A rare etiology of acute abdominal syndrome in adults: Gastric volvulus – Cases series

    PubMed Central

    Altintoprak, Fatih; Yalkin, Omer; Dikicier, Enis; Kivilcim, Taner; Arslan, Yusuf; Gunduz, Yasemin; Ozkan, Orhan Veli

    2014-01-01

    INTRODUCTION Gastric volvulus is a rare surgical emergency with a high mortality rate that requires urgent surgical management. PRESENTATION OF CASE A 19-year-old male and 51-year-old female patient underwent emergency surgery with a prediagnosis of acute abdomen syndrome, and a 60-year-old female patient underwent elective surgery due to diaphragmatic hernia. Abdominal exploration revealed gastric volvulus together with perforation in received emergency surgery patients, and a mesenteroaxial gastric volvulus due to diaphragmatic defect in third patient. DISCUSSION Gastric volvulus is classified into four subgroups depending on the mechanism of development, and organoaxial form is the most common type of gastric volvulus. The most challenging step in diagnosing gastric volvulus is the consideration of this diagnosis. CONCLUSION Preoperative diagnosis is often difficult, and its management involves surgical correction of the pathology followed by institution of resuscitative treatment. PMID:25217876

  12. Mesenteric cysts associated with recurrent small-bowel volvulus: cause or effect?

    PubMed

    Prabhu, Shailesh M; Anand, Rama; Narula, Mahender K; Shetty, Gurucharan S; Udiya, Alok K; Chauhan, Udit; Shukla, Shailaja; Grover, Jitendra Kumar

    2012-12-01

    Recurrent small-bowel volvulus is a state of recurrent intermittent or long-standing persistent twisting of small-bowel loops around its mesentery. The association of mesenteric cysts with recurrent small-bowel volvulus as the cause or effect is a much debated issue in the literature. We report two cases of mesenteric lymphangioma and one case of enteric duplication cyst seen in association with recurrent small-bowel volvulus of long duration in absence of malrotation.

  13. Gastric volvulus following diagnostic upper gastrointestinal endoscopy: a rare complication

    PubMed Central

    Karthikeyan, Vilvapathy Senguttuvan; Sistla, Sarath Chandra; Ram, Duvuru; Rajkumar, Nagarajan

    2014-01-01

    Esophagogastroduodenoscopy (EGD) is a commonly used, safe diagnostic modality for evaluation of epigastric pain and rarely its major complications include perforation, haemorrhage, dysrhythmias and death. Gastric volvulus has been reported to complicate percutaneous endoscopic gastrostomy but its occurrence after diagnostic EGD has not yet been reported in literature. The successful management relies on prompt diagnosis and gastric untwisting, decompression and gastropexy or gastrectomy in full thickness necrosis of the stomach wall. A 38-year-old woman presented with epigastric pain and EGD showed pangastritis. Immediately after EGD she developed increased severity of pain, vomiting and abdominal distension. Emergency laparotomy carried out for peritoneal signs revealed eventration of left hemidiaphragm with the stomach twisted anticlockwise in the longitudinal axis. After gastric decompression and untwisting of volvulus, anterior gastropexy and gastrostomy was carried out. Hence, we report this rare complication of diagnostic endoscopy and review the existing literature on the management. PMID:24515235

  14. Gastric dilatation and volvulus in a red panda (Ailurus fulgens).

    PubMed

    Neilsen, Colleen; Mans, Christoph; Colopy, Sara A

    2014-11-01

    To describe the successful management of gastric dilatation and volvulus (GDV) in a red panda. Clinical report. Red panda diagnosed with GDV. A 12-year-old male red panda (Ailurus fulgens) was evaluated for acute onset inappetence, staggering, collapse, and tachypnea. Gastric dilatation and volvulus (GDV) was diagnosed by radiography, abdominal ultrasonography, and exploratory celiotomy. Torsion of the stomach was corrected and an incisional gastropexy performed to prevent recurrence. No organs were devitalized, no other abnormalities detected, and the red panda recovered fully within 72 hours. GDV should be considered as a differential diagnosis for red pandas presenting with acute onset of unspecific signs such as collapse, inappetence, and abdominal distension. GDV in red pandas can be diagnosed and successfully treated as described in dogs. © Copyright 2014 by The American College of Veterinary Surgeons.

  15. Gastric Dilatation and Volvulus in a Red Panda (Ailurus fulgens)

    PubMed Central

    Neilsen, Colleen; Mans, Christoph; Colopy, Sara A.

    2014-01-01

    A 12-year-old male red panda (Ailurus fulgens) was evaluated for acute onset inappetance, staggering, collapse, and tachypnea. Gastric dilatation and volvulus (GDV) was diagnosed by radiography, abdominal ultrasonography, and exploratory celiotomy. Torsion of the stomach was corrected and an incisional gastropexy performed to prevent recurrence. No organs were devitalized, no other abnormalities detected, and the red panda recovered fully within 72 hours. PMID:24467661

  16. More patients should undergo surgery after sigmoid volvulus.

    PubMed

    Ifversen, Anne Kathrine Wewer; Kjaer, Daniel Willy

    2014-12-28

    To assess the outcome of patients treated conservatively vs surgically during their first admission for sigmoid volvulus. We conducted a retrospective study of 61 patients admitted to Aarhus University Hospital in Denmark between 1996 and 2011 for their first incidence of sigmoid volvulus. The condition was diagnosed by radiography, sigmoidoscopy or surgery. Patients treated with surgery underwent either a sigmoid resection or a percutaneous endoscopic colostomy (PEC). Conservatively treated patients were managed without surgery. Data was recorded into a Microsoft Access database and calculations were performed with Microsoft Excel. Kaplan-Meier plotting and Mantel-Cox (log-rank) testing were performed using GraphPad Prism software. Mortality was defined as death within 30 d after intervention or surgery. Among the total 61 patients, 4 underwent emergency surgery, 55 underwent endoscopy, 1 experienced resolution of the volvulus after contrast enema, and 1 died without treatment because of large bowel perforation. Following emergency treatment, 28 patients underwent sigmoid resection (semi-elective n = 18; elective n = 10). Two patients who were unfit for surgery underwent PEC and both died, 1 after 36 d and the other after 9 mo, respectively. The remaining 26 patients were managed conservatively without sigmoid resection. Patients treated conservatively on their first admission had a poorer survival rate than patients treated surgically on their first admission (95%CI: 3.67-14.37, P = 0.036). Sixty-three percent of the 26 conservatively treated patients had not experienced a recurrence 3 mo after treatment, but that number dropped to 24% 2 years after treatment. Eight of the 14 patients with recurrence after conservative treatment had surgery with no 30-d mortality. Surgically-treated sigmoid volvulus patients had a higher long-term survival rate than conservatively managed patients, indicating a benefit of surgical resection or PEC insertion if feasible.

  17. Gastric volvulus through morgagni hernia: an easily overlooked emergency.

    PubMed

    Sonthalia, Nikhil; Ray, Sayantan; Khanra, Dibbendhu; Saha, Avishek; Maitra, Subhasis; Saha, Manjari; Talukdar, Arunansu

    2013-06-01

    Intractable vomiting in an elderly patient is an emergency condition requiring prompt diagnosis and intervention. Acute gastric outlet obstruction due to gastric volvulus through Morgagni-type diaphragmatic hernia is an exceedingly rare cause of this nonspecific complaint. Our aim was to highlight that Morgagni hernia, although rare in adults, should be suspected in the appropriate clinical setting, and that a clue toward diagnosis often comes from routine chest and abdominal x-ray studies. In addition, we emphasize the atypical radiological findings and importance of emergency surgical intervention in such a case. We describe the case of a 78-year-old woman who presented to the Emergency Department with a 4-day history of intractable vomiting, and with no definitive clue to the diagnosis on examination. Her routine chest and abdomen x-ray studies suggested abnormal air-fluid level at right hemithorax, which prompted a computed tomography (CT) scan of the abdomen and an upper gastrointestinal contrast study. Gastric volvulus through a foramen of Morgagni was diagnosed and transthoracic reduction of the contents was performed, along with repair of the defect. A symptomatic Morgagni hernia in adults, although rare, can present with a variety of symptoms ranging from nonspecific complaints of bloating and indigestion to the more severe complaint of intestinal obstruction. Gastric volvulus and obstructive features are less frequently reported as acute complications of these hernias, which need early identification and intervention. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. An observational study addressing the anatomic basis of mesosigmoidopexy as a rational treatment of non-gangrenous sigmoid volvulus.

    PubMed

    Samuel, Jonathan C; Msiska, Nelson; Muyco, Arturo P; Cairns, Bruce A; Charles, Anthony G

    2012-01-01

    Sigmoid volvulus is a common cause of bowel obstruction. We describe mesosigmoidopexy, an accepted surgical technique for the management of non-gangrenous sigmoid volvulus, and provide anatomic correlations supporting the therapy. Mesosigmoidopexy should be considered as a rational alternative to resection and anastomosis when operating on non-gangrenous sigmoid volvulus.

  19. Canine Infections with Onchocerca lupi Nematodes, United States, 2011–2014

    PubMed Central

    Giannelli, Alessio; Latrofa, Maria S.; Dantas-Torres, Filipe; Trumble, Nicole Scotty; Chavkin, Matt; Kennard, Gavin; Eberhard, Mark L.; Bowman, Dwight D.

    2015-01-01

    Infections with Onchocerca lupi nematodes are diagnosed sporadically in the United States. We report 8 cases of canine onchocercosis in Minnesota, New Mexico, Colorado, and Florida. Identification of 1 cytochrome c oxidase subunit 1 gene haplotype identical to 1 of 5 from Europe suggests recent introduction of this nematode into the United States. PMID:25897859

  20. Onchocerca lupi Nematodes in Dogs Exported from the United States into Canada

    PubMed Central

    Conboy, Gary; Lejeune, Manigandan; Marron, Fany; Hanna, Paul; MacDonald, Erin; Skorobohach, Brian; Wilcock, Brian; Kutz, Susan J.; Gilleard, John S.

    2016-01-01

    The Onchocerca lupi nematode is an emerging helminth capable of infecting pets and humans. We detected this parasite in 2 dogs that were imported into Canada from the southwestern United States, a region to which this nematode is endemic. We discuss risk for establishment of O. lupi in Canada. PMID:27434170

  1. Tracking the vector of Onchocerca lupi in a rural area of Greece.

    PubMed

    Otranto, Domenico; Dantas-Torres, Filipe; Papadopoulos, Elias; Petrić, Dušan; Ćupina, Aleksandra Ignjatović; Bain, Odile

    2012-07-01

    During a hot Mediterranean summer, an expedition brought parasitologists from Brazil, France, Greece, Italy, and Serbia to a wooded area near Xanthi, Thrace, northeastern Greece, near the Turkish border, on the track of the vector of the little-known nematode Onchocerca lupi. The scientific purposes of the expedition blended then with stories of humans, animals, and parasites in this rural area.

  2. Canine Infections with Onchocerca lupi Nematodes, United States, 2011-2014.

    PubMed

    Otranto, Domenico; Giannelli, Alessio; Latrofa, Maria S; Dantas-Torres, Filipe; Trumble, Nicole Scotty; Chavkin, Matt; Kennard, Gavin; Eberhard, Mark L; Bowman, Dwight D

    2015-05-01

    Infections with Onchocerca lupi nematodes are diagnosed sporadically in the United States. We report 8 cases of canine onchocercosis in Minnesota, New Mexico, Colorado, and Florida. Identification of 1 cytochrome c oxidase subunit 1 gene haplotype identical to 1 of 5 from Europe suggests recent introduction of this nematode into the United States.

  3. Zoonotic Onchocerca lupi infection in dogs, Greece and Portugal, 2011-2012.

    PubMed

    Otranto, Domenico; Dantas-Torres, Filipe; Giannelli, Alessio; Latrofa, Maria Stefania; Papadopoulos, Elias; Cardoso, Luís; Cortes, Helder

    2013-12-01

    Onchocerca lupi infection is reported primarily in symptomatic dogs. We aimed to determine the infection in dogs from areas of Greece and Portugal with reported cases. Of 107 dogs, 9 (8%) were skin snip-positive for the parasite. DNA sequences of parasites in specimens from distinct dog populations differed genetically from those in GenBank.

  4. Laparoscopic splenopexy and gastropexy for wandering spleen associated with gastric volvulus.

    PubMed

    Okazaki, Tadaharu; Ohata, Rumi; Miyano, Go; Lane, Geoffrey J; Takahashi, Toshiaki; Yamataka, Atsuyuki

    2010-10-01

    Wandering spleen is not a common condition in childhood and has been described only rarely in association with gastric volvulus. The authors report the successful management of wandering spleen associated with gastric volvulus using laparoscopic splenopexy and gastropexy in a 4-year-old girl.

  5. Caecal volvulus in a patient with chronic intestinal pseudo-obstruction.

    PubMed

    Tatterton, M; El-Khatib, C

    2011-10-01

    Chronic intestinal pseudo-obstruction (CIPO) is a rare disorder characterised by recurrent symptoms and signs of intestinal obstruction without an underlying mechanical cause. Caecal volvulus remains a rare cause of intestinal obstruction that often requires operative intervention. We describe the previously unreported case of caecal volvulus occurring in an adult patient with CIPO, together with his subsequent management.

  6. Small intestinal volvulus in a free-ranging female dugong (Dugong dugon).

    PubMed

    Gillespie, A; Burgess, E; Lanyon, J; Owen, H

    2011-07-01

    An adult female dugong (Dugong dugon) was found dead and floating in Moreton Bay, Queensland, Australia. This animal was found to have a 360° mesenteric volvulus with infarction of the associated segment of small intestine, and fibrinous peritonitis. Mortality was attributed to the volvulus and its sequelae. The cause was not apparent on gross or histological examination.

  7. A Case of Fetal Intestinal Volvulus Without Malrotation Causing Severe Anemia

    PubMed Central

    Nakagawa, Tomoko; Tachibana, Daisuke; Kitada, Kohei; Kurihara, Yasushi; Terada, Hiroyuki; Koyama, Masayasu; Sakae, Yukari; Morotomi, Yoshiki; Nomura, Shiho; Saito, Mika

    2015-01-01

    Fetal intestinal volvulus without malrotation is a rare, life-threatening disease. Left untreated, hemorrhage from necrotic bowel tissue will lead to severe fetal anemia and even intrauterine death. We encountered a case of fetal intestinal volvulus causing severe anemia, which was diagnosed postnatally and successfully treated with surgical intervention. PMID:25628516

  8. [African Program for Onchocerciasis Control (APOC): Onchocerca volvulus transmission by Simulium damnosum s. l. in two regions of the Central African Republic].

    PubMed

    Enyong, P; Traoré, S; Louango, E; Fobi, G; Noma, M; Yaméogo, L; Kayembé, D; Sékétéli, A

    2006-03-01

    Entomological baseline data were collected in the villages of Zinga and Boali-Falls in Central African Republic (CAR) in view of the long term impact assessment of community-directed treatment with ivermectin (CDTI). Morphological determinations revealed that flies caught in both sites belong to the sub-group Sou/Sq. In Boali, the nuisance was relatively high with biting rates averaging 243 bites/man/day, with a parous rate of 61.6% and a crude annual transmission potential (ATP) of 8,259 infective larvae/man/year; and the average number of infective larvae per 1,000 parous flies was 177. In Zinga, the mean biting rate was 191 bites/man/day, with a parous rate of 51.6%, a crude ATP of 3,422, and 86 infective larvae per 1,000 porous flies. In conclusion, the vectorial capacity and the entomological indices recorded are characteristic of high onchocerciasis transmission zones. However, some of the infective larvae found, maybe of animal origin, need identification to better determine the real level of endemicity.

  9. Factors Associated with Ivermectin Non-Compliance and Its Potential Role in Sustaining Onchocerca volvulus Transmission in the West Region of Cameroon

    PubMed Central

    Senyonjo, Laura; Oye, Joseph; Bakajika, Didier; Biholong, Benjamin; Tekle, Afework; Boakye, Daniel; Schmidt, Elena; Elhassan, Elizabeth

    2016-01-01

    Background Community Directed Treatment with ivermectin is the cornerstone of current efforts to eliminate onchocerciasis. However recent studies suggest there are foci where long-term annual distribution of the drug alone has failed to ensure elimination thresholds are reached. It is important to achieve high levels of compliance in order to obtain elimination targets. An epidemiological and entomological evaluation conducted in the western region of Cameroon in 2011 revealed that two health districts remained with a high prevalence of infection, despite long-term distribution of ivermectin since 1996. This paper explores potential factors that may have contributed to the non-interruption of transmission, focusing on ivermectin treatment compliance and the importance of systematic non-compliance within the population. Methodology/Principal findings A mixed methods approach was used, including a population-based survey to assess treatment compliance and factors associated and qualitative assessments including focus group discussions and in-depth interviews with key programme stakeholders and drug distributors. Compliance was reported at 71.2% (95%CI: 61.7–79.2%;n = 853/1198). The key factors related to compliance in the most recent round related to either programmatic and delivery issues, primarily absenteeism at the time of the campaign or alternatively individual determinants. An individual’s experience of side effects in the past was strongly associated with non-compliance to ivermectin. Other factors included ethnicity, how long lived in the village and age. There was a high percentage of reported systematic non-compliance at 7.4% (95% CI: 4.3–12.3%; n = 86/1165), higher amongst females. This group may be important in facilitating the sustainment of on-going transmission. Conclusions/Significance Efforts to reduce the number of systematic non-compliers and non-compliance in certain groups may be important in ensuring the interruption of transmission in the study area. However, in areas with high pre-control force of transmission, as in these districts, annual distribution with ivermectin, even if sustaining high levels of compliance, may still be inadequate to achieve elimination. Further studies are required to better understand the transmission dynamics and focus of on-going transmission in the study districts. PMID:27529622

  10. Analysis of the mdr-1 Gene in Patients Co-Infected with Onchocerca volvulus and Loa loa Who Experienced a Post-Ivermectin Serious Adverse Event

    PubMed Central

    Bourguinat, Catherine; Kamgno, Joseph; Boussinesq, Michel; Mackenzie, Charles D.; Prichard, Roger K.; Geary, Timothy G.

    2010-01-01

    Ivermectin (IVM) is exceptionally safe in humans, and is used for mass treatment of onchocerciasis and lymphatic filariasis. However, cases of encephalopathy, sometimes fatal, have been reported in a small number of individuals who harbored large numbers of Loa loa microfilariae (mf). A loss-of-function mutation in the mdr-1 gene in some dog breeds and in mice leads to accumulation of the drug in the brain, causing coma and death. This hypothesis was tested in four individuals from Cameroon who experienced a post-IVM serious adverse event (SAE) and in nine non-SAE matched controls. No loss-of-function mutation was detected in mdr-1 in any subject. However, haplotypes, associated with altered drug disposition, were present as homozygotes in two of the SAE patients (50%), but absent as homozygotes in the controls (0%). An association of high Loa mf load and a genetic predisposition to altered IVM distribution could be involved in IVM SAEs. PMID:20595473

  11. Factors Associated with Ivermectin Non-Compliance and Its Potential Role in Sustaining Onchocerca volvulus Transmission in the West Region of Cameroon.

    PubMed

    Senyonjo, Laura; Oye, Joseph; Bakajika, Didier; Biholong, Benjamin; Tekle, Afework; Boakye, Daniel; Schmidt, Elena; Elhassan, Elizabeth

    2016-08-01

    Community Directed Treatment with ivermectin is the cornerstone of current efforts to eliminate onchocerciasis. However recent studies suggest there are foci where long-term annual distribution of the drug alone has failed to ensure elimination thresholds are reached. It is important to achieve high levels of compliance in order to obtain elimination targets. An epidemiological and entomological evaluation conducted in the western region of Cameroon in 2011 revealed that two health districts remained with a high prevalence of infection, despite long-term distribution of ivermectin since 1996. This paper explores potential factors that may have contributed to the non-interruption of transmission, focusing on ivermectin treatment compliance and the importance of systematic non-compliance within the population. A mixed methods approach was used, including a population-based survey to assess treatment compliance and factors associated and qualitative assessments including focus group discussions and in-depth interviews with key programme stakeholders and drug distributors. Compliance was reported at 71.2% (95%CI: 61.7-79.2%;n = 853/1198). The key factors related to compliance in the most recent round related to either programmatic and delivery issues, primarily absenteeism at the time of the campaign or alternatively individual determinants. An individual's experience of side effects in the past was strongly associated with non-compliance to ivermectin. Other factors included ethnicity, how long lived in the village and age. There was a high percentage of reported systematic non-compliance at 7.4% (95% CI: 4.3-12.3%; n = 86/1165), higher amongst females. This group may be important in facilitating the sustainment of on-going transmission. Efforts to reduce the number of systematic non-compliers and non-compliance in certain groups may be important in ensuring the interruption of transmission in the study area. However, in areas with high pre-control force of transmission, as in these districts, annual distribution with ivermectin, even if sustaining high levels of compliance, may still be inadequate to achieve elimination. Further studies are required to better understand the transmission dynamics and focus of on-going transmission in the study districts.

  12. [Entomology of onchocercosis in Soconusco, Chiapas. 6. Quantitative studies of the transmission of Onchocerca volvulus by 3 species of Simuliidae in a community with high endemicity].

    PubMed

    Ortega, M; Oliver, M; Ramírez, A

    1992-01-01

    In Guatemala, there is no doubt about the participation of Simulium ochraceum as vector of Onchocerciasis. However, in Mexico practically there are not studies focussed to determine the role of this species in the transmission. The objective of the present investigation was to determine which of the 3 species of Simulium founded in the Soconusco region of Chiapas, is the main, and which were secondary in the transmission of Onchocerciasis in that area. The locality of Morelos, in the Huixtla "municipio" of Chiapas, localized a 1200 meters over the sea level (mosl) were selected to carried out the present study. According to own parasitological studies, this locality is considered as highly endemic (more than 66% prevalence). From March 1979 to March, 1981, we performed captures of Simulium sp caught on human bait. Quantitative studies and of transmission potentials were also performed. The following results were obtained: a) Absolute black flies densities (nulliparous and pariparous) and infected black flies (with L1 and L2 larvae): S. ochraceum, S. metallicum and S. callidum, in that order was the distribution of densities. Infected black flies were obtained in the 3 species. However, in despite of an irregular distribution in all the year, it was possible to identify 2 peaks of maximum infection of S. ochraceum in March, 1979 and March 1981. b) Monthly bite densities and infective bites.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Transmission of Onchocerca volvulus Continues in Nyagak-Bondo Focus of Northwestern Uganda after 18 Years of a Single Dose of Annual Treatment with Ivermectin

    PubMed Central

    Katabarwa, Moses N.; Lakwo, Tom; Habomugisha, Peace; Agunyo, Stella; Byamukama, Edson; Oguttu, David; Tukesiga, Ephraim; Unoba, Dickson; Dramuke, Patrick; Onapa, Ambrose; Tukahebwa, Edridah M.; Lwamafa, Dennis; Walsh, Frank; Unnasch, Thomas R.

    2013-01-01

    The objective of the study was to determine whether annual ivermectin treatment in the Nyagak-Bondo onchocerciasis focus could safely be withdrawn. Baseline skin snip microfilariae (mf) and nodule prevalence data from six communities were compared with data collected in the 2011 follow-up in seven communities. Follow-up mf data in 607 adults and 145 children were compared with baseline (300 adults and 58 children). Flies collected in 2011were dissected, and poolscreen analysis was applied to ascertain transmission. Nodule prevalence in adults dropped from 81.7% to 11.0% (P < 0.0001), and mf prevalence dropped from 97.0% to 23.2% (P < 0.0001). In children, mf prevalence decreased from 79.3% to 14.1% (P < 0.0001). Parous and infection rates of 401 flies that were dissected were 52.9% and 1.5%, respectively, whereas the infective rate on flies examination by polymerase chain reaction (PCR) was 1.92% and annual transmission potential was 26.9. Stopping ivermectin treatment may result in onchocerciasis recrudescence. PMID:23690555

  14. Transmission of Onchocerca volvulus continues in Nyagak-Bondo focus of northwestern Uganda after 18 years of a single dose of annual treatment with ivermectin.

    PubMed

    Katabarwa, Moses N; Lakwo, Tom; Habomugisha, Peace; Agunyo, Stella; Byamukama, Edson; Oguttu, David; Tukesiga, Ephraim; Unoba, Dickson; Dramuke, Patrick; Onapa, Ambrose; Tukahebwa, Edridah M; Lwamafa, Dennis; Walsh, Frank; Unnasch, Thomas R

    2013-08-01

    The objective of the study was to determine whether annual ivermectin treatment in the Nyagak-Bondo onchocerciasis focus could safely be withdrawn. Baseline skin snip microfilariae (mf) and nodule prevalence data from six communities were compared with data collected in the 2011 follow-up in seven communities. Follow-up mf data in 607 adults and 145 children were compared with baseline (300 adults and 58 children). Flies collected in 2011 were dissected, and poolscreen analysis was applied to ascertain transmission. Nodule prevalence in adults dropped from 81.7% to 11.0% (P < 0.0001), and mf prevalence dropped from 97.0% to 23.2% (P < 0.0001). In children, mf prevalence decreased from 79.3% to 14.1% (P < 0.0001). Parous and infection rates of 401 flies that were dissected were 52.9% and 1.5%, respectively, whereas the infective rate on flies examination by polymerase chain reaction (PCR) was 1.92% and annual transmission potential was 26.9. Stopping ivermectin treatment may result in onchocerciasis recrudescence.

  15. Chronic Gastric Volvulus with Laparoscopic Gastropexy after Endoscopic Reduction: A Case Report

    PubMed Central

    Lee, Hye Yeon; Park, Jung Hyun

    2015-01-01

    Gastric volvulus is an uncommon clinical entity. There are three types of gastric volvulus; organoaxial, mesenteroaxial and combined type. This condition can lead to a closed-loop obstruction or strangulation. Traditional surgical therapy for gastric volvulus is based on an open approach. Here we report a successful case of a patient with chronic gastric volvulus with a laparoscopic treatment. A 79-year-old woman came to the emergency department with epigastric pain accompanied by nausea for 2 weeks. Abdominal computed tomography revealed markedly distended stomach with transposition of gastroesophageal Junction and gastric antrum. Barium meal study revealed presence of the antrum was folded over 180 degrees that was located above gastroesophageal junction. We attempted an endoscopic reduction, but it was unsuccessful. The patient got laparoscopic anterior gastropexy. Based on our result, laparoscopic gastropexy can be considered as a good choice of the treatment for gastric volvulus. PMID:26161290

  16. A rare case of acute on chronic gastric volvulus with Borchardt's triad.

    PubMed

    Senior, Andrew; Hari, Churunal

    2014-11-20

    Gastric volvulus is a rare condition with two forms of presentation, either acute or chronic. Since its discovery, there have been no cases of acute on chronic volvulus discussed in the literature. Its vague presentation makes diagnosis and subsequent management difficult. The diagnosis of acute gastric volvulus is made on clinical grounds via Borchardt's triad; however, barium swallow and oesophagogastroduodenoscopy have been shown to play a role. We describe a case of a 95-year-old Caucasian woman who presented with worsening dysphagia, epigastric pain, retching without vomiting and hiccups of 5 months. Initially diagnosed as a hiatus hernia, the patient subsequently died following an acute on chronic gastric volvulus. This rare, life-threatening diagnosis provides an opportunity to discuss characteristics of gastric volvulus and the difficulties in management.

  17. Sigmoid Volvulus Complicating Pregnancy Managed by Resection and Primary Anastomosis: Case report with literature review.

    PubMed

    Machado, Norman O; Machado, Lovina S M

    2009-04-01

    Sigmoid volvulus is an extremely rare cause of intestinal obstruction in pregnancy. The rarity of the condition and the fact that pregnancy itself clouds the clinical picture invariably leads to a delay in diagnosis with an increased risk of gangrene of the gut. The majority of these patients would then require resection and colostomy. However, an early diagnosis and intervention as in our patient, which would require a high index of clinical suspicion, could significantly improve the outcome of the foetus and the mother. A case of sigmoid volvulus in pregnancy is reported which was managed by resection and primary anastomosis. A review of literature revealed no previous reports of sigmoid volvulus in pregnancy managed by primary anastomosis following resection of the sigmoid volvulus. The literature is also reviewed regarding predisposing factors, management options and the outcome of sigmoid volvulus complicating pregnancy.

  18. Laparoscopic repair of hiatal hernia with mesenterioaxial volvulus of the stomach.

    PubMed

    Inaba, Kazuki; Sakurai, Yoichi; Isogaki, Jun; Komori, Yoshiyuki; Uyama, Ichiro

    2011-04-21

    Although mesenterioaxial gastric volvulus is an uncommon entity characterized by rotation at the transverse axis of the stomach, laparoscopic repair procedures have still been controversial. We reported a case of mesenterioaxial intrathoracic gastric volvulus, which was successfully treated with laparoscopic repair of the diaphragmatic hiatal defect using a polytetrafluoroethylene mesh associated with Toupet fundoplication. A 70-year-old Japanese woman was admitted to our hospital because of sudden onset of upper abdominal pain. An upper gastrointestinal series revealed an incarcerated intrathoracic mesenterioaxial volvulus of the distal portion of the stomach and the duodenum. The complete laparoscopic approach was used to repair the volvulus. The laparoscopic procedures involved the repair of the hiatal hernia using polytetrafluoroethylene mesh and Toupet fundoplication. This case highlights the feasibility and effectiveness of the laparoscopic procedure, and laparoscopic repair of the hiatal defect using a polytetrafluoroethylene mesh associated with Toupet fundoplication may be useful for preventing postoperative recurrence of hiatal hernia, volvulus, and gastroesophageal reflux.

  19. Onchocerca takaokai n. sp. (Nematoda: Filarioidea) in Japanese wild boars (Sus scrofa leucomystax): Description and molecular identification of intradermal females.

    PubMed

    Uni, Shigehiko; Fukuda, Masako; Agatsuma, Takeshi; Bain, Odile; Otsuka, Yasushi; Nakatani, Jun; Matsubayashi, Makoto; Harada, Masashi; Omar, Hasmahzaiti; Ramli, Rosli; Hashim, Rosli; Azirun, Mohd Sofian; Takaoka, Hiroyuki

    2015-12-01

    Human zoonotic onchocercosis is caused by Onchocerca dewittei japonica, parasitic in wild boars (Sus scrofa leucomystax) in Japan. Previously, microfilariae longer than those of Onchocerca dewittei japonica were observed in skin snips from wild boars during the study of O. dewittei japonica. Moreover, the third-stage larvae (L3) of these longer microfilariae were obtained from the blackfly Simulium bidentatum after experimental injections. Based on morphometric and molecular studies, similar L3 were found in blackflies during fieldwork in Oita, Japan. However, except for O. dewittei japonica, adult worms of Onchocerca have not been found in wild boars. In this study, we discovered adult females of a novel Onchocerca species in the skin of a wild boar in Oita, and named it Onchocerca takaokai n. sp. Females of this new species had longer microfilariae and differed from O. dewittei japonica in terms of their morphological characteristics and parasitic location. The molecular characteristics of the cytochrome c oxidase subunit 1 and 12S rRNA genes of the new species were identical to those of the longer microfilariae and L3 previously detected, but they differed from those of O. dewittei japonica at the species level. However, both species indicated a close affinity among their congeners and Onchocerca ramachandrini, parasitic in the warthog in Africa, was basal in the Suidae cluster of the 12S rRNA tree.

  20. Laparoscopic Diagnosis of Magnetic Malrotation with Fistula and Volvulus

    PubMed Central

    Hartin, Charles W.; Ozgediz, Doruk E.

    2012-01-01

    Introduction: Most foreign bodies that a child ingests pass harmlessly through the gastrointestinal tract. However, ingesting multiple magnets places a child at risk for serious viscus injury. Case Description: A 16-y-old boy swallowed multiple magnets and presented with abdominal pain and emesis. Upon laparoscopy, the boy was found to have malrotation with volvulus caused by a cecal magnet attracted to a gastric magnet, resulting in a gastrocecal fistula. Discussion: We review the management of magnet ingestion with an emphasis on a high index of suspicion and the use of laparoscopy for diagnosis, as well as the consequences of a coexisting rotational anomaly. PMID:23484578

  1. Spontaneous Acute Mesenteroaxial Gastric Volvulus Diagnosed by Computed Tomography Scan in a Young Man

    PubMed Central

    Jabbour, Gaby; Afifi, Ibrahim; Ellabib, Mohamed; El-Menyar, Ayman; Al-Thani, Hassan

    2016-01-01

    Patient: Male, 23 Final Diagnosis: Acute spontaneous gastric volvulus Symptoms: — Medication: — Clinical Procedure: Laparotomy Specialty: Gastroenterology and Hepatology Objective: Rare disease Background: Acute gastric volvulus is a surgical emergency that requires early recognition and treatment. Acute idiopathic mesenteroaxial gastric volvulus is a rare sub-type and there are few cases reported in children and there are even fewer reports in adults. Case Report: We report a rare case of a 23-year-old man who presented with a 1-day history of vomiting, epigastric pain, distention, and constipation. The diagnosis for mesenteroaxial type gastric volvulus was confirmed by abdominal radiography and computed tomography. The patient was successfully treated by laparotomy with resection of the ischemic stomach wall and anastomosis. Acute spontaneous mesenteroaxial gastric volvulus is rare in adults and early diagnosis is challenging due to non-specific symptoms. A missed or delayed diagnosis may result in serious complications due to gastric obstruction. Conclusions: A patient presenting with severe epigastric pain and clinical evidence of gastric outlet obstruction should be considered as a surgical emergency to rule out gastric volvulus. High index of suspicion, early diagnosis and prompt surgical management are important for favorable outcome in patients with acute spontaneous gastric volvulus. PMID:27112797

  2. Diagnosis of pediatric colonic volvulus with abdominal radiography: how good are we?

    PubMed

    Marine, Megan B; Cooper, Matthew L; Delaney, Lisa R; Jennings, Samuel Gregory; Rescorla, Frederick J; Karmazyn, Boaz

    2017-04-01

    Colonic volvulus is rare in children and associated with colonic dysmotility. Diagnosis of colonic volvulus on radiographs in these patients can be challenging. The purpose of the study was to identify the accuracy of abdominal radiographs and findings suggestive of colonic volvulus. A retrospective (2003- 2014) study of all children with colonic volvulus proven surgically or endoscopically reviewed their medical charts for underlying disease and clinical presentation as well as their original radiograph reports. Two pediatric radiologists (reader 1 and reader 2) independently reviewed the radiographs. The kappa test was used to evaluate interobserver variability. There were 19 cases of colonic volvulus in 18 patients (11 males) a mean age 14 years. Cecal volvulus was the most common finding at 14/19 cases (74%). Sixteen of 18 (89%) patients had neurological impairment and 10 of 18 (56%) had intestinal dysmotility. The most common presentation was abdominal distension (14/19 [74%]) and pain (11/19 [58%]). Colonic volvulus was diagnosed in only 7/16 (44%) of the abdominal radiographs. The specific finding of a coffee-bean sign was retrospectively observed only by reader 2 in two cases. Absence of rectal gas and focal colonic loop dilation were the most common findings by the readers (average 73.5% and 87%, respectively) with Kappa values of 0.3 and 0.38, respectively. Diagnosis of colonic volvulus in children can be challenging. Radiologists should be alerted to the possibility of colonic volvulus when there is focal colonic loop distention or absent rectal gas.

  3. The effects of diethylcarbamazine citrate, antihistamines and corticosteroid derivatives on skin reactivity to Onchocerca supernatants.

    PubMed

    Titanji, V P; Barla, E; Anyangwe, S; Ngu, J L

    1983-03-01

    A single dose of promethazine or of betamethazone, either alone or compounded with dexchloropheniramine, was found to inhibit skin wheal formation in onchocerciasis patients challenged with Onchocerca supernatants. The mean wheal diameter developing 24 hours after drug administration ranged between 40-60% less than the original pre-treatment diameter but this effect had been abolished or was significantly less by 48 hours. Diethycarbamazinecitrate had only a 20% inhibitory effect on the wheal diameter of the skin reaction. It is concluded that antihistamines and corticosteroid derivates may interfere with the immunodiagnostic skin test for onchocerciasis based on skin reactivity to Onchocerca supernatants, unless measures are taken to ensure that these drugs are not consumed within the 48 hours preceding the skin test.

  4. Small bowel volvulus in pregnancy with associated superior mesenteric artery occlusion.

    PubMed

    Esterson, Yonah B; Villani, Robert; Dela Cruz, Ronald A; Friedman, Barak; Grimaldi, Gregory M

    Here we report the case of a pregnant 28-year-old who presented with acute upper abdominal pain. CT demonstrated midgut volvulus with short segment occlusion of the superior mesenteric artery (SMA). Emergent detorsion of the small bowel was performed, at which time underlying intestinal malrotation was discovered. Following detorsion, the SMA had a bounding pulse and did not require thrombectomy or revascularization. Fewer than 25 cases of midgut volvulus during pregnancy have been reported over the past 20years. To our knowledge, this is the first report of maternal midgut volvulus in which imaging captures the resultant occlusion of the SMA.

  5. Utility of the CT Scan in Diagnosing Midgut Volvulus in Patients with Chronic Abdominal Pain

    PubMed Central

    Morshedi, Mehdi; Baradaran Jamili, Mohammad; Shafizadeh Barmi, Fatemeh

    2017-01-01

    Symptomatic intestinal malrotation first presenting in the adults is rare. Midgut volvulus is the most common complication of malrotation in the adults. Because of more differential diagnosis, Computed Tomography (CT) scan can play an important role in the evaluation of patients with this abnormality. The whirl pattern around the superior mesenteric artery found on CT scan in patients with midgut volvulus is pathognomonic and diagnostic. We describe a case of intestinal malrotation complicated by midgut volvulus in an adult patient. The preoperative CT findings were pathognomonic. PMID:28182093

  6. Volvulus of small intestine: rare complication of mesenteric pseudocyst.

    PubMed

    Fan, H-L; Chen, T-W; Hong, Z-J; Hsieh, C-B; Chan, D-C; Chen, C-J; Liu, Y-C; Yu, J-C

    2009-12-01

    Mesenteric cyst is a rare intra-abdominal lesion. Most patients with mesenteric cysts are asymptomatic. Symptomatic mesenteric cysts are associated with cyst size, cyst location, and complications, including infection, rupture, hemorrhage, and intestinal obstruction. Volvulus is a rare complication of mesenteric cyst. We report a 50-year-old woman with colicky epigastric pain for three days. The symptoms exacerbated in the supine position and were relieved in the sitting position. Computed tomography of her abdomen revealed a huge cystic lesion with a whirl sign of mesentery vessels. She had the history of gastro-esophageal reflux disease. Segmental resection of the small intestine with end-to-end anastomosis was performed. Histology indicated a hemorrhagic pseudocyst. The patient recovered well after surgery. Mesenteric pseudocyst rarely results in volvulus of small intestine. Our case is the eleventh case reported in the English literature. Atypical presentation of epigastric pain while lying down may lead to mis-diagnosis. This case reminds the clinicians this rare complication.

  7. Complicated Jejunal Diverticulosis: Small Bowel Volvulus with Obstruction

    PubMed Central

    Mohi, Rommel Singh; Moudgil, Ashish; Bhatia, Suresh Kumar; Seth, Kaushal; Kaur, Tajinder

    2016-01-01

    The incidence of the diverticulum of the small bowel varies from 0.2-1.3% in autopsy studies to 2.3% when assessed on enteroclysis. It occurs mostly in patients in the 6th decade of their life. Of all the small bowel diverticuli, jejunal diverticulum is the most common type. This rare entity is usually asymptomatic. However, they may cause chronic non-specific symptoms for a long period of time like dyspepsia, chronic postprandial pain, nausea, vomiting, borborgymi, alternating diarrhoea and constipation, weight loss, anaemia, steatorrhea or rarely lead to complications like haemorrhage, obstruction, perforation. Obstruction can be due to enterolith, adhesions, intussusception, and volvulus. The condition is difficult to diagnose because patients are generally presented with symptoms that mimic other diseases. It is important for clinicians to have awareness of this entity. Here, we present a case of multiple jejunal diverticuli with a history of repeated attacks of diverticulitis over past 20 years, which were misdiagnosed and now presented with intestinal obstruction due to volvulus of the involved segment along with mesentery around its axis. Resection of the diverticuli segment of jejunum was done with end-to-end jejuno-jejunal anastomosis. The patient is asymptomatic since 10 months of follow-up. PMID:27853337

  8. Onchocerca dewittei japonica n. subsp., a common parasite from wild boar in Kyushu Island, Japan.

    PubMed

    Uni, S; Bain, O; Takaoka, H; Miyashita, M; Suzuki, Y

    2001-09-01

    We describe Onchocerca dewittei japonica n. subsp. from the Japanese wild boar, Sus scrofa leucomystax, in Oita, Kyushu Island, where all seven animals examined were found to be infected. This study began with efforts to identify the causative species in a recent case of zoonotic onchocerciasis. Compared with Onchocerca dewittei dewittei from Sus scrofa jubatus in Malaysia, which was reexamined here, our new subspecies has much greater space between the ridges on the females. In addition, its microfilariae (from uteri) are shorter (192-210 microns compared with 228-247 microns), and only the posterior third of the microfilarial body is coiled, instead of the entire body. The Onchocerca species parasitic in suids (these two subspecies and O. ramachandrini from the warthog in the Ethiopian region) form a group sharing several characters. Among the most unusual characters are the body swellings (a specialized apparatus for mating, known in only a few other genera). In addition, longitudinal cuticular crests were found on males of both subspecies from wild boar and on females of O. ramachandrini.

  9. Phytochemical analysis and in vitro anthelmintic activity of Lophira lanceolata (Ochnaceae) on the bovine parasite Onchocerca ochengi and on drug resistant strains of the free-living nematode Caenorhabditis elegans.

    PubMed

    Kalmobé, Justin; Ndjonka, Dieudonné; Boursou, Djafsia; Vildina, Jacqueline Dikti; Liebau, Eva

    2017-08-14

    Onchocerciasis is one of the tropical neglected diseases (NTDs) caused by the nematode Onchocerca volvulus. Control strategies currently in use rely on mass administration of ivermectin, which has marked activity against microfilariae. Furthermore, the development of resistance to ivermectin was observed. Since vaccine and safe macrofilaricidal treatment against onchocerciasis are still lacking, there is an urgent need to discover novel drugs. This study was undertaken to investigate the anthelmintic activity of Lophira lanceolata on the cattle parasite Onchocerca ochengi and the anthelmintic drug resistant strains of the free living nematode Caenorhabditis elegans and to determine the phytochemical profiles of the extracts and fractions of the plants. Plant was extracted in ethanol or methanol-methylene chloride. O. ochengi, C. elegans wild-type and C. elegans drug resistant strains were cultured in RPMI-1640 and NGM-agar respectively. Drugs diluted in dimethylsulphoxide/RPMI or M9-Buffer were added in assays and monitored at 48 h and 72 h. Worm viability was determined by using the MTT/formazan colorimetric method. Polyphenol, tannin and flavonoid contents were determined by dosage of gallic acid and rutin. Acute oral toxicity was evaluated using Swiss albino mice. Ethanolic and methanolic-methylene chloride extracts killed O. ochengi with LC50 values of 9.76, 8.05, 6.39 μg/mL and 9.45, 7.95, 6.39 μg/mL respectively for leaves, trunk bark and root bark after 72 h. The lowest concentrations required to kill 50% of the wild-type of C. elegans were 1200 and 1890 μg/mL with ethanolic crude extract, 1000 and 2030 μg/mL with MeOH-CH2Cl2 for root bark and trunk bark of L. lanceolata, respectively after 72 h. Leave extracts of L. lanceolata are lethal to albendazole and ivermectin resistant strains of C. elegans after 72 h. Methanol/methylene chloride extracted more metabolites. Additionally, extracts could be considered relatively safe. Ethanolic and

  10. Wandering spleen, gastric and pancreatic volvulus and right-sided descending and sigmoid colon

    PubMed Central

    Flores-Ríos, Enrique; Méndez-Díaz, Cristina; Rodríguez-García, Esther; Pérez-Ramos, Tania

    2015-01-01

    Wandering spleen is a rare condition, characterized by a mobile spleen that is attached only by an elongated vascular pedicle, allowing it to migrate to any part of the abdomen or pelvis. Mesenteroaxial gastric volvulus usually occurs in children and may be associated with wandering spleen. Both entities result from abnormal laxity or absence of the peritoneal attachments due to abnormal fusion of the peritoneal mesenteries. Pancreatic volvulus is a very rare anomaly, with only a few isolated case reports described in association with wandering spleen. Anomalous right sided descending and sigmoid colon is a very rare entity and its association with wandering spleen has not been previously reported. We report a case of wandering spleen associated with mesenteroaxial gastric volvulus, pancreatic volvulus and rightward shift of the splenic flexure of the colon and right sided descending and sigmoid colon in a young female. PMID:26629290

  11. Wandering spleen, gastric and pancreatic volvulus and right-sided descending and sigmoid colon.

    PubMed

    Flores-Ríos, Enrique; Méndez-Díaz, Cristina; Rodríguez-García, Esther; Pérez-Ramos, Tania

    2015-10-01

    Wandering spleen is a rare condition, characterized by a mobile spleen that is attached only by an elongated vascular pedicle, allowing it to migrate to any part of the abdomen or pelvis. Mesenteroaxial gastric volvulus usually occurs in children and may be associated with wandering spleen. Both entities result from abnormal laxity or absence of the peritoneal attachments due to abnormal fusion of the peritoneal mesenteries. Pancreatic volvulus is a very rare anomaly, with only a few isolated case reports described in association with wandering spleen. Anomalous right sided descending and sigmoid colon is a very rare entity and its association with wandering spleen has not been previously reported. We report a case of wandering spleen associated with mesenteroaxial gastric volvulus, pancreatic volvulus and rightward shift of the splenic flexure of the colon and right sided descending and sigmoid colon in a young female.

  12. A rare case of post-splenectomy gastric volvulus managed by laparoscopic anterior gastropexy

    PubMed Central

    Gupta, Rahul Amreesh; Das, Rinki; Verma, Ganga Ram

    2017-01-01

    We report an extremely rare case of recurrent gastric volvulus after open splenectomy for hereditary spherocytosis. The initial episode was managed by endoscopic derotation. Later, for recurrent symptoms, she was successfully managed by laparoscopic anterior gastropexy. PMID:28281486

  13. Acute Gastric Volvulus and Atrial Fibrillation with RVR: A Coincidence or Association

    PubMed Central

    Salh, Omar

    2017-01-01

    Gastric volvulus is a rare and life-threatening condition that involves the abnormal rotation of the stomach around its axis by more than 180°. The association between acute gastric volvulus and atrial fibrillation with rapid ventricular response is rare with only few cases that have been reported. Our patient was an 86-year-old female who presented with upper abdominal pain, distension, nausea, and shortness of breath. Clinical and laboratory workup revealed acute gastric volvulus with diaphragmatic hernia. On presentation, she was also in atrial fibrillation with rapid ventricular response. She was successfully treated by laparotomy with reduction of the gastric volvulus and repair of the diaphragmatic hernia, with significant improvement. PMID:28373916

  14. Small bowel volvulus in mid and late pregnancy: can early diagnosis be established to avoid catastrophic outcomes?

    PubMed Central

    Cong, Qing; Li, Xilian; Ye, Xuping; Sun, Li; Jiang, Wei; Han, Zhigang; Lu, Weiqi; Xu, Huan

    2014-01-01

    Volvulus in pregnancy is rare and difficult to diagnose. Delayed diagnosis would result in high maternal and fetal mortality. Here we present an unusual case of small bowel volvulus in late pregnancy timely managed by emergency Cesarean section and derotation with excellent maternal and fetal outcomes. Volvulus should be considered in patients complaining ongoing abdominal pain, nausea, vomiting, constipation even diarrhea. Imaging is essential for early and precise diagnosis, including plain abdominal film, MRI and/or ultrasound. Once highly suspected or diagnosed of volvulus or ileus, emergency laparotomy should be performed immediately to avoid catastrophic outcomes, because the maternal and fetal prognosis is dependent on the interval from volvulus to operation apart from the degree of volvulus. PMID:25550984

  15. Diagnosis and treatment of mesenteric volvulus in a red kangaroo (Macropus rufus).

    PubMed

    Knafo, S Emmanuelle; Rosenblatt, Alana J; Morrisey, James K; Flanders, James A; Thompson, Margret S; Knapp-Hoch, Heather M

    2014-04-01

    An 8-year-old male red kangaroo (Macropus rufus) was evaluated with a 2-week history of vomiting and anorexia. Four days prior, the patient became refractory to medical management. The kangaroo was admitted for diagnostic testing and treatment including whole body CT, blood work, and emergency laparotomy. CT findings of a severely enlarged stomach, splenic displacement, and a whirl sign were indicative of mesenteric volvulus with gastric dilatation-volvulus (GDV). Contrast enhancement of abdominal viscera suggested intact arterial blood supply; however, compression of the caudal vena cava and portal vein indicated venous obstruction. Results of preoperative blood work suggested biliary stasis without evidence of inflammation. Additionally, a tooth root abscess was diagnosed on the basis of results of CT. Exploratory laparotomy confirmed the diagnosis of mesenteric volvulus and GDV. The volvuli were corrected by clockwise derotation, and a gastropexy was performed. Tissue samples were obtained from the spleen and liver for evaluation. The kangaroo recovered from surgery, and the abscessed tooth was extracted 6 days later. Eight days after initial evaluation, the kangaroo was discharged. In the present report, the CT whirl sign was used to diagnose volvulus of the abdominal viscera, which suggests that this diagnostic indicator has utility in veterinary patients. Mesenteric volvulus with GDV was successfully treated in a nondomestic species. The tooth root abscess, a common condition in macropods, may explain the historic episodes of anorexia reported by the owner and may have contributed to the development of mesenteric volvulus and GDV in this kangaroo.

  16. Single-port laparoscopic surgery for sigmoid volvulus

    PubMed Central

    Choi, Byung Jo; Jeong, Won Jun; Kim, Say-June; Lee, Sang Chul

    2015-01-01

    AIM: To report our experience with single-port laparoscopic surgery (SPLS) for sigmoid volvulus (SV). METHODS: Between October 2009 and April 2013, 10 patients underwent SPLS for SV. SPLS was performed transumbilically or through a predetermined stoma site. Conventional straight and rigid-type laparoscopic instruments were used. After intracorporeal, segmental resection of the affected sigmoid colon, the specimen was extracted through the single-incision site. Patient demographics and perioperative data were analyzed. RESULTS: SPLS for SV was successful in all 10 patients (4, resection and primary anastomosis; 6, Hartmann’s procedure). The median operative time and postoperative hospitalization period were 168 (range, 85-315) min and 6.5 (range, 4-29) d, respectively. No intraoperative complications were noted; there were 2 postoperative complications, including 1 anastomotic leak. CONCLUSION: SPLS was a safe and feasible therapeutic approach for SV, when performed by a surgeon experienced in conventional laparoscopic surgery. PMID:25741145

  17. Gastric dilitation-volvulus in a Red Panda (Ailurus fulgens).

    PubMed

    Schlanser, Justin R; Agnew, Dalen; Paperd, Deborah W; Harrison, Tara M

    2014-06-01

    A 10-year-old male red panda presented acutely with symptoms of shock due to acute abdominal distress and respiratory compromise. Abdominal ultrasound confirmed a severely distended stomach for which passage of an orogastric tube for relief was unsuccessful. Intra-operatively, the stomach was found to be distended and torsed around its long axis supporting the diagnosis of Gastric dilitation-volvulus (GDV). The animal arrested and died intra-operatively and was submitted for necropsy with lesions supportive of the diagnosis of GDV. No risk factors for GDV were found to correlate between the panda and those described in domestic dogs. This case suggests that red pandas can be susceptible to this condition in captive settings.

  18. Gastric Dilitation-Volvulus in a Red Panda (Ailurus fulgens)

    PubMed Central

    SCHLANSER, Justin R.; AGNEW, Dalen; PAPERD, Deborah W.; HARRISON, Tara M.

    2014-01-01

    ABSTRACT A 10-year-old male red panda presented acutely with symptoms of shock due to acute abdominal distress and respiratory compromise. Abdominal ultrasound confirmed a severely distended stomach for which passage of an orogastric tube for relief was unsuccessful. Intra-operatively, the stomach was found to be distended and torsed around its long axis supporting the diagnosis of Gastric dilitation-volvulus (GDV). The animal arrested and died intra-operatively and was submitted for necropsy with lesions supportive of the diagnosis of GDV. No risk factors for GDV were found to correlate between the panda and those described in domestic dogs. This case suggests that red pandas can be susceptible to this condition in captive settings. PMID:24521795

  19. Prevalence of Onchocerca species and Thelazia lacrimalis in horses examined post mortem in Normandy.

    PubMed

    Collobert, C; Bernard, N; Lamidey, C

    1995-05-06

    The umbilical skin and ligamentum nuchae of 368 horses were examined post mortem for Onchocerca species. Only four of the horses were infected and pathological changes were observed on the skin of two of them. Thelazia lacrimalis was recovered from 38 (10.3 per cent) of the horses, and animals aged six months to two years were more frequently infected. No ocular lesions were observed. The prevalences of these two nematodes were low when compared with the infection rates reported in the United Kingdom and North America.

  20. A preliminary investigation of serological tools for the detection of Onchocerca lupi infection in dogs.

    PubMed

    Giannelli, Alessio; Cantacessi, Cinzia; Graves, Patricia; Becker, Luke; Campbell, Bronwyn Evelyn; Dantas-Torres, Filipe; Otranto, Domenico

    2014-05-01

    Onchocerca lupi is a neglected filarioid causing nodular lesions associated with acute or chronic ocular disease in dogs. Despite the recent appraisal of its zoonotic potential, human cases are increasingly reported in the Old and New Worlds. Therefore, the development of accurate tools for the rapid diagnosis of O. lupi infections in dogs is becoming a priority. In this study, we conducted a preliminary investigation aimed at evaluating the usefulness of a commercially available ELISA test for the detection of O. lupi antigens in canine sera. The potential use of this tool for larger epidemiological studies of canine onchocerciasis is discussed.

  1. Rearing Xyleborus volvulus (Coleoptera: Curculionidae) on Media Containing Sawdust from Avocado or Silkbay, with or without Raffaelea lauricola (Ophiostomatales: Ophiostomataceae)

    USDA-ARS?s Scientific Manuscript database

    Like other ambrosia beetles, Xyleborus volvulus Fabricius (Coleoptera: Curculionidae) lives in a mutualistic symbiotic relationship with fungi that serve as food source. Until recently, X. volvulus was not considered a pest, and none of its symbionts were considered plant pathogens. However, recent ...

  2. Laparoscopic repair of a gastric volvulus occurring as a long-term complication of left pneumonectomy: report of a case.

    PubMed

    Batirel, Hasan Fevzi; Uygur-Bayramicli, Oya; Guler, Sevgi; Yildizeli, Bedrettin; Yuksel, Mustafa

    2007-01-01

    Gastric volvulus is an extremely rare late complication of pneumonectomy. We report the case of a 61-year-old man who presented with a 1-year history of progressive intolerance of solids and weight loss 33 years after a left pneumonectomy. Preoperative examinations showed a mesenteroaxial gastric volvulus. We performed a laparoscopic Toupet fundoplication and anterior gastropexy, following which his symptoms disappeared.

  3. A case of cecal volvulus mimicking Ogilvie Syndrome in a hospitalized patient with a pelvis fracture.

    PubMed

    Tampakis, Athanasios; Droeser, Raoul A; Tampaki, Ekaterini Christina; von Holzen, Urs; Delko, Tarik

    2016-05-01

    Cecal volvulus and ogilvie syndrome are two entities which may display similar clinical presentation but require different treatment approaches. An 84-year old male patient admitted for conservative treatment of a pelvis fracture, complained of abdominal cramps and flatulence on the third hospitalization day. Abdominal radiographs arose suspicion of cecal volvulus. The diagnosis was ruled out on the CT scan but however was later confirmed by an exploratory laparotomy. The management of cecal volvulus requires prompt (emergency) surgical intervention while Ogilvie syndrome can be principally managed with conservative treatment. Our patient's profile was typical for both entities. The absence of air throughout all colonic segments including the rectosigmoid on plain abdominal radiographs seems to be the most important sign in the exclusion of the Ogilvie syndrome diagnosis. Cecal volvulus and Ogilvie syndrome display overlapping clinical features at their time of presentation and need to be carefully distinguished. By uncertainty, an exploratory laparotomy should always be performed, in view of the reported high mortality rate of cecal volvulus if surgery is delayed.

  4. A case of cecal volvulus mimicking Ogilvie Syndrome in a hospitalized patient with a pelvis fracture

    PubMed Central

    Tampakis, Athanasios; Droeser, Raoul A.; Tampaki, Ekaterini Christina; von Holzen, Urs; Delko, Tarik

    2016-01-01

    Introduction Cecal volvulus and ogilvie syndrome are two entities which may display similar clinical presentation but require different treatment approaches. Presentation of case An 84-year old male patient admitted for conservative treatment of a pelvis fracture, complained of abdominal cramps and flatulence on the third hospitalization day. Abdominal radiographs arose suspicion of cecal volvulus. The diagnosis was ruled out on the CT scan but however was later confirmed by an exploratory laparotomy. Discussion The management of cecal volvulus requires prompt (emergency) surgical intervention while Ogilvie syndrome can be principally managed with conservative treatment. Our patient's profile was typical for both entities. The absence of air throughout all colonic segments including the rectosigmoid on plain abdominal radiographs seems to be the most important sign in the exclusion of the Ogilvie syndrome diagnosis. Conclusion Cecal volvulus and Ogilvie syndrome display overlapping clinical features at their time of presentation and need to be carefully distinguished. By uncertainty, an exploratory laparotomy should always be performed, in view of the reported high mortality rate of cecal volvulus if surgery is delayed. PMID:27054035

  5. An unexpected cause of small bowel obstruction in an adult patient: midgut volvulus

    PubMed Central

    Söker, Gökhan; Yılmaz, Cengiz; Karateke, Faruk; Gülek, Bozkurt

    2014-01-01

    The most important complication of intestinal malrotation is midgut volvulus because it may lead to intestinal ischaemia and necrosis. A 29-year-old male patient was admitted to the emergency department with abdominal pain. Ultrasonography (US), colour Doppler ultrasonography (CDUS), CT and barium studies were carried out. On US and CDUS, twisting of intestinal segments around the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) and alteration of the SMA–SMV relationship were detected. CT demonstrated that the small intestine was making a rotation around the SMA and SMV, which amounted to more than 360°. The upper gastrointestinal barium series revealed a corkscrew appearance of the duodenum and proximal jejunum, which is a pathognomonic finding of midgut volvulus. Prior knowledge of characteristic imaging findings of midgut volvulus is essential in order to reach proper diagnosis and establish proper treatment before the development of intestinal ischaemia and necrosis. PMID:24811563

  6. [The gastric volvulus as a cause of dyspnea. A case report].

    PubMed

    León Valdivies, Yusbiel José; Saínz Menéndez, Benito; Fernández García, Sergio; Osés Herrera, Liliana

    2015-01-01

    The gastric volvulus is a not very frequent entity that can show up in acute form or chronic. The acute volvulus can show up with the triad of Borchardt, the chronic one can be asymptomatic and its diagnosis is usually incidental. We present shows a case of an airplane pilot that presents dyspnea to the medium efforts with cough related with episodes of gastric acidity mainly after profuse foods. The diagnostic confirmation was carried out by means of radiological simple and contrasted studies. A surgical intervention was performed and the symptoms disappeared without other alterations in a period of pursuit of one year.

  7. Primary intrathoracic gastric volvulus in the neonatal period: a differential diagnosis of esophageal atresia

    PubMed Central

    El Azzouzi, Driss

    2014-01-01

    Intrathoracic gastric volvulus in the neonatal period is a rare surgical emergency. Delays in diagnosis and treatment are life-threatening due to progressive deterioration of the gastric walls. Presentation in this period can be confused with the possibility of esophageal atresia or esophageal web. The upper gastrointestinal tract contrast study is diagnostic in this disease. The authors report a case of acute intrathoracic gastric volvulus diagnosis by radiologic-contrast-study in 1-day-old girl that was confirmed at surgery. The physiopathology, classification and different presentations of this entity are briefly reviewed. PMID:25309661

  8. Gastric volvulus with diaphragmatic hernia presenting with unexplained weight loss: a delayed diagnosis.

    PubMed

    Ghatak, S

    2011-01-01

    Gastric volvulus (GV) is a rare condition that presents with epigastric pain, retching and at times, vomiting. There are two types of GV: organoaxial and mesenteroaxial. We report the case of a 49-year-old woman with chronic mesenteroaxial volvulus with left-sided diaphragmatic defect. She presented with significant weight loss over a period of two years, with nonspecific symptoms of heartburn, occasional mild epigastric pain and anorexia. The patient was diagnosed with barium meal and contrast-enhanced computed tomography imaging. She was treated with open repair of diaphragmatic defect and anterior gastropexy. She was asymptomatic and had gained weight at the six-month follow-up.

  9. Onchocerca gibsoni: increase of circulating egg antigen with chemotherapy in bovines.

    PubMed

    Forsyth, K P; Mitchell, G F; Copeman, D B

    1984-08-01

    Monoclonal antibodies directed to stage-specific surface antigens of Onchocerca gibsoni eggs were used in immunoradiometric assays to detect antigens in the sera of cattle infected with O. gibsoni. Two monoclonal antibodies detected antigens, presumably of egg origin, in sera. The target antigens appeared to be carbohydrate in nature and of variable molecular weights. Significant increases in levels of circulating egg antigens were found after treatment of infected cattle with benzimidazole compounds. These drugs cause disruption of embryogenesis and accelerated loss of worm uterine contents. In contrast, administration of either macrofilaricides or microfilaricides to infected cattle did not alter pretreatment levels of circulating egg antigens. Measurement of changes in levels of circulating antigens by immunoradiometric assays with stage-specific monoclonal antibodies provides a new means of assessing the efficacy of drugs and their site of action in onchocerciasis.

  10. Isolation of Onchocerca lupi in Dogs and Black Flies, California, USA.

    PubMed

    Hassan, Hassan K; Bolcen, Shanna; Kubofcik, Joseph; Nutman, Thomas B; Eberhard, Mark L; Middleton, Kelly; Wekesa, Joseph Wakoli; Ruedas, Gimena; Nelson, Kimberly J; Dubielzig, Richard; De Lombaert, Melissa; Silverman, Bruce; Schorling, Jamie J; Adler, Peter H; Unnasch, Thomas R; Beeler, Emily S

    2015-05-01

    In southern California, ocular infections caused by Onchocerca lupi were diagnosed in 3 dogs (1 in 2006, 2 in 2012). The infectious agent was confirmed through morphologic analysis of fixed parasites in tissues and by PCR and sequencing of amplicons derived from 2 mitochondrially encoded genes and 1 nuclear-encoded gene. A nested PCR based on the sequence of the cytochrome oxidase subunit 1 gene of the parasite was developed and used to screen Simulium black flies collected from southern California for O. lupi DNA. Six (2.8%; 95% CI 0.6%-5.0%) of 213 black flies contained O. lupi DNA. Partial mitochondrial16S rRNA gene sequences from the infected flies matched sequences derived from black fly larvae cytotaxonomically identified as Simulium tribulatum. These data implicate S. tribulatum flies as a putative vector for O. lupi in southern California.

  11. Isolation of Onchocerca lupi in Dogs and Black Flies, California, USA

    PubMed Central

    Hassan, Hassan K.; Bolcen, Shanna; Kubofcik, Joseph; Nutman, Thomas B.; Eberhard, Mark L.; Middleton, Kelly; Wekesa, Joseph Wakoli; Ruedas, Gimena; Nelson, Kimberly J.; Dubielzig, Richard; De Lombaert, Melissa; Silverman, Bruce; Schorling, Jamie J.; Adler, Peter H.; Beeler, Emily S.

    2015-01-01

    In southern California, ocular infections caused by Onchocerca lupi were diagnosed in 3 dogs (1 in 2006, 2 in 2012). The infectious agent was confirmed through morphologic analysis of fixed parasites in tissues and by PCR and sequencing of amplicons derived from 2 mitochondrially encoded genes and 1 nuclear-encoded gene. A nested PCR based on the sequence of the cytochrome oxidase subunit 1 gene of the parasite was developed and used to screen Simulium black flies collected from southern California for O. lupi DNA. Six (2.8%; 95% CI 0.6%–5.0%) of 213 black flies contained O. lupi DNA. Partial mitochondrial16S rRNA gene sequences from the infected flies matched sequences derived from black fly larvae cytotaxonomically identified as Simulium tribulatum. These data implicate S. tribulatum flies as a putative vector for O. lupi in southern California. PMID:25897954

  12. Zoonotic ocular onchocercosis caused by Onchocerca lupi in dogs in Romania.

    PubMed

    Tudor, Poliana; Turcitu, Mihai; Mateescu, Cosmin; Dantas-Torres, Filipe; Tudor, Niculae; Bărbuceanu, Florica; Ciuca, Lavinia; Burcoveanu, Ioana; Acatrinei, Dumitru; Rinaldi, Laura; Mateescu, Romanița; Bădicu, Adina; Ionașcu, Iuliana; Otranto, Domenico

    2016-02-01

    Onchocerca lupi is a filarial nematode, which infects the scleral conjunctival tissue of dogs, wolves and cats. Whilst adult nematodes localize in the conjunctive tissue of sclera or in the retrobulbar, microfilariae are found in the skin, and they are rarely diagnosed in asymptomatic animals. Since the first report of human ocular infection 5 years ago, up to 10 zoonotic cases have been identified in patients worldwide. We report, for the first time in Romania, three cases of canine ocular onchocercosis in dogs. Fragments of the harvested worms were characterized morphologically and molecularly. This article expands knowledge on the distribution of this parasite in Eastern Europe and sounds an alarm bell for ophthalmologists about the possible occurrence of human cases of O. lupi infection.

  13. First Evidence of Human Zoonotic Infection by Onchocerca lupi (Spirurida, Onchocercidae)

    PubMed Central

    Otranto, Domenico; Sakru, Nermin; Testini, Gabriella; Gürlü, Vuslat P.; Yakar, Konuralp; Lia, Riccardo P.; Dantas-Torres, Filipe; Bain, Odile

    2011-01-01

    In the past decades, cases of canine ocular onchocercosis have been reported worldwide, particularly in the United States and Europe. Onchocerca lupi, originally described from a wolf, has been implicated in some of these cases, and its zoonotic role has been hypothesized on the basis of the reexamination of two cases of human ocular onchocerciasis. In the present study, we describe, for the first time, the occurrence of O. lupi in the subconjunctival region of the human eye in a patient from Turkey. The nematode was identified as O. lupi based on its morphology and molecular phylogenetic analysis of partial cox1 and 12S ribosomal DNA genes. The results suggest that O. lupi should be considered in the differential diagnosis of other eye parasitic infections in humans. The role of dogs as natural hosts of O. lupi and the vectors of this zoonotic parasite need to be investigated. PMID:21212202

  14. The adjuvanticity of an O. volvulus-derived rOv-ASP-1 protein in mice using sequential vaccinations and in non-human primates.

    PubMed

    Wang, Jing; Tricoche, Nancy; Du, Lanying; Hunter, Meredith; Zhan, Bin; Goud, Gaddam; Didier, Elizabeth S; Liu, Jing; Lu, Lu; Marx, Preston A; Jiang, Shibo; Lustigman, Sara

    2012-01-01

    Adjuvants potentiate antigen-specific protective immune responses and can be key elements promoting vaccine effectiveness. We previously reported that the Onchocerca volvulus recombinant protein rOv-ASP-1 can induce activation and maturation of naïve human DCs and therefore could be used as an innate adjuvant to promote balanced Th1 and Th2 responses to bystander vaccine antigens in mice. With a few vaccine antigens, it also promoted a Th1-biased response based on pronounced induction of Th1-associated IgG2a and IgG2b antibody responses and the upregulated production of Th1 cytokines, including IL-2, IFN-γ, TNF-α and IL-6. However, because it is a protein, the rOv-ASP-1 adjuvant may also induce anti-self-antibodies. Therefore, it was important to verify that the host responses to self will not affect the adjuvanticity of rOv-ASP-1 when it is used in subsequent vaccinations with the same or different vaccine antigens. In this study, we have established rOv-ASP-1's adjuvanticity in mice during the course of two sequential vaccinations using two vaccine model systems: the receptor-binding domain (RBD) of SARS-CoV spike protein and a commercial influenza virus hemagglutinin (HA) vaccine comprised of three virus strains. Moreover, the adjuvanticity of rOv-ASP-1 was retained with an efficacy similar to that obtained when it was used for a first vaccination, even though a high level of anti-rOv-ASP-1 antibodies was present in the sera of mice before the administration of the second vaccine. To further demonstrate its utility as an adjuvant for human use, we also immunized non-human primates (NHPs) with RBD plus rOv-ASP-1 and showed that rOv-ASP-1 could induce high titres of functional and protective anti-RBD antibody responses in NHPs. Notably, the rOv-ASP-1 adjuvant did not induce high titer antibodies against self in NHPs. Thus, the present study provided a sound scientific foundation for future strategies in the development of this novel protein adjuvant.

  15. The Adjuvanticity of an O. volvulus-Derived rOv-ASP-1 Protein in Mice Using Sequential Vaccinations and in Non-Human Primates

    PubMed Central

    Wang, Jing; Tricoche, Nancy; Du, Lanying; Hunter, Meredith; Zhan, Bin; Goud, Gaddam; Didier, Elizabeth S.; Liu, Jing; Lu, Lu; Marx, Preston A.; Jiang, Shibo; Lustigman, Sara

    2012-01-01

    Adjuvants potentiate antigen-specific protective immune responses and can be key elements promoting vaccine effectiveness. We previously reported that the Onchocerca volvulus recombinant protein rOv-ASP-1 can induce activation and maturation of naïve human DCs and therefore could be used as an innate adjuvant to promote balanced Th1 and Th2 responses to bystander vaccine antigens in mice. With a few vaccine antigens, it also promoted a Th1-biased response based on pronounced induction of Th1-associated IgG2a and IgG2b antibody responses and the upregulated production of Th1 cytokines, including IL-2, IFN-γ, TNF-α and IL-6. However, because it is a protein, the rOv-ASP-1 adjuvant may also induce anti-self-antibodies. Therefore, it was important to verify that the host responses to self will not affect the adjuvanticity of rOv-ASP-1 when it is used in subsequent vaccinations with the same or different vaccine antigens. In this study, we have established rOv-ASP-1's adjuvanticity in mice during the course of two sequential vaccinations using two vaccine model systems: the receptor-binding domain (RBD) of SARS-CoV spike protein and a commercial influenza virus hemagglutinin (HA) vaccine comprised of three virus strains. Moreover, the adjuvanticity of rOv-ASP-1 was retained with an efficacy similar to that obtained when it was used for a first vaccination, even though a high level of anti-rOv-ASP-1 antibodies was present in the sera of mice before the administration of the second vaccine. To further demonstrate its utility as an adjuvant for human use, we also immunized non-human primates (NHPs) with RBD plus rOv-ASP-1 and showed that rOv-ASP-1 could induce high titres of functional and protective anti-RBD antibody responses in NHPs. Notably, the rOv-ASP-1 adjuvant did not induce high titer antibodies against self in NHPs. Thus, the present study provided a sound scientific foundation for future strategies in the development of this novel protein adjuvant. PMID

  16. Wandering Spleen and Organoaxial Gastric Volvulus after Morgagni Hernia Repair: A Case Report and Review of the Literature.

    PubMed

    Cantone, Noemi; Gulia, Caterina; Miele, Vittorio; Trinci, Margherita; Briganti, Vito

    2016-01-01

    Wandering spleen and gastric volvulus are two rare entities that have been described in association with congenital diaphragmatic hernia. The diagnosis is difficult and any delay can result in ischemia and necrosis of both organs. We present a case of a 13-year-old girl, previously operated on for anterior diaphragmatic hernia and intrathoracic gastric volvulus, that presented to our service for a subdiaphragmatic gastric volvulus recurrence associated with a wandering spleen. In this report we reviewed the literature, analyzing the clinical presentation, diagnostic assessment, and treatment options of both conditions, in particular in the case associated with diaphragmatic hernia.

  17. Wandering Spleen and Organoaxial Gastric Volvulus after Morgagni Hernia Repair: A Case Report and Review of the Literature

    PubMed Central

    Gulia, Caterina; Miele, Vittorio; Trinci, Margherita; Briganti, Vito

    2016-01-01

    Wandering spleen and gastric volvulus are two rare entities that have been described in association with congenital diaphragmatic hernia. The diagnosis is difficult and any delay can result in ischemia and necrosis of both organs. We present a case of a 13-year-old girl, previously operated on for anterior diaphragmatic hernia and intrathoracic gastric volvulus, that presented to our service for a subdiaphragmatic gastric volvulus recurrence associated with a wandering spleen. In this report we reviewed the literature, analyzing the clinical presentation, diagnostic assessment, and treatment options of both conditions, in particular in the case associated with diaphragmatic hernia. PMID:27703832

  18. Resection and primary anastomosis with or without modified blow-hole colostomy for sigmoid volvulus

    PubMed Central

    Coban, Sacid; Yilmaz, Mehmet; Terzi, Alpaslan; Yildiz, Fahrettin; Ozgor, Dincer; Ara, Cengiz; Yologlu, Saim; Kirimlioglu, Vedat

    2008-01-01

    AIM: To evaluate the efficacy of resection and primary anastomosis (RPA) and RPA with modified blow-hole colostomy for sigmoid volvulus. METHODS: From March 2000 to September 2007, 77 patients with acute sigmoid volvulus were treated. A total of 47 patients underwent RPA or RPA with modified blow-hole colostomy. Twenty-five patients received RPA (Group A), and the remaining 22 patients had RPA with modified blow-hole colostomy (Group B). The clinical course and postoperative complications of the two groups were compared. RESULTS: The mean hospital stay, wound infection and mortality did not differ significantly between the groups. Superficial wound infection rate was higher in group A (32% vs 9.1%). Anastomotic leakage was observed only in group A, with a rate of 6.3%. The difference was numerically impressive but was statistically not significant. CONCLUSION: RPA with modified blow-hole colostomy provides satisfactory results. It is easy to perform and may become a method of choice in patients with sigmoid volvulus. Further studies are required to further establish its role in the treatment of sigmoid volvulus. PMID:18810779

  19. [Management of sigmoid volvulus in the tropical area of Thies (Senegal)].

    PubMed

    Ba, P A; Diop, B; Soumah, S A

    2015-01-01

    The aim of this study is to report our experience in the management of sigmoid volvulus in a tropical environment. This retrospective study covers the period from June 1, 2010, to December 31, 2013, in the department of emergency surgery at the regional hospital of Thiés: 40 patients were admitted with sigmoid volvulus: 36 men and 4 women, with a mean age of 45 years (20-89 years). Twelve had chronic constipation. All four signs of occlusion were present in 72.5% of cases. Abdominal radiography confirmed the diagnosis in all cases. The volvulus resolved spontaneously in one patient, while the other 39 required laparotomy: 25 had a one-stage colectomy, and 11 patients a sigmoidectomy with a temporary colostomy. Two patients underwent a sigmoidopexy, one with a simple closure of a perforated duodenal ulcer. The morbidity rate was 7.5%, due mainly to complications of infection. The mortality rate was 10%. After a mean follow-up of 2.77 months (range: 15 days-12 months), no recurrences were observed. Sigmoid volvulus is a common condition in Africa especially in younger patients. The diagnosis is easy, based on clinical and abdominal radiography findings. Several procedures have been described but the one-stage colectomy remains the method of choice, especially in tropical areas where socioeconomic conditions are difficult.

  20. Filaricidal activities on Onchocerca ochengi and Loa loa, toxicity and phytochemical screening of extracts of Tragia benthami and Piper umbellatum.

    PubMed

    Cho-Ngwa, Fidelis; Monya, Elvis; Azantsa, Boris K; Manfo, Faustin Pascal T; Babiaka, Smith B; Mbah, James A; Samje, Moses

    2016-08-30

    Onchocerciasis is the world's second leading infectious cause of blindness. Its control is currently hampered by the lack of a macrofilaricidal drug and by severe adverse events observed when the lone recommended microfilaricide, ivermectin is administered to individuals co-infected with Loa loa. Therefore, there is the need for a safe and effective macrofilaricidal drug that will be able to cure the infection and break transmission cycles, or at least, an alternative microfilaricide that does not kill L. loa microfilariae (mf). Fourteen extracts from two medicinal plants, Tragia benthami and Piper umbellatum were screened in vitro against Onchocerca ochengi parasite and L. loa mf. Activities of extracts on male worms and microfilariae were assessed by motility reduction, while MTT/Formazan assay was used to assess biochemically the death of female worms. Cytotoxicity and acute toxicity of active extracts were tested on monkey kidney cells and Balb/c mice, respectively. At 500 μg/mL, all extracts showed 100 % activity on Onchocerca ochengi males and microfilariae, while 9 showed 100 % activity on female worms. The methylene chloride extract of Piper umbellatum leaves was the most active on adult male and female worms (IC50s: 16.63 μg/mL and 35.65 μg/mL, respectively). The three most active extracts on Onchocerca ochengi females were also highly active on Loa loa microfilariae, with IC50s of 35.12 - 13.9 μg/mL. Active extracts were generally more toxic to the worms than to cells and showed no acute toxicity to Balb/c mice. Phytochemical screening revealed the presence of saponins, steroids, tannins and flavanoids in the promising extracts. These results unfold potential sources of novel anti-Onchocerca lead compounds and validate the traditional use of the plants in onchocerciasis treatment.

  1. Rare small intestinal volvulus from entrapment in hepato-diaphragmatic adhesions in a 45-year-old lady

    PubMed Central

    Olaoye, Iyiade Olatunde; Adesina, Micheal Dapo

    2016-01-01

    Small intestinal volvulus is rare in adults and rarely caused by string adhesions between the liver and the diaphragm. Similar adhesions were described in Fitz-Hugh-Curtis syndrome. We report a 45-year-old lady with small intestinal volvulus from entrapment of a loop in string adhesions between the liver and the diaphragm. Her plain radiographs showed a significant shadow of the trapped loop. PMID:28003317

  2. Intussusception and volvulus secondary to jejunal adenocarcinoma in an adult Nigerian male: a case report.

    PubMed

    Okolo, C A; Afolabi, A O; Sahabi, S M

    2010-12-01

    A 31 year-old Nigerian man with jejuno-jejunal intussusception with the lead point being an adenocarcinoma complicated by small intestinal volvulus is presented. The subtle clinical features of an underlying small bowel malignancy were masked by the overwhelming clinical and radiological features of intussusception. rare case is reported to remind clinicians to have an increased index of suspicion of malignancy in patients who present with the usual features of chronic anemia, weight loss and loss of appetite with an intra-abdominal mass. The presentation of acute intestinal obstruction, with mesenteric vein thrombosis probably due to intussusception or volvulus should not however lower the suspicion. Histological evaluation of surgical biopsies is of immense importance.

  3. [Volvulus of the small bowel due to ascaris lumbricoides package: about a case].

    PubMed

    Diouf, Cheikh; Kane, Ahmed; Ndoye, Ndeye Aby; Ndour, Oumar; Faye-Fall, Aimé Lakh; Fall, Mbaye; Alumeti, Désiré Munyali; Ngom, Gabriel

    2016-01-01

    We report an exceptional case of a 7 year-old patient with necrotic small bowel volvulus due to adult ascaris lumbricoides. At the admission, the child had intestinal obstruction evolving since two days with alteration of general state. Abdominal radiography without preparation showed small bowel air-fluid levels and tiger-stripe appearance evoking the diagnosis of acute intestinal obstruction associated with abdominal mass. After resuscitation, the surgical treatment consisted of laparotomy which showed necrotic volvulus of the terminal ileum containing adult ascaris lumbricoides. The patient underwent small bowel resection, approximately one meter of affected section was removed and then an ileostomy was performed. The evolution was favorable. The patient underwent ileorectal anastomosis four weeks later. After a 2 year follow-up period the child had no symptoms.

  4. Gastric dilatation and volvulus in a brachycephalic dog with hiatal hernia.

    PubMed

    Aslanian, M E; Sharp, C R; Garneau, M S

    2014-10-01

    A brachycephalic dog was presented with an acute onset of retching and abdominal discomfort. The dog had a chronic history of stertor and exercise intolerance suggestive of brachycephalic airway obstructive syndrome. Radiographs were consistent with a Type II hiatal hernia. The dog was referred and within hours of admission became acutely painful and developed tympanic abdominal distension. A right lateral abdominal radiograph confirmed gastric dilatation and volvulus with herniation of the pylorus through the hiatus. An emergency exploratory coeliotomy was performed, during which the stomach was derotated, and an incisional gastropexy, herniorrhaphy and splenectomy were performed. A staphylectomy was performed immediately following the exploratory coeliotomy. The dog recovered uneventfully. Gastric dilatation and volvulus is a potentially life-threatening complication that can occur in dogs with Type II hiatal hernia and should be considered a surgical emergency. © 2014 British Small Animal Veterinary Association.

  5. Le volvulus gastrique idiopathique aigu: à propos d'une nouvelle observation

    PubMed Central

    Abdelilah, Mouhsine; Jihad, Anzaoui; Rachid, Bouchentouf

    2013-01-01

    Le volvulus gastrique est une rotation anormale de l'estomac autour de son axe. La forme aiguë constitue une urgence chirurgicale. Le diagnostic est souvent retardé en raison d'une symptomatologie fréquemment non spécifique. Des signes respiratoires tels la dyspnée et le hoquet peuvent révéler cette pathologie. Les auteurs rapportent une nouvelle observation de volvulus gastrique aigu chez un adolescent de 17 ans, diagnostiqué par la tomodensitométrie, et confirmé par une intervention chirurgicale. Le traitement est chirurgical et consiste à détordre et fixer l'estomac pour prévenir la récidive. PMID:23503200

  6. Volvulus de la vésicule biliaire: à propos d'une observation

    PubMed Central

    Tandian, Foulaké; Cissé, Mamadou; Touré, Alpha Oumar; Seck, Mamadou; Thiam, Ousmane; Guèye, Mohamadou Lamine

    2015-01-01

    Le volvulus de la vésicule biliaire (VVB) est une affection rare et de diagnostic difficile; le plus souvent per opératoire. Nous rapportons 1 cas de VVB avec gangrène de la vésicule biliaire chez un enfant de 10 ans. Le diagnostic a été porté à l'exploration chirurgicale réalisée en urgence pour un syndrome occlusif fébrile. Il s'agissait d'un volvulus total de la vésicule biliaire. A cette occasion, nous rappelons les aspects diagnostiques et thérapeutiques de cette affection. PMID:26140071

  7. [Predisposing factors, clinical picture and mortality in volvulus of the small intestine].

    PubMed

    Díaz Plasencia, J; Huaynalaya, E; Rodríguez, F; Rebaza, H

    1992-01-01

    This retrospective study evaluated predisposing factors, clinical picture and the methods of treatment related to morbidity and mortality of 19 small bowel volvulus (SBV) who underwent operation at Belen Hospital (Trujillo-Peru) during the last 26 years (1966-1992). The SBV was 1.6% of all cases of intestinal obstruction in this period and 10.8% of all intestinal volvulus. The median age was of 43 +/- 20.5 years (range, 6 to 78 years) and the majority of them were between 41 and 60 years. Sixteen cases (84.2%) were men from Indian and Spanish extraction and most of them were farmers and came from the Sierra of the Department of La Libertad. Two cases (10.5%) had non-related antecedents previous surgery. In six patients (31.6%) the volvulus was less than seven day's duration and in thirty (68.4%) it was more eight day's duration with previous attacks of obstruction (median: 19.3 days, range: 17 hours to 94 days). Pain, vomiting and distention were present in almost all of these cases. The most frequent abdominal finding was distention. The location of the volvulus was: ileum, 12 cases (63.2%), root of mesentery, 4 cases (21%) and jejunum, 3 cases (15.8%). Gangrenous bowel was present in six patients (31.5) and gangrenous intestine with perforation in two cases (10.5%) who underwent resection of the involved segment with primary anastomosis. In this group one patient (5.2%) died of sepsis and the wound infection rate was of 37.5%. There was no statistically significant correlation with the duration of illness and the presence of gangrenous loops or the mortality rate (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Gastric dilatation-volvulus as complication after surgical removal of a splenic haemangiosarcoma in a dog.

    PubMed

    Marconato, L

    2006-09-01

    An 8-year-old crossbreed dog presented after one episode of acute collapse due to rupture of a splenic haemangiosarcoma. Following splenectomy the dog recovered well. Two days after discharge the dog re-presented because of gastric dilatation-volvulus (GDV) that eventually led to his death. Splenectomy to remove a voluminous splenic tumour may predispose to GDV and dogs may benefit from concurrent prophylactic gastropexy.

  9. Struggling with a Gastric Volvulus Secondary to a Type IV Hiatal Hernia

    PubMed Central

    George, Dafnomilis; Apostolos, Pappas V.; Athanasios, Panoutsopoulos; Emmanuel, Lagoudianakis E.; Nikolaos, Koronakis E.; Nikolaos, Panagiotopoulos; Charalampos, Seretis; George, Karanikas; Andreas, Manouras J.

    2010-01-01

    Type IV hiatal hernias are characterized by herniation of the stomach along with associated viscera such as the spleen, colon, small bowel, and pancreas through the esophageal hiatus. They are relatively rare, representing only about 5%–7% of all hernias, and can be associated with severe complications. We report a 71-year-old veteran wrestler who presented to our department with a type IV paraesophageal hernia containing a gastric volvulus and treated successfully with emergency operation. PMID:20981251

  10. Sigmoid volvulus in a young woman nearly misdiagnosed as fecal impaction.

    PubMed

    Chang, Chih-Jung; Hsieh, Tsung-Hung; Tsai, Kuang-Chau; Fan, Chieh-Min

    2013-03-01

    Volvulus of the sigmoid colon is a potentially life-threatening condition rarely seen in younger age groups and is male predominant. We report a previously healthy young woman with the triad of constipation, progressive abdominal distension, and severe abdominal pain, with plain-film x-ray studies mimicking stool impaction and computed tomography disclosing the typical findings of sigmoid volvulus. The case reminds Emergency Physicians to consider sigmoid volvulus if mechanical obstruction is suspected, even in a young patient. A 33-year-old woman had the triad of symptoms for 3 days. Physical examination did not show peritoneal signs. Digital rectal examination disclosed neither palpable mass nor stool in rectum. Computed tomography revealed "coffee bean" sign and "whirl" sign. Laparoscopy demonstrated redundant sigmoid colon and she was treated with detorsion with colopexy uneventfully. Sigmoid volvulus is rarely seen in developed countries. Clinical manifestations vary with disease progression, but it typically presents with a triad of constipation, progressive abdominal distension, and severe abdominal pain. Plain-film x-ray studies can demonstrate a coffee bean or "omega loop" (inverted-U sigmoid) sign in <60% cases, but it was reported as high as 86% in computed tomography. The whirl sign on computed tomography might also be observed. The cause is multifactorial and colonic length is the most important predisposing factor. Flexible colon fiberscopic decompression followed by elective definitive surgery is the treatment choice, but exploratory laparotomy is mandatory if any complicated entity occurs. The mortality rate is still >50% when bowel gangrene develops. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. First detection of Onchocerca lupi infection in dogs in southern Spain.

    PubMed

    Miró, Guadalupe; Montoya, Ana; Checa, Rocío; Gálvez, Rosa; Mínguez, Juan José; Marino, Valentina; Otranto, Domenico

    2016-05-18

    Onchocerca lupi causes ocular pathology of varying severity in dogs from south-western United States, western Europe and northern Asia. This filarioid has also been recognized as a zoonotic agent in Tunisia, Turkey, Iran and the USA, though the information about the biology and epidemiology of this infection is largely unknown. In Europe, O. lupi has been reported in dogs from Germany, Greece, Hungary, Portugal and Romania and in a cat from Portugal. The present study was designed to establish the occurrence of O. lupi in dogs in southwestern Spain. In the present study a total of 104 dogs of different breed, sex, and age living in a shelter in Huelva (SW Spain) were examined. Skin snip samples were collected using a disposable scalpel in the forehead and inter-scapular regions and stored as aliquots in saline solution (0.5 ml) before light microscopy observation of individual sediments (20 μl) and molecular examination. Of the 104 dogs examined, 5 (4.8 %) were skin snip-positive for O. lupi: two by microscopy and three by PCR. One of the O. lupi infected dogs showed neurological signs but ocular ultrasonography and/or MRI detected no abnormalities. This first report of O. lupi infection in dogs in southern Spain expands the range of geographical distribution of this parasite and sounds an alarm bell for practitioners and physicians working in that area.

  12. Case report of an epidural cervical Onchocerca lupi infection in a 13-year-old boy.

    PubMed

    Chen, Tsinsue; Moon, Karam; deMello, Daphne E; Feiz-Erfan, Iman; Theodore, Nicholas; Bhardwaj, Ratan D

    2015-08-01

    A 13-year-old boy presented with fever and neck pain and stiffness, which was initially misdiagnosed as culture-negative meningitis. Magnetic resonance images of the brain and cervical spine demonstrated what appeared to be an intradural extramedullary mass at the C1-3 level, resulting in moderate cord compression, and a Chiari Type I malformation. The patient underwent a suboccipital craniectomy and a C1-3 laminectomy with intradural exploration for excisional biopsy and resection. The lesion containing the parasite was extradural, extending laterally through the C2-3 foramina. Inflammatory tissue secondary to Onchocerca lupi infection was identified, and treatment with steroids and doxycycline was initiated. At the 6-month follow-up, the patient remained asymptomatic, with MR images demonstrating a significant reduction in lesional size. However, 10 weeks postoperatively, the infection recurred, necessitating a second operation. The patient was treated with an additional course of doxycycline and is currently maintained on ivermectin therapy. This is the second reported case of cervical O. lupi infection in a human. In the authors' experience, oral doxycycline alone was insufficient in controlling the disease, and the addition of ivermectin therapy was necessary.

  13. Onchocerciasis caused by Onchocerca lupi: an emerging zoonotic infection. Systematic review.

    PubMed

    Grácio, António J Santos; Richter, Joachim; Komnenou, Anastasia Th; Grácio, Maria Amélia

    2015-07-01

    Globalization has increased circulation of people, their food, livestock and pets in the world, and changes in the environment, climate and human behaviour have led to the rapid expansion of emerging infections throughout the world. One of the reasons of a new pathogen affecting humans is the passage from an animal to a human being. Onchocerca (O.) lupi, a filarial worm first described in a wolf in 1967, is an emerging pathogen which has been incriminated as the etiological agent for 205 canine, 2 feline and 18 human infections in Europe, Tunisia, Turkey, Iran and the USA. Most frequent findings in animals and humans are monolateral or asymmetrical variably painful subconjunctival swellings and nodules containing immature or mature worms affecting the eye and/or adjacent tissues accompanied by conjunctival hyperemia. Occasionally, subcutaneous nodules and masses affecting the spinal cord have been observed in humans. Diagnosis of O. lupi is achieved by microscopy of excised adult female worms which exhibit a particular cuticular structure and molecular analysis. Treatment consists in worm removal accompanied by antihelminthic, antibiotic and anti-inflammatory therapy.

  14. Small bowel volvulus with intussusception: an unusual revelation of neuroendocrine tumor.

    PubMed

    Lachhab, Imad; Traoré, Boubacar Zan; Saoud, Omar; Khedid, Yahia Zain Al Abidine; Zouaidia, Fouad; Echarrab, Mahjoub; Chkoff, Mohamed Rachid

    2015-01-01

    The primary malignant tumors of the small bowel are rare, representing 1 to 1.4% of all gastrointestinal tumors. We report a case of a 33 year-old women, admitted to our emergency department of visceral surgery for acute abdomen. The clinical examination revealed diffuse abdominal distension, defenseless, the hernia orifices were free and the rectal examination was normal. The biological test showed no hydro electrolytic disorders with normal hemoglobin and normal renal function. The abdominal CT-Scan showed signs of bowel obstruction due to a volvulus with intussusception without ischemia. The patient was operated urgently; the exploration has revealed a small bowel obstruction in the ileum with volvulus, an intussusceptum associated with a retractile mesenteritis, and the hepatic exploration found no metastases. The patient underwent a bowel resection taking away the intussusceptum with the infiltrated mesentery. The postoperative course was uneventful. The pathological result has proved a well-differentiated neuroendocrine tumor with five free nodes. Through this observation, we aim to highlight that an obstruction of small bowel with volvulus and intussusception could be exceptionally due to a neuroendocrine tumor, this complication has enabled a relatively early diagnosis in the absence of metastases and a 6-month follow-up without recurrence is a demonstration.

  15. [Elective laparoscopic right colectomy for caecal volvulus: case report and literature review].

    PubMed

    Ramírez-Ramírez, Moisés Marino; Villanueva-Sáenz, Eduardo; Ramírez-Wiella-Schwuchow, Gustavo

    Caecal volvulus is an uncommon cause of intestinal obstruction. Its clinical presentation is non-specific, with the diagnosis usually confirmed by barium enema and abdominal computed tomography. Treatment depends on many factors, and minimally invasive approaches are becoming the treatment of choice. A 54 years old female, admitted to the Emergency Department with clinical symptoms of intestinal obstruction. On physical examination she had a palpable, firm, and tympanitic mass in the right abdomen, with peritoneal irritation. The radiographs of the abdomen, barium enema and abdominal computed tomography showed caecal volvulus. As she showed a full remission after the barium enema, with no clinical or biochemical data of systemic inflammatory response syndrome or peritoneal irritation, she was discharged to her home. Two weeks later, a laparoscopic right hemicolectomy was performed with an ileo-transverse extracorporeal anastomosis. Her progress was satisfactory, and she was discharged 4 days after surgery due to improvement. Caecal volvulus is a rare cause of intestinal obstruction, with high mortality rates, and is caused by excessive mobility of the caecum. Its incidence is increasing. Treatment depends on many factors. Early non-surgical untwisting, followed by an elective laparoscopic surgical procedure offers several advantages and reduces mortality. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  16. Imaging, Endoscopic and Genetic Assessment of Marfan Syndrome Presenting with Sigmoid Volvulus: A Review.

    PubMed

    Inayat, Faisal; Hurairah, Abu; Shaikh, Faiq

    2016-05-21

    The Marfan syndrome (MFS) is a pleiotropic, autosomal dominant disorder of connective tissue with highly variable clinical manifestations. It primarily involves the skeletal, cardiovascular, and ocular systems; however, gastrointestinal complications are rare. Herein, we describe the case of a 31-year-old male who initially presented with acute abdominal pain for one day. His imaging features revealed a dilated sigmoid colon, consistent with sigmoid volvulus that was immediately decompressed. Surgical resection was recommended to treat the sigmoid volvulus. Preceding the treatment, the patient underwent an extensive workup, including an echocardiography that revealed aortic root dilatation. His clinical history, physical exam, and echocardiographic findings raised the suspicion for MFS. Subsequently, the diagnosis of MFS was confirmed on genetic testing. This is a case that highlights the multidisciplinary (clinical, radiological, endoscopic, molecular/genetic) approach to diagnose a patient with MFS who presented with symptomatic sigmoid volvulus. As this presentation may be a harbinger of more severe manifestations of MFS, it is important to identify it as such in order to accomodate for timely management.

  17. An unusual cause of paediatric abdominal pain: Mesenteric masses accompanied with volvulus.

    PubMed

    Yang, Chao; Wang, Shan; Zhang, Jun; Kong, Xiang Ru; Zhao, Zhenzhen; Li, Chang Chun

    2016-07-01

    Volvulus caused by mesenteric masses is rare and may result in serious consequences. This study aimed to better characterize volvulus caused by mesenteric masses in children. A retrospective study was conducted in 24 patients who underwent surgical treatment between January 1994 and January 2014 in one single institution. There were 10 boys and 14 girls. The most frequent findings were abdominal pain (100%), emesis (91.7%) and nausea (83.3%). Physical examination showed positive ileus signs in majority cases, and palpable mass was found in half of the patients. Ultrasound and CT scans revealed mesenteric masses in 21 and 24 patients, and 'whirlpool sign' was observed in 19 and 22 patients, respectively. Emergency laparotomy was performed in all patients. Histological examination revealed that 18 cystic masses were lymphangioma, 5 solid cases were lipoma and the remaining one was lipoblastoma. The postoperative course was uneventful in 22 patients, and postoperative obstruction and incision infection occurred in 2 patients. There was no evidence of recurrence at follow-up. Volvulus caused by mesenteric masses is a rare but potentially life-threatening cause of abdominal pain, which should be considered in the differential diagnosis of paediatric acute abdominal pain.

  18. Imaging, Endoscopic and Genetic Assessment of Marfan Syndrome Presenting with Sigmoid Volvulus: A Review

    PubMed Central

    Hurairah, Abu; Shaikh, Faiq

    2016-01-01

    The Marfan syndrome (MFS) is a pleiotropic, autosomal dominant disorder of connective tissue with highly variable clinical manifestations. It primarily involves the skeletal, cardiovascular, and ocular systems; however, gastrointestinal complications are rare. Herein, we describe the case of a 31-year-old male who initially presented with acute abdominal pain for one day. His imaging features revealed a dilated sigmoid colon, consistent with sigmoid volvulus that was immediately decompressed. Surgical resection was recommended to treat the sigmoid volvulus. Preceding the treatment, the patient underwent an extensive workup, including an echocardiography that revealed aortic root dilatation. His clinical history, physical exam, and echocardiographic findings raised the suspicion for MFS. Subsequently, the diagnosis of MFS was confirmed on genetic testing. This is a case that highlights the multidisciplinary (clinical, radiological, endoscopic, molecular/genetic) approach to diagnose a patient with MFS who presented with symptomatic sigmoid volvulus. As this presentation may be a harbinger of more severe manifestations of MFS, it is important to identify it as such in order to accomodate for timely management. PMID:27382527

  19. Operative factors associated with short-term outcome in horses with large colon volvulus: 47 cases from 2006 to 2013

    PubMed Central

    Gonzalez, L. M.; Fogle, C. A.; Baker, W. T.; Hughes, F. E.; Law, J. M.; Motsinger-Reif, A. A.; Blikslager, A. T.

    2014-01-01

    Summary Reasons for performing the study There is an important need for objective parameters that accurately predict the outcome of horses with large colon volvulus. Objectives To evaluate the predictive value of a series of histomorphometric parameters on short-term outcome, as well as the impact of colonic resection on horses with large colon volvulus. Study Design Retrospective cohort study Methods Adult horses admitted to the Equine and Farm Animal Veterinary Center at North Carolina State University, Peterson & Smith and Chino Valley Equine Hospitals between 2006–2013 undergoing an exploratory celiotomy, diagnosed with large colon volvulus of ≥360 degrees, where a pelvic flexure biopsy was obtained, and that recovered from general anaesthesia, were selected for inclusion in the study. Logistic regression was used to determine associations between signalment, histomorphometric measurements of interstitial: crypt ratio, degree of haemorrhage, percentage loss of luminal and glandular epithelium, as well as colonic resection with short-term outcome (discharge from the hospital). Results Pelvic flexure biopsies from 47 horses with large colon volvulus were evaluated. Factors that were significantly associated with short-term outcome on univariate logistic regression were Thoroughbred breed (P = 0.04), interstitial: crypt ratio >1 (P = 0.02) and haemorrhage score ≥3 (P = 0.005). Resection (P = 0.92) was not found to be significantly associated with short-term outcome. No combined factors increased the likelihood of death in forward stepwise logistic regression modelling. A digitally quantified haemorrhage area measurement strengthened the association of haemorrhage with non-survival in cases of large colon volvulus. Conclusions Histomorphometric measurements of interstitial: crypt ratio and degree of haemorrhage predict short-term outcome in cases of large colon volvulus. Resection was not associated with short-term outcome in horses selected for this study

  20. Analysis of glutathione-enhanced differentiation by microfilariae of Onchocerca lienalis (Filarioidea: Onchocercidae) in vitro.

    PubMed

    Pollack, R J; Lok, J B; Donnelly, J J

    1988-06-01

    Reduced glutathione (GSH), but not its oxidized form (GSSG), stimulated development of Onchocerca lienalis microfilariae to the late first-larval stage in vitro. The degree and frequency of development was dose-related with a peak of activity at 15 mM, a concentration that is similar to known intracellular levels of GSH. To determine the mode(s) of action of this multifunctional compound, other reducing agents (L-cysteine, dithiothreitol), cysteine delivery agents (N-acetyl-L-cysteine, L-thiazolidine-4-carboxylic acid, L-2-oxothiazolidine-4-carboxylic acid), cysteine analogues (S-methyl-L-cysteine, D-glucose-L-cysteine, cysteine ethyl ester), free-component amino acids of GSH (glutamic acid, cysteine, and glycine), a specific metabolic inhibitor of gamma-glutamyl synthetase (buthionine sulfoximine), and an inhibitor of gamma-glutamyl transpeptidase (gamma-glutamyl glutamic acid) were also tested at concentrations of 0.01-50 mM in this system. N-acetyl-L-cysteine at 1-5 mM and D-glucose-L-cysteine at 2.5-10 mM significantly enhanced development. In contrast to those worms maintained in GSH-supplemented medium, microfilariae exposed to GSH for only the first 24 hr showed no enhancement by day 7 in culture. Neither buthionine sulfoximine nor gamma-glutamyl glutamic acid at 0.01-35 mM inhibited the effects of 15 mM GSH or 1 mM N-acetyl-L-cysteine. Results indicate that GSH or other cysteine analogues possessing a free sulfhydryl group must be present in the extranematodal environment to support microfilarial differentiation in vitro.

  1. Vector competence of Simulium oyapockense s.l. and S. incrustatum for Onchocerca volvulus: Implications for ivermectin-based control in the Amazonian focus of human onchocerciasis, a multi-vector-host system.

    PubMed

    Grillet, María-Eugenia; Villamizar, Nestor J; Frontado, Hortencia L; Cortez, José; Escalona, Marisela; Botto, Carlos; Basáñez, María-Gloria

    2008-08-01

    Although it is now well established that in the Amazonian onchocerciasis focus, straddling between Venezuela and Brazil, the main vectors in the highland (hyperendemic) and lowland (hypoendemic) areas, are respectively Simulium guianense sensu lato Wise and S. oyapockense s.l. Floch and Abonnenc, investigation of the vectorial role of a third anthropophagic species, Simulium incrustatum Lutz has remained inconclusive. Here we compare the vector competence of S. incrustatum with that of S. oyapockense s.l. by conducting, in the Venezuelan part of the focus, a series of feeding experiments designed to analyze their relative: (a) microfilarial intakes when fed upon the same skin load; (b) proportions of microfilariae (mf) surviving damage inflicted by the cibarial armature (present in both species); and (c) infective (L3) larval outputs. Although the ability of S. oyapockense s.l. to ingest mf, for a given microfilaridermia, was markedly higher than that of S. incrustatum, the (density-dependent) proportions of those ingested mf that were damaged by the armature were also consistently higher, with the resulting output of L3 larvae being significantly lower in S. oyapockense s.l. than in S. incrustatum. These results indicate that S. incrustatum plays a more important role in onchocerciasis transmission in the Amazonian focus than previously realized. We discuss the implications of our findings for the control and elimination of onchocerciasis with mass administration of ivermectin in this focus, where the three main anthropophagic species often co-occur.

  2. New tools and insights to assist with the molecular identification of Simulium guianense s.l., main Onchocerca volvulus vector within the highland areas of the Amazonia onchocerciasis focus.

    PubMed

    Crainey, James L; Mattos-Glória, Aline; Hamada, Neusa; Luz, Sérgio L B

    2014-03-01

    Following the success of the Onchocerciasis Elimination Programme for the Americas (OEPA), there is now just one Latin American onchocerciasis focus where onchocerciasis transmission is described as 'on-going:' the Amazonia Onchocerciasis focus. In the hyperendemic highland areas of the Amazonia focus, Simulium guianense s.l. Wise are the most important vectors of the disease. Populations of S. guianense s.l. are, however, known to vary in their cytogenetics and in a range of behaviours, including in their biting habits. In the hypoendemic lowland areas of the Amazonia focus, for example, S. guianense s.l. are generally regarded as zoophilic and consequently unimportant to disease transmission. Robust tools, to discriminate among various populations of S. guianense s.l. have, however, not yet been developed. In the work reported here, we have assessed the utility of a ribosomal DNA sequence fragment spanning the nuclear ribosomal ITS-1, ITS-2 and 5.8S sequence regions and a ∼850 nucleotide portion of the mitochondrial cytochrome oxidase gene (CO1) for species-level identification and for resolving the within species substructuring. We report here how we have generated 78 CO1 sequences from a rich set of both zoophilic and anthropophilic populations of S. guianense s.l. that were collected from eight sites that are broadly distributed across Brazil. Consistent with previous findings, our analysis supports the genetic isolation of Simulium litobranchium from S. guianense s.l. In contrast with previous findings, however, our results did not provide support for the divergence of the two species prior to the radiation of S. guianense s.l. In our analysis of the S. guianense s.l. ribosomal DNA sequence trace files we generated, we provide clear evidence of multiple within-specimen single nucleotide polymorphisms and indels suggesting that S. guianense s.l. ribosomal DNA is not a good target for conventional DNA barcoding. This is the first report of S. guianense s.l. within individual ribosomal DNA variation and thus the first evidence that the species is not subject to the normal effects of concerted evolution. Collectively, these data illustrate the need for diverse sampling in the development of robust molecular tools for vector identification and suggest that ribosomal DNA might be able to assist with resolving S. guianense s.l. species substructuring that C01 barcoding has hitherto failed to.

  3. Defining parasite biodiversity at high latitudes of North America: new host and geographic records for Onchocerca cervipedis (Nematoda: Onchocercidae) in moose and caribou

    USDA-ARS?s Scientific Manuscript database

    Onchocerca cervipedis is a filarioid nematode of cervids reported from Central America to boreal regions of North America. It is found primarily in subcutaneous tissues of the legs, and is popularly known as ‘legworm’. Blackflies are intermediate hosts and transmit larvae to ungulates when they bloo...

  4. Laparoscopic gastropexy for the treatment of gastric volvulus associated with wandering spleen.

    PubMed

    François-Fiquet, Caroline; Belouadah, Mohamed; Chauvet, Philippe; Lefebvre, Francis; Lefort, Gérard; Poli-Merol, Marie Laurence

    2009-04-01

    A 2.5-year-old boy was referred to the emergency room for a sudden onset of diffuse and increasing abdominal pain with lethargy, abdominal distension, and vomiting, all in the past 24 hours. A plain abdominal X-ray showed gastric distension. Two liters of gastric contents were evacuated by suction. The abdominal sonogram showed an unusual position of the spleen in the left-lower quadrant, with no splenic ischemia. The diagnosis of gastric volvulus associated with a wandering spleen was then evoked. Laparoscopic exploration revealed a nonischemic spleen, absence of normal supporting ligaments for the spleen, and gastric distension with flaccid gastric walls. The spleen was then easily moved in the left-under quadrant. A parietal peritoneal posterolateral incision was made, opposite the large gastric curve, up to the diaphragm (7 cm). This delimitated a sharp demarcation zone between the two edges of the incised peritoneum. The stomach was fixed to the peritoneal incision, covering and anchoring the spleen in a good position. Recovery was uneventful, and an abdominal sonogram performed 4 years after the surgery shows a viable spleen in its correct location. The rarity of gastric volvulus associated with a wandering spleen and its fast clinical improvement with medical treatment often delays the diagnosis and the surgical treatment. Laparoscopy in this case has a dual relevance: diagnosis and therapeutic management (splenectomy or gastropexy). Laparoscopic gastropexy for the treatment of gastric volvulus associated with a wandering spleen is an easy procedure and combines the advantages of all the surgical techniques previously described.

  5. Volvulus du mesentere sur lipome mesenterique: à propos d’un cas

    PubMed Central

    Dème, Hamidou; Badji, Nfally; Akpo, Léra Géraud; Touré, Mouhamed Hamine; Draha, Ronald; Niang, Fallou Gallas; Diop, Abdoulaye Dione; Niang, El Hadj

    2016-01-01

    Nous rapportons le cas d'une patiente de 7 ans qui a consulté pour une douleur abdominale aigue paroxystique siégeant au niveau de l'épigastre associée à des vomissements sans arrêt des matières et des gaz. L'examen clinique ainsi que le bilan biologique étaient sans particularité. L'échographie abdominale demandée en première intention a montré une masse du flanc et de la fosse iliaque droite échogène, homogène à contours réguliers sans signal vasculaire au Doppler associée à un signe du tourbillon des vaisseaux mésentériques. A la tomodensitométrie cette masse correspondait à une formation lipomateuse, bien limitée, exerçant un effet de masse sur le cœcum avec volvulus du mésentère au contact. La disposition des vaisseaux mésentériques à leur origine était normale. Le diagnostic de volvulus du mésentère sur lipome a été retenu. La prise en charge chirurgicale et l'analyse anatomopathologique de la pièce opératoire a confirmé le diagnostic. Nous allons à travers ce cas clinique revoir l'apport de l'échographie et du scanner dans le diagnostic de volvulus du mésentère. PMID:28250879

  6. Imperforate Anus with Jejunal Atresia Complicated by Intestinal Volvulus: A Case Report.

    PubMed

    Joung, Hae Soo; Guerrero, Alexandra Leon; Tomita, Sandra; Kuenzler, Keith A

    2016-01-01

    Anorectal malformations (ARMs) commonly co-occur with other congenital anomalies, particularly VACTERL (vertebral, anorectal, cardiac, tracheal, esophageal, renal, limb, and duodenal) associations. However, this collection of associations is not comprehensive, and other concurrent anomalies may exist that can be missed during the standard work-up of patients with ARMs. We present a rare case of a neonate with a low ARM with concurrent jejuno-ileal atresia that was diagnosed after the correction of the ARM when the patient developed segmental volvulus. This case illustrates the importance of having a high index of suspicion when deviation from a classic presentation occurs.

  7. Neonatal intestinal volvulus and preduodenal portal vein associated with situs ambiguus: report of a case.

    PubMed

    Watanabe, Toshihiko; Nakano, Miwako; Yamazawa, Kazuki; Maeyama, Katsuhiro; Endo, Masao

    2011-05-01

    Situs ambiguus is a rare lateralization anomaly that is frequently associated with other malformations, including preduodenal portal vein (PDPV), intestinal malrotation, and cardiovascular anomalies. This is a case report on a newborn that was clinically diagnosed with situs ambiguus and midgut volvulus. During surgery the patient was found to have intestinal malrotation, Meckel's diverticulum, and PDPV that was not a direct cause of duodenal obstruction. The patient was treated with Ladd's procedure and resection of Meckel's diverticulum. It is important to be familiar with the spectrum of situs anomalies to prevent trauma to the portal vein with serious complications during surgery.

  8. Imperforate Anus with Jejunal Atresia Complicated by Intestinal Volvulus: A Case Report

    PubMed Central

    Joung, Hae Soo; Guerrero, Alexandra Leon; Tomita, Sandra; Kuenzler, Keith A.

    2016-01-01

    Anorectal malformations (ARMs) commonly co-occur with other congenital anomalies, particularly VACTERL (vertebral, anorectal, cardiac, tracheal, esophageal, renal, limb, and duodenal) associations. However, this collection of associations is not comprehensive, and other concurrent anomalies may exist that can be missed during the standard work-up of patients with ARMs. We present a rare case of a neonate with a low ARM with concurrent jejuno-ileal atresia that was diagnosed after the correction of the ARM when the patient developed segmental volvulus. This case illustrates the importance of having a high index of suspicion when deviation from a classic presentation occurs. PMID:27896167

  9. Total management of short gut secondary to midgut volvulus without prolonged total parenteral alimentation.

    PubMed

    Tepas, J J; MacLean, W C; Kolbach, S; Shermeta, D W

    1978-12-01

    Absorption studies in rats have shown that intestinal adaptation after catastrophic injury can be stimulated by early enteral feeding. Using this concept, we have devised a technique of early initiation and advancement of oral feedings that begins with Cho-Free and Polycose and gradually adds sucrose and MCT in increasing proportions. The increasing complexity and caloric density of this diet provide sufficient nutrition to allow weaning from total parenteral alimentation within 2--3 wk. Our preliminary experience in babies with midgut volvulus, necrotizing enterocolitis, and gastroschisis has been successful and uncomplicated. These patients have demonstrated consistent weight gain and have been spared the complications associated with prolonged parenteral alimentation.

  10. Volvulus du grêle sur paquet d’ascaris: à propos d’un cas

    PubMed Central

    Diouf, Cheikh; Kane, Ahmed; Ndoye, Ndeye Aby; Ndour, Oumar; Faye-Fall, Aimé Lakh; Fall, Mbaye; Alumeti, Désiré Munyali; Ngom, Gabriel

    2016-01-01

    Nous rapportons un cas exceptionnel de volvulus nécrosé de l'intestin grêle dû à des ascaris adultes chez un enfant de 7 ans. A l'admission, l'enfant présentait le tableau d'occlusion intestinale qui évoluait depuis deux jours avec altération de l'état général. La radiographie de l'abdomen sans préparation retrouvait des niveaux hydroaériques de type grêlique et un aspect tigré évoquant le diagnostic d'une occlusion intestinale haute sur masse abdominale. Après la réanimation, le traitement chirurgical consistait en une laparotomie qui avait retrouvé un volvulus nécrosé de l'iléon terminale contenant des ascaris adultes. Une résection du grêle sur environ un mètre emportant le segment nécrosé suivie d'une iléostomie était réalisée. L'évolution a été favorable, l'anastomose iléo-colique fut réalisée quatre semaines plus tard. Au recul de deux ans l'enfant est indemne de tout symptôme. PMID:27795803

  11. Small bowel volvulus in the adult populace of the United States: results from a population-based study.

    PubMed

    Coe, Taylor M; Chang, David C; Sicklick, Jason K

    2015-08-01

    Small bowel volvulus is a rare entity in Western adults. Greater insight into epidemiology and outcomes may be gained from a national database inquiry. The Nationwide Inpatient Sample (1998 to 2010), a 20% stratified sample of United States hospitals, was retrospectively reviewed for small bowel volvulus cases (International Classification of Diseases, 9th Edition [ICD-9] code 560.2 excluding gastric/colonic procedures) in patients greater than or equal to 18 years old. There were 2,065,599 hospitalizations for bowel obstruction (ICD-9 560.x). Of those, there were 20,680 (1.00%) small bowel volvulus cases; 169 were attributable to intestinal malrotation. Most cases presented emergently (89.24%) and operative management was employed more frequently than nonoperative (65.21% vs 34.79%, P < .0001). Predictors of mortality included age greater than 50 years, Charlson comorbidity index greater than or equal to 1, emergent admission, peritonitis, acute vascular insufficiency, coagulopathy, and nonoperative management (P < .0001). As the first population-based epidemiological study of small bowel volvulus, our findings provide a robust representation of this rare cause of small bowel obstruction in American adults. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Gallbladder Volvulus in a Patient with Type I Choledochal Cyst: A Case Report and Review of the Literature

    PubMed Central

    Younan, George; Schumm, Max

    2016-01-01

    Introduction. Gallbladder volvulus is a rare, potentially fatal condition unless diagnosed and treated early. Choledochal cysts are rare congenital malformations of the biliary tree predisposing to different pathologies and posing the risk of degradation into cholangiocarcinoma and gallbladder cancer. Dealing with both diseases at once has not been published yet in the literature. Presentation of Case. We report a case of gallbladder volvulus in an elderly female who happened to have a concomitant type I choledochal cyst. Treatment was achieved with a cholecystectomy and observation and follow-up of the choledochal cyst. Discussion. Prompt diagnosis and surgical management of gallbladder volvulus is important to avoid the morbidity and mortality of gangrenous cholecystitis and biliary peritonitis in a frail old population of patients. Precise clinical diagnosis, supplemented with specific imaging clues, helps in the diagnosis. Management of choledochal cysts is also surgical; however the timing of surgery is still a matter of debate. Conclusion. We describe in this report the first case of gallbladder volvulus in a patient with a choledochal cyst and propose a management algorithm of a very rare biliary tree pathology combination. PMID:27747125

  13. Zoonotic infection with Onchocerca dewittei japonica in an 11-year-old boy in Kansai Region, Western Honshu, Japan.

    PubMed

    Uni, Shigehiko; Fukuda, Masako; Ogawa, Kou; Lim, Yvonne Ai-Lian; Agatsuma, Takeshi; Bunchom, Naruemon; Saijuntha, Weerachai; Otsuka, Yasushi; Bhassu, Subha; Mat Udin, Ahmad Syihan; Zainuri, Nur Afiqah; Omar, Hasmahzaiti; Nakatani, Jun; Matsubayashi, Makoto; Maruyama, Haruhiko; Ramli, Rosli; Azirun, Mohd Sofian; Takaoka, Hiroyuki

    2017-10-01

    An 11-year-old boy living in Otsu City, Shiga Prefecture, Kansai Region, Western Honshu, Japan had zoonotic onchocercosis. The patient developed a painful swelling on the little finger of his left hand. The worm detected in the excised mass had external transverse ridges but did not have inner striae in the cuticle. On the basis of the parasite's histopathological characteristics, the causative agent was identified as a female Onchocerca dewittei japonica (Spirurida: Onchocercidae). The species of the filarial parasite was confirmed by sequencing the cox1 gene of the parasite. The Japanese wild boar Sus scrofa leucomystax is a definitive host for O. dewittei japonica, which is then transmitted by blackflies as the vector to humans. The current case described occurred in the Kansai Region, Western Honshu, where such infections were previously not reported. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Duodenal obstruction caused by duodenal sigmoid flexure volvulus in dairy cattle: 29 cases (2006-2010).

    PubMed

    Vogel, Susan R; Nichols, Sylvain; Buczinski, Sébastien; Desrochers, André; Babkine, Marie; Veillette, Manon; Francoz, David; Doré, Elizabeth; Fecteau, Gilles; Bélanger, Anne-Marie; Badillo, Mauricio

    2012-09-01

    To characterize duodenal sigmoid flexure volvulus (DSFV) and determine the prognosis for affected cattle undergoing surgery. Retrospective case series. 29 dairy cattle. The medical records were analyzed for history, signalment, clinical signs, medical management, surgical findings, and outcome. 29 cattle were determined to have DSFV between December 2006 and August 2010. Twenty cattle had had an omentopexy or pyloropexy performed 1 day to 2 years before initial evaluation. Cattle were afebrile, tachycardic, and moderately dehydrated, with a small zone of percussion with a ping at the 10th to 12th right intercostal spaces and associated succussion. Biochemical changes were a severe hypokalemic (mean ± SD, 2.9 ± 0.5 mmol/L; median, 3.1 mmol/L; range, 2.08 to 3.92 mmol/L), hypochloremic (mean, 69.7 ± 11.1 mmol/L; median, 71.7 mmol/L; range, 49.1 to 94.1 mmol/L) metabolic alkalosis (mean total CO(2), 44.5 ± 7.4 mmol/L; median, 45.3 mmol/L; range, 31.5 to 59.6 mmol/L) and hyperbilirubinemia (mean, 32.4 ± 29.0 μmol/L; median, 20.5 μmol/L; range, 7.8 to 107 μmol/L). Surgical findings for DSFV included an empty descending duodenum adjacent to a dorsally displaced and dilated cranial segment of the duodenum, distended abomasum and gallbladder, and a tight volvulus at the base of the duodenal sigmoid flexure. Manual reduction was considered successful if the descending duodenum filled after cranial duodenal massage. Twenty-two patients were successfully treated; the remaining 7 died or were euthanized within 4 days after surgery. A condition clinically resembling abomasal volvulus but affecting the duodenal sigmoid flexure has been recognized in dairy cattle. When a focal, dorsal right-sided ping and succussion are present combined with severe hypokalemic, hypochloremic metabolic alkalosis and high bilirubin concentration, DSFV should be suspected, especially when there is a history of prior abomasal fixation. After surgical correction, the prognosis is fair to good.

  15. [Surgical treatment of colonic volvulus. 10-year experience at the Instituto Nacional de la Nutrición Salvador Zubirán].

    PubMed

    Remes-Troche, J M; Pérez-Martínez, C; Rembis, V; Arch Ferrer, J; Ayala González, M; Takahashi, T

    1997-01-01

    To analyze morbidity-mortality and results of surgical treatment for colonic volvulus. Retrospective review of 33 patients who underwent surgical treatment for colonic volvulus from 1986 through 1996. Mean age was 62 +/- 20 years (SD) with predominance of female sex (2:1). There were 25 cases of sigmoid volvulus (76%), 7 in the cecum (21%) and 1 in the transverse colon (3%). Colonic necrosis and/or perforation were most frequently seen in the right and transverse colon (50%) than in the sigmoid (4%) (P < 0.002). Operative morbidity was 45% with mortality of 21%. Age was the only variable statistically significant for operative morbidity (52 +/- 23 years in patients without morbidity vs 71 +/- 17 years in patients with morbidity, P = 0.02). Surgical procedures for sigmoid volvulus were resection in 13 and fixation in 12. Recurrence after fixation was 38% to 12 months and 69% to 24 months (Kaplan-Meier), with associated mortality of 50%. There was no recurrence after resections. Treatment for cecal volvulus was cecopexy in 4 cases, with one recurrence; and right hemicolectomy without recurrence. The results should encourage resective procedures in sigmoid volvulus because the risk of recurrence after fixation is high and the morbidity-mortality is similar. Elderly patients are more susceptible to complications.

  16. Gallbladder Volvulus: A Rare Emergent Cause of Acute Cholecystitis, if Untreated, Progresses to Necrosis and Perforation

    SciTech Connect

    Justin L, Regner Angela, Lomas

    2016-03-25

    An 86 year-old woman with a past medical history significant for abdominal hernia and Alzheimer dementia presented to the Emergency Department with a 24 hour history of acute right upper quadrant pain associated with nausea and non-bilious emesis. Physical exam revealed right sided abdominal tenderness with associated mass. All laboratory values were within normal ranges. Both abdominal ultrasound and computed tomography of the abdomen/pelvis revealed a large distended gallbladder with wall thickening and gallstones. Based on presentation and radiologic findings, the emergency general surgery service was consulted for suspected acute cholecystitis. The patient was then admitted for intravenous antibiotics and scheduled for laparoscopic cholecystectomy the following day. Intra-operative findings revealed volvulus with acute necrosis of the entire gallbladder. The gallbladder had a long pedunculated cystic duct and artery that was detorsed before proceeding with resection. Postoperatively, the patient did well and was discharged a few days later tolerating a regular diet.

  17. Laparoscopic repair of a late-presenting Bochdalek diaphragmatic hernia with acute gastric volvulus

    PubMed Central

    Hadjittofi, Christopher; Matter, Ibrahim; Eyal, Ori; Slijper, Nadav

    2013-01-01

    An otherwise healthy 17-year-old boy presented to the paediatric emergency department with acute severe epigastric pain. An admission abdominal radiograph demonstrated gastric dilation, associated with an elevated left hemidiaphragm. Subsequent barium contrast imaging confirmed the diagnosis of organoaxial acute gastric volvulus (AGV). Emergent exploratory laparoscopy revealed AGV with migration of the stomach, spleen, pancreatic tail, splenic flexure, left kidney and adrenal through a left-sided Bochdalek diaphragmatic hernia. Following careful mobilisation of the displaced structures, a mesh closure of the diaphragmatic defect was performed. The patient's postoperative chest radiograph was unremarkable, and he was discharged on the sixth postoperative day after an uneventful recovery. At 2 months the patient was well and asymptomatic, with normal barium contrast imaging results. PMID:23519514

  18. Combined laparoscopic ovariectomy and laparoscopic-assisted gastropexy in dogs susceptible to gastric dilatation-volvulus

    PubMed Central

    Rivier, Pablo; Furneaux, Rob; Viguier, Eric

    2011-01-01

    This prospective study describes a simple method of combining laparoscopic ovariectomy and laparoscopic-assisted prophylactic gastropexy and determines the duration of surgery, complications, and long-term outcome including prevention of gastric dilatation-volvulus (GDV). Laparoscopic ovariectomy and laparoscopic-assisted gastropexy were performed on 26 sexually intact female dogs susceptible to GDV. The mean surgery time was 60.8 ± 12.4 min. No GDV episode was seen during the study period (mean follow-up: 5.2 ± 1.4 y). All dogs had an intact gastropexy attachment assessed by ultrasonography at 1 y. Post-operative complications were minor and owners were satisfied with the procedure. Combined laparoscopic ovariectomy and laparoscopic- assisted gastropexy appears to be a successful and low morbidity alternative procedure to both ovariectomy/ovariohysterectomy and gastropexy via open ventral-midline laparotomy. PMID:21461209

  19. Acute gastric dilatation and volvulus in a free-living polar bear

    USGS Publications Warehouse

    Amstrup, Steven C.; Nielsen, Carol A.

    1989-01-01

    A large, adult male polar bear (Ursus maritimus) was found dead on a barrier island north of Prudhoe Bay, Alaska (USA), in June 1987. There were no external signs of trauma. A twisted distended stomach, distinctive parenchymal and fascial congestion, and significant difficulty in repositioning the anterior abdominal organs, indicated that gastric dilatation-volvulus (GDV) was the proximate cause of death. Polar bears frequently consume large quantities of food at one time and have large stomachs that are well adapted to periodic gorging. The scarcity of food in winter and early spring, combined with voluntary fasting and protracted vigorous activity during the breeding season in late spring may have predisposed this bear to GDV. The relationship between GDV and postprandial exercise emphasizes the need for a better understanding of how the present human invasion of arctic habitats may influence polar bear activities.

  20. A case of child death caused by intestinal volvulus following magnetic toy ingestion.

    PubMed

    Olczak, Mieszko; Skrzypek, Ewa

    2015-05-01

    An 8-year boy was admitted to the ER of one of Warsaw's pediatric hospitals with a history of having bloody vomiting the day before. During admission the boy collapsed and lost consciousness. CPR was unsuccessful. On medico-legal autopsy, two foreign objects (small magnetic spheres--0.5 cm in diameter) were found in two different places in the small and large intestines and were notably attracted magnetically one to another. A loop of approximately 1-m length with features of small intestinal hemorrhagic necrosis and small intestinal mechanical obstruction was found. The cause of death was intestinal volvulus and small intestinal mechanical obstruction caused by ingestion of foreign objects (two neodymium magnets). Most likely these small magnetic spheres were part of a popular toy, the safety of which, lately, has been widely discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Ivermectin in loiasis and concomitant O. volvulus and M. perstans infections.

    PubMed

    Richard-Lenoble, D; Kombila, M; Rupp, E A; Pappayliou, E S; Gaxotte, P; Nguiri, C; Aziz, M A

    1988-11-01

    Two clinical studies were carried out in Gabon, Africa to evaluate the efficacy, safety, and tolerability of ivermectin in the treatment of patients with Loa loa infection. In the first study, 35 patients received single oral doses of ivermectin, 5-200 mcg/kg body weight. Blood microfilariae levels did not decrease after a single oral 5, 10, 30, or 50 mcg/kg dose of ivermectin, but levels did decrease after doses of 100, 150, and 200 mcg/kg. The most efficacious dose was 200 mcg/kg; mean blood microfilariae levels decreased to 12% of mean pretreatment values by day 15 and remained decreased for 28 days. A second study evaluated the safety and efficacy of ivermectin in patients with multifilarial infections. All 17 patients had concomitant Loa loa and O. volvulus infection. M. perstans affected 5 of the patients. Sixteen patients also had infections due to intestinal nematodes. The patients each received single oral doses of 200 mcg/kg ivermectin. Ten days later, the mean Loa loa blood microfilariae level had decreased to 20% of the mean pretreatment level. O. volvulus dermal microfilariae densities were reduced to 2% of the pretreatment levels. A minimal increase in blood microfilaria levels was observed on day 28. In contrast, dermal microfilariae levels remained near zero for the duration of the study. Intestinal infection due to Ascaris was eradicated in all of the affected patients by day 23; efficacy against Trichuris and hookworm infections, however, was poor. All patients tolerated ivermectin well including those with multiple infections.

  2. Volvulus du grêle sur lipome du mésentère

    PubMed Central

    Mbaye, Papa Alassane; Faye, Aime Lakh; Sagna, Aloise; Ndoye, Ndeye Aby; Seck, Ndeye Fatou; Ndour, Oumar; Ngom, Gabriel

    2017-01-01

    Nous rapportons l'observation d'une fillette âgée de 7ans qui reçue dans un tableau de syndrome sub-occlusif avec une douleur abdominale aigue paroxystique siégeant au niveau de l'épigastre associée à des vomissements et un arrêt des matières. L'examen physique mettait en évidence une sensibilité à la palpation de l'épigastre. L'échographie abdominale a montré une formation tissulaire intra péritonéale mal limitée sans caractère vasculaire au doppler, exerçant un effet de masse sur les structures de voisinage ; les vaisseaux mésentériques étaient en position normale. A la tomodensitométrie cette masse correspondait à une formation lipomateuse bien limitée exerçant un effet de masse sur le caecum avec un volvulus du grêle. Le diagnostic de volvulus du grêle sur lipome mésentérique a été retenu. L'exploration chirurgicale confirmait ce diagnostic. Une détorsion grélique et une énucléation lipomateuse étaient réalisées. Les suites opératoires étaient simples après un recul de 6 mois. L'examen anatomopathologique confirmait la nature lipomateuse de la masse. PMID:28819497

  3. On the possibility of bovine Onchocerca species infecting Simulium damnosum s.l. in the forest zone of Sierra Leone. I. Parasitological aspects.

    PubMed

    Trees, A J; McCall, P J; Davies, J B

    1989-12-01

    As part of a study to assess to what extent Onchocerca-like infections in S. damnosum s.l. in the forest zone of Sierra Leone were likely to be of bovine origin, Onchocerca infections were studied by post mortem examination of cattle killed at Bo abattoir and by examination of skin biopsies from cattle born and reared at Njala, in the forest zone, and Musaia, in the savanna zone. Post mortem studies of 45 cattle which had originated from northern Sierra Leone and Guinea revealed a prevalence of infection with microfilariae (mff) of O. gutturosa of 87%, O. ochengi 18% and O. armillata 7%. Examination of indigenous cattle revealed transmission of O. gutturosa in both forest (Njala) and savanna (Musaia) areas, and age prevalence analysis at Njala indicated a high intensity of transmission. Autochthonous transmission of O. armillata occurred at Njala at low intensity. Onchocerca gutturosa from Sierra Leone resembled U.K. isolates of O. gutturosa in terms of glucose phosphate isomerase electrophoretic mobility and acid phosphatase activity of in situ-stained mff. Hide mapping of O. gutturosa revealed skin concentrations of mff dorsally at the withers area and also ventrally at the dewlap, brisket and upper forelegs. It was concluded that only O. gutturosa was transmitted at high intensity to cattle in the forest zone of Sierra Leone. Hence, subsequent studies were directed towards determining the vector of O. gutturosa.

  4. A double-blind comparison of the efficacy and safety of ivermectin and diethylcarbamazine in a placebo controlled study of Senegalese patients with onchocerciasis.

    PubMed

    Diallo, S; Aziz, M A; Lariviere, M; Diallo, J S; Diop-Mar, I; N'Dir, O; Badiane, S; Py, D; Schulz-Key, H; Gaxotte, P

    1986-01-01

    Ivermectin (MK-933) has been compared with diethylcarbamazine (DEC) and placebo in a double-blind study in 30 adult male Senegalese patients with Onchocerca volvulus infection. 10 patients were randomly assigned to each treatment group. Ivermectin was administered as a single oral dose of 12 mg and DEC as 50 mg daily for two days and 100 mg twice daily for the following six days, total 1.3 g in eight days. Skin O. volvulus microfilaria densities remained near pre-study values in the placebo patients, but decreased rapidly with both active drugs to mean values about 2% of pretreatment (Day 8) and then increased slowly, reaching in 12 months about 4% of pre-treatment (ivermectin) and 18% (DEC). This difference is statistically significant. Clinical adverse reactions were recorded in four ivermectin, ten DEC and three placebo patients. One ivermectin and six DEC patients received steroid treatment for relief of these reactions. Serious adverse ocular changes were not seen in any patients, possibly because of the steroid therapy in the DEC patients. Adult O. volvulus from onchocercal nodules one and six months after treatment showed no effect of either drug on viability. Intra-uterine developing forms of the microfilariae appeared normal in all three treatment groups at the one month examination but deformed and degenerated forms were evident at six months in the ivermectin group but not in the DEC and placebo patients. Ivermectin as a single oral dose appears to be a safer and more effective microfilaricidal drug in human onchocerciasis than DEC in the standard multi-dose regimen.

  5. Volvulus - childhood

    MedlinePlus

    ... in the abdomen Nausea or vomiting Shock Vomiting green material Symptoms are very often severe. The infant in such cases is taken to the emergency room. Early treatment can be critical for survival.

  6. Sigmoid volvulus during pregnancy: A rare non-obstetric complication. Report of a case and review of the literature

    PubMed Central

    Al Maksoud, Ahmed M.; Barsoum, Adel K.; Moneer, Mohamed M.

    2015-01-01

    Introduction Sigmoid volvulus is a rare cause of intestinal obstruction during pregnancy associated with high maternal and foetal mortality. Effective management represents a challenge due to delayed presentation, obstructive symptoms regarded as pregnancy-related and hesitation in using radiological evaluation. Presentation of case We report a case of a lady, pregnant for 26 weeks and with a 5 day history of abdominal pain and constipation. She underwent concomitant caesarean section and laparotomy for intestinal obstruction. Intra-operatively, the sigmoid colon was extensively dilated and gangrenous. The ischemic colon was resected and a Hartmann’s procedure was performed. A preterm male child was delivered and admitted to neonatal intensive care. The post operative course was uneventful and the patient was discharged home on the 9th post-operative day. Six months later she underwent an uneventful reversal of the Hartmann’s procedure. Discussion Sigmoid volvulus is the most common cause of bowel obstruction during pregnancy, accounting for up to 44% of reported cases. We have reviewed the available literature on this topic and present another case managed at our institution. Conclusion Diagnosis of sigmoid volvulus in pregnancy is a challenge, but a delay in diagnosis increases the rates of feto-maternal mortality. A high incidence of clinical suspicion and timely surgical intervention are the key to a favourable outcome. PMID:26551555

  7. Fetal Midgut Volvulus with a Cystic Appearance, Accompanying a Sinus Rhythm and an Increased Peak Systolic Velocity without Anemia

    PubMed Central

    Kaba, Metin; Oksuzoglu, Aysegul; Kaba, Gokcen; Timur, Hakan; Akbaba, Eren; Turgut, Kadriye

    2015-01-01

    A midgut volvulus rarely occurs in a fetus; however, when it does, it requires an immediate diagnosis and surgery. Thirty-week pregnant was referred to our clinic with a diagnosis of a fetal abdominal cystic mass and preterm labor. The initial ultrasound examination revealed a female fetus with a 55 × 50 mm cystic mass in the lower abdomen, which was preliminarily diagnosed as an ovarian cyst. There was a sinusoidal rhythm on cardiography. The middle cerebral artery peak systolic velocity was 60.4 cm/sec, compatible with 1.49 MoMs that suggested fetal anemia on Doppler examination. Uterine contractions were observed with tocography and maternal hydration was administered for tocolytic treatment. Despite hydration, uterine contractions continued and the infant was delivered. A newborn ultrasonographic evaluation revealed a 6 cm abdominal cyst, and plain abdominal radiographs revealed distended loops of the small bowel on the left side. Emergency surgery was performed. A midgut volvulus leading to dilatation and necrosis of the small bowel without anatomical causes was observed during laparotomy. The necrotic bowel loop was resected and an end-to-end anastomosis was performed. The newborn died due to multiorgan failure. Obstetricians should be familiar with the appropriate diagnosis and management of a fetal volvulus. PMID:26779358

  8. Small volume resuscitation with hypertonic sodium chloride solution in cattle undergoing surgical correction of abomasal volvulus.

    PubMed

    Sickinger, M; Doll, K; Roloff, N C; Halekoh, U

    2014-09-01

    A randomized clinical trial was conducted to compare the efficacy of rapid intravenous (IV) infusion of a 7.2% hypertonic saline solution with that of continuous application of an isotonic solution in stabilizing the circulation of cows with abomasal volvulus. Cattle treated with hypertonic saline had a significantly greater reduction in volume deficit within the first 10 min of therapy than cows treated with isotonic saline (from 5.9 ± 4.8 to 2.1 ± 4.4 L/100 kg vs. 7.0 ± 4.5 to 4.9 ± 3.8 L/100 kg, respectively). The central venous pressure (CVP) of the cows given the hypertonic saline rose within the first 10 min of therapy from 7.3 ± 3.5 to 10.8 ± 3.4 cm H2O, while the CVP of the cattle treated with isotonic saline did not increase significantly during this time. Sixty minutes after the start of the infusion, the CVP of the isotonic group was still significantly lower than that of the hypertonic group (9.5 ± 2.1 vs. 10.3 ± 3.3 cm H2O, respectively). Within the first 60 min, the base excess decreased from 5.5 ± 6.9 to 4.7 ± 6.2 mmol/L in the hypertonic group whereas it increased from 5.6 ± 5.7 to 6.8 ± 5.4 mmol/L in the isotonic group. These results suggest that for cows with abomasal volvulus, IV therapy with hypertonic saline may improve the haemodynamic and circulatory situation considerably faster and more effectively than continuous infusion with isotonic saline. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Repeated high doses of avermectins cause prolonged sterilisation, but do not kill, Onchocerca ochengi adult worms in African cattle

    PubMed Central

    deC Bronsvoort, Barend M; Renz, Alfons; Tchakouté, Virginia; Tanya, Vincent N; Ekale, David; Trees, Alexander J

    2005-01-01

    Background Ivermectin (Mectizan™, Merck and CO. Inc.) is being widely used in the control of human onchocerciasis (Onchoverca volvulus) because of its potent effect on microfilariae. Human studies have suggested that, at the standard dose of 150 μg/kg an annual treatment schedule of ivermectin reversibly interferes with female worm fertility but is not macrofilaricidal. Because of the importance of determining whether ivermectin could be macrofilaricidal, the efficacy of high and prolonged doses of ivermectin and a related avermectin, doramectin, were investigated in cattle infected with O. ochengi. Methods Drugs with potential macrofilaricidal activity, were screened for the treatment of human onchocerciasis, using natural infections of O. ochengi in African cattle. Three groups of 3 cows were either treated at monthly intervals (7 treatments) with ivermectin (Ivomec®, Merck and Co. Inc.) at 500 μg/kg or doramectin (Dectamax®, Pfizer) at 500 μg/kg or not treated as controls. Intradermal nodules were removed at 6 monthly intervals and adult worms were examined for signs of drug activity. Results There was no significant decline in nodule diameter, the motility of male and female worms, nor in male and female viability as determined by the ability to reduce tetrazolium, compared with controls, at any time up to 24 months from the start of treatments (mpt). Embryogenesis, however, was abrogated by treatment, which was seen as an accumulation of dead and dying intra-uterine microfilariae (mf) persisting for up to 18 mpt. Skin mf densities in treated animals had fallen to zero by <3 mpt, but by 18 mpt small numbers of mf were found in the skin of some treated animals and a few female worms were starting to produce multi-cellular embryonic stages. Follow-up of the doramectin treated group at 36 mpt showed that mf densities had still only regained a small proportion of their pre-treatment levels. Conclusion These results have important implications for

  10. Meteorological influence on the occurrence of gastric dilatation-volvulus in military working dogs in Texas

    NASA Astrophysics Data System (ADS)

    Moore, George E.; Levine, Michael; Anderson, Johnna D.; Trapp, Robert J.

    2008-01-01

    Gastric dilatation-volvulus (GDV) is a life-threatening condition in dogs and other species in which the stomach dilates and rotates on itself. The etiology of the disease is multi-factorial, but explicit precipitating causes are unknown. This study sought to determine if there was a significant association between changes in hourly-measured temperature and/or atmospheric pressure and the occurrence of GDV in the population of high-risk working dogs in Texas. The odds of a day being a GDV day, given certain temperature and atmospheric pressure conditions for that day or the day before, was estimated using logistic regression models. There were 57 days in which GDV(s) occurred, representing 2.60% of the days in the 6-year study period. The months of November, December, and January collectively accounted for almost half (47%) of all cases. Disease risk was negatively associated with daily maximum temperature. An increased risk of GDV was weakly associated with the occurrence of large hourly drops in temperature that day and of higher minimum barometric pressure that day and the day before GDV occurrence, but extreme changes were not predictive of the disease.

  11. Effects of flunixin meglumine on dogs with experimental gastric dilatation-volvulus.

    PubMed

    Davidson, J R; Lantz, G C; Salisbury, S K; Kazacos, E A; Bottoms, G D

    1992-01-01

    Gastric dilatation-volvulus (GDV) was created experimentally and maintained for 90 minutes in 16 anesthetized, mixed-breed dogs. After the GDV was corrected, normal saline solution (0.044 mL/kg intravenously [IV]) was administered to eight dogs (controls), and flunixin meglumine (2.2 mg/kg IV) was administered to eight dogs. Microspheres labeled with radioactive cobalt, scandium, tin, or niobium were injected intravenously at baseline (before GDV) and minutes 90, 100, and 270, respectively, to determine tissue blood flows. Plasma endotoxin and prostacyclin were measured at the same intervals. Electrocardiogram, mean arterial pressure, portal pressure, and cardiac output were recorded continuously. Dogs were euthanatized at minute 270 and necropsied. There was no significant difference between treatment groups for any measured variable at any time. Endotoxin levels increased significantly during GDV. Prostacyclin levels were lower in dogs treated with flunixin meglumine than in controls at minutes 210 and 270. Histopathologic findings were similar for all dogs and consistent with those associated with endotoxemia. Flunixin meglumine treatment did not alter cardiac indices or tissue blood flows significantly. However, elevation of prostacyclin was inhibited by flunixin meglumine, which suggested that continued effects of endotoxic damage might be attenuated or inhibited.

  12. Cardiovascular and systemic effects of gastric dilatation and volvulus in dogs.

    PubMed

    Sharp, Claire R; Rozanski, Elizabeth A

    2014-09-01

    Gastric dilatation and volvulus (GDV) is a common emergency condition in large and giant breed dogs that is associated with high morbidity and mortality. Dogs with GDV classically fulfill the criteria for the systemic inflammatory response syndrome (SIRS) and can go on to develop multiple organ dysfunction syndrome (MODS). Previously reported organ dysfunctions in dogs with GDV include cardiovascular, respiratory, gastrointestinal, coagulation and renal dysfunction. Cardiovascular manifestations of GDV include shock, cardiac arrhythmias and myocardial dysfunction. Respiratory dysfunction is also multifactorial, with contributory factors including decreased respiratory excursion due to gastric dilatation, decreased pulmonary perfusion and aspiration pneumonia. Gastrointestinal dysfunction includes gastric necrosis and post-operative gastrointestinal upset such as regurgitation, vomiting, and ileus. Coagulation dysfunction is another common feature of MODS in dogs with GDV. Disseminated intravascular coagulation can occur, putting them at risk of complications associated with thrombosis in the early hypercoagulable state and hemorrhage in the subsequent hypocoagulable state. Acute kidney injury, acid-base and electrolyte disturbances are also reported in dogs with GDV. Understanding the potential for systemic effects of GDV allows the clinician to monitor patients astutely and detect such complications early, facilitating early intervention to maximize the chance of successful management.

  13. Biting on human body parts of Simulium vectors and its implication for the manifestation of Onchocerca nodules along Osun River, southwestern Nigeria.

    PubMed

    Adeleke, Monsuru Adebayo; Sam-Wobo, Sammy Olufemi; Akinwale, Olaoluwa Pheabian; Olatunde, Ganiyu Olatunji; Mafiana, Chiedu Felix

    2012-09-01

    The biting preference of Simulium vectors has been known to influence the distribution of Onchocerca nodules and microfilariae in human body. There is, however, variation in biting pattern of Simulium flies in different geographical locations. This study investigates the biting pattern on human parts by Simulium vectors along Osun river system where Simulium soubrense Beffa form has been implicated as the dominant vector and its possible implication on the distribution of Onchocerca nodules on human body along the river. Flies were collected by consented fly capturers on exposed human parts namely head/neck region, arms, upper limb and lower limb in Osun Eleja and Osun Budepo along Osun river in the wet season (August-September) and the dry season (November-December) in 2008. The residents of the communities were also screened for palpable Onchocerca nodules. The results showed that number of flies collected below the ankle region was significantly higher than the number collected on other exposed parts (p <0.05) while the least was collected on head/neck region in both seasons. The lower trunk was the most common site (60%) for nodule location at Osun Eleja followed by upper trunk (40%). Nodules were not found in the head and limb regions. At Osun Budepo, the upper trunk was the most common site of the nodule location (53.8%) followed by the lower trunk (38.5%) and head region (7.7%). Though, most of the flies were caught at the ankle region, the biting of other parts coupled with the presence of nodules at the head and upper trunk regions showed that Simulium vectors could obtain microfilariae from any part of the body, thus increasing the risk of onchocerciasis transmission.

  14. Cross-sectional study of the association of abomasal displacement or volvulus with serum electrolyte and mineral concentrations in dairy cows.

    PubMed Central

    Delgado-Lecaroz, R; Warnick, L D; Guard, C L; Smith, M C; Barry, D A

    2000-01-01

    The objective of this study was to evaluate serum mineral and electrolyte concentrations at the time of on-farm diagnosis of left displaced abomasum, right displaced abomasum, or abomasal volvulus in dairy cows. Data were collected from 104 affected cows and 96 control cows matched with cases, based on herd, parity, and stage of lactation. Cows with abomasal displacement or volvulus had significantly lower calcium, phosphorous, magnesium, potassium, and chloride concentrations and increased anion gap at the time of diagnosis compared with control cows from the same herds. The percentages of cases and controls with total serum calcium concentrations below the lower limit of the laboratory reference range (2.08 mmol/L [8.3 mg/dL]) were 70% and 23%, respectively. Based on the large percentage of cases with hypocalcemia, administering calcium salts at the time of treatment of field cases of abomasal displacement or volvulus may be beneficial. PMID:10769767

  15. Levels of infection, pathology and nodule size of Onchocerca flexuosa (Nematoda: Onchocercidae) in red deer (Cervus elaphus) from northern Spain.

    PubMed

    Hidalgo, M R; Martínez, A; Carreño, R A; González, S; Ferreras, M C; Díez, N

    2015-05-01

    Between 2005 and 2007, the presence of Onchocerca flexuosa (Wedl, 1856) was discovered and investigated in 110 red deer (Cervus elaphus) shot in the Riaño Regional Hunting Reserve, in the province of León (north-western Spain). Nodules containing O. flexuosa were located in the dorsal region and flanks of the deer. These were collected and measured, and some adult parasites were extracted from the nodules and identified by morphology and by obtaining mitochondrial 12S rDNA sequences, which were identical to those of previously published sequences for O. flexuosa. Some nodules were prepared for histology, embedded in paraffin, sectioned and stained with haematoxylin-eosin. Histologically, the worms were found in several compartments separated by an infiltrated fibrous tissue. These compartments were inhabited by several females and males, surrounded by a fibrous capsule. A total of 85.45% (95% confidence interval (CI): 78.86-92.04%) of red deer were parasitized, with a mean intensity of 9.53 ± 12.27 nodules/host, ranging between 1 and 74 nodules/deer. Significant differences in prevalence and intensity of infection were found between young and adult red deer, and also between seasons. However, no significant differences between males and females were observed. Five hundred and ninety-seven nodules were measured (15.81 ± 3.94 mm) and classified by sizes into small ( < 10 mm), medium (10-20 mm) and large (>20 mm). No relation was found between the size of the nodules and the time of infection. The high values found in the studied parameters show that northern Spain is an area of high-intensity infection for deer.

  16. Acute gastric volvulus associated with wandering spleen in an adult treated laparoscopically after endoscopic reduction: a case report.

    PubMed

    Omata, Jiro; Utsunomiya, Katsuyuki; Kajiwara, Yoshiki; Takahata, Risa; Miyasaka, Nobuo; Sugasawa, Hidekazu; Sakamoto, Naoko; Yamagishi, Yoji; Fukumura, Makiko; Kitagawa, Daiki; Konno, Mitsuhiko; Okusa, Yasushi; Murayama, Michinori

    2016-12-01

    A 43-year-old female was referred to our hospital for sudden onset of abdominal pain, fullness, and vomiting. Physical examination revealed abdominal distension with mild epigastric tenderness. Abdominal radiography showed massive gastric distension and plain computed tomography (CT) a markedly enlarged stomach filled with gas and fluid. A large volume of gastric contents was suctioned out via a nasogastric (NG) tube. Contrast-enhanced CT showed a grossly distended stomach with displacement of the antrum above the gastroesophageal junction, and the spleen was dislocated inferiorly. Upper gastrointestinal (GI) series showed the greater curvature to be elevated and the gastric fundus to be lower than normal. Acute mesenteroaxial gastric volvulus was diagnosed. GI endoscopy showed a distortion of the gastric anatomy with difficulty intubating the pylorus. Various endoscopic maneuvers were required to reposition the stomach, and the symptoms showed immediate and complete solution. GI fluoroscopy was performed 3 days later. Initially, most of the contrast medium accumulated in the fundus, which was drawn prominently downward, and then began flowing into the duodenum with anteflexion. Elective laparoscopic surgery was performed 1 month later. The stomach was in its normal position, but the fundus was folded posteroinferiorly. The spleen attached to the fundus was normal in size but extremely mobile. We diagnosed a wandering spleen based on the operative findings. Gastropexy was performed for the treatment of gastric volvulus and wandering spleen. The patient remained asymptomatic, and there was no evidence of recurrence during a follow-up period of 24 months. This report describes a rare adult case of acute gastric volvulus associated with wandering spleen. Because delay in treatment can result in lethal complications, it is critical to provide a prompt and correct diagnosis and surgical intervention. We advocate laparoscopic surgery after endoscopic reduction because

  17. Gastric dilation-volvulus in dogs attending UK emergency-care veterinary practices: prevalence, risk factors and survival.

    PubMed

    O'Neill, D G; Case, J; Boag, A K; Church, D B; McGreevy, P D; Thomson, P C; Brodbelt, D C

    2017-08-21

    To report prevalence, risk factors and clinical outcomes for presumptive gastric dilation-volvulus diagnosed among an emergency-care population of UK dogs. The study used a cross-sectional design using emergency-care veterinary clinical records from the VetCompass Programme spanning September 1, 2012 to February 28, 2014 and risk factor analysis using multivariable logistic regression modelling. The study population comprised 77,088 dogs attending 50 Vets Now clinics. Overall, 492 dogs had presumptive gastric dilation-volvulus diagnoses, giving a prevalence of 0·64% (95% Confidence interval: 0·58 to 0·70%). Compared with cross-bred dogs, breeds with the highest odds ratios for the diagnosis of presumptive gastric dilation-volvulus were the great Dane (odds ratio: 114·3, 95% Confidence interval 55·1 to 237·1, P<0·001), akita (odds ratio: 84·4, 95% Confidence interval 33·6 to 211·9, P<0·001) and dogue de Bordeaux (odds ratio: 82·9, 95% Confidence interval 39·0 to 176·3, P<0·001). Odds increased as dogs aged up to 12 years and neutered male dogs had 1·3 (95% Confidence interval 1·0 to 1·8, P=0·041) times the odds compared with entire females. Of the cases that were presented alive, 49·7% survived to discharge overall, but 79·3% of surgical cases survived to discharge. Approximately 80% of surgically managed cases survived to discharge. Certain large breeds were highly predisposed. © 2017 British Small Animal Veterinary Association.

  18. An Internet-based survey of risk factors for surgical gastric dilatation-volvulus in dogs.

    PubMed

    Pipan, Marko; Brown, Dorothy Cimino; Battaglia, Carmelo L; Otto, Cynthia M

    2012-06-15

    To evaluate risk factors for gastric dilatation-volvulus (GDV) in a large number of privately owned dogs across a wide geographic area. Internet-based, cross-sectional study. 2,551 privately owned dogs. A questionnaire addressed dog-specific, management, environmental, and personality-associated risk factors for GDV in dogs. Respondents were recruited through the posting of the electronic link to the questionnaire on websites for dog owners; the information was also disseminated at meetings of dog owners and via newsletters, e-mail lists for dog owners and breeders, owner-oriented dog publications, and e-mails forwarded by participants. Descriptive statistics and logistic regression analysis were performed. Factors significantly associated with an increased risk of GDV were being fed dry kibble, anxiety, residence in the United Kingdom, being born in the 1990s, being a family pet, and spending at least 5 hours a day with the owner. Factors associated with a decreased risk of GDV were playing with other dogs and running the fence after meals, fish and egg dietary supplements, and spending equal time indoors and outdoors. A significant interaction between sex and neuter status was observed, with sexually intact females having the highest risk for GDV. In dogs with a high risk of GDV, regular moderate daily and postprandial activity appeared to be beneficial. Feeding only commercial dry dog food may not be the best choice for dogs at risk; however, supplements with fish or eggs may reduced this risk. The effect of neuter status on GDV risk requires further characterization.

  19. Preventative effect of massage on gastric volvulus in infants with gastroesophageal reflux-induced pneumonia.

    PubMed

    Yan, Suqi; Xiong, Xiaoli; Wan, Qi; Liu, Fan; Tang, Jianqiao; Jiang, Zhixia; Zhou, Lishan; Yuan, Kai; Xie, Dong

    2015-10-01

    To study the preventative effects of massage on gastric volvulus (GV) in infants with gastroesophageal reflux (GER)-induced pneumonia. One-hundred and eighty GV with GER-induced pneumonia inpatients were divided randomly into four groups: basic treatment 1 (n = 60), basic treatment 2 (n = 30), massage treatment 1 (n = 60) and massage treatment 2 (n = 30). Clinical examinations selected between groups 1 and 2 were different. Radiography of the upper gastrointestinal tract using iodine-containing contrast was assessed in group 1 before and after treatment, whereas 24-h pH monitoring of the distal esophagus was assessed in group 2 before and after treatment. Symptom scores and chest radiography were assessed in all groups upon hospital admission and after procedures. Clinical effects were estimated after procedures in all groups. The prevalence of severe pneumonia among the four groups was compared. Massage treatment groups showed a significantly higher percentage of cure and total effect (P < 0.05, P < 0.01) and a lower prevalence of recurrence (but with no statistic difference, P > 0.05) than basic treatment groups. Furthermore, massage treatment groups had remarkably lower scores for symptoms and signs (P < 0.05, P < 0.01), especially for choking on milk, than basic treatment groups. There was significant attenuation of chest inflammation (P < 0.05, P < 0.01), GV (P < 0.05, P < 0.01) and GER (P < 0.05, P < 0.01) in massage treatment groups compared with those in basic treatment groups. Finally, massage treatment groups demonstrated a lower prevalence of severe pneumonia than basic treatment groups (P < 0.05). Massage treatment can prevent GV with GER-induced pneumonia in infants by timely correction of stomach rotation and subsequent attenuation of GER.

  20. Concurrent gall bladder, liver lobe torsion, and bile peritonitis in a German shepherd dog 2 months after gastric dilatation/volvulus gastropexy and splenectomy.

    PubMed

    Tubby, Kurtis G

    2013-08-01

    Postmortem examination of a 7-year-old German shepherd dog which had gastric dilatation/volvulus and splenectomy 2 months earlier revealed that the right middle and quadrate liver lobes were diffusely congested and torsed. The gall bladder was grossly distended and torsed along its long axis and there was evidence of bile peritonitis.

  1. Parasitological diagnosis of onchocerciasis: comparisons of incubation media and incubation times for skin snips.

    PubMed

    Collins, R C; Brandling-Bennett, A D; Holliman, R B; Campbell, C C; Darsie, R F

    1980-01-01

    Tissue culture fluid NCTC 135 (Hank's base) was compared to water and to saline as incubation media for the detection of microfilariae of Onchocerca volvulus in skin snips. NCTC 135 allowed detection of significantly more positive persons than did water (P less than 0.001) or saline (P less than 0.05) when two snips per person were incubated for periods of 0.5 or 24 hours. In addition, snips containing microfilariae were incubated in NCTC 135 or in saline and the number of emerged microfilariae was determined at various intervals of time up to 24 hours. After incubation, snips were either fixed in 10% formalin, serially sectioned, and the microfilariae counted, or they were digested in collagenase solution to free unemerged microfilaire. Of the total number of microfilariae present in the snips, 43.9% +/- 18.5, 80.2% +/- 22.2, 83.0% +/- 19.5, and 85.3% +/- 18.0 had emerged by 0.5, 4, 8, and 24 hours of incubation, respectively. Of the microfilariae that remained in the skin after incubation, most were located deep in the dermis.

  2. Enteric Duplication Cyst Leading to Volvulus: An Unusual Cause of Acute Intestinal Obstruction – A Case Report

    PubMed Central

    Nyuwi, Kuotho T; Singh, Chabungbam Gyan; Sangtam, Ty Apila; Varte, Lalhruaitluanga

    2016-01-01

    Enteric Duplication Cysts (EDC) is a rare congenital malformation, usually found in mesenteric side of Gastrointestinal (GI) tract. Generally patients present with non-specific symptoms depending on size and location of the cyst in GI tract. EDC presenting as small bowel volvulus is a rare clinical entity. Herein, we are reporting a 16-year-old adolescent girl who presented to Emergency Department (ED) with the features of acute bowel obstruction with septicemia. Patient underwent exploratory laparotomy which revealed dilated, twisted, gangrenous bowel due to a cystic lesion adjacent to the mesenteric side. Resection of the cystic lesion along with the affected gangrenous segment of bowel with an end to end anastomosis performed. PMID:28208934

  3. Volvulus grêlique sur hydatidose péritonéale: une cause rare d'occlusion

    PubMed Central

    Bouassria, Abdesslam; Mazine, Khalid; Elbouhaddouti, Hicham; Mouaqit, Ouadii; Ousadden, Abdelmalek; Mazaz, Khalid; Benjelloun, Elbachir; Taleb, Khalid Ait

    2014-01-01

    L'hydatidose péritonéale peut être primitive, hématogène ou hétérotopique, comme elle peut être secondaire et résulte de la fissuration d'un kyste hydatique, le plus souvent hépatique. Cliniquement polymorphe, elle peut se révéler par des douleurs abdominales ou par la palpation d'une masse abdominale. Nous rapportons le cas d'une patiente chez qui l'hydatidose péritonéale était révélée par un accident occlusif: un volvulus grêlique dû à un volumineux kyste hydatique mésentérique. Le traitement de l'hydatidose péritonéale est chirurgical, couplé à un traitement médical à base d'albendazole. PMID:25400846

  4. Sigmoid colon morphology in the population groups of Durban, South Africa, with special reference to sigmoid volvulus.

    PubMed

    Madiba, T E; Haffajee, M R

    2011-05-01

    Sigmoid volvulus demonstrates geographical, racial, and gender variation. This autopsy study was undertaken to establish morphological differences of the sigmoid colon and its mesocolon in which the length and other characteristics were assessed. A total of 590 cadavers were examined (403 African, 91 Indian, and 96 White). Length and height of the sigmoid colon and mesocolon were significantly longer in Africans, and mesocolon root was significantly narrower in Africans. Mesocolic ratio for Africans, Indians, and Whites was 1.1 ± 0.8, 1.8 ± 0.7, and 1.9 ± 1.0, respectively. Africans had a significantly high incidence of redundant sigmoid colon with the long-narrow type and suprapelvic position predominating (P = 0.003); the opposite applied to the classic type. There was no difference in sigmoid colon length, mesocolon height, and width between males and females in all population groups. Among Africans, the long-narrow type was more common in males, and the classic and long-broad types were more common in females. Splaying of teniae coli and thickening of the mesentery were more common in Africans. Tethering of the sigmoid colon to the posterior abdominal wall was less common in Africans compared with other population groups. In conclusion, the sigmoid colon was longer, and the sigmoid mesocolon root was narrower in Africans compared with the other population groups, and the sigmoid colon had a suprapelvic disposition among Africans. In Africans, the sigmoid colon was longer in males with a long-narrow shape. These differences may explain geographical and racial differences in sigmoid volvulus.

  5. Volvulus gastrique aigu sur éventration diaphragmatique de l'adulte: à propos d'un cas et revue de la littérature

    PubMed Central

    Guèye, Mohamadou Lamine; Touré, Alpha Oumar; Thiam, Ousmane; Seck, Mamadou; Cissé, Mamadou; Kâ, Ousmane; Dieng, Madieng; Touré, Cheikh Tidiane

    2015-01-01

    Le volvulus gastrique aigu sur éventration diaphragmatique est une affection rare et une urgence diagnostique et thérapeutique. Sa présentation clinique est peu spécifique et la tomodensitométrie abdominale permet de confirmer le diagnostic. Nous rapportons le cas d'un patient de 22 ans qui présentaitun syndrome occlusif et une voussure épigastrique. A la radiographie de l'Abdomen Sans Préparation, on notait 2 niveaux hydro-aériques sous la coupole diaphragmatique gauche qui était surélevée. Une dévolvulation et une gastrectomie atypique ont été réalisées devant un volvulus gastrique aigu avec nécrose du fundus mis en évidence à la laparotomie. Les suites opératoires ont été simples. PMID:26161223

  6. Incarceration of a large cell neuroendocrine carcinoma arising from the proximal stomach with an organoaxial gastric volvulus through an esophageal hiatal hernia: report of a case.

    PubMed

    Iso, Yukihiro; Tagaya, Nobumi; Nemoto, Takehiko; Kita, Junji; Sawada, Tokihiko; Kubota, Keiichi

    2009-01-01

    An 86-year-old woman was admitted to the hospital to undergo an examination for tarry stools. Laboratory tests showed hypoproteinemia and renal dysfunction. Upper gastrointestinal endoscopy demonstrated a type 5 tumor located in the upper body of the stomach. An upper gastrointestinal series and computed tomography revealed an organoaxial gastric volvulus and the dislocation of the proximal stomach through an esophageal hiatal hernia. The preoperative diagnosis was the incarceration of a gastric carcinoma arising from the proximal stomach with an organoaxial gastric volvulus through an esophageal hiatal hernia. A total gastrectomy and hernia repair were performed. A microscopic examination of the surgical specimen revealed a gastric large cell neuroendocrine carcinoma (GLCNEC). The patient was discharged 22 days after the surgery. Although the prognosis of GLCNEC is significantly worse than that of a conventional adenocarcinoma, the patient was doing well without recurrence at 15 months after surgery. The details of this case are reported with some bibliographical comments.

  7. Defining parasite biodiversity at high latitudes of North America: new host and geographic records for Onchocerca cervipedis (Nematoda: Onchocercidae) in moose and caribou.

    PubMed

    Verocai, Guilherme G; Lejeune, Manigandan; Beckmen, Kimberlee B; Kashivakura, Cyntia K; Veitch, Alasdair M; Popko, Richard A; Fuentealba, Carmen; Hoberg, Eric P; Kutz, Susan J

    2012-10-30

    Onchocerca cervipedis is a filarioid nematode of cervids reported from Central America to boreal regions of North America. It is found primarily in subcutaneous tissues of the legs, and is more commonly known as 'legworm'. Blackflies are intermediate hosts and transmit larvae to ungulates when they blood-feed. In this article we report the first records of O. cervipedis from high latitudes of North America and its occurrence in previously unrecognized host subspecies including the Yukon-Alaska moose (Alces americanus gigas) and the Grant's caribou (Rangifer tarandus granti). We examined the subcutaneous connective tissues of the metacarpi and/or metatarsi of 34 moose and one caribou for parasitic lesions. Samples were collected from animals killed by subsistence hunters or animals found dead in the Northwest Territories (NT), Canada and Alaska (AK), USA from 2005 to 2012. Genomic DNA lysate was prepared from nematode fragments collected from two moose. The nd5 region of the mitochondrial DNA was amplified by PCR and sequenced. Subcutaneous nodules were found in 12 moose from the NT and AK, and one caribou from AK. Nematodes dissected from the lesions were identified as Onchocerca cervipedis based on morphology of female and male specimens. Histopathological findings in moose included cavitating lesions with multifocal granulomatous cellulitis containing intralesional microfilariae and adults, often necrotic and partially mineralized. Lesions in the caribou included periosteitis with chronic cellulitis, eosinophilic and lymphoplasmacytic infiltrate, and abundant granulation associated with intralesional adult nematodes and larvae. Sequences of the nd5 region (471bp), the first generated for this species, were deposited with Genbank (JN580791 and JN580792). Representative voucher specimens were deposited in the archives of the United States National Parasite Collection. The geographic range of O. cervipedis is broader than previously thought, and extends into

  8. Defining parasite biodiversity at high latitudes of North America: new host and geographic records for Onchocerca cervipedis (Nematoda: Onchocercidae) in moose and caribou

    PubMed Central

    2012-01-01

    Background Onchocerca cervipedis is a filarioid nematode of cervids reported from Central America to boreal regions of North America. It is found primarily in subcutaneous tissues of the legs, and is more commonly known as ‘legworm’. Blackflies are intermediate hosts and transmit larvae to ungulates when they blood-feed. In this article we report the first records of O. cervipedis from high latitudes of North America and its occurrence in previously unrecognized host subspecies including the Yukon-Alaska moose (Alces americanus gigas) and the Grant’s caribou (Rangifer tarandus granti). Methods We examined the subcutaneous connective tissues of the metacarpi and/or metatarsi of 34 moose and one caribou for parasitic lesions. Samples were collected from animals killed by subsistence hunters or animals found dead in the Northwest Territories (NT), Canada and Alaska (AK), USA from 2005 to 2012. Genomic DNA lysate was prepared from nematode fragments collected from two moose. The nd5 region of the mitochondrial DNA was amplified by PCR and sequenced. Results Subcutaneous nodules were found in 12 moose from the NT and AK, and one caribou from AK. Nematodes dissected from the lesions were identified as Onchocerca cervipedis based on morphology of female and male specimens. Histopathological findings in moose included cavitating lesions with multifocal granulomatous cellulitis containing intralesional microfilariae and adults, often necrotic and partially mineralized. Lesions in the caribou included periosteitis with chronic cellulitis, eosinophilic and lymphoplasmacytic infiltrate, and abundant granulation associated with intralesional adult nematodes and larvae. Sequences of the nd5 region (471bp), the first generated for this species, were deposited with Genbank (JN580791 and JN580792). Representative voucher specimens were deposited in the archives of the United States National Parasite Collection. Conclusions The geographic range of O. cervipedis is broader than

  9. Comparison between the Skin Snip Test and Simple Dot Blot Assay as Potential Rapid Assessment Tools for Onchocerciasis in the Postcontrol Era in Ghana

    PubMed Central

    Guzmán, G. E.; Awadzi, K.; Opoku, N.; Narayanan, R. B.; Akuffo, H. O.

    2002-01-01

    Successful control of onchocerciasis through mass distribution of ivermectin needs to be coupled with reliable, sensitive, specific, yet affordable diagnostic methods to monitor and ensure the efficacy of such measures. The effort put into the development of diagnostic methods for onchocerciasis that can substitute for or work in combination with the present “gold standard,” the skin snip test, has resulted in the discovery of a number of immunogenic proteins with potential use as diagnostic tools in the postcontrol era. Most of these proteins have now been produced through recombinant DNA techniques. However, when costs are not a trivial issue, none of them have yet found their way into the areas where the disease still exists. In the present study, we have evaluated the performance of a simple dot blot assay which uses a mixture of native proteins designated PakF as a serious contender in the quest for a less invasive and more sensitive method to detect Onchocerca volvulus infection in areas with diverse endemicities. Our results indicate that the assay we propose is more sensitive than the skin snip test and shows high specificity, both characteristics required for a suitable tool for the monitoring of onchocerciasis in the postcontrol era. PMID:12204952

  10. Proximal duodenoileal anastomosis for treatment of small intestinal obstruction and volvulus in a green iguana (Iguana iguana).

    PubMed

    Wills, Sarah; Beaufrère, Hugues; Watrous, Gwyneth; Oblak, Michelle L; Smith, Dale A

    2016-11-01

    CASE DESCRIPTION A 13-year-old female green iguana (Iguana iguana) was examined because of a 6-day history of vomiting, anorexia, and lethargy and a 4-day history of decreased fecal and urate output. CLINICAL FINDINGS Physical examination revealed a distended abdomen, signs of depression, pallor, tachycardia, harsh lung sounds, and vomiting. Abdominal radiographs revealed gas distention of the stomach and small intestine with fluid lines evident on the lateral view. Plasma biochemical analysis indicated hypochloremic metabolic alkalosis, hyperglycemia, and hyperuricemia. TREATMENT AND OUTCOME Exploratory laparotomy confirmed a diagnosis of small intestinal entrapment and 170° volvulus involving approximately 80% (20 to 30 cm) of the small intestine. The portion of the small intestine extending from the middle portion of the duodenum to the caudal extent of the ileum was resected, and end-to-end anastomosis of the remaining small intestine was performed. The iguana recovered without apparent complications and was reportedly doing well 1 year after surgery. CLINICAL RELEVANCE Findings suggested that iguanas, as hindgut fermenters, may tolerate > 70% resection of the small intestine with a good outcome and no clinical evidence of residual gastrointestinal dysfunction.

  11. 13C-sodium acetate breath test for evaluation of gastric emptying times in dogs with gastric dilatation-volvulus.

    PubMed

    Schmitz, S; Jansen, N; Failing, K; Neiger, R

    2013-01-01

    The aim of the study was to assess solid phase gastric emptying via non-invasive 13C-sodium acetate breath test in large breed dogs with or without gastric dilatation-volvulus (GDV). Dogs were recruited into one of the following groups: group 1 = healthy large breed dogs with no history of GDV, group 2 = dogs that underwent elective abdominal surgery for reasons unrelated to the gastrointestinal tract, and group 3 = dogs that underwent laparotomy and gastropexy to correct GDV. The dogs were fed a test meal containing 100 mg 13C-sodium acetate (for group 2 and 3, this was < 48 hours post-operatively). Breath samples were obtained at baseline and every 30 minutes for 3 hours, then every hour for a total of 7 hours. 12CO2/13CO2 ratio was measured for each breath sample via non-dispersive infrared spectroscopy and 25%, 50% and 75% gastric emptying times were calculated and compared between groups. Gastric emptying times were significantly prolonged in dogs undergoing surgery (group 2) compared to group 1 and 3. Also, gastric emptying times of dogs with GDV were significantly prolonged compared to controls, but not to the same extent as dogs in group 2. There was a significant effect of abdominal surgery on gastric emptying times. Surprisingly, dogs after GDV surgery and gastropexy had shorter gastric emptying times than dogs undergoing laparotomy for reasons other than GDV, but still prolonged compared to healthy controls. The reason for these differences requires further study.

  12. Major Sperm Protein Genes from Globodera rostochiensis

    PubMed Central

    Novitski, Charles E.; Brown, Shiela; Chen, Ru; Corner, Adam S.; Atkinson, Howard J.; McPherson, Michael J.

    1993-01-01

    Three genes in the major sperm protein (MSP) gene family from the potato cyst nematode Globodera rostochiensis were cloned and sequenced. In contrast to the absence of introns in Caenorhabditis elegans MSP genes, these genes in G. rostochiensis contained a 57 nucleotide intron, with normal exon-intron boundaries, in the same relative location as the intron in Onchocerca volvulus. The MSP genes of G. rostochiensis had putative CAAT, TATA, and polyadenylation signals. The predicted G. rostochiensis MSP gene product is 126 amino acids long, one residue shorter than the products in the other species. The comparison of MSP amino acid sequences from four diverse nematode species suggests that O. volvulus, Ascaris suum, and C. elegans may be more closely related to each other than they are to G. rostochiensis. PMID:19279808

  13. Reproductive careers of Thoroughbred broodmares before and after surgical correction of ≥360 degree large colon volvulus.

    PubMed

    Leahy, E R; Holcombe, S J; Hackett, E S; Scoggin, C F; Embertson, R M

    2017-08-10

    Limited data exist describing broodmare longevity and reproductive efficiency after surgical correction of ≥360 degree large colon volvulus (° LCV). Compare career duration and foals delivered for broodmares before and after ≥360° LCV surgery. Retrospective case series. Broodmares registered with The Jockey Club that had surgical correction of ≥360° LCV and survived to hospital discharge at Rood and Riddle Equine Hospital from 1 January 2000 to 31 December 2015 were included. Information was collected from the hospital's medical data base and The Jockey Club produce records about the mares' reproductive careers. Data were evaluated using parametric and nonparametric tests, P≤0.05. Mares that were bred but never foaled prior to surgery (n = 19) had shorter careers (mean ± standard deviation [s.d.]), 4.4 ± 4.5 years, and fewer foals, 3.1 ± 3.3, compared with mares that delivered ≥1 foal before surgery (n = 565), 10.4 ± 4.5 years and 7.4 ± 3.4 foals, respectively, P<0.001. Broodmares that delivered foals before surgery produced more foals in the years before surgery, 4.8 ± 3.0, than after surgery, 2.6 ± 2.4, P<0.001, and had longer breeding careers, 5.9 ± 3.8 vs. 4.5 ± 3.3 years before compared with after surgery, P<0.001. No significant differences in career length or number of foals delivered were detected for mares with a single compared with multiple LCV surgeries. Mares that were 3-11 years old at the time of surgery had significantly more foals after surgery compared with mares ≥12 years old, P<0.001, as expected. Retrospective collection of data. Broodmares had productive careers following surgery for ≥360° LCV that were largely influenced by the mares' age at the time of surgery. © 2017 EVJ Ltd.

  14. Prenatal diagnosis of the acute meconium peritonitis secondary to ileum volvulus perforation: a case report.

    PubMed

    Keskin, Uğur; Karasahin, Kazım Emre; Ozturk, Mustafa; Atabek, Cüneyt; Demirbağ, Suzi; Ergün, Ali

    2015-02-01

    This is an unusual case in comparison to other sonographically described prenatal cases due to very early diagnosis and surgical intervention following prompt delivery. A 40-year-old pregnant, ultrasonography showed presence of cystic structure in the fetal abdomen that was consistent with intestinal dilatation. At 32 weeks' of gestation, repeat ultrasound showed collapse of the bowel dilatation along with the presence of hyperechogenic fluid in the fetal abdominal cavity. Cesarean section was performed. The clinical utility of this report is the recognition that meconium peritonitis (MP) may be diagnosed in the acute phase with typical ultrasound features, and should be considered in the differential diagnoses of cases presented with reduced fetal movements. Although it appears that morbidity and mortality in MP cases depend upon gestational age, this case report may help to manage similar cases for defining the appropriate delivery time and treatment modality after prenatal identification of the problem.

  15. Volvulus du grêle sur mésentère commun incomplet - une redoutable complication rare chez l'adulte: à propos de 1 cas

    PubMed Central

    Coulibaly, Mahamadoun; Boukatta, Brahim; Derkaoui, Ali; Sbai, Hicham; Ousadden, Abdelmalek; Kanjaa, Nabil

    2015-01-01

    Le mésentère commun résulte d'une anomalie de rotation du tube digestif. Il est caractérisé par la persistance d'une disposition anatomique embryonnaire secondaire à une anomalie de rotation de l'anse ombilicale primitive, constituant ainsi un méso commun à toute l'anse intestinale et une racine du mésentère extrêmement courte. Cette insuffisance de rotation est le plus souvent associée à un défaut d'accolement. Ces anomalies de rotation intestinale peuvent aboutir à des complications redoutables parfois mortelles, qui surviennent généralement au cours de la période néonatale où à l’âge pédiatrique. On estime que la prévalence de ces malformations congénitales à l’âge adulte est de l'ordre de 0,2% à 0,5% âge auquel elles demeurent très souvent asymptomatiques et donc non diagnostiquées. Le diagnostic de volvulus total du grêle peut se faire dans des circonstances très variées: en urgence devant un tableau d'occlusion intestinale aiguë, voire un état de choc pouvant conduire au décès, devant un tableau de douleurs abdominales répétées plus ou moins associées à des troubles du transit. Nous rapportons l'observation d'un patient de 18 ans admis pour volvulus total du grêle sur mésentère commun incomplet chez qui l’évolution était favorable. PMID:26113900

  16. Full-thickness small intestine necrosis with midgut volvulus, distributed in a patchy fashion, is reversible with moderate blood flow: resumption of normal function to non-viable intestine.

    PubMed

    Amano, Hizuru; Uchida, Hiroo; Kawashima, Hiroshi; Tanaka, Yujiro; Kishimoto, Hiroshi

    2014-08-01

    Midgut volvulus is a highly life-threatening condition that carries a high risk of short gut syndrome. We report a case of catastrophic neonatal midgut volvulus in which second-look laparotomy revealed apparently non-viable remnant small intestine but with a moderate blood supply. Full-thickness small intestine necrosis was distributed in a patchy fashion, with non-viable and necrotic areas distributed so widely that no portion of the intestine could be resected. A section of full-thickness necrotic intestine preserved at surgery was able to regenerate, and normal function was restored over a period of 1 month. This case indicated that intestinal resumption may be dependent on blood flow. Even when intestinal viability is questionable, preservation enables the chance of regeneration if moderate blood flow is present.

  17. Ivermectin Inhibits Growth of Chlamydia trachomatis in Epithelial Cells

    PubMed Central

    Pettengill, Matthew A.; Lam, Verissa W.; Ollawa, Ikechukwu; Marques-da-Silva, Camila; Ojcius, David M.

    2012-01-01

    Ivermectin is currently approved for treatment of both clinical and veterinary infections by nematodes, including Onchocerca cervicalis in horses and Onchocerca volvulus in humans. However, ivermectin has never been shown to be effective against bacterial pathogens. Here we show that ivermectin also inhibits infection of epithelial cells by the bacterial pathogen, Chlamydia trachomatis, at doses that could be envisioned clinically for sexually-transmitted or ocular infections by Chlamydia. PMID:23119027

  18. Small bowel volvulus after transabdominal preperitoneal hernia repair due to improper use of V-Loc™ barbed absorbable wire - do we always "read the instructions first"?

    PubMed

    Filser, Joerg; Reibetanz, Joachim; Krajinovic, Katica; Germer, Christoph-Thomas; Dietz, Ulrich Andreas; Seyfried, Florian

    2015-01-01

    Transabdominal preperitoneal endoscopic hernia repair (TAPP) is part of primary surgical health care. While both, the reported recurrence rate and procedure specific morbidity are consistently low, rare serious complications occur. A 36-year-old male patient developed bowel obstruction three days after both-sided TAPP for inguinal hernia repair. A computer tomography scan of the abdomen revealed a small bowel volvulus in the right lower quadrant of the abdomen requiring urgent revisional surgery. Intraoperatively, the small bowel and its mesenterial vessels were found to be twisted around a 5cm long V-Loc™ barbed absorbable suturing wire. After successful laparoscopic adhesiolysis, removal of the wire and detorquing of the bowel conglomerate, resection of small intestine was not necessary. The patient's further postoperative recovery was uneventful. Due to the barbed configuration of the V-Loc™ wire, a gapless continuous suturing of the peritoneum without laparoscopic knotting is easily and fast to accomplish. In this case the recommendation of the manufacturer to shorten the wire was not strictly followed and neither had the suture stump been extraperitonealized in order to avoid such rare complications. Surgeons need to be aware of relevant "tricks and traps" of routinely performed procedures and have to know all tools and material they use very well. This case may therefore increase our attention when it comes to little things which actually do matter. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Microfilariae in the cerebrospinal fluid, and neurological complications, during treatment of onchocerciasis with diethylcarbamazine.

    PubMed

    Duke, B O; Vincelette, J; Moore, P J

    1976-06-01

    Microfilariae of Onchocerca volvulus were found in the cerebrospinal fluid (CSF) of 5/8 heavily infected onchocerciasis patients. During treatment with diethylcarbamazine citrate 10/11 patients showed increased numbers of 0. volvulus microfilariae in the CSF. Patients with concentrations of 8-31 mf/ml CSF developed severe vertigo, and some other neurological manifestations, during treatment. A hypothesis is put forward to account for this clinical piciture, and its importance in relation to the treatment of onchocerciasis is discussed.

  20. Comparative efficacy of moxidectin 2% equine oral gel and ivermectin 2% equine oral paste against Onchocerca cervicalis (Railliet and Henry, 1910) microfilariae in horses with naturally acquired infections in Formosa (Argentina).

    PubMed

    Mancebo, O A; Verdi, J H; Bulman, G M

    1997-12-31

    On the basis of positive skin snips for Onchocerca cervicalis microfilariae (MF), 45 horses were chosen from 48 in a total of 257 screened on 12 locations in the northeast Province of Formosa (Argentina), and randomly assigned to two treatment groups of 20 horses each, and a nontreated control group of five horses. On Day 14 post-treatment (PT), skin snip samples in the ivermectin-treated (0.2 mg/kg) group were negative for normal viable microfilariae (MF), while horses in the control group maintained their pretreatment level of infection. On the same Day in the moxidectin-treated (0.4 mg/kg) group, 18 horses were negative for MF, but the remaining two had a total of 1 and 2 MF, respectively (equivalent to 10 and 20 MF/g of skin), but all three parasites showed marked cuticular and structural damage. Both horses were negative in a repeat biopsy on Day 21. From Day 3 PT, one ivermectin-treated horse (5%) evidenced an approximate 15 x 2 x 3 cm-sized, apparently nonpainful, oedematous swelling on the ventral midline, 20 cm in front of the navel, which remained unchanged on Day 14 PT. Adverse reactions were not observed in the moxidectin-treated group. Parasitaemia was found in 18.7% of sampled horses (48 of 257), and the number of MF varied between 10-1820/g of skin snip (mean 172). Similar prevalence and total counts had been described previously in 1985 and 1986 in cattle-farm horses in the same area of Argentina; in surveys in Texas (1974) and Louisiana (1995) in the USA, infection rates were also similar, but total counts much higher. It is concluded that moxidectin 2% equine oral gel and ivermectin 2% equine oral paste, were equally 100% effective in the control of O. cervicalis MF. Contrary to ivermectin, moxidectin did not cause post-treatment dermal reactions.

  1. Small bowel volvulus after transabdominal preperitoneal hernia repair due to improper use of V-Loc™ barbed absorbable wire – do we always “read the instructions first”?

    PubMed Central

    Filser, Joerg; Reibetanz, Joachim; Krajinovic, Katica; Germer, Christoph-Thomas; Dietz, Ulrich Andreas; Seyfried, Florian

    2015-01-01

    Introduction Transabdominal preperitoneal endoscopic hernia repair (TAPP) is part of primary surgical health care. While both, the reported recurrence rate and procedure specific morbidity are consistently low, rare serious complications occur. Presentiation of case A 36-year-old male patient developed bowel obstruction three days after both-sided TAPP for inguinal hernia repair. A computer tomography scan of the abdomen revealed a small bowel volvulus in the right lower quadrant of the abdomen requiring urgent revisional surgery. Intraoperatively, the small bowel and its mesenterial vessels were found to be twisted around a 5 cm long V-Loc™ barbed absorbable suturing wire. After successful laparoscopic adhesiolysis, removal of the wire and detorquing of the bowel conglomerate, resection of small intestine was not necessary. The patient's further postoperative recovery was uneventful. Discussion Due to the barbed configuration of the V-Loc™ wire, a gapless continuous suturing of the peritoneum without laparoscopic knotting is easily and fast to accomplish. In this case the recommendation of the manufacturer to shorten the wire was not strictly followed and neither had the suture stump been extraperitonealized in order to avoid such rare complications. Conclusion Surgeons need to be aware of relevant “tricks and traps” of routinely performed procedures and have to know all tools and material they use very well. This case may therefore increase our attention when it comes to little things which actually do matter. PMID:25704567

  2. Changes in antibody profile after treatment of human onchocerciasis.

    PubMed

    Lee, S J; Francis, H L; Awadzi, K; Ottesen, E A; Nutman, T B

    1990-08-01

    To define the changes in antibody response to Onchocerca volvulus antigens after treatment of patients with onchocerciasis, IgG and IgE antibodies were examined quantitatively and qualitatively in 21 patients and 3 control individuals before and sequentially for 14 days after treatment with diethylcarbamazine. The quantitative levels of IgE and IgG responses (both polyclonal and O. volvulus-specific) remained essentially unchanged for all patients, but 9 of the 21 patients showed intensified responses to one or more parasite-specific antigens, and 8 of 21 developed antibodies to previously undetected antigens. There was a significant correlation between the intensities of infection and the development of newly recognized anti-O. volvulus antibodies. These studies demonstrate that O. volvulus-specific IgE and IgG antibody responses are, at least transiently, enhanced by treatment with diethylcarbamazine and that after treatment, parasites possibly release antigens previously hidden from the host's immune response.

  3. Of Mice, Cattle, and Humans: The Immunology and Treatment of River Blindness

    PubMed Central

    Allen, Judith E.; Adjei, Ohene; Bain, Odile; Hoerauf, Achim; Hoffmann, Wolfgang H.; Makepeace, Benjamin L.; Schulz-Key, Hartwig; Tanya, Vincent N.; Trees, Alexander J.; Wanji, Samuel; Taylor, David W.

    2008-01-01

    River blindness is a seriously debilitating disease caused by the filarial parasite Onchocerca volvulus, which infects millions in Africa as well as in South and Central America. Research has been hampered by a lack of good animal models, as the parasite can only develop fully in humans and some primates. This review highlights the development of two animal model systems that have allowed significant advances in recent years and hold promise for the future. Experimental findings with Litomosoides sigmodontis in mice and Onchocerca ochengi in cattle are placed in the context of how these models can advance our ability to control the human disease. PMID:18446236

  4. Onchocerciasis-associated limb swelling in a traveler returning from Cameroon.

    PubMed

    Ezzedine, Khaled; Malvy, Denis; Dhaussy, Ines; Steels, Emmanuelle; Castelein, Carine; De Dobbeler, Gilbert; Heenen, Michel

    2006-01-01

    Travelers to West Central Africa are at risk for infection with Onchocerca volvulus. We describe the case of an adventurous traveler who became infected with O volvulus after a 10-day stay in rural Cameroon. Two years after his return, he was diagnosed with a 3-month history of limb swelling with pruritus and fixed edema of the right arm. He was successfully treated by a single dose of ivermectin, with an additional treatment with doxycycline. The patient was followed-up during 1 year after therapy without relapse. Such travelers experiencing unusual dermatitis syndromes should prompt evaluation for onchocerciasis.

  5. DPA1*02012: A DPA1*0201-related Mhc class II allele in West Africa

    SciTech Connect

    Meyer, C.G.; May, J.; Spauke, D.; Schnittger, L.

    1994-12-31

    DNA techniques such as sequence-specific oligonucleotide probe (SSOP) hybridizations, restriction-fragment length polymorphism (RFLP) analyses, and DNA sequencing have greatly supported the characterization of Mhc class II allelic polymorphism. Here the authors describe a DPA 1 allele which has been identified in two male individuals from Liberia and Benin, West Africa, during a survey study on Mhc class II associations with the different manifestations after infection with Onchocerca volvulus. 4 refs., 1 fig.

  6. [Pruritus after taking chloroquine and filariasis].

    PubMed

    Soro, B; Rey, J L; Houdier, R; Coulibaly, A; Saki, Z; Yao, K F; Delolme, H G

    1989-01-01

    A study of relations between pruritus after doses of chloroquine and on the one hand the infection by Mansonella perstans (filariasis frequent in some areas but pathogenic) and on the other hand the infection by Onchocerca volvulus (filariasis frequent in some other areas but not very pathogenic) was carried out in two villages in Ivory Coast. It is not possible to show an obvious relation between the presence of pruritus and the two filariasis.

  7. Factors in the pathogenesis of ocular onchocerciasis

    PubMed Central

    Kirk, R.

    1957-01-01

    This article briefly reviews the history and distribution of Onchocerca volvulus, and the disease for which it is responsible. The importance is stressed of ophthalmic examination, as opposed to clinical inspection, in determining the incidence of onchocerciasis in a region, such as the Sudan, where eye diseases are common. A description of the ocular manifestations of the infection is given, and their etiology is discussed. PMID:13472405

  8. Recent developments in the treatment of onchocerciasis*

    PubMed Central

    Taylor, Hugh R.

    1984-01-01

    The treatment of onchocerciasis using diethylcarbamazine and suramin sodium, which can kill different stages of the parasite, Onchocerca volvulus, remains unsatisfactory. Recent studies have more clearly defined the serious limitations of the existing forms of treatment. However, two new classes of compounds, the benzimidazoles and avermectins, offer exciting new leads in the search for a safe and effective treatment that could be used on a large scale. PMID:6333293

  9. MRI findings in people with epilepsy and nodding syndrome in an area endemic for onchocerciasis: an observational study.

    PubMed

    Winkler, A S; Friedrich, K; Velicheti, S; Dharsee, J; König, R; Nassri, A; Meindl, M; Kidunda, A; Müller, T H; Jilek-Aall, L; Matuja, W; Gotwald, T; Schmutzhard, E

    2013-06-01

    Onchocerciasis has been implicated in the pathogenesis of epilepsy. The debate on a potential causal relationship between Onchocerca volvulus and epilepsy has taken a new direction in the light of the most recent epidemic of nodding syndrome. To document MRI changes in people with different types of epilepsy and investigate whether there is an association with O. volvulus infection. In a prospective study in southern Tanzania, an area endemic for O. volvulus with a high prevalence of epilepsy and nodding syndrome, we performed MRI on 32 people with epilepsy, 12 of which suffered from nodding syndrome. Polymerase chain reaction (PCR) of O. volvulus was performed in skin and CSF. The most frequent abnormalities seen on MRI was atrophy (twelve patients (37.5%)) followed by intraparenchymal pathologies such as changes in the hippocampus (nine patients (28.1%)), gliotic lesions (six patients (18.8%)) and subcortical signal abnormalities (three patients (9.4%)). There was an overall trend towards an association of intraparenchymal cerebral pathologies and infection with O. volvulus based on skin PCR (Fisher's Exact Test p=0.067) which was most pronounced in children and adolescents with nodding syndrome compared to those with other types of epilepsy (Fisher's Exact Test, p=0.083). Contrary to skin PCR results, PCR of CSF was negative in all patients. The observed trend towards an association of intraparenchymal cerebral pathological results on MRI and a positive skin PCR for O. volvulus despite negative PCR of CSF is intriguing and deserves further attention.

  10. The identification of infective filarial larvae in Simuliidae*

    PubMed Central

    Nelson, G. S.; Pester, F. R. N.

    1962-01-01

    Although it is recognized that the presence of animal filariae can lead to confusion in the interpretation of infection rates in mosquito vectors of filariasis, the filariae found in man-biting simuliids are usually assumed to be Onchocerca volvulus. The authors of this paper emphasize that it is unwise to calculate transmission indices from infection rates in man-biting simuliids unless there is confidence in the identification of the filarial larvae. In this respect they cite their observations on Mount Elgon in Uganda which show that the majority of the filarial larvae in Simulium neavei—the local vector of onchocerciasis—are of species that do not affect man. To assist in the correct interpretation of infection rates in the vectors the authors made a detailed study of the morphological character of O. volvulus infective larvae and established criteria for distinguishing O. volvulus from other filariae known to be transmitted by simuliids. PMID:13938041

  11. [Adult intestinal malrotation associated with intestinal volvulus].

    PubMed

    Hernando-Almudí, Ernesto; Cerdán-Pascual, Rafael; Vallejo-Bernad, Cristina; Martín-Cuartero, Joaquín; Sánchez-Rubio, María; Casamayor-Franco, Carmen

    2016-06-23

    Intestinal malrotation is a congenital anomaly of the intestinal rotation and fixation, and usually occurs in the neonatal age. Description of a clinical case associated with acute occlusive symptoms. A case of intestinal malrotation is presented in a previously asymptomatic woman of 46 years old with an intestinal obstruction, with radiology and surgical findings showing an absence of intestinal rotation. Intestinal malrotation in adults is often asymptomatic, and is diagnosed as a casual finding during a radiological examination performed for other reasons. Infrequently, it can be diagnosed in adults, associated with an acute abdomen. Copyright © 2016 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  12. Repurposing Auranofin as a Lead Candidate for Treatment of Lymphatic Filariasis and Onchocerciasis

    PubMed Central

    Bulman, Christina A.; Bidlow, Chelsea M.; Lustigman, Sara; Cho-Ngwa, Fidelis; Williams, David; Rascón, Jr, Alberto A.; Tricoche, Nancy; Samje, Moses; Bell, Aaron; Suzuki, Brian; Lim, K. C.; Supakorndej, Nonglak; Supakorndej, Prasit; Wolfe, Alan R.; Knudsen, Giselle M.; Chen, Steven; Wilson, Chris; Ang, Kean-Hooi; Arkin, Michelle; Gut, Jiri; Franklin, Chris; Marcellino, Chris; McKerrow, James H.; Debnath, Anjan; Sakanari, Judy A.

    2015-01-01

    Two major human diseases caused by filariid nematodes are onchocerciasis, or river blindness, and lymphatic filariasis, which can lead to elephantiasis. The drugs ivermectin, diethylcarbamazine (DEC), and albendazole are used in control programs for these diseases, but are mainly effective against the microfilarial stage and have minimal or no effect on adult worms. Adult Onchocerca volvulus and Brugia malayi worms (macrofilariae) can live for up to 15 years, reproducing and allowing the infection to persist in a population. Therefore, to support control or elimination of these two diseases, effective macrofilaricidal drugs are necessary, in addition to current drugs. In an effort to identify macrofilaricidal drugs, we screened an FDA-approved library with adult worms of Brugia spp. and Onchocerca ochengi, third-stage larvae (L3s) of Onchocerca volvulus, and the microfilariae of both O. ochengi and Loa loa. We found that auranofin, a gold-containing drug used for rheumatoid arthritis, was effective in vitro in killing both Brugia spp. and O. ochengi adult worms and in inhibiting the molting of L3s of O. volvulus with IC50 values in the low micromolar to nanomolar range. Auranofin had an approximately 43-fold higher IC50 against the microfilariae of L. loa compared with the IC50 for adult female O. ochengi, which may be beneficial if used in areas where Onchocerca and Brugia are co-endemic with L. loa, to prevent severe adverse reactions to the drug-induced death of L. loa microfilariae. Further testing indicated that auranofin is also effective in reducing Brugia adult worm burden in infected gerbils and that auranofin may be targeting the thioredoxin reductase in this nematode. PMID:25700363

  13. Repurposing auranofin as a lead candidate for treatment of lymphatic filariasis and onchocerciasis.

    PubMed

    Bulman, Christina A; Bidlow, Chelsea M; Lustigman, Sara; Cho-Ngwa, Fidelis; Williams, David; Rascón, Alberto A; Tricoche, Nancy; Samje, Moses; Bell, Aaron; Suzuki, Brian; Lim, K C; Supakorndej, Nonglak; Supakorndej, Prasit; Wolfe, Alan R; Knudsen, Giselle M; Chen, Steven; Wilson, Chris; Ang, Kean-Hooi; Arkin, Michelle; Gut, Jiri; Franklin, Chris; Marcellino, Chris; McKerrow, James H; Debnath, Anjan; Sakanari, Judy A

    2015-02-01

    Two major human diseases caused by filariid nematodes are onchocerciasis, or river blindness, and lymphatic filariasis, which can lead to elephantiasis. The drugs ivermectin, diethylcarbamazine (DEC), and albendazole are used in control programs for these diseases, but are mainly effective against the microfilarial stage and have minimal or no effect on adult worms. Adult Onchocerca volvulus and Brugia malayi worms (macrofilariae) can live for up to 15 years, reproducing and allowing the infection to persist in a population. Therefore, to support control or elimination of these two diseases, effective macrofilaricidal drugs are necessary, in addition to current drugs. In an effort to identify macrofilaricidal drugs, we screened an FDA-approved library with adult worms of Brugia spp. and Onchocerca ochengi, third-stage larvae (L3s) of Onchocerca volvulus, and the microfilariae of both O. ochengi and Loa loa. We found that auranofin, a gold-containing drug used for rheumatoid arthritis, was effective in vitro in killing both Brugia spp. and O. ochengi adult worms and in inhibiting the molting of L3s of O. volvulus with IC50 values in the low micromolar to nanomolar range. Auranofin had an approximately 43-fold higher IC50 against the microfilariae of L. loa compared with the IC50 for adult female O. ochengi, which may be beneficial if used in areas where Onchocerca and Brugia are co-endemic with L. loa, to prevent severe adverse reactions to the drug-induced death of L. loa microfilariae. Further testing indicated that auranofin is also effective in reducing Brugia adult worm burden in infected gerbils and that auranofin may be targeting the thioredoxin reductase in this nematode.

  14. The evolution of ocular onchocerciasis in the Volta River Basin Area over a period of five years of vector control.

    PubMed

    Dadzie, K Y; Rolland, A; Thylefors, B

    1984-03-01

    The results of an ophthalmological evaluation conducted in seven West African savannah villages before and after 5 years of vector control, were analysed to determine the effect of an interrupted or greatly reduced transmission of Onchocerca volvulus on the evolution of ocular onchocerciasis. Cross-sectional data showed a significant reduction of the prevalence of ocular onchocerciasis in five of the villages, and the rates of irreversible ocular lesions and blindness were generally lower after 5 years of vector control. A longitudinal study of a defined population showed that the ocular status of most patients with ocular onchocerciasis remained stable or improved over the 5 year period, particularly in lightly infected cases. The evolution of ocular onchocerciasis showed a deterioration in a minor proportion, restricted to cases of already existing severe lesions, resulting in blindness. A comparison of ophthalmic data from adjacent areas without vector control, indicates that a five year period of vector control may reduce the risk of developing eye lesions or blindness due to onchocerciasis by 50%.

  15. Studies of metrifonate in onchocerciasis.

    PubMed

    Awadzi, K; Orme, M L; Breckenridge, A M; Haddock, D; Gilles, H M

    1981-01-01

    Metrifonate has been studied in the treatment of infections with Onchocerca volvulus in West Africa. In doses of 10 mg/kg daily for six days, metrifonate was effective against the microfilariae but produced unpleasant reactions due both to the death of the microfilariae and to the muscarinic effects of the drug. In a comparison of 10 mg/kg metrifonate, for 3 doses at 10 day intervals, with diethylcarbamazine (D.E.C.) in a total dose of 6.6 g, metrifonate was significantly less effective than D.E.C. in killing microfilariae but produced significantly fewer adverse effects. In a final study comparing metrifonate 10 mg/kg/day given for 3 or for 6 days there was little difference in their therapeutic effect. However, metrifonate 10 mg/kg given for 6 days produced more severe adverse reactions due largely to the muscarinic and nicotinic effects of acetylcholine and these effects were not prevented by the administration of belladonna alkaloids. Metrifonate 10 mg/kg given for 3 doses at 10 day intervals is effective in the treatment of onchocerciasis but is unlikely to replace diethylcarbamazine. Metrifonate has no action on the adult worms.

  16. Potential of a soluble tetrazolium/formazan assay for the evaluation of filarial viability.

    PubMed

    Comley, J C; Turner, C H

    1990-04-01

    Using female Acanthocheilonema viteae we have investigated the bioreduction of the tetrazolium reagent XTT (2,3-bis(2-methoxy-4-nitro-sulphonyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide). Unlike the formazan formed by other tetrazolium salts, that derived from XTT readily diffuses out of A. viteae in vitro. Formazan formation can therefore be quantified by direct absorbance reading of the incubation medium, eliminating the need for a DMSO solubilization step. Optimum assay conditions involved a 4 h incubation, in the presence of the electron coupling agent phenazine methosulphate (PMS). Repeat 4 h incubations with XTT-PMS were well tolerated by worms for 5 consecutive days. This confirmed the low toxicity of XTT formazan and its usefulness in the semi-continuous assessment of filarial viability. In comparison to our previously reported MTT (3-(4, 5 dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide)-reduction assay XTT-PMS reduction showed comparable drug sensitivity and accuracy, however XTT-PMS appears to be at least 10-15 times less efficiently reduced by A. viteae females. A possible application of the XTT assay using female Onchocerca volvulus is discussed.

  17. Genetic response to an environmental pathogenic agent: HLA-DQ and onchocerciasis in northwestern Ecuador.

    PubMed

    De Angelis, F; Garzoli, A; Battistini, A; Iorio, A; De Stefano, G F

    2012-02-01

    The aim of this study is to explore human leukocyte antigen (HLA)-DQ variability in two populations (Cayapas Amerindians and Afro-Ecuadorians) who live near one another along the Cayapa River and who are exposed to the same environmental stresses, such as infection by Onchocerca volvulus. HLA-DQA1 and HLA-DQB1 of 149 unrelated individuals (74 Cayapas and 75 Afro-Ecuadorians) have been analyzed. HLA high-resolution molecular typing was performed by sequence-based typing, sequence-specific oligonucleotides hybridization and sequence-specific primer (SSP) amplification. The comparison between affected (cases) and unaffected people (controls) in both populations shows the key role of several HLA-DQA1 alleles in susceptibility and protection against onchocerciasis. In both populations, there is strong evidence related to the protective role of DQA1*0401 against onchocerciasis. Alleles HLA-DQA1*0102 and *0103 seem to represent risk factors in Afro-Ecuadorians, while HLA-DQA1*0301 is only a suggestive susceptibility allele in Cayapas. These findings represent new positive/negative associations with onchocerciasis in South America, whereas previous findings pertained only to African populations.

  18. In a bovine model of onchocerciasis, protective immunity exists naturally, is absent in drug-cured hosts, and is induced by vaccination

    PubMed Central

    Tchakouté, Virginia L.; Graham, Simon P.; Jensen, Siv Aina; Makepeace, Benjamin L.; Nfon, Charles K.; Njongmeta, Leo M.; Lustigman, Sara; Enyong, Peter A.; Tanya, Vincent N.; Bianco, Albert E.; Trees, Alexander J.

    2006-01-01

    Onchocerciasis (river blindness) is a major parasitic disease of humans in sub-Saharan Africa caused by the microfilarial stage of the nematode Onchocerca volvulus. Using Onchocerca ochengi, a closely related species which infects cattle and is transmitted by the same black fly vector (Simulium damnosum sensu lato) as O. volvulus, we have conducted longitudinal studies after either natural field exposure or experimental infection to determine whether, and under what circumstances, protective immunity exists in onchocerciasis. On the basis of the adult worm burdens (nodules) observed, we determined that cattle reared in endemic areas without detectable parasites (putatively immune) were significantly less susceptible to heavy field challenge than age-matched, naïve controls (P = 0.002), whereas patently infected cattle, cured of infection by adulticide treatment with melarsomine, were fully susceptible. Cattle immunized with irradiated third-stage larvae were significantly protected against experimental challenge (100% reduction in median nodule load, P = 0.003), and vaccination also conferred resistance to severe and prolonged field challenge (64% reduction in median nodule load, P = 0.053; and a significant reduction in microfilarial positivity rates and density, P < 0.05). These results constitute evidence of protective immunity in a naturally evolved host–Onchocerca sp. relationship and provide proof-of-principle for immunoprophylaxis under experimental and field conditions. PMID:16585501

  19. Zoonotic onchocerciasis caused by a parasite from wild boar in Oita, Japan. A comprehensive analysis of morphological characteristics of the worms for its diagnosis.

    PubMed

    Takaoka, H; Bain, O; Uni, S; Korenaga, M; Kozek, W J; Shirasaka, C; Aoki, C; Otsuka, Y; Fukuda, M; Eshita, Y; Daa, T

    2004-09-01

    Histological examination of a nodule removed from the back of the hand of a 58-year-old woman from Oita, Kyushu, Japan showed an Onchocerca female sectioned through the posterior region of the worm (ovaries identifiable) and young (thin cuticle). Six Onchocerca species are enzootic in that area: O. gutturosa and O. lienalis in cattle, O. suzukii in serows (Capricornis crispus), O. skrjabini and an Onchocerca sp. in Cervus nippon nippon, and O. dewittei japonica in wild boar (Sus scrofa leucomystax). Diagnostic characters of female Onchocerca species, such as the cuticle and its ridges, change along the body length. Tables of the histologic morphology of the mid- and posterior body-regions of the local species are presented. In addition, it was observed that transverse ridges arose and thickened during the adult stage (examination of fourth stage and juvenile females of O. volvulus). The specimen described in this report, with its prominent and widely spaced ridges, was identified as O. d. japonica. Four of the 10 zoonotic cases of onchocerciasis reported worldwide were from Oita, three of them being caused by O. d. japonica, the prevalence of which in local wild boar was 22 of 24 (92%).

  20. River blindness. Protection for 54 cents a year.

    PubMed

    Vieta, F

    1998-01-01

    Infection by onchocerca volvulus, a parasitic worm, causes onchocerciasis (river blindness), a debilitating and often blinding disease endemic to tropical areas of Africa and Central and South America. The adult onchocerca volvulus invades the human host where it lives and reproduces for up to 14 years, creating millions of infant worms which cause itching, loss of skin color, rapid aging, and disfiguring skin disease in the host. Onchocerciasis often causes blindness in the human host by approximately age 35 years, and is the third leading cause of blindness in Africa. Onchocerca volvulus is transmitted among humans through the bite of blackflies which breed in fast-flowing rivers. The Onchocerciasis Control Program (OCP) was formally launched in 1974 by the UN's Food and Agriculture Organization (FAO), the UN Development Program (UNDP), the World Bank, and the World Health Organization (WHO) in Benin, Burkina Faso, Ghana, Cote d'Ivoire, Mali, Niger, and Togo. Vector control is the central strategy of the OCP, consisting of weekly helicopter spraying of larvacide to prevent the blackfly from reproducing and transmitting the disease. In addition, Merck & Co. is providing drug therapy against the infant worms in the human host free of charge to 16 million people in endemic areas. Onchocerciasis has now almost been eradicated in the 7 original target countries. Also through the OCP, by 1996, more than 34 million people were protected against the disease, about 2 million who were seriously infected have fully recovered, and an estimated 600,000 people have been prevented from going blind. 12 million infants born since the launch of the OCP face no risk of contracting the disease, and approximately 25 million hectares of arable fertile riverine land has been opened for resettlement. Labor productivity has also increased.

  1. Wavelength Comparison

    NASA Image and Video Library

    2016-10-27

    The difference in features that are visible in different wavelengths of extreme ultraviolet light can be stunning as we see when we compare very large coronal holes, easily seen in the AIA 171 image (colorized bronze) yet hardly perceptible in the AIA 304 image (colorized red). Both were taken at just about the same time (Oct. 27, 2016). Coronal holes are areas of open magnetic field that carry solar wind out into space. In fact, these holes are currently causing a lot of geomagnetic activity here on Earth. The bronze image wavelength captures material that is much hotter and further up in the corona than the red image. The comparison dramatizes the value of observing the sun in multiple wavelengths of light. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA15377

  2. Ivermectin: pharmacology and application in dermatology.

    PubMed

    Dourmishev, Assen L; Dourmishev, Lyubomir A; Schwartz, Robert A

    2005-12-01

    Ivermectin is a synthetic derivative of the antiparasitic class of compounds known as avermectins. It is a macrolide endectocide with activity against both endoparasites with cutaneous tropism (Strongyloides stercoralis, Ancylostoma braziliense, Cochliomyia hominivorax, Dermatobia hominis, Filaria bancrofti, Wucheria malayi, Onchocerca volvulus, Loa-loa) and ectoparasites such as Sarcoptes scabies, Pediculus humanus, Demodex folliculorum, and Cheyletiella sp. Ivermectin is of great interest in the treatment of patients with different forms of scabies, head lice, demodecidosis, cutaneous larva migrans, cutaneous larva currens, myiasis, and filariasis.

  3. [Management in Senegal of the 1st efficacy and tolerability studies of ivermectin (MK 933) in human onchocerciasis].

    PubMed

    Diallo, S; Larivière, M; Diop Mar, I; N'Dir, O; N'Diaye, R; Badiane, S; Porta, M; Aziz, M

    1984-01-01

    In 1981, 32 adult Senegalese males infected with Onchocerca volvulus but without ocular involvement were treated by groups of 8 with single oral dosages of 5, 10, 30 or 50 micrograms/kg of ivermectin . As soon as the second day after treatment, we observed a marked decrease of the dermal microfilaremic charge after a posology of 30 micrograms/kg. However the decrease is most important in the group subjected to 50 micrograms/kg and 75% of them had no more microfilariae in the dermis 28 days following treatment.

  4. Clinical and laboratory changes consequent to diethylcarbamazine in patients with onchocerciasis.

    PubMed

    Fazen, L E; Anderson, R I; Fazen, L E; Marroquin, H F

    1976-03-01

    This controlled study assesses the effect of a single oral dose of diethylcarbamazine (DEC) in a Guatemalan population with light infections of Onchocerca volvulus. From 8 to 24 hours after DEC, microfilariae were found with increased frequency in the urine, blood, and sputum, while the number of microfilariae per mm2 of skin decreased. The onset of signs and symptoms of reaction coincided with the appearance of microfilariae in the body fluids. Motile microfilariae were noted in the anterior chamber of the eye after the administration of diethylcarbamazine. Medication with corticosteroids appeared to reduce the symptoms of reaction without changing the laboratory results.

  5. Onchocerciasis in Canada.

    PubMed

    Seah, S K

    1974-03-16

    The first two cases of onchocerciasis seen in Canada are reported. The patients had come from West Africa to study in Canada several months prior to admission to hospital. The presenting symptom in each case was intense pruritus. One of the patients had early ocular involvement. The diagnosis was made by means of microscopic examination of a skin snip. The subcutaneous nodule excised from one of the patients showed the adult Onchocerca volvulus. Both patients also had urinary schistosomiasis. The clinical features, laboratory findings, treatment and public health aspects of onchocerciasis are discussed.

  6. Onchocerciasis in Canada

    PubMed Central

    Seah, S. K. K.

    1974-01-01

    The first two cases of onchocerciasis seen in Canada are reported. The patients had come from West Africa to study in Canada several months prior to admission to hospital. The presenting symptom in each case was intense pruritus. One of the patients had early ocular involvement. The diagnosis was made by means of microscopic examination of a skin snip. The subcutaneous nodule excised from one of the patients showed the adult Onchocerca volvulus. Both patients also had urinary schistosomiasis. The clinical features, laboratory findings, treatment and public health aspects of onchocerciasis are discussed. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:4817212

  7. Dirofilariasis in a 22-year-old airman deployed to the Mediterranean.

    PubMed

    Udall, Don N

    2011-09-01

    A 22-year-old male U.S. Navy airman with new nontender subcutaneous, 4-cm mass inferior to the right anterior costal margin was sent for routine biopsy. Sudden appearance of axillary lymph nodes prompted immediate excisional biopsy of the primary mass. Pathological evaluation was initially read as Onchocerca volvulus, the filarial nematode classically responsible for river blindness. Subsequent evaluation by Armed Forces Institute of Pathology resulted in a change of diagnosis to Dirofilaria species, not pathogenic in humans. The author discusses the literature of Dirofilaria infestations in humans, and how they may affect U.S. servicemen and women traveling to endemic areas.

  8. Prevalence of filariasis in symptomatic patients in Moyen Chari district, south of Chad.

    PubMed

    Bregani, Enrico Rino; Balzarini, Laura; Mbaïdoum, Narassem; Rovellini, Angelo

    2007-07-01

    Filarial parasites infect an estimated 140 million people worldwide. Wuchereria bancrofti, Onchocerca volvulus, Loa loa and Mansonella perstans are responsible for most filarial infections in sub-Saharan Africa. We describe the prevalence and the clinical characteristics of filariasis in symptomatic patients in Goundi Sanitary district:167 patients were enrolled (99 men, 68 women). M. perstans microfilariae were isolated in peripheral blood in 164 cases, while Loa loa and Wuchereria bancrofti filariasis were diagnosed in only six and three cases, respectively. The most frequent filariasis observed in our study were due to M. perstans and L. loa, while the few cases of W. bancrofti filariasis seem to have been acquired abroad. No cases of O. volvulus were observed. Microfilarial burden was not related to symptoms, but a correlation between eosinophilia and pruritus was evident. No relationship was observed between eosinophils and symptoms. The prevalence observed in symptomatic patients could reflect the real prevalence of filariasis.

  9. Optimization of the Esperanza window trap for the collection of the African onchocerciasis vector Simulium damnosum sensu lato.

    PubMed

    Toé, Laurent D; Koala, Lassane; Burkett-Cadena, Nathan D; Traoré, Bizini M; Sanfo, Moussa; Kambiré, Sié Roger; Cupp, Eddie W; Traoré, Soungalo; Yameogo, Laurent; Boakye, Daniel; Rodríguez-Pérez, Mario A; Unnasch, Thomas R

    2014-09-01

    A simple inexpensive trap (Esperanza window trap) was shown recently to collect significant numbers of Simulium ochraceum sensu lato, a major vector of Onchocerca volvulus in Mesoamerica. Here, we report studies optimizing this trap for the collection of Simulium damnosum s.l., the major vector of O. volvulus in Africa. A shortened, blue and black striped version of the Esperanza window trap, when baited with a combination of CO2 and worn trousers, rivalled human landing collections in the number of S. damnosum s.l. females collected. Traps baited with a commercially available human skin lure and CO2 resulted in collections that were not significantly different than those obtained from traps baited with worn trousers and CO2. This suggests that the Esperanza window trap may offer a replacement for human landing collections for monitoring onchocerciasis transmission in Africa.

  10. Research notes from the Onchocerciasis Chemotherapy Research Centre, Ghana.

    PubMed

    Awadzi, K

    1997-10-01

    Brief notes are given on drugs which have been tested at the Onchocerciasis Chemotherapy Research Centre at Tamale and Hohoe and found to have activity against Onchocerca volvulus. Ivermectin in single doses as high as 800 micrograms/kg was found to be no more effective than the standard dose of 150 micrograms/kg. The benzimidazole carbamates, mebendazole and albendazole, differ in their effects on O. volvulus. The former has microfilaricidal effects and is toxic to developing embryos surrounded by an egg shell but not the stretched microfilariae. Albendazole has no microfilaricidal activity but is toxic to all intra-uterine stages. The reasons for these differences are unclear. Early studies with amocarzine are described; the maximum tolerable dose is 20 mg/kg and the predominant activity, against the microfilariae, is marked only at doses greater than 12 mg/kg. None of the drugs tested has macrofilaricidal activity.

  11. Efficacy and tolerance of ivermectin in human onchocerciasis.

    PubMed

    Aziz, M A; Diallo, S; Diop, I M; Lariviere, M; Porta, M

    1982-07-24

    Initial clinical studies in 32 Senegalese subjects have demonstrated the efficacy of ivermectin in Onchocerca volvulus infection (river blindness). Although O. volvulus microfilariae in skin snips were not reduced in number after single oral doses of 5 micrograms or 10 micrograms/kg body-weight, they were greatly reduced in all subjects after single oral doses of 30 micrograms or 50 micrograms/kg and were eliminated completely in 6 of th 8 subjects who received the 50 micrograms/kg dose. All subjects tolerated the drug well. Transient pruritus which did not require treatment was observed on the day the dose was given in 2 of the 8 subjects after the 30 micrograms/kg dose and in 4 of the 8 who received the 50 micrograms/kg dose. Ivermectin produced no abnormal laboratory results.

  12. Exposure to multiple parasites is associated with the prevalence of active convulsive epilepsy in sub-Saharan Africa.

    PubMed

    Kamuyu, Gathoni; Bottomley, Christian; Mageto, James; Lowe, Brett; Wilkins, Patricia P; Noh, John C; Nutman, Thomas B; Ngugi, Anthony K; Odhiambo, Rachael; Wagner, Ryan G; Kakooza-Mwesige, Angelina; Owusu-Agyei, Seth; Ae-Ngibise, Kenneth; Masanja, Honorati; Osier, Faith H A; Odermatt, Peter; Newton, Charles R

    2014-01-01

    Epilepsy is common in developing countries, and it is often associated with parasitic infections. We investigated the relationship between exposure to parasitic infections, particularly multiple infections and active convulsive epilepsy (ACE), in five sites across sub-Saharan Africa. A case-control design that matched on age and location was used. Blood samples were collected from 986 prevalent cases and 1,313 age-matched community controls and tested for presence of antibodies to Onchocerca volvulus, Toxocara canis, Toxoplasma gondii, Plasmodium falciparum, Taenia solium and HIV. Exposure (seropositivity) to Onchocerca volvulus (OR = 1.98; 95%CI: 1.52-2.58, p<0.001), Toxocara canis (OR = 1.52; 95%CI: 1.23-1.87, p<0.001), Toxoplasma gondii (OR = 1.28; 95%CI: 1.04-1.56, p = 0.018) and higher antibody levels (top tertile) to Toxocara canis (OR = 1.70; 95%CI: 1.30-2.24, p<0.001) were associated with an increased prevalence of ACE. Exposure to multiple infections was common (73.8% of cases and 65.5% of controls had been exposed to two or more infections), and for T. gondii and O. volvulus co-infection, their combined effect on the prevalence of ACE, as determined by the relative excess risk due to interaction (RERI), was more than additive (T. gondii and O. volvulus, RERI = 1.19). The prevalence of T. solium antibodies was low (2.8% of cases and 2.2% of controls) and was not associated with ACE in the study areas. This study investigates how the degree of exposure to parasites and multiple parasitic infections are associated with ACE and may explain conflicting results obtained when only seropositivity is considered. The findings from this study should be further validated.

  13. Immediate hypersensitivity responses in the immunopathogenesis of human onchocerciasis.

    PubMed

    Ottesen, E A

    1985-01-01

    It is not clear what role immediate hypersensitivity immune responses have in the pathogenesis of human onchocerciasis, but it is certain that these responses are prominent both in the course of natural infection and during the Mazzotti reactions that follow treatment with diethylcarbamazine. In humans, the levels of total serum IgE associated with onchocerciasis are as high or higher than those associated with almost any helminth infection, although specific IgE antibodies to Onchocerca volvulus appear to be a small and still poorly characterized fraction of the total serum IgE. Evidence about the relationship of these prominent IgE responses in patients with onchocerciasis to the onchocercal skin disease that manifests as pruritus and papular eruptions is conflicting, but in a guinea pig model of ocular pathology induced by onchocerca microfilariae evidence for the pathogenetic importance of IgE and immediate hypersensitivity is much less equivocal. The suggestive findings from this model make it imperative to carry out similar studies of Onchocerca-affected human eyes to determine whether immediate hypersensitivity responses play a similar critical role in the pathogenesis of the ocular lesions in humans.

  14. Down-Regulated Lymphoproliferation Coincides with Parasite Maturation and with the Collapse of Both Gamma Interferon and Interleukin-4 Responses in a Bovine Model of Onchocerciasis†

    PubMed Central

    Graham, Simon P.; Trees, Alexander J.; Collins, Robert A.; Moore, Davina M.; Guy, Francis M.; Taylor, Mark J.; Bianco, Albert E.

    2001-01-01

    Onchocerciasis is a debilitating parasitic infection caused by the filarial nematode Onchocerca volvulus. Infections are chronic, and persistence of the parasites for several years argues for highly adapted mechanisms of immune evasion. Due to the restricted host repertoire of O. volvulus, we have used the cattle parasite Onchocerca ochengi to investigate the nature of immunomodulation underpinning these long-term infections. Cattle were infected with a single inoculation of 350 infective-stage larvae under laboratory conditions (n = 6). Intradermal nodules containing immature adult worms were detected from 110 days postinfection, and microfilariae in skin were detected from day 280 postinfection. Parasite-specific responses during early infection were nonpolarized with respect to the major Th cytokines (interleukin-4 [IL-4], IL-2, and gamma interferon [IFN-γ]) produced by antigen-stimulated peripheral blood mononuclear cells (PBMC) or serum antibody isotypes. Antigen-induced proliferation of PBMC peaked shortly after exposure and remained high during the prepatent infection. As the parasites matured and animals developed patent infections, there was a profound down-regulation of lymphoproliferation, accompanied by sharp falls in the expression of both IL-4 and IFN-γ and a gradual decline in IL-2. Levels of immunoglobulin G2 (IgG2) fell, while those of IgG1 remained high. We conclude that neither a classical Th2 response nor a simple Th1-to-Th2 switch is sufficient to explain the immunomodulation associated with patent Onchocerca infections. Instead, there is an initial Th0 response, which matures into a response with some, but not all of the features of a Th2 response. The natural host-parasite relationship of O. ochengi in cattle may be useful as both a descriptive and predictive tool to test more refined models of immunomodulation in onchocerciasis. PMID:11401968

  15. Novel retinoid-binding proteins from filarial parasites.

    PubMed Central

    Sani, B P; Vaid, A; Comley, J C; Montgomery, J A

    1985-01-01

    The present study deals with the discovery and partial characterization of specific binding proteins for retinol and retinoic acid from filarial parasites (worms of the superfamily Filarioidea), including those from two species of Onchocerca. These binding proteins, which are distinct in their physicochemical properties and in the mode of ligand interactions from the host-tissue retinoid-binding proteins, may be involved in the mediation of the putative biological roles of retinoids in the control of parasitic growth, differentiation and reproduction. Parasite retinol-binding protein and retinoic acid-binding protein exhibited specificity for binding retinol and retinoic acid respectively. Both the binding proteins showed an s20,w value of 2.0 S. On gel filtration, both proteins were retarded to a position corresponding to the same molecular size (19.0 kDa). On preparative columns, the parasite binding proteins exhibited isoelectric points at pH 5.7 and 5.75. Unlike the retinoid-binding proteins of mammalian and avian origin, the parasite retinoid-binding proteins showed a lack of mercurial sensitivity in ligand binding. The comparative amounts of retinoic acid-binding protein in five parasites, Onchocerca volvulus, Onchocerca gibsoni, Dipetalonema viteae, Brugia pahangi and Dirofilaria immitis, were between 2.7 and 3.1 pmol of retinoic acid bound/mg of extractable protein. However, the levels of parasite retinol-binding protein were between 4.8 and 5.8 pmol/mg, which is considerably higher than the corresponding levels of cellular retinol-binding protein of mammalian and avian origin. Both retinol- and retinoic acid-binding-protein levels in O. volvulus-infected human nodules and O. gibsoni-infected bovine nodules were similar to their levels in mammalian tissues. Also, these nodular binding proteins, like the host-binding proteins, exhibited mercurial sensitivity to ligand interactions. PMID:3004410

  16. The further application of MTT-formazan colorimetry to studies on filarial worm viability.

    PubMed

    Comley, J C; Townson, S; Rees, M J; Dobinson, A

    1989-09-01

    Experiments have confirmed that MTT-formazan colorimetry in its simplest form (incubation of intact worms with MTT and direct visualisation of any formazan formed) can be readily applied to several species of filariae including Onchocerca volvulus. Data is presented which will assist the development of quantitative MTT reduction viability tests for a selection of the smaller filarial species. Assays of pieces of Onchocerca gutturosa and O. volvulus females have led us to tentatively conclude that the tips of filariae, particularly the anterior ends, may well be metabolically the most active part of the worm. Selective sampling of these regions for Onchocerca might therefore be a useful indicator for the viability of the parasite. An example of how MTT-formazan colorimetry has been applied to yield additional data to support motility observations on the in vitro survival of male O. gutturosa is also given. The in vitro timecourse of worm death caused by 10 microM CGP 20376 on Acanthocheilonema viteae females has been examined by MTT reduction and compared with 6 other non-subjective parameters. The results suggests that the parameters examined could be divided into two groups according to the time taken for CGP 20376 to cause 50% inhibition (t50) of the parameter. Fast response parameters had t50's between 1 and 6 h (motility indices, 14CO2 evolution, adenine uptake and leucine uptake), they are more sensitive measures of viability and indicate possible worm damage which may or may not be reversible. Slow response parameters had t50's between 34 and 48.5 h (lactate output, MTT reduction and adenine leakage), and are probably linked with severe degenerative changes and are indicative of worm death.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Co-endemicity of Loiasis and Onchocerciasis in Rain Forest Communities in Southwestern Nigeria

    PubMed Central

    Ojurongbe, Olusola; Akindele, Akeem Abiodun; Adeleke, Monsuru Adebayo; Oyedeji, Matthew Oyebode; Adedokun, Samuel Adeyinka; Ojo, Josephine Folashade; Akinleye, Callistus Adewale; Bolaji, Oloyede Samuel; Adefioye, Olusegun Adelowo; Adeyeba, Oluwaseyi Adegboyega

    2015-01-01

    Background Loiasis is currently receiving attention as a disease of public health importance because of the possibility of increased risk of developing neurologic serious adverse event following mass ivermectin treatment against onchocerciasis in individual co-infected with Onchocerca volvulus and Loa loa. Methodology/Principal Findings Rapid assessment procedure for loiasis (RAPLOA) was conducted in 12 communities covering the 3 senatorial districts of Osun State, Nigeria. A total of 960 people were interviewed for history of eye worm using the WHO guidelines for rapid assessment. The survey confirmed the presence of loiasis in all the 12 communities with 4 in Osun East/Ife south senatorial district being at high risk with a prevalence of over 40%. Based on the RAPLOA results, communities within Osun East/Ife south senatorial district were selected for microfilaraemic assessment of L. loa and O. volvulus. A total of 1115 and 1091 individuals were screened for L. loa and O. volvulus microfilaria worms respectively. 160 (14.3%) had L. loa microfilaria detected in their blood with 8 (5.0%) individuals having L. loa loads above 8000 mf/ml. 166 (15.2%) subjects had O. volvulus microfilaria (range 4-504 mf/ml) detected in their skin snip. 30 (2.69%) subjects were co-infected with both L. loa and O. volvulus. There was a significant variation in the prevalence (2.1% to 33.3%) of onchocerciasis in the communities studied (p = 0.001). Five (41.7%) of the studied communities had a prevalence that is equal to or greater than 20%. Conclusions/Significance Low prevalence of onchocerciasis and loiasis co-infection in this study suggests that loiasis may not pose a serious epidemiological threat to the continuous distribution and sustainability of ivermectin for the treatment of onchocerciasis. Evaluation of the interruption of onchocerciasis transmissions in this region using all the indicators set forth by WHO is therefore suggested. PMID:25812086

  18. Filariasis in the Kaiyamba Chiefdom, Moyamba District Sierra Leone: an epidemiological and clinical study.

    PubMed

    Gbakima, A A; Sahr, F

    1996-05-01

    In a cross-sectional epidemiological and clinical study of human filariasis, 630 individuals were examined for Onchocerca volvulus, Wuchereria bancrofti and Mansonella perstans infections in five communities in the Kaiyamba Chiefdom, Moyamba District, Sierra Leone. The overall prevalence of O. volvulus infection in males 144(39.1%) and females 94(35.9%) was not significantly different and the sex prevalence rate between communities was also not significant (G = 3, d.f. = 4, P > 0.05). Prevalence of O. volvulus was significantly lower (G = 42.331, d.f. = 5, P < 0.001) in the 5-9 age group (13.3%) compared to the 40-49 age group (61.9%). Sixty-four (10.2%) and 38(6.0%) of individuals examined were positive for W. bancrofti and M. perstans infections respectively and prevalence of both infections in the five communities was not significant. Mixed infections with the all three filaria parasites were recorded in 10(3.2%) of the individuals. One hundred and sixty-four (71.3%) clinical cases due to W. bancrofti were inflammatory in nature; 36.5% were chronic, of which, 26.6% were hydroceles and 9.4% involved elephantiasis of both the scrotum and the lower legs. All 19(3.0%) of M. perstans-related clinical cases were inflammatory. Ninety-three(63.3%) of O. volvulus positive individuals that presented symptoms were inflammatory in nature, 14(9.5%) had ocular symptoms and 57(38.8%) had subcutaneous nodules. These data indicate that infections due to O. volvulus, W. bancrofti and M. perstans may be of public health importance in Sierra Leone.

  19. Human Onchocerciasis and Tetanus Vaccination: Impact on the Postvaccination Antitetanus Antibody Response

    PubMed Central

    Cooper, Philip J.; Espinel, Ivan; Wieseman, Moira; Paredes, Wilson; Espinel, Mauricio; Guderian, Ronald H.; Nutman, Thomas B.

    1999-01-01

    To investigate whether helminth infections may affect the efficacy of vaccines by impairing the immune response to nonparasite vaccine antigens, we compared the antibody responses to tetanus toxoid (TT) after tetanus vaccination in 193 subjects with Onchocerca volvulus infection with 85 comparable noninfected controls. After vaccination, the proportions of subjects in each group attaining protective levels of antitetanus antibodies were similar (96.9% infected versus 97.6% noninfected). Postvaccination increases in antitetanus immunoglobulin G (IgG) and the predominant IgG isotype, IgG1, were equivalent in both groups, as were increases in specific IgG4 and IgE; however, significantly greater increases in specific IgG2 (P < 0.05) and IgG3 (P < 0.001) were observed in the noninfected group. Stratification of the O. volvulus-infected group into two groups representing light and heavy infections revealed a significantly impaired antitetanus IgG response in those with heavy infections compared to those with light infections (P < 0.01) or no infection (P < 0.05). The impact of concurrent intestinal helminth infections on the antitetanus response was also examined; an increased IgG4/IgE ratio was seen in those infected with Strongyloides stercoralis (P < 0.05) and when all helminth infections were combined as a single group (P < 0.05). These findings indicate that concurrent infection with O. volvulus does not prevent the development of a protective antitetanus response, although heavier O. volvulus infections are able to alter the magnitude of this response, and concurrent helminth infections (O. volvulus and intestinal helminths) may alter TT-specific antibody isotype responses. PMID:10531253

  20. Dimensional comparison theory.

    PubMed

    Möller, Jens; Marsh, Herb W

    2013-07-01

    Although social comparison (Festinger, 1954) and temporal comparison (Albert, 1977) theories are well established, dimensional comparison is a largely neglected yet influential process in self-evaluation. Dimensional comparison entails a single individual comparing his or her ability in a (target) domain with his or her ability in a standard domain (e.g., "How good am I in math compared with English?"). This article reviews empirical findings from introspective, path-analytic, and experimental studies on dimensional comparisons, categorized into 3 groups according to whether they address the "why," "with what," or "with what effect" question. As the corresponding research shows, dimensional comparisons are made in everyday life situations. They impact on domain-specific self-evaluations of abilities in both domains: Dimensional comparisons reduce self-concept in the worse off domain and increase self-concept in the better off domain. The motivational basis for dimensional comparisons, their integration with recent social cognitive approaches, and the interdependence of dimensional, temporal, and social comparisons are discussed.

  1. Research for new drugs for elimination of onchocerciasis in Africa.

    PubMed

    Kuesel, Annette C

    2016-12-01

    Onchocerciasis is a parasitic, vector borne disease caused by the filarial nematode Onchocerca volvulus. More than 99% of the population at risk of infection live in Africa. Onchocerciasis control was initiated in West Africa in 1974 with vector control, later complemented by ivermectin mass drug administration and in the other African endemic countries in 1995 with annual community directed treatment with ivermectin (CDTI.) This has significantly reduced infection prevalence. Together with proof-of-concept for onchocerciasis elimination with annual CDTI from foci in Senegal and Mali, this has resulted in targeting onchocerciasis elimination in selected African countries by 2020 and in 80% of African countries by 2025. The challenges for meeting these targets include the number of endemic countries where conflict has delayed or interrupted control programmes, cross-border foci, potential emergence of parasite strains with low susceptibility to ivermectin and co-endemicity of loiasis, another parasitic vector borne disease, which slows down or prohibits CDTI implementation. Some of these challenges could be addressed with new drugs or drug combinations with a higher effect on Onchocerca volvulus than ivermectin. This paper reviews the path from discovery of new compounds to their qualification for large scale use and the support regulatory authorities provide for development of drugs for neglected tropical diseases. The status of research for new drugs or treatment regimens for onchocerciasis along the path to regulatory approval and qualification for large scale use is reviewed. This research includes new regimens and combinations of ivermectin and albendazole, antibiotics targeting the O. volvulus endosymbiont Wolbachia, flubendazole, moxidectin and emodepside and discovery of new compounds.

  2. Acquisition of Comparison Constructions

    ERIC Educational Resources Information Center

    Hohaus, Vera; Tiemann, Sonja; Beck, Sigrid

    2014-01-01

    This article presents a study on the time course of the acquisition of comparison constructions. The order in which comparison constructions (comparatives, measure phrases, superlatives, degree questions, etc.) show up in English- and German-learning children's spontaneous speech is quite fixed. It is shown to be insufficiently determined by…

  3. Acquisition of Comparison Constructions

    ERIC Educational Resources Information Center

    Hohaus, Vera; Tiemann, Sonja; Beck, Sigrid

    2014-01-01

    This article presents a study on the time course of the acquisition of comparison constructions. The order in which comparison constructions (comparatives, measure phrases, superlatives, degree questions, etc.) show up in English- and German-learning children's spontaneous speech is quite fixed. It is shown to be insufficiently determined by…

  4. Pairwise-Comparison Software

    NASA Technical Reports Server (NTRS)

    Ricks, Wendell R.

    1995-01-01

    Pairwise comparison (PWC) is computer program that collects data for psychometric scaling techniques now used in cognitive research. It applies technique of pairwise comparisons, which is one of many techniques commonly used to acquire the data necessary for analyses. PWC administers task, collects data from test subject, and formats data for analysis. Written in Turbo Pascal v6.0.

  5. Ocular and systemic complications of diethylcarbamazine therapy for onchocerciasis: association with circulating immune complexes.

    PubMed

    Greene, B M; Taylor, H R; Brown, E J; Humphrey, R L; Lawley, T J

    1983-05-01

    Diethylcarbamazine (DEC) therapy for Onchocerca volvulus infection results in frequent ocular and systemic complications, but the pathogenesis of these complications is unclear. Twenty men with O. volvulus infection were treated over a period of six months with DEC given daily for one week and weekly thereafter. Major systemic and ocular complications included proteinuria, severe pruritus, visual field constriction, optic nerve pallor, chorioretinitis, anterior uveitis, and punctate keratitis. Levels of circulating immune complexes (CICs) were increased (greater than 11% [125I]C1q binding) in 14 of the 20 men prior to treatment. Persons with pretreatment C1q binding activity of greater than 30% were at increased risk to develop constriction of visual fields (P less than 0.05) and proteinuria (P less than 0.015). Linear regression analysis revealed a striking correlation between pretreatment levels of CICs and the total number of both systemic and ocular complications (P less than 0.001) and ocular complications alone (P less than 0.005). These results suggest that CICs may be important in the pathogenesis of the delayed systemic and ocular complications following DEC therapy for O. volvulus infection.

  6. Elevated antifilarial IgG4 antibody levels in microfilaremic and microfilaridermic Gabonese adults and children.

    PubMed

    Egwang, T G; Nguiri, C; Kombila, M; Duong, T H; Richard-Lenoble, D

    1993-07-01

    Immunologic analyses of sera from 47 selected individuals living in a mixed filariasis transmission zone in Gabon were carried out. Onchocerca volvulus, Loa loa, Mansonella streptocerca, and M. perstans are transmitted in this region. Based on parasitologic findings and age, the 47 individuals were stratified into four groups: microfilaria negative (Mf-) children (3-15 years old), Mf- adults (> 15 years old), microfilaria positive (Mf+) children and Mf+ adults. For descriptive purposes, the term microfilaria positive refers to individuals with skin and blood microfilariae. Antifilarial antibody titers were determined using an enzyme-linked immunosorbent assay with Dipetalonema viteae antigens. In general, children had higher titers of IgG antibodies than adults. For the IgG1, IgG2, and IgG3 subclass responses, both age and microfilarial status appeared to be important variables since Mf- children consistently had the highest titers whereas Mf- adults had the lowest titers. For the IgG4 antifilarial response, only the microfilarial status was an important variable. All Mf+ individuals had significantly higher levels of IgG4 antibody than Mf- individuals. Pooled sera of Mf- and Mf+ individuals reacted with similar O. volvulus antigens on Western blots. Control sera of individuals who did not reside in the study area, but who had single infections with L. loa or M. perstans, did not react with any O. volvulus antigens.

  7. The chromosomes of the Filariae

    PubMed Central

    Post, Rory

    2005-01-01

    An understanding of the nature of the chromosomes of the filariae is expected to greatly assist the future interpretation of genome data. Filarial development is not eutelic, and there does not seem to be a fixed number of cell divisions in the way that there is in Caenorhabditis. It is not clear whether the chromosomes of the filariae have localized centromeres or whether they are holocentric. Sex determination is by a chromosomal "balance" X0 system in most filariae, but in some Onchocercidae there has been a chromosomal fusion to create a neo-XY system. It is presumed that the molecular basis of sex determination in filariae is similar to Caenorhabditis. The ancestral karyotype of the filariae is probably 5A+X0, but in some Onchocercidae this has been reduced to 4A+XY, and in O. volvulus and O. gibsoni it has been further reduced to 3A+XY. Onchocerca volvulus and O. gibsoni both have supernumary (B-) chromosomes and in O. volvulus there is a single active nucleolus organising region near the middle of the long autosome. PMID:16266430

  8. Conventional parasitology and DNA-based diagnostic methods for onchocerciasis elimination programmes.

    PubMed

    Lloyd, Melanie M; Gilbert, Rebecca; Taha, Nathalie Tebao; Weil, Gary J; Meite, Aboulaye; Kouakou, Ilunga M M; Fischer, Peter U

    2015-06-01

    Commonly used methods for diagnosing Onchocerca volvulus infections (microscopic detection of microfilariae in skin snips and nodule palpation) are insensitive. Improved methods are needed for monitoring and evaluation of onchocerciasis elimination programmes and for clinical diagnosis of individual patients. A sensitive probe-based qPCR assay was developed for detecting O. volvulus DNA, and this was tested with samples collected from an endemic area in eastern Côte d'Ivoire. The new test was evaluated with dried skin snip pairs from 369 subjects and compared to routine skin snip microscopy and nodule palpation results from the same individuals. Onchocerciasis prevalence for these samples by qPCR, skin snip microscopy, and nodule palpation were 56.9%, 26.0%, and 37.9%, respectively. Furthermore, the combination of all three tests produced an infection prevalence of 72.9%, which was significantly higher than 53.1% detected by microscopy plus nodule palpation without qPCR. However, the qPCR assay was negative for 54 of 229 individuals with palpable nodules. qPCR could be a useful tool for detecting residual O. volvulus infections in human populations as prevalence decreases in areas following community-directed treatment with ivermectin.

  9. Double-blind study of ivermectin and diethylcarbamazine in African onchocerciasis patients with ocular involvement.

    PubMed

    Lariviere, M; Vingtain, P; Aziz, M; Beauvais, B; Weimann, D; Derouin, F; Ginoux, J; Schulz-Key, H; Gaxotte, P; Basset, D

    1985-07-27

    In a randomised double-blind study, ivermectin was compared with diethylcarbamazine (DEC) and placebo in the treatment of onchocerciasis in 30 male patients from Mali with moderate to heavy Onchocerca volvulus infections and ocular involvement. 10 patients received a single oral dose of ivermectin, 12 mg, 10 received DEC daily for eight days (total dose 1.3 g), and 10 received matching placebo. Patients were examined periodically for twelve months. Punctate keratitis disappeared in 6 of 7 ivermectin patients but increased in DEC patients. Numbers of O volvulus microfilariae (mf) in the anterior chamber decreased slowly and eventually disappeared in most ivermectin patients during the six months following treatment; anterior chamber mf disappeared more rapidly in some patients after DEC, but reappeared within six months of stopping treatment. Both ivermectin and DEC caused a prompt decrease in mean skin mf density; density then increased in both groups over the twelve month observation period, reaching 9% of pretreatment values in ivermectin patients and 45% in the DEC group. Analysis of adult O volvulus from nodules excised at three and twelve months post treatment showed no effect of either drug on viability; however, there was evidence of degeneration of intra-uterine developing mf in the ivermectin group. Side-effects were less frequent and less severe in ivermectin patients than in DEC patients. Ivermectin as a single oral dose appears to be a more effective microfilaricidal drug than DEC in onchocerciasis.

  10. Uncertainty and Social Comparison

    ERIC Educational Resources Information Center

    Gruder, Charles L.; And Others

    1975-01-01

    The purpose of the present research was to determine how experimental manipulations of certainty would affect social comparison choices in the paradigm used by Wheeler et al. (1969) and Gruder (1971). (Author)

  11. Uncertainty and Social Comparison

    ERIC Educational Resources Information Center

    Gruder, Charles L.; And Others

    1975-01-01

    The purpose of the present research was to determine how experimental manipulations of certainty would affect social comparison choices in the paradigm used by Wheeler et al. (1969) and Gruder (1971). (Author)

  12. Anchored paired comparisons

    NASA Astrophysics Data System (ADS)

    Dalal, E. N.; Handley, J. C.; Wu, W.; Wang, J.

    2008-01-01

    The method of paired comparisons is often used in image quality evaluations. Psychometric scale values for quality judgments are modeled using Thurstone's Law of Comparative Judgment in which distance in a psychometric scale space is a function of the probability of preference. The transformation from psychometric space to probability is a cumulative probability distribution. The major drawback of a complete paired comparison experiment is that every treatment is compared to every other, thus the number of comparisons grows quadratically. We ameliorate this difficulty by performing paired comparisons in two stages, by precisely estimating anchors in the psychometric scale space which are spaced apart to cover the range of scale values and comparing treatments against those anchors. In this model, we employ a generalized linear model where the regression equation has a constant offset vector determined by the anchors. The result of this formulation is a straightforward statistical model easily analyzed using any modern statistics package. This enables model fitting and diagnostics. This method was applied to overall preference evaluations of color pictorial hardcopy images. The results were found to be compatible with complete paired comparison experiments, but with significantly less effort.

  13. Model comparison in ANOVA.

    PubMed

    Rouder, Jeffrey N; Engelhardt, Christopher R; McCabe, Simon; Morey, Richard D

    2016-12-01

    Analysis of variance (ANOVA), the workhorse analysis of experimental designs, consists of F-tests of main effects and interactions. Yet, testing, including traditional ANOVA, has been recently critiqued on a number of theoretical and practical grounds. In light of these critiques, model comparison and model selection serve as an attractive alternative. Model comparison differs from testing in that one can support a null or nested model vis-a-vis a more general alternative by penalizing more flexible models. We argue this ability to support more simple models allows for more nuanced theoretical conclusions than provided by traditional ANOVA F-tests. We provide a model comparison strategy and show how ANOVA models may be reparameterized to better address substantive questions in data analysis.

  14. Prevalence and risk factors for Active Convulsive Epilepsy in Kintampo, Ghana

    PubMed Central

    Ae-Ngibise, Kenneth Ayuurebobi; Akpalu, Bright; Ngugi, Anthony; Akpalu, Albert; Agbokey, Francis; Adjei, Patrick; Punguyire, Damien; Bottomley, Christian; Newton, Charles; Owusu-Agyei, Seth

    2015-01-01

    Introduction Epilepsy is common in sub-Saharan Africa, but there is little data in West Africa, to develop public health measures for epilepsy in this region. Methods We conducted a three-stage cross-sectional survey to determine the prevalence and risk factors for active convulsive epilepsy (ACE), and estimated the treatment gap in Kintampo situated in the middle of Ghana. Results 249 people with ACE were identified in a study population of 113,796 individuals. After adjusting for attrition and the sensitivity of the screening method, the prevalence of ACE was 10.1/1000 (95% Confidence Interval (95%CI) 9.5-10.7). In children aged <18 years, risk factors for ACE were: family history of seizures (OR=3.31; 95%CI: 1.83-5.96), abnormal delivery (OR=2.99; 95%CI: 1.07-8.34), problems after birth (OR=3.51; 95%CI: 1.02-12.06), and exposure to Onchocerca volvulus (OR=2.32; 95%CI: 1.12-4.78). In adults, a family history of seizures (OR=1.83; 95%CI: 1.05-3.20), never attended school (OR=11.68; 95%CI: 4.80-28.40), cassava consumption (OR=3.92; 95%CI: 1.14-13.54), pork consumption (OR=1.68; 95%CI: 1.09-2.58), history of snoring at least 3 nights per week (OR=3.40: 95%CI: 1.56-7.41), exposure to Toxoplasma gondii (OR=1.99; 95%CI: 1.15-3.45) and Onchocerca volvulus (OR=2.09: 95%CI: 1.29-3.40) were significant risk factors for the development of ACE. The self-reported treatment gap was 86.9% (95%CI: 83.5%-90.3%). Conclusion ACE is common within the middle belt of Ghana and could be reduced with improved obstetric care and prevention of parasite infestations such as Onchocerca volvulus and Toxoplasma gondii. PMID:26401223

  15. MCNP and GADRAS Comparisons

    SciTech Connect

    Klasky, Marc Louis; Myers, Steven Charles; James, Michael R.; Mayo, Douglas R.

    2016-04-19

    To facilitate the timely execution of System Threat Reviews (STRs) for DNDO, and also to develop a methodology for performing STRs, LANL performed comparisons of several radiation transport codes (MCNP, GADRAS, and Gamma-Designer) that have been previously utilized to compute radiation signatures. While each of these codes has strengths, it is of paramount interest to determine the limitations of each of the respective codes and also to identify the most time efficient means by which to produce computational results, given the large number of parametric cases that are anticipated in performing STR's. These comparisons serve to identify regions of applicability for each code and provide estimates of uncertainty that may be anticipated. Furthermore, while performing these comparisons, examination of the sensitivity of the results to modeling assumptions was also examined. These investigations serve to enable the creation of the LANL methodology for performing STRs. Given the wide variety of radiation test sources, scenarios, and detectors, LANL calculated comparisons of the following parameters: decay data, multiplicity, device (n,γ) leakages, and radiation transport through representative scenes and shielding. This investigation was performed to understand potential limitations utilizing specific codes for different aspects of the STR challenges.

  16. Comparison of Nursing Roles.

    ERIC Educational Resources Information Center

    Macdonough, Georgia P.

    2001-01-01

    This 1972 paper presents 12 comparisons of the nurse's role in the school versus in the hospital. For example, in the hospital, patients know they are ill and want to get well, while in school patients may not recognize that they need help. In the hospital, the nurse's workload is determined for her, while in school, it is self-determined. (SM)

  17. Fall 2013 International Comparisons

    ERIC Educational Resources Information Center

    Northwest Evaluation Association, 2014

    2014-01-01

    This Fall report is an aggregated statistical analysis of Measures of Academic Progress® (MAP®) data from international schools. The report provides a consistent means of comparisons of specific sub-groups by subject and grade, which allows partners to compare their MAP® results with other schools within their region or membership organization.…

  18. Filariasis in the Igwun River Basin, Nigeria: an epidemiological and clinical study with a note on the vectors.

    PubMed

    Udonsi, J K

    1988-02-01

    In a cross-sectional, epidemiological and parasitological study of human filariasis, 845 individuals were examined in settlements along the Igwun Basin, Imo State, Nigeria. Four different filarial nematode species were identified. Two hundred and fifty-six (30.3%) of the individuals examined were positive for Onchocerca volvulus, 113 (13.4%) for Mansonella perstans, 76 (9.6%) for Wuchereria bancrofti and 77 (9.1%) for Loa loa. Microfilarial rates increased with age of individuals and showed a tendency towards higher prevalence rates in males than in females. The intensity of O. volvulus infection was high, with the highest microfilarial density of 44 mf mg-1 snip which occurred in the 40-49-year-old individuals. In W. bancrofti and L. loa infections, infections of over 1000 mf 20 ml-1 blood were recorded in 15.8% and 19.5% of individuals, respectively. Observed clinical signs were associated with inflammatory, lympho-obstructive and ocular manifestations. In M. perstans infections all clinical cases were inflammatory. In W. bancrofti, 44.4% of clinical cases were inflammatory, and lympho-obstructive manifestations consisted of 23.8% chyluria, 12.7% hydrocele and 19.1% elephantiasis. In L. loa infections all clinical cases were inflammatory with indications of Calabar swellings. In O. volvulus infections 23.5% of clinical cases were inflammatory, while 76.5% showed ocular manifestations. The absence of blindness despite high O. volvulus infection rates was remarkable. The presence of potential insect vectors and the occurrence of clinical signs are indications of active transmissions.

  19. Repositioning of an existing drug for the neglected tropical disease Onchocerciasis

    PubMed Central

    Gloeckner, Christian; Garner, Amanda L.; Mersha, Fana; Oksov, Yelena; Tricoche, Nancy; Eubanks, Lisa M.; Lustigman, Sara; Kaufmann, Gunnar F.; Janda, Kim D.

    2010-01-01

    Onchocerciasis, or river blindness, is a neglected tropical disease caused by the filarial nematode Onchocerca volvulus that affects more than 37 million people, mainly in third world countries. Currently, the only approved drug available for mass treatment is ivermectin, however, drug resistance is beginning to emerge, thus, new therapeutic targets and agents are desperately needed to treat and cure this devastating disease. Chitin metabolism plays a central role in invertebrate biology due to the critical structural function of chitin for the organism. Taken together with its absence in mammals, targeting chitin is an appealing therapeutic avenue. Importantly, the chitinase OvCHT1 from O. volvulus was recently discovered, however, its exact role in the worm’s metabolism remains unknown. A screening effort against OvCHT1 was conducted using the Johns Hopkins Clinical Compound Library that contains over 1,500 existing drugs. Closantel, a veterinary anthelmintic with known proton ionophore activities, was identified as a potent and specific inhibitor of filarial chitinases, an activity not previously reported for this compound. Notably, closantel was found also to completely inhibit molting of O. volvulus infective L3 stage larvae. Closantel appears to target two important biochemical processes essential to filarial parasites. To begin to unravel closantel’s effects, a retro-fragment-based study was used to define structural elements critical for closantel’s chitinase inhibitor function. As resources towards the development of new agents that target neglected tropical diseases are scant, the finding of an existing drug with impact against O. volvulus provides promise in the hunt for new therapies against river blindness. PMID:20142509

  20. Repositioning of an existing drug for the neglected tropical disease Onchocerciasis.

    PubMed

    Gloeckner, Christian; Garner, Amanda L; Mersha, Fana; Oksov, Yelena; Tricoche, Nancy; Eubanks, Lisa M; Lustigman, Sara; Kaufmann, Gunnar F; Janda, Kim D

    2010-02-23

    Onchocerciasis, or river blindness, is a neglected tropical disease caused by the filarial nematode Onchocerca volvulus that affects more than 37 million people, mainly in third world countries. Currently, the only approved drug available for mass treatment is ivermectin, however, drug resistance is beginning to emerge, thus, new therapeutic targets and agents are desperately needed to treat and cure this devastating disease. Chitin metabolism plays a central role in invertebrate biology due to the critical structural function of chitin for the organism. Taken together with its absence in mammals, targeting chitin is an appealing therapeutic avenue. Importantly, the chitinase OvCHT1 from O. volvulus was recently discovered, however, its exact role in the worm's metabolism remains unknown. A screening effort against OvCHT1 was conducted using the Johns Hopkins Clinical Compound Library that contains over 1,500 existing drugs. Closantel, a veterinary anthelmintic with known proton ionophore activities, was identified as a potent and specific inhibitor of filarial chitinases, an activity not previously reported for this compound. Notably, closantel was found also to completely inhibit molting of O. volvulus infective L3 stage larvae. Closantel appears to target two important biochemical processes essential to filarial parasites. To begin to unravel closantel's effects, a retro-fragment-based study was used to define structural elements critical for closantel's chitinase inhibitor function. As resources towards the development of new agents that target neglected tropical diseases are scant, the finding of an existing drug with impact against O. volvulus provides promise in the hunt for new therapies against river blindness.

  1. Exposure to Multiple Parasites Is Associated with the Prevalence of Active Convulsive Epilepsy in Sub-Saharan Africa

    PubMed Central

    Kamuyu, Gathoni; Bottomley, Christian; Mageto, James; Lowe, Brett; Wilkins, Patricia P.; Noh, John C.; Nutman, Thomas B.; Ngugi, Anthony K.; Odhiambo, Rachael; Wagner, Ryan G.; Kakooza-Mwesige, Angelina; Owusu-Agyei, Seth; Ae-Ngibise, Kenneth; Masanja, Honorati; Osier, Faith H. A.; Odermatt, Peter; Newton, Charles R.

    2014-01-01

    Background Epilepsy is common in developing countries, and it is often associated with parasitic infections. We investigated the relationship between exposure to parasitic infections, particularly multiple infections and active convulsive epilepsy (ACE), in five sites across sub-Saharan Africa. Methods and Findings A case-control design that matched on age and location was used. Blood samples were collected from 986 prevalent cases and 1,313 age-matched community controls and tested for presence of antibodies to Onchocerca volvulus, Toxocara canis, Toxoplasma gondii, Plasmodium falciparum, Taenia solium and HIV. Exposure (seropositivity) to Onchocerca volvulus (OR = 1.98; 95%CI: 1.52–2.58, p<0.001), Toxocara canis (OR = 1.52; 95%CI: 1.23–1.87, p<0.001), Toxoplasma gondii (OR = 1.28; 95%CI: 1.04–1.56, p = 0.018) and higher antibody levels (top tertile) to Toxocara canis (OR = 1.70; 95%CI: 1.30–2.24, p<0.001) were associated with an increased prevalence of ACE. Exposure to multiple infections was common (73.8% of cases and 65.5% of controls had been exposed to two or more infections), and for T. gondii and O. volvulus co-infection, their combined effect on the prevalence of ACE, as determined by the relative excess risk due to interaction (RERI), was more than additive (T. gondii and O. volvulus, RERI = 1.19). The prevalence of T. solium antibodies was low (2.8% of cases and 2.2% of controls) and was not associated with ACE in the study areas. Conclusion This study investigates how the degree of exposure to parasites and multiple parasitic infections are associated with ACE and may explain conflicting results obtained when only seropositivity is considered. The findings from this study should be further validated. PMID:24875312

  2. On molecular graph comparison.

    PubMed

    Melo, Jenny A; Daza, Edgar

    2011-06-01

    Since the last half of the nineteenth century, molecular graphs have been present in several branches of chemistry. When used for molecular structure representation, they have been compared after mapping the corresponding graphs into mathematical objects. However, direct molecular comparison of molecular graphs is a research field less explored. The goal of this mini-review is to show some distance and similarity coefficients which were proposed to directly compare molecular graphs or which could be useful to do so.

  3. Retained gas inventory comparison

    SciTech Connect

    BARTON, W.B.

    1999-05-18

    Gas volume data derived from four different analytical methods were collected and analyzed for comparison to volumes originally used in the technical basis for the Basis for Interim Operations (BIO). The original volumes came from Hodgson (1996) listed in the reference section of this document. Hodgson (1996) screened all 177 single and double-shell tanks for the presence of trapped gas in waste via two analytical methods: Surface Level Rise (SLR), and Barometric Pressure Effect (BPE). More recent gas volume projections have been calculated using different analytical techniques along with updates to the parameters used as input to the SLR and BPE models. Gas volumes derived from new analytical instruments include those as measured by the Void Fraction Instrument (VFI) and Retained Gas Sampler (RGS). The results of this comparison demonstrate that the original retained gas volumes of Hodgson (1996) used as a technical basis in developing the BIO were conservative, and were conservative from a safety analysis standpoint. These results represent only comparisons to the original reported volumes using the limited set of newly acquired data that is available.

  4. Selective primary health care: strategies for control of disease in the developing world. VI. Onchocerciasis.

    PubMed

    Greene, B M

    1983-01-01

    Onchocerca volvulus, a major filarial parasite of humans, infects tens of millions of people and is a leading cause of blindness. It also causes disabling or disfiguring dermatitis and lymph node involvement. The infection is transmitted by the bite of female blackflies of Simulium species, which breed around freely flowing waterways. Vector control by aerial spraying of rivers and streams with larvicide has achieved some success in the Volta River Basin, but other areas are less well-suited for such an approach. Efforts to control onchocerciasis are plagued by emerging resistance of blackflies, excessive costs of spraying, and the lack of suitable chemotherapy for existing cases. Mass chemotherapy for infected persons as a means to limit the disease and its impact is not feasible because existing drug regiments are too complex, too toxic, or not effective enough. Selective chemotherapy directed at persons at high risk of complications may be a more effective means of minimizing the impact of the disease.

  5. A survey of Simulium control in Africa.

    PubMed

    BROWN, A W

    1962-01-01

    It has become possible to control or even eradicate the Simulium fly vectors of Onchocerca volvulus, the causative organism of onchocerciasis. There are two vectors in Africa-namely, S. damnosum, characteristic of the rivers of West Africa, and S. neavei, which breeds on the carapaces of crabs in the streams of East Africa. The use of DDT applied to the water at a concentration as low as 0.1 p.p.m. for 30 minutes eliminates the larvae of Simulium. Such larvicidal methods have eradicated S. neavei from western Kenya and virtually eradicated S. damnosum from the Victoria Nile in Uganda. Excellent control sufficient to render the transmission of onchocerciasis almost negligible has been obtained at Léopoldville (Republic of the Congo) and in circumscribed areas in southern Chad, Northern Nigeria, and Sierra Leone. The following survey describes operational research on Simulium control carried out in Kenya, Uganda, the Congo, Chad, Nigeria, Ghana, Upper Volta and Sierra Leone.

  6. [Important parasitic nephropathies: update from the recent literature].

    PubMed

    Duvic, C; Nedelec, G; Debord, T; Herody, M; Didelot, F

    1999-01-01

    Renal involvement in parasitic infections are polymorphic. Plasmodium malariae often leads to membranoproliferative glomerulonephritis whereas acute tubular necrosis or post-infectious acute glomerulonephritis are observed with Plasmodium falciparum. Urogenital taxis of Schistosoma haematobium is responsible for frequency of chronic tubular and interstitial nephritis. Without specific treatment, the renal function progressively deteriorates and urological complications appear. Schistosoma mansoni mainly leads to mesangial and membranoproliferative glomerulonephritis. Membranoproliferative and membranous glomerulonephritis are reported with loasis. Onchocerca volvulus also leads to membranoproliferative glomerulonephritis and lipoid nephrosis. Renal involvement with Wuchereria bancrofti is rare. With leishmaniosis, it is often mild but more serious observations are described: acute glomerulonephritis, nephrotic syndrome or acute interstitial nephritis. Renal hydatic cysts are diagnosed in two or three per cent of cases. Surgery is the only treatment. Immunosuppressive or antimalarial treatments seem to be ineffective in the outcome of chronic glomerulonephritis.

  7. Filariasis in Gongola State Nigeria. I: Clinical and parasitological studies in Mutum-Biyu District.

    PubMed

    Akogun, O B

    1992-08-01

    A total of 2,552 persons living in 9 villages along the Benue river valley, Mutum Biyu district of Gongola State, Nigeria were examined between October and December 1989 for filariasis. It is the first time a filariasis survey will be carried out in this state. 276 (10.8%) had Wuchereria bancrofti, 50 (2.0%) had Loa loa, 281 (11.0%) were positive for Mansonella perstans while 12 (0.5%) were positive for Onchocerca volvulus. Villages located near the Benue river had higher prevalence rates than those further away. Dermatitis and hydrocoele were common and clinical manifestations were associated with parasite types. Clinical symptoms without microfilaremia and microfilaremia without clinical symptoms were also observed.

  8. Filariasis in Gongola State Nigeria. I: Clinical and parasitological studies in Mutum-Biyu district.

    PubMed

    Akogun, O B

    1991-01-01

    A total of 2552 persons living in 9 villages along the Benue river valley, Mutum-Biyu district of Gongola State, Nigeria were examined between October and December 1989 for filariasis. It is the first time a filariasis survey will be carried out in this State. 276 (10.8%) had Wuchereria bancrofti, 50 (2.0%) had Loa loa, 281 (11.0%) were positive for Mansonella perstans while 12 (0.5%) were positive for Onchocerca volvulus. Villages located near the Benue river had higher prevalence rates than those further away. Dermatitis and hydrocoele were common and clinical manifestations were associated with parasite types. Clinical symptoms without microfilaremia and microfilaremia without clinical symptoms were also observed. The study will fill the gap in our knowledge of filariasis in this part of Nigeria.

  9. Efficacy of ivermectin in the treatment of concomitant Mansonella perstans infections in onchocerciasis patients.

    PubMed

    Schulz-Key, H; Albrecht, W; Heuschkel, C; Soboslay, P T; Banla, M; Görgen, H

    1993-01-01

    As part of an ivermectin dose-ranging study of onchocerciasis patients in Togo, 55 onchocerciasis patients with concomitant mansonelliasis received single oral doses either of ivermectin (100 to 200 micrograms/kg body weight) or placebo. As expected, Onchocerca volvulus microfilariae in the skin were greatly reduced in number soon after drug treatment, but microfilariae of Mansonella perstans reacted differently. Microfilarial densities of M. perstans were assessed with a filtration technique both before, and 4 times after, treatment. In untreated patients microfilarial densities were stable until the end of the study at 6 months. In patients receiving ivermectin, microfilarial densities dropped on average to less than 60% of the pre-treatment level and remained there until the final post-treatment examination. This partial reduction was probably not caused by a microfilaricidal effect of ivermectin, but rather by an altered distribution of microfilariae in the peripheral blood and in a suspected microfilarial reservoir.

  10. Adverse reactions to ivermectin treatment in Simulium neavei-transmitted onchocerciasis.

    PubMed

    Kipp, Walter; Bamhuhiiga, Jotham; Rubaale, Tom; Büttner, Dietrich W

    2003-12-01

    To assess adverse effects of ivermectin treatment in a Simulium neavei-transmitted focus of onchocerciasis, a study was conducted with 1,246 patients infected with Onchocerca volvulus in eight villages in western Uganda. Study participants were treated the first time with a single dose of 150 microg/kg of ivermectin. Adverse reactions to ivermectin were determined through questioning and clinical examination during house-to-house visits to the participants within 48 hours after ivermectin treatment. Overall adverse reactions were observed in 737 (59.1%) patients. Severe reactions were rare (10 patients, 1.4%). Our data show that adverse reactions to ivermectin in an S. neavei-transmitted onchocerciasis focus in western Uganda occur frequently. In spite of the fact that many patients showed adverse reactions to ivermectin, the drug was well accepted and appreciated by the population.

  11. Ivermectin does not reduce the burden of itching in an onchocerciasis endemic community.

    PubMed

    Whitworth, J A; Luty, A J; Maude, G H; Morgan, D; Downham, M D; Taylor, D W

    1992-01-01

    Degrees of itching were estimated before and for 6 months after a fourth dose of ivermectin or placebo was given to 97 subjects in Sierra Leone. There was no reduction in itching attributable to ivermectin at any stage, but there were non-significant increases in the prevalence, severity and localization of itching within the first 2 months after ivermectin compared to placebo. We also found that cell-mediated immune responses to Onchocerca volvulus were significantly increased 4 weeks after a single dose of ivermectin compared to before treatment. A temporary reversal of the state of immunosuppression in people with onchocerciasis may counterbalance the reduction in skin microfilarial loads following ivermectin, with no consequent reduction in itching. The lack of effect of ivermectin on itching, a major symptom of onchocerciasis, while disappointing, need not detract from the success of mass distribution programmes.

  12. Immunohistological and electron microscopic studies of microfilariae in skin and lymph nodes from onchocerciasis patients after ivermectin treatment.

    PubMed

    Darge, K; Lucius, R; Monson, M H; Behrendsen, J; Büttner, D W

    1991-12-01

    Microfilariae were studied in skin and lymph node biopsies from Liberian patients with generalised onchocerciasis 12-78 hours after administration of a single dose of 150 micrograms/kg body weight using histology, transmission electron microscopy and immunocytological staining with antibodies against an immunodominant antigen of Onchocerca volvulus. Most microfilariae in the skin appeared morphologically intact and beginning signs of degeneration were seen only on the ultrastructural level. The densities of microfilariae in the lymph nodes were about thousandfold higher in ivermectin treated patients. More than 90% of the microfilariae in the lymph nodes showed distinct signs of degeneration. Early changes were seen in the muscle cells. The disintegrating microfilariae in the lymph nodes were always encircled by eosinophils or macrophages or both cells. Immunohistological staining with antifilarial antibodies increased the detection of small and disintegrating pieces of microfilariae considerably.

  13. Cutaneous onchocerciasis in Dumbu, a pastoral area in the North-West region of Cameroon: diagnostic challenge and socio-economic implications.

    PubMed

    Njim, Tsi; Ngum, Joel Mbigha; Aminde, Leopold Ndemnge

    2015-01-01

    Onchocerciasis is a severe parasitic infestation caused by Onchocerca volvulus which causes disabling skin and subcutaneous tissue changes and ultimately leads to blindness. It has a huge public health impact due to its socioeconomic burden and the vast number of people it affects in developing countries. In this case, a 60 years old woman was encountered with leopard skin like changes, rashes and pruritus on the left leg; which had been managed as cutaneous mycosis for over a period of 8 years. A diagnosis of onchocerciasis was finally made after a skin snip identified onchocercal microfilariae. The above case shows that onchocerciasis is still a neglected tropical disease (NTD) in Cameroon. This emphasizes the need for more expansive outreach programs in remote areas in Cameroon, a change in health policies to ensure the eradication of this disabling disease and health promotion amongst vulnerable populations.

  14. Nodding Syndrome, Western Uganda, 1994

    PubMed Central

    Kaiser, Christoph; Rubaale, Tom; Tukesiga, Ephraim; Kipp, Walter; Asaba, George

    2015-01-01

    Nodding syndrome (NS) is a poorly understood condition, which was delineated in 2008 as a new epilepsy syndrome. So far, confirmed cases of NS have been observed in three circumscribed African areas: southern Tanzania, southern Sudan, and northern Uganda. Case–control studies have provided evidence of an association between NS and infection with Onchocerca volvulus, but the causation of NS is still not fully clarified. We report a case of a 15-year old boy with head nodding seizures and other characteristic features of NS from an onchocerciasis endemic area in western Uganda, with no contiguity to the hitherto known areas. We suggest that the existence of NS should be systematically investigated in other areas. PMID:25918208

  15. DNA sequence analysis using hierarchical ART-based classification networks

    SciTech Connect

    LeBlanc, C.; Hruska, S.I.; Katholi, C.R.; Unnasch, T.R.

    1994-12-31

    Adaptive resonance theory (ART) describes a class of artificial neural network architectures that act as classification tools which self-organize, work in real-time, and require no retraining to classify novel sequences. We have adapted ART networks to provide support to scientists attempting to categorize tandem repeat DNA fragments from Onchocerca volvulus. In this approach, sequences of DNA fragments are presented to multiple ART-based networks which are linked together into two (or more) tiers; the first provides coarse sequence classification while the sub- sequent tiers refine the classifications as needed. The overall rating of the resulting classification of fragments is measured using statistical techniques based on those introduced to validate results from traditional phylogenetic analysis. Tests of the Hierarchical ART-based Classification Network, or HABclass network, indicate its value as a fast, easy-to-use classification tool which adapts to new data without retraining on previously classified data.

  16. Adverse reactions after community treatment of onchocerciasis with ivermectin in Guatemala.

    PubMed

    Zea-Flores, R; Richards, F O; González-Peralta, C; Castro Ramirez, J; Zea-Flores, G; Collins, R C; Cupp, E

    1992-01-01

    Male and female residents on a Guatemalan coffee plantation where Onchocerca volvulus infections were hyperendemic were offered oral ivermectin (100-200 micrograms/kg) as part of a community-wide treatment programme for onchocerciasis. Forty-five persons were treated and then questioned daily for 28 d about changes in their health. Those with complaints were monitored until all signs and symptoms had resolved. Sixty-seven percent complained of some adverse event after treatment; 60% developed observable adverse reactions attributed clinically to ivermectin. No reaction was life-threatening; the most common were oedema (53%) and fever (47%). Expulsion of intestinal helminths was reported by 38%. Almost all reactions began 24-48 h after treatment; their mean duration was 5 d, despite treatment with acetaminophen and antihistamines. Three patients had oedematous changes lasting over 2 weeks. Incidence, but not severity, of reactions was related to the pretreatment density of microfilariae in skin.

  17. Serine Proteases of Parasitic Helminths

    PubMed Central

    Yang, Yong; Wen, Yun jun; Cai, Ya Nan; Vallée, Isabelle; Boireau, Pascal; Liu, Ming Yuan; Cheng, Shi Peng

    2015-01-01

    Serine proteases form one of the most important families of enzymes and perform significant functions in a broad range of biological processes, such as intra- and extracellular protein metabolism, digestion, blood coagulation, regulation of development, and fertilization. A number of serine proteases have been identified in parasitic helminths that have putative roles in parasite development and nutrition, host tissues and cell invasion, anticoagulation, and immune evasion. In this review, we described the serine proteases that have been identified in parasitic helminths, including nematodes (Trichinella spiralis, T. pseudospiralis, Trichuris muris, Anisakis simplex, Ascaris suum, Onchocerca volvulus, O. lienalis, Brugia malayi, Ancylostoma caninum, and Steinernema carpocapsae), cestodes (Spirometra mansoni, Echinococcus granulosus, and Schistocephalus solidus), and trematodes (Fasciola hepatica, F. gigantica, and Schistosoma mansoni). Moreover, the possible biological functions of these serine proteases in the endogenous biological phenomena of these parasites and in the host-parasite interaction were also discussed. PMID:25748703

  18. THE ARTHROPOD-BORNE ONCHOCERCIASIS: IS IT DESERVED TO BE NEGLECTED?.

    PubMed

    El-Bahnasawy, Mamdouh M M; Morsy, Ayman T A; Morsy, Tosson A

    2015-12-01

    Onchocerciasis a filarial parasitic nematode, also known as river blindness and Robles disease, is a neglected tropical disease infecting more than 18 million people mainly in sub-Saharan of Africa, the Middle East, South and Central America and many other countries. Disease infectivity initiates from Onchocerca volvulus (Filarioidea: Onchocercidae) transmitted by the blackfly, Simulium sp. which introduces the infective stage larva with its saliva into the skin. Within human body, adult females (macrofilaria) produce thousands of larvae (microfilariae) which migrate in skin and eye. Infection results in severe visual impairment or blindness for about 2 million, as being the world's second-leading cause of blindness after trachoma, as well as skin onchocercomata.

  19. Serosurveillance to monitor onchocerciasis elimination: the Ugandan experience.

    PubMed

    Oguttu, David; Byamukama, Edson; Katholi, Charles R; Habomugisha, Peace; Nahabwe, Christine; Ngabirano, Monica; Hassan, Hassan K; Lakwo, Thomson; Katabarwa, Moses; Richards, Frank O; Unnasch, Thomas R

    2014-02-01

    Uganda is the only African country whose onchocerciasis elimination program uses a two-pronged approach of vector control and mass drug distribution. The Ugandan program relies heavily upon the use of serosurveys of children to monitor progress toward elimination. The program has tested over 39,000 individuals from 11 foci for Onchocerca volvulus exposure, using the Ov16 ELISA test. The data show that the Ov16 ELISA is a useful operational tool to monitor onchocerciasis transmission interruption in Africa at the World Health Organization (WHO) recommended threshold of < 0.1% in children. The Ugandan experience has also resulted in a re-examination of the statistical methods used to estimate the boundary of the upper 95% confidence interval for the WHO prevalence threshold when all samples tested are negative. This has resulted in the development of Bayesian and hypergeometric statistical methods that reduce the number of individuals who must be tested to meet the WHO criterion.

  20. Ivermectin treatment of ocular onchocerciasis.

    PubMed

    Taylor, H R

    1990-01-01

    Ivermectin, a recently developed macrocyclic lactone with broad antiparasitic activity, has been shown by a series of clinical trials to be safe and effective in the treatment of human infection with Onchocerca volvulus. Although it is rapidly microfilaricidal, it does not cause a severe reaction as is seen with diethylcarbamazine treatment. In patients with onchocerciasis, a single oral dose of ivermectin (150 micrograms/Kg) repeated once a year leads to a marked reduction in skin microfilaria counts and ocular involvement, although ivermectin has no known long-lasting effects on the adult worms. With treatment there is no significant exacerbation of either anterior or posterior segment eye disease even in those with severe ocular disease. Treatment leads to a marked and prolonged improvement in ocular status. Because of its safety and efficacy, ivermectin can be used on a mass scale and promises to revolutionize the treatment of onchocerciasis.

  1. Ocular changes with oral and transepidermal diethylcarbamazine therapy of onchocerciasis.

    PubMed

    Taylor, H R; Greene, B M

    1981-07-01

    Twenty men with moderate infection of Onchocerca volvulus were studied in a double-masked, controlled clinical trial to compare the safety and efficacy of oral diethylcarbamazine (DEC) with topical DEC lotion. Visual acuity and colour vision did not alter during the 6 months of observation, although 2 patients receiving DEC lotion and 3 patients receiving oral DEC developed either visual field constriction or optic atrophy. Fluffy corneal opacities were common in both groups. Intraocular microfilariae also appeared in both groups but to a greater extent in those receiving DEC lotion. New chorioretinal changes developed in 4 men receiving lotion and in only 1 receiving tablets. It is concluded that DEC lotion offers no advantage over tablets in the treatment of ocular onchocerciasis and in fact may be associated with more ocular complications than the conventional oral treatment.

  2. The status of ivermectin in the treatment of human onchocerciasis.

    PubMed

    Taylor, H R; Greene, B M

    1989-10-01

    Ivermectin is a macrocyclic lactone that has widespread antiparasitic activity. Numerous clinical trials have shown that ivermectin is safe and effective in the treatment of human infection with Onchocerca volvulus. Although it is rapidly microfilaricidal, it does not cause a severe reaction, as is seen with diethylcarbamazine treatment. The drug temporarily interrupts production of microfilaria but has not known long-lasting effects on the adult worms. In patients with onchocerciasis, a single oral dose of ivermectin (150 micrograms/kg) repeated once a year leads to a marked reduction in skin microfilaria counts and ocular involvement. At this dose, ivermectin causes minimal side effects and is sufficiently free of severe reactions to be used on a mass scale. It promises to revolutionize the treatment of onchocerciasis.

  3. Ocular changes with oral and transepidermal diethylcarbamazine therapy of onchocerciasis.

    PubMed Central

    Taylor, H R; Greene, B M

    1981-01-01

    Twenty men with moderate infection of Onchocerca volvulus were studied in a double-masked, controlled clinical trial to compare the safety and efficacy of oral diethylcarbamazine (DEC) with topical DEC lotion. Visual acuity and colour vision did not alter during the 6 months of observation, although 2 patients receiving DEC lotion and 3 patients receiving oral DEC developed either visual field constriction or optic atrophy. Fluffy corneal opacities were common in both groups. Intraocular microfilariae also appeared in both groups but to a greater extent in those receiving DEC lotion. New chorioretinal changes developed in 4 men receiving lotion and in only 1 receiving tablets. It is concluded that DEC lotion offers no advantage over tablets in the treatment of ocular onchocerciasis and in fact may be associated with more ocular complications than the conventional oral treatment. Images PMID:7020746

  4. Ivermectin treatment of onchocerciasis.

    PubMed

    Taylor, H R

    1989-11-01

    Ivermectin is a recently developed macrocyclic lactone that has widespread antiparasitic activity. A series of clinical trials has shown that ivermectin is safe and effective in the treatment of human infection with Onchocerca volvulus. Although it is rapidly microfilaricidal, it does not cause a severe reaction as is seen with diethylcarbamazine treatment. The drug also temporarily interrupts production of microfilaria but has no known long-lasting effects on the adult worms. In patients with onchocerciasis, a single oral dose of ivermectin (150 micrograms/kg) repeated once a year leads to a marked reduction in skin microfilaria counts and ocular involvement. At this dose, ivermectin causes minimal side effects and appears to be sufficiently free of severe adverse reactions to be used on a mass scale. Its use promises to revolutionise the treatment of onchocerciasis.

  5. Ocular onchocerciasis

    PubMed Central

    Thylefors, B.

    1978-01-01

    Well over 20 million people in the world are infected with Onchocerca volvulus and it is probable that 200 000-500 000 people are blind as a result of this infection, which is the most important cause of blindness in certain areas of Africa and Latin America. Treatment of the disease is difficult and often produces serious adverse reactions in the patient. Combined use of diethylcarbamazine citrate and suramin is still the most suitable form of treatment. Screening for the early detection of cases at high risk of ocular manifestations must be organized, and their treatment undertaken, if blindness is to be avoided. Prevention of ocular onchocerciasis is feasible, using vector control methods to reduce transmission, but the procedures are costly and may have to be maintained for many years. Research is needed to improve treatment and to find a chemoprophylactic agent or a preventive vaccine. PMID:307448

  6. [Apropos of 5 new cases of onchocerciasis edema].

    PubMed

    Nozais, J P; Caumes, E; Datry, A; Bricaire, F; Danis, M; Gentilini, M

    1997-01-01

    We report 5 cases of onchocerciasis presenting as limb's swelling collected in the tropical disease unit of a parisian hospital between 1982 and 1993. They are 5 men which have lived between 3 weeks and 4 years in forested areas of Cameroon in four cases and Côte d'Ivoire in one case. The incubation period varied from 5 months to 2 years. The limb oedema was always located to one arm. It was associated with a blood eosinophilia above 2000/mm3 in 4 of 5 patients. The skin detection of microfilaria of Onchocerca volvulus was positive in every case. The serodiagnostic tests were negative for indirect immunoflurescent assay and immunoelectrophoresis with exception of one patient. These patients were cured with ivermectine and/or diethylcarbamazine. In addition, 26 other cases described in the literature are discussed.

  7. NTP comparison process

    NASA Astrophysics Data System (ADS)

    Corban, Robert

    The systems engineering process for the concept definition phase of the program involves requirements definition, system definition, and consistent concept definition. The requirements definition process involves obtaining a complete understanding of the system requirements based on customer needs, mission scenarios, and nuclear thermal propulsion (NTP) operating characteristics. A system functional analysis is performed to provide a comprehensive traceability and verification of top-level requirements down to detailed system specifications and provides significant insight into the measures of system effectiveness to be utilized in system evaluation. The second key element in the process is the definition of system concepts to meet the requirements. This part of the process involves engine system and reactor contractor teams to develop alternative NTP system concepts that can be evaluated against specific attributes, as well as a reference configuration against which to compare system benefits and merits. Quality function deployment (QFD), as an excellent tool within Total Quality Management (TQM) techniques, can provide the required structure and provide a link to the voice of the customer in establishing critical system qualities and their relationships. The third element of the process is the consistent performance comparison. The comparison process involves validating developed concept data and quantifying system merits through analysis, computer modeling, simulation, and rapid prototyping of the proposed high risk NTP subsystems. The maximum amount possible of quantitative data will be developed and/or validated to be utilized in the QFD evaluation matrix. If upon evaluation of a new concept or its associated subsystems determine to have substantial merit, those features will be incorporated into the reference configuration for subsequent system definition and comparison efforts.

  8. NTP comparison process

    NASA Technical Reports Server (NTRS)

    Corban, Robert

    1993-01-01

    The systems engineering process for the concept definition phase of the program involves requirements definition, system definition, and consistent concept definition. The requirements definition process involves obtaining a complete understanding of the system requirements based on customer needs, mission scenarios, and nuclear thermal propulsion (NTP) operating characteristics. A system functional analysis is performed to provide a comprehensive traceability and verification of top-level requirements down to detailed system specifications and provides significant insight into the measures of system effectiveness to be utilized in system evaluation. The second key element in the process is the definition of system concepts to meet the requirements. This part of the process involves engine system and reactor contractor teams to develop alternative NTP system concepts that can be evaluated against specific attributes, as well as a reference configuration against which to compare system benefits and merits. Quality function deployment (QFD), as an excellent tool within Total Quality Management (TQM) techniques, can provide the required structure and provide a link to the voice of the customer in establishing critical system qualities and their relationships. The third element of the process is the consistent performance comparison. The comparison process involves validating developed concept data and quantifying system merits through analysis, computer modeling, simulation, and rapid prototyping of the proposed high risk NTP subsystems. The maximum amount possible of quantitative data will be developed and/or validated to be utilized in the QFD evaluation matrix. If upon evaluation of a new concept or its associated subsystems determine to have substantial merit, those features will be incorporated into the reference configuration for subsequent system definition and comparison efforts.

  9. On Leighton's comparison theorem

    NASA Astrophysics Data System (ADS)

    Ghatasheh, Ahmed; Weikard, Rudi

    2017-06-01

    We give a simple proof of a fairly flexible comparison theorem for equations of the type -(p (u‧ + su)) ‧ + rp (u‧ + su) + qu = 0 on a finite interval where 1 / p, r, s, and q are real and integrable. Flexibility is provided by two functions which may be chosen freely (within limits) according to the situation at hand. We illustrate this by presenting some examples and special cases which include Schrödinger equations with distributional potentials as well as Jacobi difference equations.

  10. Foundation fieldbus economics comparison

    PubMed

    Verhappen

    2000-01-01

    This paper will provide a life cycle cost comparison between installations of three different control system configurations. 1. Conventional analogue instruments. 2. HART protocol instruments with a parallel asset management system. 3. Foundation fieldbus installation. Engineering, procurement, construction, commissioning and ongoing maintenance costs will be included as part of the analysis. Data for the analysis includes equipment from multiple manufacturers so a range of expected expenses will also be provided to indicate the sensitivity of the economic calculations to supplier. All calculations will be based on the median equipment values.

  11. Immunisation with a Multivalent, Subunit Vaccine Reduces Patent Infection in a Natural Bovine Model of Onchocerciasis during Intense Field Exposure

    PubMed Central

    Makepeace, Benjamin L.; Jensen, Siv Aina; Laney, Sandra J.; Nfon, Charles K.; Njongmeta, Leo M.; Tanya, Vincent N.; Williams, Steven A.; Bianco, Albert E.; Trees, Alexander J.

    2009-01-01

    Human onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is controlled almost exclusively by the drug ivermectin, which prevents pathology by targeting the microfilariae. However, this reliance on a single control tool has led to interest in vaccination as a potentially complementary strategy. Here, we describe the results of a trial in West Africa to evaluate a multivalent, subunit vaccine for onchocerciasis in the naturally evolved host-parasite relationship of Onchocerca ochengi in cattle. Naïve calves, reared in fly-proof accommodation, were immunised with eight recombinant antigens of O. ochengi, administered separately with either Freund's adjuvant or alum. The selected antigens were orthologues of O. volvulus recombinant proteins that had previously been shown to confer protection against filarial larvae in rodent models and, in some cases, were recognised by serum antibodies from putatively immune humans. The vaccine was highly immunogenic, eliciting a mixed IgG isotype response. Four weeks after the final immunisation, vaccinated and adjuvant-treated control calves were exposed to natural parasite transmission by the blackfly vectors in an area of Cameroon hyperendemic for O. ochengi. After 22 months, all the control animals had patent infections (i.e., microfilaridermia), compared with only 58% of vaccinated cattle (P = 0.015). This study indicates that vaccination to prevent patent infection may be an achievable goal in onchocerciasis, reducing both the pathology and transmissibility of the infection. The cattle model has also demonstrated its utility for preclinical vaccine discovery, although much research will be required to achieve the requisite target product profile of a clinical candidate. PMID:19901988

  12. Black fly (Diptera:Simuliidae) salivary secretions: importance in vector competence and disease.

    PubMed

    Cupp, E W; Cupp, M S

    1997-03-01

    When blood-feeding, black flies introduce secretions into the feeding lesion that act in a coordinated manner on the 3 arms of the vertebrate hemostatic system (platelet aggregation, coagulation, and vasoconstriction). Apyrase activity inhibits platelet aggregation and is ubiquitous in the saliva of black flies, although activity per gland varies by species and has a positive association with anthropophagy. Anticoagulants target components in the final common pathway of the coagulation cascade, including factors V, Xa, and II (thrombin). The antithrombin salivary protein may exert a redundant effect by inhibiting the role of thrombin in platelet aggregation. Antithrombin presence and activity also varies among black fly species, and exhibits a positive correlation with zoophagy. Vasodilation of capillaries to increase blood supply to the feeding wound appears to be an important requirement for Simulium spp., because substantial erythema-inducing activity, has been demonstrated in salivary glands of all New World species examined. Salivary glands of Simulium ochraceum (Walker), a highly anthropophilic vector of Onchocerca volvulus (Leuckhart), contain greater vasodilator activity than several other species, including S. metallicum Bellardi, a secondary zoophagic vector of human onchocerciasis. Simulium vittatum Zetterstedt saliva affects immune cell responses and cytokine production. The ability of the saliva to modulate components of the host immune system provides an opportunity for enhancing transmission of pathogens during bloodfeeding. Thus, the likely possibility that effective pathogen transmission relies on vector saliva may complement present efforts aimed at target epitopes of O. volvulus or identify additional molecules to be investigated as part of a "river blindness" vaccine cocktail. Components in saliva also may enhance the transmission of other microbial agents either by a cofeeding process similar to that observed in ixodid ticks or through rupture

  13. MACPEX Water Measurement Comparison

    NASA Astrophysics Data System (ADS)

    Al-Saadi, J. A.; Thornhill, A.; Alston, E. J.; Chen, G.; Fahey, D. W.; Jensen, E. J.; Mace, G. G.

    2012-12-01

    The Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) airborne field campaign was conducted in March and April 2011 to investigate cirrus cloud properties and the processes that affect their impact on radiation. In pursuit of this goal the NASA WB-57 was outfitted with dozens of in-situ instruments from government and university science teams including a wide range of water instruments. This provided an unprecedented situation to compare eight water instruments on one platform measuring water vapor (CIMS, DLH, HWV, JLH, and ULH), total water (ALIAS and FISH) and ice water content (CLH/IWC) for 14 flight days. Objective and data-driven approaches were applied to analyze the comparison data and to assess the consistency levels between the instruments and instrument uncertainties. The analysis is primarily focused on the upper tropospheric and lower stratospheric conditions, paying particular attention to water levels below 20 ppmv and between 20 - 120 ppmv depending on specific instrument data coverage. To be presented are comparison results suggesting the level of the agreement among the instrument as a function of atmospheric conditions, e.g., temperature and water vapor. Also discussed are some exploratory analyses of instrument precisions.

  14. Notes on the Comparison Class

    NASA Astrophysics Data System (ADS)

    Solt, Stephanie

    This paper investigates the role of comparison classes in the semantics of gradable adjectives in the positive form, focusing on the case where the comparison class is expressed overtly via a for-phrase (e.g. John is tall for a jockey). Two central questions are addressed: what information does the comparison class provide, and how is this information integrated compositionally? It is shown that the standard of comparison invoked by the positive form can be analyzed as a range of values whose width is based on the degree of dispersion in the comparison class. Compositionally, the comparison class can be analyzed as an argument of a null positive morpheme (contra Kennedy [13]), in parallel to recent proposals for the superlative (e.g. Heim [9]). The implications of the analysis for the choice between degree- and delineation-based analyses of gradable adjectives are discussed.

  15. Long History of IAM Comparisons

    SciTech Connect

    Smith, Steven J.; Clarke, Leon E.; Edmonds, James A.; Kejun, Jiang; Kriegler, Elmar; Masui, Toshihiko; Riahi, Keywan; Shukla, Priyadarshi R.; Tavoni, Massimo; Van Vuuren, Detlef; Weyant, John

    2015-04-23

    Correspondence to editor: We agree with the editors that the assumptions behind models of all types, including integrated assessment models (IAMs), should be as transparent as possible. The editors were in error, however, when they implied that the IAM community is just “now emulating the efforts of climate researchers by instigating their own model inter-comparison projects (MIPs).” In fact, model comparisons for integrated assessment and climate models followed a remarkably similar trajectory. Early General Circulation Model (GCM) comparison efforts, evolved to the first Atmospheric Model Inter-comparison Project (AMIP), which was initiated in the early 1990s. Atmospheric models evolved to coupled atmosphere-ocean models (AOGCMs) and results from the first Coupled Model Inter-Comparison Project (CMIP1) become available about a decade later. Results of first energy model comparison exercise, conducted under the auspices of the Stanford Energy Modeling Forum, were published in 1977. A summary of the first comparison focused on climate change was published in 1993. As energy models were coupled to simple economic and climate models to form IAMs, the first comparison exercise for IAMs (EMF-14) was initiated in 1994, and IAM comparison exercises have been on-going since this time.

  16. Geology orbiter comparison study

    NASA Technical Reports Server (NTRS)

    Cutts, J. A. J.; Blasius, K. R.; Davis, D. R.; Pang, K. D.; Shreve, D. C.

    1977-01-01

    Instrument requirements of planetary geology orbiters were examined with the objective of determining the feasibility of applying standard instrument designs to a host of terrestrial targets. Within the basic discipline area of geochemistry, gamma-ray, X-ray fluorescence, and atomic spectroscopy remote sensing techniques were considered. Within the discipline area of geophysics, the complementary techniques of gravimetry and radar were studied. Experiments using these techniques were analyzed for comparison at the Moon, Mercury, Mars and the Galilean satellites. On the basis of these comparative assessments, the adaptability of each sensing technique was judged as a basic technique for many targets, as a single instrument applied to many targets, as a single instrument used in different mission modes, and as an instrument capability for nongeoscience objectives.

  17. Glovebox decontamination technology comparison

    SciTech Connect

    Quintana, D.M.; Rodriguez, J.B.; Cournoyer, M.E.

    1999-09-26

    Reconfiguration of the CMR Building and TA-55 Plutonium Facility for mission requirements will require the disposal or recycle of 200--300 gloveboxes or open front hoods. These gloveboxes and open front hoods must be decontaminated to meet discharge limits for Low Level Waste. Gloveboxes and open front hoods at CMR have been painted. One of the deliverables on this project is to identify the best method for stripping the paint from large numbers of gloveboxes. Four methods being considered are the following: conventional paint stripping, dry ice pellets, strippable coatings, and high pressure water technology. The advantages of each technology will be discussed. Last, cost comparisons between the technologies will be presented.

  18. Deforestation and the spatio-temporal distribution of savannah and forest members of the Simulium damnosum complex in southern Ghana and south-western Togo.

    PubMed

    Wilson, M D; Cheke, R A; Flasse, S P J; Grist, S; Osei-Ateweneboana, M Y; Tetteh-Kumah, A; Fiasorgbor, G K; Jolliffe, F R; Boakye, D A; Hougard, J M; Yameogo, L; Post, R J

    2002-01-01

    Spatio-temporal data on cytotaxonomic identifications of larvae of different members of the Simulium damnosum complex collected from rivers in southern Ghana and south-western Togo from 1975 until 1997 were analysed. When the data were combined, the percentages of savannah blackflies (S. damnosum sensu stricto and S. sirbanum) in the samples were shown to have been progressively increasing since 1975. The increases were statistically significant (P < 0.001), but the rates of increase were not linear. Further analyses were conducted according to the collection seasons and locations of the samples, to account for possible biases such as savannah flies occurring further south in the dry season or a preponderance of later samples from northern rivers having more savannah flies. These analyses showed that the increasing trend was statistically significant (P < 0.0001) only during the periods April to June and October to December. The presence of adult savannah flies carrying infective larvae (L3) indistinguishable from those of Onchocerca volvulus in the study zone was confirmed by examinations of captured flies. The percentages of savannah flies amongst the human-biting populations and the percentages with L3s in the head were higher during dry seasons than wet seasons and the savannah species were found furthest south (5 degrees 25'N) in the dry season. Comparisons of satellite images taken in 1973 and 1990 over a study area in south-western Ghana encompassing stretches of the Tano and Bia rivers demonstrated that there have been substantial increases in urban and savannah areas, at the expense of forest. This was so not only for the whole images but also for subsamples of the images taken at 1, 2, 4, 8 and 16 km distant from sites alongside the River Tano. At every distance from the river, the percentages of pixels classified as urban or savannah have increased in 1990 compared with 1973, while those classified as degraded or dense forest have decreased. The

  19. Human filarial Wolbachia lipopeptide directly activates human neutrophils in vitro

    PubMed Central

    Tamarozzi, F; Wright, H L; Johnston, K L; Edwards, S W; Turner, J D; Taylor, M J

    2014-01-01

    The host inflammatory response to the Onchocerca volvulus endosymbiont, Wolbachia, is a major contributing factor in the development of chronic pathology in humans (onchocerciasis/river blindness). Recently, the toll-like pattern recognition receptor motif of the major inflammatory ligands of filarial Wolbachia, membrane-associated diacylated lipoproteins, was functionally defined in murine models of pathology, including mediation of neutrophil recruitment to the cornea. However, the extent to which human neutrophils can be activated in response to this Wolbachia pattern recognition motif is not known. Therefore, the responses of purified peripheral blood human neutrophils to a synthetic N-terminal diacylated lipopeptide (WoLP) of filarial Wolbachia peptidoglycan-associated lipoprotein (PAL) were characterized. WoLP exposure led to a dose-dependent activation of healthy, human neutrophils that included gross morphological alterations and modulation of surface expressed integrins involved in tethering, rolling and extravasation. WoLP exposure induced chemotaxis but not chemokinesis of neutrophils, and secretion of the major neutrophil chemokine, interleukin 8. WoLP also induced and primed the respiratory burst, and enhanced neutrophil survival by delay of apoptosis. These results indicate that the major inflammatory motif of filarial Wolbachia lipoproteins directly activates human neutrophils in vitro and promotes a molecular pathway by which human neutrophils are recruited to sites of Onchocerca parasitism. PMID:24909063

  20. Ocular Filariasis in US Residents, Returning Travelers, and Expatriates.

    PubMed

    Diaz, James H

    2015-01-01

    Several factors acting in concert now place US residents, returning travelers, and expatriates at risks of contracting ocular filariasis including increasing seroprevalence rates of zoonotic filariasis, international travel bringing tourists to and expatriates from filariasis-endemic regions, and warming temperatures extending distribution ranges of arthropod vectors. To describe the epidemiology and outcomes of ocular filariasis and to recommend strategies for the diagnosis, management, and prevention of ocular filariasis, internet search engines were queried with the key words in order to examine case reports and series of ocular filariasis in the US and elsewhere. Descriptive epidemiological, morphological, and molecular evidence now support increasing cases of ocular filariasis in domestic and wild animals and humans, with most cases caused by filarial worms including Dirofilaria repens and other zoonotic Dirofilaria species and Onchocerca lupi and other zoonotic Onchocerca species. Clinicians should maintain early suspicion of ocular filariasis in US residents, returning travelers, and expatriates who complain of combinations of red eye, eye pain, foreign body sensation, reduced visual acuity, and migrating ocular worms, even without significant peripheral eosinophilia or microfilaremia. Microfilariae of Wuchereria bancrofti, Brugia malayi, and O. volvulus may traverse the eye, but can usually be treated medically. Mobile adult worms trapped in the subconjunctiva or anterior chamber should be removed by ophthalmologists to permit species identification, prevent posterior uveitis and iritis, and stop worm migration into the posterior chamber which could require lens removal and vitrectomy for worm extraction causing further eye damage.

  1. Human filarial Wolbachia lipopeptide directly activates human neutrophils in vitro.

    PubMed

    Tamarozzi, F; Wright, H L; Johnston, K L; Edwards, S W; Turner, J D; Taylor, M J

    2014-10-01

    The host inflammatory response to the Onchocerca volvulus endosymbiont, Wolbachia, is a major contributing factor in the development of chronic pathology in humans (onchocerciasis/river blindness). Recently, the toll-like pattern recognition receptor motif of the major inflammatory ligands of filarial Wolbachia, membrane-associated diacylated lipoproteins, was functionally defined in murine models of pathology, including mediation of neutrophil recruitment to the cornea. However, the extent to which human neutrophils can be activated in response to this Wolbachia pattern recognition motif is not known. Therefore, the responses of purified peripheral blood human neutrophils to a synthetic N-terminal diacylated lipopeptide (WoLP) of filarial Wolbachia peptidoglycan-associated lipoprotein (PAL) were characterized. WoLP exposure led to a dose-dependent activation of healthy, human neutrophils that included gross morphological alterations and modulation of surface expressed integrins involved in tethering, rolling and extravasation. WoLP exposure induced chemotaxis but not chemokinesis of neutrophils, and secretion of the major neutrophil chemokine, interleukin 8. WoLP also induced and primed the respiratory burst, and enhanced neutrophil survival by delay of apoptosis. These results indicate that the major inflammatory motif of filarial Wolbachia lipoproteins directly activates human neutrophils in vitro and promotes a molecular pathway by which human neutrophils are recruited to sites of Onchocerca parasitism. © 2014 The Authors. Parasite Immunology Published by John Wiley & Sons Ltd.

  2. Social Comparison Processes in Organizations

    ERIC Educational Resources Information Center

    Greenberg, Jerald; Ashton-James, Claire E.; Ashkanasy, Neal M.

    2007-01-01

    We systematically analyze the role of social comparison processes in organizations. Specifically, we describe how social comparison processes have been used to explain six key areas of organizational inquiry: (1) organizational justice, (2) performance appraisal, (3) virtual work environments, (4) affective behavior in the workplace, (5) stress,…

  3. Learning a Network of Comparisons

    ERIC Educational Resources Information Center

    Moeser, Shannon D.; Tarrant, Barbara L.

    1977-01-01

    Using a network of comparisons, B. Hayes-Roth and F. Hayes-Roth found that subjects performed better on adjacent than on nonadjacent comparisons. Results suggested that such networks are processed in a manner fundamentally different from simple linear arrays. Here subjects were required to learn a similar knowledge structure. These results…

  4. Social Comparison Processes in Organizations

    ERIC Educational Resources Information Center

    Greenberg, Jerald; Ashton-James, Claire E.; Ashkanasy, Neal M.

    2007-01-01

    We systematically analyze the role of social comparison processes in organizations. Specifically, we describe how social comparison processes have been used to explain six key areas of organizational inquiry: (1) organizational justice, (2) performance appraisal, (3) virtual work environments, (4) affective behavior in the workplace, (5) stress,…

  5. Internal Comparisons in Everyday Life

    ERIC Educational Resources Information Center

    Moller, Jens; Husemann, Nicole

    2006-01-01

    According to the internal/external frame of reference (I/E) model (H. W. Marsh, 1986), students not only compare their own abilities in a domain with those of other students (social comparison), they also compare their own achievements in different domains (internal comparison). The main purpose of this study was to investigate internal comparison…

  6. Social Comparison in the Classroom: A Review

    ERIC Educational Resources Information Center

    Dijkstra, Pieternel; Kuyper, Hans; van der Werf, Greetje; Buunk, Abraham P.; van der Zee, Yvonne G.

    2008-01-01

    This article reviews research conducted on social comparison processes in the classroom since Festinger proposed his theory of social comparison. It covers the theoretical framework of social comparison theory, and it is organized around the following themes: motives for social comparison, dimensions of social comparison, direction of social…

  7. Data storage technology comparisons

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.

    1990-01-01

    The role of data storage and data storage technology is an integral, though conceptually often underestimated, portion of data processing technology. Data storage is important in the mass storage mode in which generated data is buffered for later use. But data storage technology is also important in the data flow mode when data are manipulated and hence required to flow between databases, datasets and processors. This latter mode is commonly associated with memory hierarchies which support computation. VLSI devices can reasonably be defined as electronic circuit devices such as channel and control electronics as well as highly integrated, solid-state devices that are fabricated using thin film deposition technology. VLSI devices in both capacities play an important role in data storage technology. In addition to random access memories (RAM), read-only memories (ROM), and other silicon-based variations such as PROM's, EPROM's, and EEPROM's, integrated devices find their way into a variety of memory technologies which offer significant performance advantages. These memory technologies include magnetic tape, magnetic disk, magneto-optic disk, and vertical Bloch line memory. In this paper, some comparison between selected technologies will be made to demonstrate why more than one memory technology exists today, based for example on access time and storage density at the active bit and system levels.

  8. [Anemia: guidelines comparison].

    PubMed

    Del Vecchio, Lucia

    2009-01-01

    The development of recombinant human erythropoietin and its introduction into the market in the late 1980s has significantly improved the quality of life of patients with chronic kidney disease (CKD) and reduced the need for blood transfusions. Starting from a cautious target, a progressive increase in the recommended hemoglobin levels has been observed over the years, in parallel with an increase in the obtained levels. This trend has gone together with the publication of findings of observational studies showing a relationship between the increase in hemoglobin levels and a reduction in the mortality risk, with the conduction of clinical trials testing the effects of complete anemia correction, and with the compilation of guidelines on anemia control in CKD patients by scientific societies and organizations. In the last two years, evidence of a possible increase in the mortality risk in those patients who were randomized to high hemoglobin levels has resulted in a decrease in the upper limit of the recommended Hb target to be obtained with erythropoietin stimulating agents (ESA), and consequently in a narrowing of the target range. Comparison of guidelines on anemia control in CKD patients is an interesting starting point to discuss single recommendations, strengthen their importance, or suggest new topics of research to fill up important gaps in knowledge.

  9. {sup 129}I interlaboratory comparison

    SciTech Connect

    Roberts, M.L.; Caffee, M.W.; Proctor, L.D.

    1996-05-01

    An interlaboratory comparison exercise for {sup 129}I has been organized and conducted. A total of seven laboratories participated in the exercise to either a full or limited extent. In the comparison, a suite of 11 samples were used. This suite of standards contained both synthetic `standard type` materials(i.e., AgI) and environmental materials. The isotopic {sup 129}I/{sup 127}I ratio of the samples varied from 10{sup -8} to 10{sup -14}. Preliminary results of the comparison are presented.

  10. The significance of guinea worm infection in the immunological diagnosis of onchocerciasis and bancroftian filariasis.

    PubMed

    Bloch, P; Simonsen, P E; Weiss, N; Nutman, T B

    1998-01-01

    Infections with Dracunculus medinensis frequently occur in the same geographical area as infections with Onchocerca volvulus and Wuchereria bancrofti. This study analysed the significance of D. medinensis infections for the specificity and sensitivity of available tests for antibody-based diagnosis of onchocerciasis (using individual recombinant clones OV-10, OV-11 and OV-16, and the OV-7/OV-10/OV-16 tri-cocktail, in an enzyme-linked immunosorbent assay) and for circulating antigen-based diagnosis of bancroftian filariasis (using the TropBio and the ICT card tests). Some immunological cross-reactivity was observed with all tests. When using individual recombinant O.volvulus antigens, the highest assay indices were obtained for clone OV-10, and the lowest for clone OV-16. Testing the serum responses against the tri-cocktail of recombinant antigens did not notably improve the assay indices. Two of 40 serum samples from individuals with patent dracunculiasis gave a false positive response in the ICT test and one of these was also positive in the TropBio test. Possible implications of applying these diagnostic assays in areas endemic for dracunculiasis are discussed.

  11. A novel, helminth-derived immunostimulant enhances human recall responses to hepatitis C virus and tetanus toxoid and is dependent on CD56+ cells for its action.

    PubMed

    MacDonald, A J; Libri, N A; Lustigman, S; Barker, S J; Whelan, M A; Semper, A E; Rosenberg, W M

    2008-05-01

    We have described previously an immunostimulant derived from Onchocerca volvulus, the helminth parasite that causes onchocerciasis. Recombinant O. volvulus activation-associated secreted protein-1 (rOv-ASP-1) was a potent adjuvant for antibody and cellular responses to protein, polypeptide and small peptide antigens. Our aims were to determine whether rOv-ASP-1 is immunostimulatory for human peripheral blood mononuclear cells (PBMC) and, if so, whether it could augment cellular responses against human pathogen antigens in vitro. Cytokines from rOv-ASP-1-stimulated human PBMC were measured by a fluorescence activated cell sorter-based multiplex assay. Recall responses of normal healthy donor (NHD) and chronic hepatitis C virus (c-HCV)-infected patient PBMC to tetanus toxoid (TT) or HCV core (HCVco) antigen, respectively, were measured by interferon-gamma enzyme-linked immunospot assays. Interferon-gamma was the predominant cytokine induced by rOv-ASP-1. 77.3% of NHD anti-TT and 88.9% of c-HCV anti-HCVco responses were enhanced by rOv-ASP-1. The immunostimulant effect was dependent upon contact between CD56+ and CD56- fractions of PBMC. We have described a helminth-derived protein that can act as an immunostimulant for human recall responses in vitro to TT and, perhaps more importantly, HCV antigens in patients with chronic HCV infection. Our longer-term goal would be to boost anti-viral responses in chronic infections such as HCV.

  12. A novel, helminth-derived immunostimulant enhances human recall responses to hepatitis C virus and tetanus toxoid and is dependent on CD56+ cells for its action

    PubMed Central

    MacDonald, A J; Libri, N A; Lustigman, S; Barker, S J; Whelan, M A; Semper, A E; Rosenberg, W M

    2008-01-01

    We have described previously an immunostimulant derived from Onchocerca volvulus, the helminth parasite that causes onchocerciasis. Recombinant O. volvulus activation-associated secreted protein-1 (rOv-ASP-1) was a potent adjuvant for antibody and cellular responses to protein, polypeptide and small peptide antigens. Our aims were to determine whether rOv-ASP-1 is immunostimulatory for human peripheral blood mononuclear cells (PBMC) and, if so, whether it could augment cellular responses against human pathogen antigens in vitro. Cytokines from rOv-ASP-1-stimulated human PBMC were measured by a fluorescence activated cell sorter-based multiplex assay. Recall responses of normal healthy donor (NHD) and chronic hepatitis C virus (c-HCV)-infected patient PBMC to tetanus toxoid (TT) or HCV core (HCVco) antigen, respectively, were measured by interferon-γ enzyme-linked immunospot assays. Interferon-γ was the predominant cytokine induced by rOv-ASP-1. 77·3% of NHD anti-TT and 88·9% of c-HCV anti-HCVco responses were enhanced by rOv-ASP-1. The immunostimulant effect was dependent upon contact between CD56+ and CD56− fractions of PBMC. We have described a helminth-derived protein that can act as an immunostimulant for human recall responses in vitro to TT and, perhaps more importantly, HCV antigens in patients with chronic HCV infection. Our longer-term goal would be to boost anti-viral responses in chronic infections such as HCV. PMID:18341617

  13. Wolbachia endosymbionts induce neutrophil extracellular trap formation in human onchocerciasis

    PubMed Central

    Tamarozzi, Francesca; Turner, Joseph D.; Pionnier, Nicolas; Midgley, Angela; Guimaraes, Ana F.; Johnston, Kelly L.; Edwards, Steven W.; Taylor, Mark J.

    2016-01-01

    The endosymbiotic bacteria, Wolbachia, induce neutrophilic responses to the human helminth pathogen Onchocerca volvulus. The formation of Neutrophil Extracellular Traps (NETs), has been implicated in anti-microbial defence, but has not been identified in human helminth infection. Here, we demonstrate NETs formation in human onchocerciasis. Extracellular NETs and neutrophils were visualised around O. volvulus in nodules excised from untreated patients but not in nodules from patients treated with the anti-Wolbachia drug, doxycycline. Whole Wolbachia or microspheres coated with a synthetic Wolbachia lipopeptide (WoLP) of the major nematode Wolbachia TLR2/6 ligand, peptidoglycan associated lipoprotein, induced NETosis in human neutrophils in vitro. TLR6 dependency of Wolbachia and WoLP NETosis was demonstrated using purified neutrophils from TLR6 deficient mice. Thus, we demonstrate for the first time that NETosis occurs during natural human helminth infection and demonstrate a mechanism of NETosis induction via Wolbachia endobacteria and direct ligation of Wolbachia lipoprotein by neutrophil TLR2/6. PMID:27752109

  14. Some unsolved problems in the epidemiology of onchocerciasis.

    PubMed

    Southgate, B A

    1987-01-01

    The descriptive epidemiology of onchocerciasis is well understood in the major foci of infection; a great stimulus to epidemiological research has been the implementation of the first control programme, which led to the eradication of infection in Kenya and, more recently, the vast Onchocerciasis Control Programme in the Volta River Basin of West Africa. However, there are still significant gaps in epidemiological knowledge which hamper the planning of future control programmes and the evaluation of current programmes. The four most important unsolved problems are: the refinement of field diagnostic techniques to identify skin microfilariae at the ultra-low densities that will become common in the late stages of vector-control campaigns; the definitive identification of Onchocerca volvulus infective larvae in Simulium species; strain analysis in the field of microfilariae from humans and of developing stages from Simulium, to determine their potential for ocular pathogenicity; determination of the lifespan, or maximum fecundity span, of adult female O. volvulus after the interruption of transmission. Three other unsolved problems are of enormous interest epidemiologically, although less urgent in practical importance. They are the identification of factors causing severe disease as opposed to heavy infection; the effects of seasonal as opposed to perennial transmission; and the importance of transplacental transmission of microfilariae or soluble antigens.

  15. Topical application of diethylcarbamazine to detect onchocerciasis recrudescence in west Africa.

    PubMed

    Toè, L; Adjami, A G; Boatin, B A; Back, C; Alley, E S; Dembélé, N; Brika, P G; Pearlman, E; Unnasch, T R

    2000-01-01

    The Onchocerciasis Control Programme in West Africa (OCP) has succeeded in eliminating blinding onchocerciasis as a public health problem throughout much of West Africa. The efforts of the OCP are now turning towards surveillance, with the goal of rapidly detecting and controlling outbreaks of infection in the onchocerciasis-free zone. With this goal in mind, cutaneous application of a solution of diethylcarbamazine (the DEC-patch test) was evaluated in 1996-99 as a method to detect patent Onchocerca volvulus infection in children and adolescents, a sentinel population for the detection of recrudescence. In an analysis of 1887 individuals in Côte d'Ivoire and Burkina Faso, the DEC-patch test produced prevalence estimates comparable to those obtained by skin snip. The sensitivity of the DEC-patch assay was marginally greater in children and adolescents than in adults, and was greater in individuals who had received prior Mectizan treatment. These data suggest that the DEC-patch test may be a useful tool for detecting recrudescence of O. volvulus infection in a sentinel population of children and young adults within the onchocerciasis-free zone created by the OCP.

  16. Field applicability of a rapid-format anti-Ov-16 antibody test for the assessment of onchocerciasis control measures in regions of endemicity.

    PubMed

    Lipner, Ettie M; Dembele, Noumouza; Souleymane, Sanou; Alley, William Soumbey; Prevots, D Rebecca; Toe, Laurent; Boatin, Boayke; Weil, Gary J; Nutman, Thomas B

    2006-07-15

    A previously developed, specific, rapid-format immunochromatographic card test that detects immunoglobulin G4 to the recombinant Onchocerca volvulus antigen Ov-16 was modified to detect antibodies in whole blood. Ov-16 card test results were assessed in 1511 subjects > or =2 years of age in 7 West African villages with varying histories of onchocerciasis control measures. In villages in which control measures had been implemented, anti-Ov-16 antibody prevalence rates ranged from 5.2% to 65.1%. Antibody prevalence rates were close to zero among subjects born after effective control measures had been implemented. In 2 villages without a history of control measures where onchocerciasis was endemic, microfilariae (MF) prevalence rates were 82.8% and 65.1%, and antibody prevalence rates were 73.1% and 62.1%. In these 2 villages, the sensitivity of the Ov-16 card test was 81.1% and 76.5%, the specificity was 100%, and the positive predictive value was 91.8% and 80.5%. MF and antibody prevalence rates were correlated (Spearman's r=0.815; P<.038). The Ov-16 card test is field applicable, exhibits high sensitivity and specificity for O. volvulus infection, and has great potential as a tool for surveillance and for evaluating the success of onchocerciasis control measures.

  17. The Onchocerciasis Control Programme in West Africa (OCP).

    PubMed

    Boatin, B

    2008-09-01

    The Onchocerciasis Control Programme in West Africa (OCP) started operations in 1975. Its main objectives were to eliminate human onchocerciasis, as a disease of public-health importance and an obstacle to socio-economic development, from the Programme area. By the end of 2002, the OCP covered 11 West African countries, and had introduced large-scale Mectizan (ivermectin) distribution to about 10 million people, through the communitydirected treatment approach, with treatment coverages ranging from 51%-81%. Research on large-scale Mectizan use illustrated the importance of evidence-based results, the power of multicountry studies, the need for social science in community-driven endeavours and operations research, and the value of empowering communities as allies in disease control. The generous donation of Mectizan by Merck & Co., Inc., has increased general interest in health-related public-private partnerships and generated the momentum for other donations to tackle other diseases. The vector control on which the OCP was initially based successfully interrupted the transmission of the parasite causing human onchocerciasis, Onchocerca volvulus, in many areas. The introduction of Mectizan led to the decline in anterior-segment lesions in the eye and the arrest of posterior-segment lesions. The drug continues to be highly effective in morbidity control, although recently there have been reports of sub-optimal responses in some adult O. volvulus, albeit in a few, very small and isolated foci.

  18. Validation of onchocerciasis biomarker N-acetyltyramine-O-glucuronide (NATOG).

    PubMed

    Globisch, Daniel; Eubanks, Lisa M; Shirey, Ryan J; Pfarr, Kenneth M; Wanji, Samuel; Debrah, Alexander Y; Hoerauf, Achim; Janda, Kim D

    2017-08-01

    The Neglected Tropical Disease onchocerciasis is a parasitic disease. Despite many control programmes by the World Health Organization (WHO), large communities in West and Central Africa are still affected. Besides logistic challenges during biannual mass drug administration, the lack of a robust, point-of-care diagnostic is limiting successful eradication of onchocerciasis. Towards the implementation of a non-invasive and point-of-care diagnostic, we have recently reported the discovery of the biomarker N-acetyltyramine-O-glucuronide (NATOG) in human urine samples using a metabolomics-mining approach. NATOG's biomarker value was enhanced during an investigation in a rodent model. Herein, we further detail the specificity of NATOG in active onchocerciasis infections as well as the co-infecting parasites Loa loa and Mansonella perstans. Our results measured by liquid chromatography coupled with mass spectrometry (LC-MS) reveal elevated NATOG values in mono- and co-infection samples only in the presence of the nematode Onchocerca volvulus. Metabolic pathway investigation of l-tyrosine/tyramine in all investigated nematodes uncovered an important link between the endosymbiotic bacterium Wolbachia and O. volvulus for the biosynthesis of NATOG. Based on these extended studies, we suggest NATOG as a biomarker for tracking active onchocerciasis infections and provide a threshold concentration value of NATOG for future diagnostic tool development. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  19. Density-Dependent Mortality of the Human Host in Onchocerciasis: Relationships between Microfilarial Load and Excess Mortality

    PubMed Central

    Wagner, Karen S.; Soumbey-Alley, Edoh W.; Boatin, Boakye A.; Basáñez, María-Gloria

    2012-01-01

    Background The parasite Onchocerca volvulus has, until recently, been regarded as the cause of a chronic yet non-fatal condition. Recent analyses, however, have indicated that in addition to blindness, the parasite can also be directly associated with human mortality. Such analyses also suggested that the relationship between microfilarial load and excess mortality might be non-linear. Determining the functional form of such relationship would contribute to quantify the population impact of mass microfilaricidal treatment. Methodology/Principal Findings Data from the Onchocerciasis Control Programme in West Africa (OCP) collected from 1974 through 2001 were used to determine functional relationships between microfilarial load and excess mortality of the human host. The goodness-of-fit of three candidate functional forms (a (log-) linear model and two saturating functions) were explored and a saturating (log-) sigmoid function was deemed to be statistically the best fit. The excess mortality associated with microfilarial load was also found to be greater in younger hosts. The attributable mortality risk due to onchocerciasis was estimated to be 5.9%. Conclusions/Significance Incorporation of this non-linear functional relationship between microfilarial load and excess mortality into mathematical models for the transmission and control of onchocerciasis will have important implications for our understanding of the population biology of O. volvulus, its impact on human populations, the global burden of disease due to onchocerciasis, and the projected benefits of control programmes in both human and economic terms. PMID:22479660

  20. Impact of long-term treatment of onchocerciasis with ivermectin in Ecuador: potential for elimination of infection.

    PubMed

    Vieira, Juan Carlos; Cooper, Philip J; Lovato, Raquel; Mancero, Tamara; Rivera, Jorge; Proaño, Roberto; López, Andrea A; Guderian, Ronald H; Guzmán, José Rumbea

    2007-05-23

    Onchocerciasis is a leading cause of blindness worldwide, hence elimination of the infection is an important health priority. Community-based treatment programs with ivermectin form the basis of control programs for the disease in Latin America. The long-term administration of ivermectin could eliminate Onchocerca volvulus infection from endemic areas in Latin America. A strategy of annual to twice-annual treatments with ivermectin has been used for onchocerciasis in endemic communities in Ecuador for up to 14 years. The impact of ivermectin treatment on ocular morbidity, and O. volvulus infection and transmission was monitored in seven sentinel communities. Over the period 1990-2003, high rates of treatment coverage of the eligible population were maintained in endemic communities (mean 85.2% per treatment round). Ivermectin reduced the prevalence of anterior segment disease of the eye to 0% in sentinel communities and had a major impact on the prevalence and transmission of infection, with possible elimination of infection in some foci. The distribution of ivermectin in endemic communities in Ecuador might have eliminated ocular morbidity and significant progress has been made towards elimination of the infection. A strategy of more frequent treatments with ivermectin may be required in communities where the infection persists to achieve the objective of elimination of the infection from Ecuador. The elimination of the infection from an endemic country in Latin America would be a major public health achievement and could stimulate the implementation of elimination strategies in other endemic countries.

  1. Supergroup C Wolbachia, mutualist symbionts of filarial nematodes, have a distinct genome structure

    PubMed Central

    Comandatore, Francesco; Cordaux, Richard; Bandi, Claudio; Blaxter, Mark; Darby, Alistair; Makepeace, Benjamin L.; Montagna, Matteo; Sassera, Davide

    2015-01-01

    Wolbachia pipientis is possibly the most widespread endosymbiont of arthropods and nematodes. While all Wolbachia strains have historically been defined as a single species, 16 monophyletic clusters of diversity (called supergroups) have been described. Different supergroups have distinct host ranges and symbiotic relationships, ranging from mutualism to reproductive manipulation. In filarial nematodes, which include parasites responsible for major diseases of humans (such as Onchocerca volvulus, agent of river blindness) and companion animals (Dirofilaria immitis, the dog heartworm), Wolbachia has an obligate mutualist role and is the target of new treatment regimens. Here, we compare the genomes of eight Wolbachia strains, spanning the diversity of the major supergroups (A–F), analysing synteny, transposable element content, GC skew and gene loss or gain. We detected genomic features that differ between Wolbachia supergroups, most notably in the C and D clades from filarial nematodes. In particular, strains from supergroup C (symbionts of O. volvulus and D. immitis) present a pattern of GC skew, conserved synteny and lack of transposable elements, unique in the Wolbachia genus. These features could be the consequence of a distinct symbiotic relationship between C Wolbachia strains and their hosts, highlighting underappreciated differences between the mutualistic supergroups found within filarial nematodes. PMID:26631376

  2. Human infection patterns and heterogeneous exposure in river blindness

    PubMed Central

    Filipe, João A. N.; Boussinesq, Michel; Renz, Alfons; Collins, Richard C.; Vivas-Martinez, Sarai; Grillet, María-Eugenia; Little, Mark P.; Basáñez, María-Gloria

    2005-01-01

    Here we analyze patterns of human infection with Onchocerca volvulus (the cause of river blindness) in different continents and ecologies. In contrast with some geohelminths and schistosome parasites whose worm burdens typically exhibit a humped pattern with host age, patterns of O. volvulus infection vary markedly with locality. To test the hypothesis that such differences are partly due to heterogeneity in exposure to vector bites, we develop an age- and sex-structured model for intensity of infection, with parasite regulation within humans and vectors. The model is fitted to microfilarial data from savannah villages of northern Cameroon, coffee fincas of central Guatemala, and forest-dwelling communities of southern Venezuela that were recorded before introducing ivermectin treatment. Estimates of transmission and infection loads are compared with entomological and epidemiological field data. Host age- and sex-heterogeneous exposure largely explains locale-specific infection patterns in onchocerciasis (whereas acquired protective immunity has been invoked for other helminth infections). The basic reproductive number,R0, ranges from 5 to 8, which is slightly above estimates for other helminth parasites but well below previously presented values. PMID:16217028

  3. Species-specific sequence in the repeat 3 region of the gene encoding a putative Loa loa allergen: a diagnostic tool for occult loiasis.

    PubMed

    Toure, F S; Egwang, T G; Wahl, G; Millet, P; Bain, O; Georges, A J

    1997-01-01

    A polymerase chain reaction (PCR)-based method to detect Loa loa DNA in the blood lysate of infected individuals is described. A set of primers was designed to amplify the repeat 3 sequence (15r3) of the gene encoding a putative L. loa allergen. The qualitative PCR was carried out using blood lysates from subjects from an L. loaendemic area of Gabon where loiasis exists sympatrically with Mansonella perstans, and from individuals from a loiasis-free area in Togo infected concomitantly with M. perstans and Onchocerca volvulus. No specific amplification was observed after ethidium bromide staining of a gel containing M. perstans and O. volvulus control samples. In contrast, a 396-basepair (bp) DNA was detected in all L. loa microfilaremic individuals and in seven of the 20 L. loa amicrofilaremic subjects diagnosed by leukoconcentration. Qualitative Southern blots carried out at high stringency (65 degrees C) using 15r3 oligonucleotide probe revealed hybridization only with L. loa samples (5 of 5 microfilaremic individuals and 15 of 20 amicrofilaremic individuals), confirming the results obtained with ethidium bromide staining of PCR products. We conclude that this 396-bp sequence could be used as a species-specific diagnostic tool for occult loiasis in an endemic area with concurrent filarial infections.

  4. Studies on filariasis in Bauchi State, Nigeria. II. The prevalence of human filariasis in Darazo Local Government area.

    PubMed

    Anosike, J C; Onwuliri, C O

    1994-11-01

    In an eleven months study of eleven communities of Darazo Local Government Area of Bauchi state, northern Nigeria, 293 (21.7) of 1,349 persons examined harboured various filarial parasites. Of the sampled population, 18%, 1.9%, 1.6%, 0.5% and 0.2% had microfilariae of Onchocerca volvulus, Wuchereria bancrofti, Mansonella perstans, M. streptocerca and Loa loa respectively. Of the 637 females examined, 90 (14.1%) were infected, while 203 (23.5%) of 712 males sampled had filarial infections. The high rate in males was significant (P < 0.001). O. volvulus mf-rate increased gradually from the first decade to the seventh decade of life but declined thereafter. Prevalence of bancroftian filariasis was consistently lower in females of reproductive age, while the distribution of various filarial parasites varied significantly among age groups and communities (P < 0.05). Fishermen (42.9%), farmers (42.4%) and cattle rearers (40.9%) were the most affected occupational categories. Control strategies are highlighted.

  5. Clinical and laboratory aspects of filariasis.

    PubMed Central

    Nanduri, J; Kazura, J W

    1989-01-01

    Human filarial infections afflict over 150 million persons worldwide and are major causes of morbidity in many developing countries. Onchocerca volvulus infection is a leading preventable cause of blindness, while bancroftian and brugian filariasis may produce lymphatic obstruction of the genitalia and extremities (elephantiasis). Definitive diagnosis of these helminthic infections currently depends on demonstration of microfilariae in host tissues, i.e., the skin in the case of O. volvulus and the bloodstream in the cases of Wuchereria bancrofti and Brugia malayi. Many investigations are now directed at developing specific and sensitive serum antigen assays that will allow diagnosis of active infection (i.e., presence of adult-stage parasites) in the absence of detectable microfilariae. With respect to the immunology of these parasitic infections, efforts are being directed at elucidating the role of T- and B-cell responses in the development of pathologic lesions and resistance to reinfection. These data as well as molecular biologic approaches to identify and study filarial molecules which are immunogenic are discussed. Finally, since treatment of filariases at present depends on antiparasitic drugs, the clinical indications and dosages of diethylcarbamazine and ivermectin are summarized. PMID:2644023

  6. Impact of long-term treatment of onchocerciasis with ivermectin in Ecuador: potential for elimination of infection

    PubMed Central

    Vieira, Juan Carlos; Cooper, Philip J; Lovato, Raquel; Mancero, Tamara; Rivera, Jorge; Proaño, Roberto; López, Andrea A; Guderian, Ronald H; Guzmán, José Rumbea

    2007-01-01

    Background Onchocerciasis is a leading cause of blindness worldwide, hence elimination of the infection is an important health priority. Community-based treatment programs with ivermectin form the basis of control programs for the disease in Latin America. The long-term administration of ivermectin could eliminate Onchocerca volvulus infection from endemic areas in Latin America. Methods A strategy of annual to twice-annual treatments with ivermectin has been used for onchocerciasis in endemic communities in Ecuador for up to 14 years. The impact of ivermectin treatment on ocular morbidity, and O. volvulus infection and transmission was monitored in seven sentinel communities. Results Over the period 1990–2003, high rates of treatment coverage of the eligible population were maintained in endemic communities (mean 85.2% per treatment round). Ivermectin reduced the prevalence of anterior segment disease of the eye to 0% in sentinel communities and had a major impact on the prevalence and transmission of infection, with possible elimination of infection in some foci. Conclusion The distribution of ivermectin in endemic communities in Ecuador might have eliminated ocular morbidity and significant progress has been made towards elimination of the infection. A strategy of more frequent treatments with ivermectin may be required in communities where the infection persists to achieve the objective of elimination of the infection from Ecuador. The elimination of the infection from an endemic country in Latin America would be a major public health achievement and could stimulate the implementation of elimination strategies in other endemic countries. PMID:17521449

  7. Chitinase is stored and secreted from the inner body of microfilariae and has a role in exsheathment in the parasitic nematode Brugia malayi

    PubMed Central

    Wu, Yang; Preston, Gillian; Bianco, Albert E.

    2008-01-01

    Chitinase expression in microfilariae of the parasitic nematode Brugia malayi (B. malayi, Bm) is coincidental with the onset of their infectivity to mosquitoes. An antibody raised to Onchocerca volvulus (O. volvulus, Ov) infective-stage larval chitinase (Ov-CHI-1) was specifically reactive against B. malayi microfilarial chitinase and was used to study the localization of chitinase in B. malayi during microfilarial development and transmission to the insect vector. Immuno-electron microscopy (IEM) was used to demonstrate that the chitinase was confined to the inner body of the microfilariae and furthermore that chitinase was only present in sheathed microfilarial species, although the inner body is present in all species. Observation using the IEM implicates two distinct routes of chitinase secretion from the inner body, via either the pharyngeal thread, or during transmission of the microfilariae to the vector, contained in vesicle-like structures. Many morphological studies have described the structure of the inner body, but no function has been assigned to it as of yet. Although it has been commented that the cells surrounding the inner body and pharyngeal thread are those destined to become the intestine and pharynx and that the inner body represents a store of material. Our studies suggest that chitinase is one such product stored in the inner body and that it is secreted during the exsheathment of the microfilaria in the mosquito. PMID:18611418

  8. Development of a Novel Trap for the Collection of Black Flies of the Simulium ochraceum Complex

    PubMed Central

    Rodríguez-Pérez, Mario A.; Adeleke, Monsuru A.; Burkett-Cadena, Nathan D.; Garza-Hernández, Javier A.; Reyes-Villanueva, Filiberto; Cupp, Eddie W.; Toé, Laurent; Salinas-Carmona, Mario C.; Rodríguez-Ramírez, Américo D.; Katholi, Charles R.; Unnasch, Thomas R.

    2013-01-01

    Background Human landing collections are currently the standard method for collecting onchocerciasis vectors in Africa and Latin America. As part of the efforts to develop a trap to replace human landing collections for the monitoring and surveillance of onchocerciasis transmission, comprehensive evaluations of several trap types were conducted to assess their ability to collect Simulium ochraceum sensu lato, one of the principal vectors of Onchocerca volvulus in Latin America. Methodology/Principal Findings Diverse trap designs with numerous modifications and bait variations were evaluated for their abilities to collect S. Ochraceum s.l. females. These traps targeted mostly host seeking flies. A novel trap dubbed the “Esperanza window trap” showed particular promise over other designs. When baited with CO2 and BG-lure (a synthetic blend of human odor components) a pair of Esperanza window traps collected numbers of S. Ochraceum s.l. females similar to those collected by a team of vector collectors. Conclusions/Significance The Esperanza window trap, when baited with chemical lures and CO2 can be used to collect epidemiologically significant numbers of Simulium ochraceum s.l., potentially serving as a replacement for human landing collections for evaluation of the transmission of O. volvulus. PMID:24116169

  9. Supergroup C Wolbachia, mutualist symbionts of filarial nematodes, have a distinct genome structure.

    PubMed

    Comandatore, Francesco; Cordaux, Richard; Bandi, Claudio; Blaxter, Mark; Darby, Alistair; Makepeace, Benjamin L; Montagna, Matteo; Sassera, Davide

    2015-12-01

    Wolbachia pipientis is possibly the most widespread endosymbiont of arthropods and nematodes. While all Wolbachia strains have historically been defined as a single species, 16 monophyletic clusters of diversity (called supergroups) have been described. Different supergroups have distinct host ranges and symbiotic relationships, ranging from mutualism to reproductive manipulation. In filarial nematodes, which include parasites responsible for major diseases of humans (such as Onchocerca volvulus, agent of river blindness) and companion animals (Dirofilaria immitis, the dog heartworm), Wolbachia has an obligate mutualist role and is the target of new treatment regimens. Here, we compare the genomes of eight Wolbachia strains, spanning the diversity of the major supergroups (A-F), analysing synteny, transposable element content, GC skew and gene loss or gain. We detected genomic features that differ between Wolbachia supergroups, most notably in the C and D clades from filarial nematodes. In particular, strains from supergroup C (symbionts of O. volvulus and D. immitis) present a pattern of GC skew, conserved synteny and lack of transposable elements, unique in the Wolbachia genus. These features could be the consequence of a distinct symbiotic relationship between C Wolbachia strains and their hosts, highlighting underappreciated differences between the mutualistic supergroups found within filarial nematodes. © 2015 The Authors.

  10. Comparison of Artificial Compressibility Methods

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Housman, Jeffrey; Kwak, Dochan

    2004-01-01

    Various artificial compressibility methods for calculating the three-dimensional incompressible Navier-Stokes equations are compared. Each method is described and numerical solutions to test problems are conducted. A comparison based on convergence behavior, accuracy, and robustness is given.

  11. [Comparison between paraphilia and psychosis].

    PubMed

    Abraham, G; Vlatkovic, D; Dallon, C

    2008-03-26

    It is difficult in principle to make a diagnosis of psychoses in most cases of paraphilic behaviour. It is possible, on the contrary, to discover some structural similarities between a psychotic state and paraphilic tendencies. In any case as we assume psychoses to be a severe disorder in comparison to, for instance, a neurotic syndrome, the same comparison can be made between a permanent paraphilic disorder and a dysfunctional sexual disturbance.

  12. Onchocerciasis Transmission in Ghana: Persistence under Different Control Strategies and the Role of the Simuliid Vectors

    PubMed Central

    Lamberton, Poppy H. L.; Cheke, Robert A.; Winskill, Peter; Tirados, Iñaki; Walker, Martin; Osei-Atweneboana, Mike Y.; Biritwum, Nana-Kwadwo; Tetteh-Kumah, Anthony; Boakye, Daniel A.; Wilson, Michael D.; Post, Rory J.; Basañez, María-Gloria

    2015-01-01

    Background The World Health Organization (WHO) aims at eliminating onchocerciasis by 2020 in selected African countries. Current control focuses on community-directed treatment with ivermectin (CDTI). In Ghana, persistent transmission has been reported despite long-term control. We present spatial and temporal patterns of onchocerciasis transmission in relation to ivermectin treatment history. Methodology/Principal Findings Host-seeking and ovipositing blackflies were collected from seven villages in four regions of Ghana with 3–24 years of CDTI at the time of sampling. A total of 16,443 flies was analysed for infection; 5,812 (35.3%) were dissected for parity (26.9% parous). Heads and thoraces of 12,196 flies were dissected for Onchocerca spp. and DNA from 11,122 abdomens was amplified using Onchocerca primers. A total of 463 larvae (0.03 larvae/fly) from 97 (0.6%) infected and 62 (0.4%) infective flies was recorded; 258 abdomens (2.3%) were positive for Onchocerca DNA. Infections (all were O. volvulus) were more likely to be detected in ovipositing flies. Transmission occurred, mostly in the wet season, at Gyankobaa and Bosomase, with transmission potentials of, respectively, 86 and 422 L3/person/month after 3 and 6 years of CDTI. The numbers of L3/1,000 parous flies at these villages were over 100 times the WHO threshold of one L3/1,000 for transmission control. Vector species influenced transmission parameters. At Asubende, the number of L3/1,000 ovipositing flies (1.4, 95% CI = 0–4) also just exceeded the threshold despite extensive vector control and 24 years of ivermectin distribution, but there were no infective larvae in host-seeking flies. Conclusions/Significance Despite repeated ivermectin treatment, evidence of O. volvulus transmission was documented in all seven villages and above the WHO threshold in two. Vector species influences transmission through biting and parous rates and vector competence, and should be included in transmission models

  13. Onchocerciasis transmission in Ghana: persistence under different control strategies and the role of the simuliid vectors.

    PubMed

    Lamberton, Poppy H L; Cheke, Robert A; Winskill, Peter; Tirados, Iñaki; Walker, Martin; Osei-Atweneboana, Mike Y; Biritwum, Nana-Kwadwo; Tetteh-Kumah, Anthony; Boakye, Daniel A; Wilson, Michael D; Post, Rory J; Basañez, María-Gloria

    2015-04-01

    The World Health Organization (WHO) aims at eliminating onchocerciasis by 2020 in selected African countries. Current control focuses on community-directed treatment with ivermectin (CDTI). In Ghana, persistent transmission has been reported despite long-term control. We present spatial and temporal patterns of onchocerciasis transmission in relation to ivermectin treatment history. Host-seeking and ovipositing blackflies were collected from seven villages in four regions of Ghana with 3-24 years of CDTI at the time of sampling. A total of 16,443 flies was analysed for infection; 5,812 (35.3%) were dissected for parity (26.9% parous). Heads and thoraces of 12,196 flies were dissected for Onchocerca spp. and DNA from 11,122 abdomens was amplified using Onchocerca primers. A total of 463 larvae (0.03 larvae/fly) from 97 (0.6%) infected and 62 (0.4%) infective flies was recorded; 258 abdomens (2.3%) were positive for Onchocerca DNA. Infections (all were O. volvulus) were more likely to be detected in ovipositing flies. Transmission occurred, mostly in the wet season, at Gyankobaa and Bosomase, with transmission potentials of, respectively, 86 and 422 L3/person/month after 3 and 6 years of CDTI. The numbers of L3/1,000 parous flies at these villages were over 100 times the WHO threshold of one L3/1,000 for transmission control. Vector species influenced transmission parameters. At Asubende, the number of L3/1,000 ovipositing flies (1.4, 95% CI = 0-4) also just exceeded the threshold despite extensive vector control and 24 years of ivermectin distribution, but there were no infective larvae in host-seeking flies. Despite repeated ivermectin treatment, evidence of O. volvulus transmission was documented in all seven villages and above the WHO threshold in two. Vector species influences transmission through biting and parous rates and vector competence, and should be included in transmission models. Oviposition traps could augment vector collector methods for monitoring

  14. Differential Evolutionary Selection and Natural Evolvability Observed in ALT Proteins of Human Filarial Parasites.

    PubMed

    Devoe, Neil C; Corbett, Ian J; Barker, Linsey; Chang, Robert; Gudis, Polyxeni; Mullen, Nathan; Perez, Kailey; Raposo, Hugo; Scholz, John; May, Meghan

    2016-01-01

    The abundant larval transcript (ALT-2) protein is present in all members of the Filarioidea, and has been reported as a potential candidate antigen for a subunit vaccine against lymphatic filariasis. To assess the potential for vaccine escape or heterologous protection, we examined the evolutionary selection acting on ALT-2. The ratios of nonsynonymous (K(a)) to synonymous (K(s)) mutation frequencies (ω) were calculated for the alt-2 genes of the lymphatic filariasis agents Brugia malayi and Wuchereria bancrofti and the agents of river blindness and African eyeworm disease Onchocerca volvulus and Loa loa. Two distinct Bayesian models of sequence evolution showed that ALT-2 of W. bancrofti and L. loa were under significant (P<0.05; P < 0.001) diversifying selection, while ALT-2 of B. malayi and O. volvulus were under neutral to stabilizing selection. Diversifying selection as measured by ω values was notably strongest on the region of ALT-2 encoding the signal peptide of L. loa and was elevated in the variable acidic domain of L. loa and W. bancrofti. Phylogenetic analysis indicated that the ALT-2 consensus sequences formed three clades: the first consisting of B. malayi, the second consisting of W. bancrofti, and the third containing both O. volvulus and L. loa. ALT-2 selection was therefore not predictable by phylogeny or pathology, as the two species parasitizing the eye were selected differently, as were the two species parasitizing the lymphatic system. The most immunogenic regions of L. loa and W. bancrofti ALT-2 sequence as modeled by antigenicity prediction analysis did not correspond with elevated levels of diversifying selection, and were not selected differently than predicted antigenic epitopes in B. malayi and O. volvulus. Measurements of ALT-2 evolvability made by χ2 analysis between alleles that were stable (O. volvulus and B. malayi) and those that were under diversifying selection (W. bancrofti and L. loa) indicated significant (P<0

  15. O-5S quantitative real-time PCR: a new diagnostic tool for laboratory confirmation of human onchocerciasis.

    PubMed

    Mekonnen, Solomon A; Beissner, Marcus; Saar, Malkin; Ali, Solomon; Zeynudin, Ahmed; Tesfaye, Kassahun; Adbaru, Mulatu G; Battke, Florian; Poppert, Sven; Hoelscher, Michael; Löscher, Thomas; Bretzel, Gisela; Herbinger, Karl-Heinz

    2017-10-02

    Onchocerciasis is a parasitic disease caused by the filarial nematode Onchocerca volvulus. In endemic areas, the diagnosis is commonly confirmed by microscopic examination of skin snip samples, though this technique is considered to have low sensitivity. The available melting-curve based quantitative real-time PCR (qPCR) using degenerated primers targeting the O-150 repeat of O. volvulus was considered insufficient for confirming the individual diagnosis, especially in elimination studies. This study aimed to improve detection of O. volvulus DNA in clinical samples through the development of a highly sensitive qPCR assay. A novel hydrolysis probe based qPCR assay was designed targeting the specific sequence of the O. volvulus O-5S rRNA gene. A total of 200 clinically suspected onchocerciasis cases were included from Goma district in South-west Ethiopia, from October 2012 through May 2013. Skin snip samples were collected and subjected to microscopy, O-150 qPCR, and the novel O-5S qPCR. Among the 200 individuals, 133 patients tested positive (positivity rate of 66.5%) and 67 negative by O-5S qPCR, 74 tested positive by microscopy (37.0%) and 78 tested positive by O-150 qPCR (39.0%). Among the 133 O-5S qPCR positive individuals, microscopy and O-150 qPCR detected 55.6 and 59.4% patients, respectively, implying a higher sensitivity of O-5S qPCR than microscopy and O-150 qPCR. None of the 67 individuals who tested negative by O-5S qPCR tested positive by microscopy or O-150 qPCR, implying 100% specificity of the newly designed O-5S qPCR assay. The novel O-5S qPCR assay is more sensitive than both microscopic examination and the existing O-150 qPCR for the detection of O. volvulus from skin snip samples. The newly designed assay is an important step towards appropriate individual diagnosis and control of onchocerciasis.

  16. Ivermectin-induced immunopotentiation in onchocerciasis: recognition of selected antigens following a single dose of ivermectin.

    PubMed

    Akuffo, H; Maasho, K; Lavebratt, C; Engström, K; Britton, S

    1996-02-01

    Onchocerciasis is associated with blindness and gross skin changes, believed to be a consequence of the immune response to antigens released from the offspring of the female worm of Onchocerca volvulus, the microfilariae (mf). An effective microfilaricidal drug is now available which quickly reduces the mf burden without affecting the adult worm. There exist foci in onchocerciasis endemic areas where some of the patients have many mf in their skin but relatively few clinical symptoms. This state of hyposensitivity is believed to be due to immunosuppression. The aim of this study was to address the question of the basis of, and the effect of ivermectin treatment on this immunosuppression. Female adult worms of O. volvulus were used as whole or fractionated antigens to stimulate peripheral blood mononuclear cells. Microfilariae are found in the reproduction tract of the female worms, and thus an antigen preparation of the female adult O. volvulus contains both exclusive adult antigens as well as antigens from microfilariae. Cells were obtained from onchocerciasis patients, individuals of similar socio-economic status living in the same Ghanaian village, but who showed no parasitological or clinical evidence of onchocerciasis (exposed endemic controls), healthy Ghanaians living in areas where transmission of onchocerciasis does not seem to occur (non-exposed endemic controls) and unexposed healthy Swedish donors. As a group, cells from onchocerciasis patients proliferated to a lesser degree than cells from the exposed endemic control and the non-exposed endemic control groups to the whole worm antigen, whereas the phytohaemagglutinin (PHA) response was strongest in the patients. Proliferative responses of above 1000 ct/min to fractions of the worm extract were only evident in the cells from a few individuals in each of the various groups. However, 28 days following ivermectin treatment, cells from all onchocerciasis patients were able to mount significantly enhanced

  17. Differential Evolutionary Selection and Natural Evolvability Observed in ALT Proteins of Human Filarial Parasites

    PubMed Central

    Devoe, Neil C.; Corbett, Ian J.; Barker, Linsey; Chang, Robert; Gudis, Polyxeni; Mullen, Nathan; Perez, Kailey; Raposo, Hugo; Scholz, John; May, Meghan

    2016-01-01

    The abundant larval transcript (ALT-2) protein is present in all members of the Filarioidea, and has been reported as a potential candidate antigen for a subunit vaccine against lymphatic filariasis. To assess the potential for vaccine escape or heterologous protection, we examined the evolutionary selection acting on ALT-2. The ratios of nonsynonymous (K(a)) to synonymous (K(s)) mutation frequencies (ω) were calculated for the alt-2 genes of the lymphatic filariasis agents Brugia malayi and Wuchereria bancrofti and the agents of river blindness and African eyeworm disease Onchocerca volvulus and Loa loa. Two distinct Bayesian models of sequence evolution showed that ALT-2 of W. bancrofti and L. loa were under significant (P<0.05; P < 0.001) diversifying selection, while ALT-2 of B. malayi and O. volvulus were under neutral to stabilizing selection. Diversifying selection as measured by ω values was notably strongest on the region of ALT-2 encoding the signal peptide of L. loa and was elevated in the variable acidic domain of L. loa and W. bancrofti. Phylogenetic analysis indicated that the ALT-2 consensus sequences formed three clades: the first consisting of B. malayi, the second consisting of W. bancrofti, and the third containing both O. volvulus and L. loa. ALT-2 selection was therefore not predictable by phylogeny or pathology, as the two species parasitizing the eye were selected differently, as were the two species parasitizing the lymphatic system. The most immunogenic regions of L. loa and W. bancrofti ALT-2 sequence as modeled by antigenicity prediction analysis did not correspond with elevated levels of diversifying selection, and were not selected differently than predicted antigenic epitopes in B. malayi and O. volvulus. Measurements of ALT-2 evolvability made by χ2 analysis between alleles that were stable (O. volvulus and B. malayi) and those that were under diversifying selection (W. bancrofti and L. loa) indicated significant (P<0

  18. Large-Scale Sequence Comparison.

    PubMed

    Lal, Devi; Verma, Mansi

    2017-01-01

    There are millions of sequences deposited in genomic databases, and it is an important task to categorize them according to their structural and functional roles. Sequence comparison is a prerequisite for proper categorization of both DNA and protein sequences, and helps in assigning a putative or hypothetical structure and function to a given sequence. There are various methods available for comparing sequences, alignment being first and foremost for sequences with a small number of base pairs as well as for large-scale genome comparison. Various tools are available for performing pairwise large sequence comparison. The best known tools either perform global alignment or generate local alignments between the two sequences. In this chapter we first provide basic information regarding sequence comparison. This is followed by the description of the PAM and BLOSUM matrices that form the basis of sequence comparison. We also give a practical overview of currently available methods such as BLAST and FASTA, followed by a description and overview of tools available for genome comparison including LAGAN, MumMER, BLASTZ, and AVID.

  19. Jupiter Stratospheric Haze Comparison

    NASA Technical Reports Server (NTRS)

    1996-01-01

    These two views of Jupiter obtained by the imaging system aboard the Galileo spacecraft show evidence of strikingly different stratospheric hazes between the polar regions and low or mid latitudes. The Great Red Spot shows in one mosaic, centered at about 20 degrees South latitude and taken on June 26, 1996 at a range of 1.46 million kilometers. The other mosaic is centered near 50 degrees North latitude, and was taken on November 4, 1996 at a range of 1.60 million kilometers.

    North is at the top in both images. In the Red Spot image, the edge of the planet (limb) runs in a single arc from lower left to upper right, with dark space at lower right. In the polar image, the limb runs in two segments across the top right corner, with dark space at top right. Both images are mosaics; the offset of the individual frames of the mosaic produces the jagged border and the break in the polar limb.

    These are false color images, constructed specifically to reveal cloud elevation differences. Three color channels are used. The red channel is an image taken at a near infrared wavelength where methane in Jupiter's atmosphere is strongly absorbing, and therefore gives no information about deep clouds but reveals high clouds. The green channel is a weaker methane band, and the blue channel is assigned to a wavelength where Jupiter's atmosphere is transparent. Thus red features indicate high hazes. A view near the edge of the planet accentuates the high hazes because of the slanting path of the line of sight.

    The pronounced reddening near the edge of the planet in polar regions indicates a high stratospheric haze. Comparison with the Great Red Spot shows that such a high haze is absent at that latitude. Detailed analysis shows that a stratospheric haze exists at both latitudes but is approximately 50 km higher near the poles. It is likely that the high polar haze is produced by magnetospheric particles, which travel along magnetic field lines and bombard the upper atmosphere

  20. Identification of Human Semiochemicals Attractive to the Major Vectors of Onchocerciasis

    PubMed Central

    Young, Ryan M.; Burkett-Cadena, Nathan D.; McGaha, Tommy W.; Rodriguez-Perez, Mario A.; Toé, Laurent D.; Adeleke, Monsuru A.; Sanfo, Moussa; Soungalo, Traore; Katholi, Charles R.; Noblet, Raymond; Fadamiro, Henry; Torres-Estrada, Jose L.; Salinas-Carmona, Mario C.; Baker, Bill; Unnasch, Thomas R.; Cupp, Eddie W.

    2015-01-01

    Background Entomological indicators are considered key metrics to document the interruption of transmission of Onchocerca volvulus, the etiological agent of human onchocerciasis. Human landing collection is the standard employed for collection of the vectors for this parasite. Recent studies reported the development of traps that have the potential for replacing humans for surveillance of O. volvulus in the vector population. However, the key chemical components of human odor that are attractive to vector black flies have not been identified. Methodology/Principal Findings Human sweat compounds were analyzed using GC-MS analysis and compounds common to three individuals identified. These common compounds, with others previously identified as attractive to other hematophagous arthropods were evaluated for their ability to stimulate and attract the major onchocerciasis vectors in Africa (Simulium damnosum sensu lato) and Latin America (Simulium ochraceum s. l.) using electroantennography and a Y tube binary choice assay. Medium chain length carboxylic acids and aldehydes were neurostimulatory for S. damnosum s.l. while S. ochraceum s.l. was stimulated by short chain aliphatic alcohols and aldehydes. Both species were attracted to ammonium bicarbonate and acetophenone. The compounds were shown to be attractive to the relevant vector species in field studies, when incorporated into a formulation that permitted a continuous release of the compound over time and used in concert with previously developed trap platforms. Conclusions/Significance The identification of compounds attractive to the major vectors of O. volvulus will permit the development of optimized traps. Such traps may replace the use of human vector collectors for monitoring the effectiveness of onchocerciasis elimination programs and could find use as a contributing component in an integrated vector control/drug program aimed at eliminating river blindness in Africa. PMID:25569240

  1. Long term impact of large scale community-directed delivery of doxycycline for the treatment of onchocerciasis.

    PubMed

    Tamarozzi, Francesca; Tendongfor, Nicholas; Enyong, Peter A; Esum, Mathias; Faragher, Brian; Wanji, Samuel; Taylor, Mark J

    2012-03-20

    Anti-Wolbachia treatment with doxycycline is effective in sterilising and killing adult Onchocerca volvulus nematodes, proving superior to ivermectin and of great potential as an alternative approach for the treatment and control of onchocerciasis, particularly in areas of Loa loa co-endemicity. Nevertheless, the length of the required treatment poses potential logistical problems and risk of poor compliance, raising a barrier to the use of doxycycline in Mass Drug Administration (MDA) strategies. In 2007 and 2008 a feasibility trial of community-directed treatment with doxycycline was carried out in two health districts in Cameroon, co-endemic for O. volvulus and L. loa. With 17,519 eligible subjects, the therapeutic coverage was 73.8% with 97.5% compliance, encouraging the feasibility of using doxycycline community-directed delivery in restricted populations of this size. The current study evaluated the effectiveness of this community-directed delivery of doxycycline four years after delivery. Infection with O. volvulus was evaluated by skin biopsy and nodule palpation. Of the 507 subjects recruited, 375 had completed the treatment with doxycycline followed by one or two rounds of annual ivermectin MDA and 132 received one or two rounds of annual ivermectin MDA alone. Statistically significant lower microfilarial prevalence (17.0% [doxycycline plus ivermectin group], 27.0% [ivermectin only group], p = 0.014) and load (p = 0.012) were found in people that had received doxycycline followed by ivermectin compared to those who received ivermectin only. This study demonstrates the long-term effectiveness of doxycycline treatment delivered with a community-directed strategy even when evaluated four years after delivery in an area of ongoing transmission. This finding shows that a multi-week course of treatment is not a barrier to community-delivery of MDA in restricted populations of this size and supports its implementation to compliment existing control strategies

  2. Frequent detection of worm movements in onchocercal nodules by ultrasonography

    PubMed Central

    Mand, Sabine; Marfo-Debrekyei, Yeboah; Debrah, Alex; Buettner, Marcelle; Batsa, Linda; Pfarr, Kenneth; Adjei, Ohene; Hoerauf, Achim

    2005-01-01

    Background Ultrasonography (USG) is known to be a suitable tool for diagnosis in lymphatic filariasis as the adult filarial nematode Wuchereria bancrofti in scrotal lymphatic vessels of infected men can be detected by the characteristic pattern of movement, the Filaria Dance Sign. In onchocerciasis, moving adult worms have not yet been demonstrated by USG. In addition the verification of drug effects on living adult Onchocerca volvulus filariae in trials is hampered by the lack of tools for longitudinal observation of alterations induced by potentially macrofilaricidal drugs in vivo. The present study was carried out to determine the frequency of detection of moving adult filariae of O. volvulus by USG. Methods In an endemic region for onchocerciasis in Ghana, 61 patients infected with onchocerciasis were recruited by palpation and onchocercomas examined by USG using an ultrasound system equipped with a 7.5 – 10 MHz linear transducer. Onchocercomas were recorded on videotape and evaluated with regard to location, number and size, as well as to movements of adult filariae. Results In the 61 patients 303 onchocercomas were found by palpation and 401 onchocercomas were detected by USG. In 18 out of 61 patients (29.5%), altogether 22 nodules with moving adult O. volvulus filariae were detected and are presented in animated ultrasound images as mp-4 videos. Conclusion Ultrasonographical examinations of onchocercomas where living adult filariae can be displayed may serve as a new tool for the longitudinal observation in vivo of patients with onchocerciasis undergoing treatment and as an adjunct to histological evaluation. PMID:15788103

  3. Long term impact of large scale community-directed delivery of doxycycline for the treatment of onchocerciasis

    PubMed Central

    2012-01-01

    Background Anti-Wolbachia treatment with doxycycline is effective in sterilising and killing adult Onchocerca volvulus nematodes, proving superior to ivermectin and of great potential as an alternative approach for the treatment and control of onchocerciasis, particularly in areas of Loa loa co-endemicity. Nevertheless, the length of the required treatment poses potential logistical problems and risk of poor compliance, raising a barrier to the use of doxycycline in Mass Drug Administration (MDA) strategies. In 2007 and 2008 a feasibility trial of community-directed treatment with doxycycline was carried out in two health districts in Cameroon, co-endemic for O. volvulus and L. loa. With 17,519 eligible subjects, the therapeutic coverage was 73.8% with 97.5% compliance, encouraging the feasibility of using doxycycline community-directed delivery in restricted populations of this size. The current study evaluated the effectiveness of this community-directed delivery of doxycycline four years after delivery. Findings Infection with O. volvulus was evaluated by skin biopsy and nodule palpation. Of the 507 subjects recruited, 375 had completed the treatment with doxycycline followed by one or two rounds of annual ivermectin MDA and 132 received one or two rounds of annual ivermectin MDA alone. Statistically significant lower microfilarial prevalence (17.0% [doxycycline plus ivermectin group], 27.0% [ivermectin only group], p = 0.014) and load (p = 0.012) were found in people that had received doxycycline followed by ivermectin compared to those who received ivermectin only. Conclusions This study demonstrates the long-term effectiveness of doxycycline treatment delivered with a community-directed strategy even when evaluated four years after delivery in an area of ongoing transmission. This finding shows that a multi-week course of treatment is not a barrier to community-delivery of MDA in restricted populations of this size and supports its implementation to

  4. 5) Review of the Biology and Ecology of Adult Blackflies in Relation to the Transmission of Onchocerciasis in Guatemala

    PubMed Central

    2015-01-01

    Recent studies on the biology and ecology of adult blackflies in relation to the transmission of human onchocerciasis in Guatemala are reviewed. First, earlier studies on the transmission of the disease since its discovery by Dr. R. Robles in 1915 are outlined. Second, eleven blackfly species caught on humans are evaluated for vector status on the basis of their natural and experimental infections with third-stage larvae of Onchocerca volvulus, and Simulium ochraceum,* S. metallicum* and S. callidum are confirmed as natural vectors of the disease in Guatemala in descending order of importance, whereas S. gonzalezi, S. haematopotum, S. veracruzanum and S. horacioi are potential vectors. Third, the migration and fate of O. volvulus microfilariae ingested by female blackflies are highlighted on the basis of the findings of the cibarial armature of S. ochraceum and physiological incompatibility of S. metallicum as main barriers against microfilariae, both of which greatly decrease the number of ingested O. volvulus microfilariae developing to the third-stage larvae per female. Fourth, among many ecological factors of female blackfly populations, geographical and altitudinal distributions, habits of blood feeding, host preferences for blood feeding, preference for human body parts, parous rates, daily and seasonal fluctuations of biting activities, in particular, of parous females, gonotrophic cycle, longevity, flight range, and annual transmission potential are reviewed, and their influences on the transmission dynamics of the disease agents are considered. Fifth, effects of air temperatures on the O. volvulus–S. ochraceum complex are examined, with a special reference to the characteristic altitudinal distributions of the disease. The importance of reliable identification of both the vector blackfly species and filarial larvae found in female blackflies is emphasized to understand the transmission of the disease. [*It is now known that these two species are actually

  5. Analysis of age-dependent trends in Ov16 IgG4 seroprevalence to onchocerciasis.

    PubMed

    Golden, Allison; Faulx, Dunia; Kalnoky, Michael; Stevens, Eric; Yokobe, Lindsay; Peck, Roger; Karabou, Potochoziou; Banla, Méba; Rao, Ramakrishna; Adade, Kangi; Gantin, Richard G; Komlan, Kossi; Soboslay, Peter T; de Los Santos, Tala; Domingo, Gonzalo J

    2016-06-13

    Diagnostics provide a means to measure progress toward disease elimination. Many countries in Africa are approaching elimination of onchocerciasis after successful implementation of mass drug administration programs as well as vector control. An understanding of how markers for infection such as skin snip microfilaria and Onchocerca volvulus-specific seroconversion perform in near-elimination settings informs how to best use these markers. All-age participants from 35 villages in Togo were surveyed in 2013 and 2014 for skin snip Onchocerca volvulus microfilaria and IgG4 antibody response by enzyme-linked immunosorbent assay (ELISA) to the Onchocerca volvulus-specific antigen Ov16. A Gaussian mixture model applying the expectation-maximization (EM) algorithm was used to determine seropositivity from Ov16 ELISA data. For a subset of participants (n = 434), polymerase chain reaction (PCR) was performed on the skin snips taken during surveillance. Within the 2,005 participants for which there was Ov16 ELISA data, O. volvulus microfilaremia prevalence and Ov16 seroprevalence were, 2.5 and 19.7 %, respectively, in the total population, and 1.6 and 3.6 % in children under 11. In the subset of 434 specimens for which ELISA, PCR, and microscopy data were generated, it was found that in children under 11 years of age, the anti-Ov16 IgG4 antibody response demonstrate a sensitivity and specificity of 80 and 97 %, respectively, against active infections as determined by combined PCR and microscopy on skin snips. Further analysis was performed in 34 of the 35 villages surveyed. These villages were stratified by all-age seroprevalence into three clusters: < 15 %; 15-20 %; and > 20 %. Age-dependence of seroprevalence for each cluster was best reflected by a two-phase force-of-infection (FOI) catalytic model. In all clusters, the lower of the two phases of FOI was associated with a younger age group, as reflected by the seroconversion rates for each phase. The age at

  6. Protein Structure Comparison and Classification

    NASA Astrophysics Data System (ADS)

    Çamoǧlu, Orhan; Singh, Ambuj K.

    The success of genome projects has generated an enormous amount of sequence data. In order to realize the full value of the data, we need to understand its functional role and its evolutionary origin. Sequence comparison methods are incredibly valuable for this task. However, for sequences falling in the twilight zone (usually between 20 and 35% sequence similarity), we need to resort to structural alignment and comparison for a meaningful analysis. Such a structural approach can be used for classification of proteins, isolation of structural motifs, and discovery of drug targets.

  7. NCSL National Measurement Interlaboratory Comparison Database requirements

    SciTech Connect

    WHEELER,JAMES C.; PETTIT,RICHARD B.

    2000-04-20

    With the recent development of an International Comparisons Database which provides worldwide access to measurement comparison data between National Measurement Institutes, there is currently renewed interest in developing a database of comparisons for calibration laboratories within a country. For many years, the National Conference of Standards Laboratories (NCSL), through the Measurement Comparison Programs Committee, has sponsored Interlaboratory Comparisons in a variety of measurement areas. This paper will discuss the need for such a National database which catalogues and maintains Interlaboratory Comparisons data. The paper will also discuss future requirements in this area.

  8. Educational Comparisons and the Educator.

    ERIC Educational Resources Information Center

    Simkin, Keith

    This paper examines how educational comparisons might be used by the educational practitioners, and how the educator can contribute to the comparativists' work. Currently, it is argued, a gap exists between comparative educational study and the theory and practice of education. This leads to three areas of need. First, professional comparativists…

  9. International Comparisons and Educational Reform.

    ERIC Educational Resources Information Center

    Purves, Alan C., Ed.

    Increasingly over the past decade there have appeared in the press bar graphs comparing the performance of U.S. students with their counterparts in other countries. Usually these graphs have been accompanied by dire warnings and pointing fingers. The main source of the data on international comparisons has been the International Association for…

  10. Comparison of fiber length analyzers

    Treesearch

    Don Guay; Nancy Ross Sutherland; Walter Rantanen; Nicole Malandri; Aimee Stephens; Kathleen Mattingly; Matt Schneider

    2005-01-01

    In recent years, several fiber new fiber length analyzers have been developed and brought to market. The new instruments provide faster measurements and the capability of both laboratory and on-line analysis. Do the various fiber analyzers provide the same length, coarseness, width, and fines measurements for a given fiber sample? This paper provides a comparison of...

  11. A comparison of five benchmarks

    NASA Technical Reports Server (NTRS)

    Huss, Janice E.; Pennline, James A.

    1987-01-01

    Five benchmark programs were obtained and run on the NASA Lewis CRAY X-MP/24. A comparison was made between the programs codes and between the methods for calculating performance figures. Several multitasking jobs were run to gain experience in how parallel performance is measured.

  12. Matrixed business support comparison study.

    SciTech Connect

    Parsons, Josh D.

    2004-11-01

    The Matrixed Business Support Comparison Study reviewed the current matrixed Chief Financial Officer (CFO) division staff models at Sandia National Laboratories. There were two primary drivers of this analysis: (1) the increasing number of financial staff matrixed to mission customers and (2) the desire to further understand the matrix process and the opportunities and challenges it creates.

  13. Inhibition in Dot Comparison Tasks

    ERIC Educational Resources Information Center

    Clayton, Sarah; Gilmore, Camilla

    2015-01-01

    Dot comparison tasks are commonly used to index an individual's Approximate Number System (ANS) acuity, but the cognitive processes involved in completing these tasks are poorly understood. Here, we investigated how factors including numerosity ratio, set size and visual cues influence task performance. Forty-four children aged 7-9 years completed…

  14. Inhibition in Dot Comparison Tasks

    ERIC Educational Resources Information Center

    Clayton, Sarah; Gilmore, Camilla

    2015-01-01

    Dot comparison tasks are commonly used to index an individual's Approximate Number System (ANS) acuity, but the cognitive processes involved in completing these tasks are poorly understood. Here, we investigated how factors including numerosity ratio, set size and visual cues influence task performance. Forty-four children aged 7-9 years completed…

  15. Metric-Free Distributional Comparisons.

    ERIC Educational Resources Information Center

    Haertel, Edward H.; And Others

    Two methods are presented for comparing distributions, such as achievement test score distributions, for distinctly different groups of persons in such a way that the comparison will not be influenced by the particular metric of the test being used. Both methods use percentile scores. One method, attributed to Flanagan, fits a straight line to the…

  16. Group membership and everyday social comparison experiences

    PubMed Central

    SMITH, HEATHER J.; LEACH, COLIN W.

    2006-01-01

    In two everyday experience studies, we examined the degree to which everyday social comparisons are framed by group membership. In the first study, 30 undergraduates attending a public university in the United States completed short questionnaires about their social comparison experiences whenever they were signalled. In the second study, 34 ethnic minority undergraduates from the same university completed similar questionnaires about their social comparison experiences. Across both studies, comparisons in which participants viewed themselves as an ingroup member in comparison to an outgroup comprised less than 10% of the comparison experiences reported by participants. However, minorities in the second study who reported closer identification with their ethnic group reported more comparison experiences in which they mentioned their own or the comparison target's ethnicity. PMID:16691290

  17. A comparison of high cycle fatigue methodologies

    NASA Technical Reports Server (NTRS)

    Herda, D. A.

    1992-01-01

    To evaluate alternate turbopump development (ATD) high cycle fatigue (HCF) methodology, a comparison was made with the space shuttle main engine (SSME) methodology. This report documents the comparison and evaluates ATD's HCF system.

  18. Performance Comparison: Superbeams, Beta Beams, Neutrino Factory

    SciTech Connect

    Winter, Walter

    2011-10-06

    In this talk, the performance comparison among superbeams (SB), beta beams (BB), and the Neutrino Factory (NF) is discussed. The ingredients to such a comparison are described, and the optimization and status of BB and NF are addressed. Finally, one example for the performance comparison is shown.

  19. Self-Construal and Social Comparison Effects

    ERIC Educational Resources Information Center

    Cheng, Rebecca Wing-yi; Lam, Shui-fong

    2007-01-01

    Background: Social comparison research usually demonstrates that students will have higher self-evaluation in downward comparison but lower self-evaluation in upward comparison. However, the existence of this contrast effect may depend on people's self-construal. The contrast effect may exist only for people with independent self-construal. For…

  20. High pressure rinsing system comparison

    SciTech Connect

    D. Sertore; M. Fusetti; P. Michelato; Carlo Pagani; Toshiyasu Higo; Jin-Seok Hong; K. Saito; G. Ciovati; T. Rothgeb

    2007-06-01

    High pressure rinsing (HPR) is a key process for the surface preparation of high field superconducting cavities. A portable apparatus for the water jet characterization, based on the transferred momentum between the water jet and a load cell, has been used in different laboratories. This apparatus allows to collected quantitative parameters that characterize the HPR water jet. In this paper, we present a quantitative comparison of the different water jet produced by various nozzles routinely used in different laboratories for the HPR process