Burgess, Ian F; Brown, Christine M; Lee, Peter N
Objective To evaluate the efficacy and safety of 4% dimeticone lotion for treatment of head louse infestation. Design Randomised controlled equivalence trial. Setting Community, with home visits. Participants 214 young people aged 4 to 18 years and 39 adults with active head louse infestation. Interventions Two applications seven days apart of either 4.0% dimeticone lotion, applied for eight hours or overnight, or 0.5% phenothrin liquid, applied for 12 hours or overnight. Outcome measures Cure of infestation (no evidence of head lice after second treatment) or reinfestation after cure. Results Cure or reinfestation after cure occurred in 89 of 127 (70%) participants treated with dimeticone and 94 of 125 (75%) treated with phenothrin (difference -5%, 95% confidence interval -16% to 6%). Per protocol analysis showed that 84 of 121 (69%) participants were cured with dimeticone and 90 of 116 (78%) were cured with phenothrin. Irritant reactions occurred significantly less with dimeticone (3/127, 2%) than with phenothrin (11/125, 9%; difference -6%, -12% to -1%). Per protocol this was 3 of 121 (3%) participants treated with dimeticone and 10 of 116 (9%) treated with phenothrin (difference -6%, -12% to -0.3%). Conclusion Dimeticone lotion cures head louse infestation. Dimeticone seems less irritant than existing treatments and has a physical action on lice that should not be affected by resistance to neurotoxic insecticides. PMID:15951310
Koch, Ellen; Clark, John Marshall; Cohen, Bernard; Meinking, Terri L; Ryan, William G; Stevenson, Audrey; Yetman, Robert; Yoon, Kyong Sup
Head lice are a source of scalp irritation, social disruption, and loss of school time. Health care providers need authoritative information to help avoid the costs and risks of ineffective treatment. A review was completed to provide relevant information on infestation treatments available in the United States. Three major biomedical databases were searched from 1985, when current products were first available, to 2014, focusing on U.S. A total of 579 references remained after duplicates were removed. A search of the U.S. Food and Drug Administration website and labels of approved products were reviewed. A marked decline in the effectiveness of permethrin and synergized pyrethrins was found, probably because of resistance arising from widespread and indiscriminate use, and the emergence of knockdown resistance mutations. The potential toxicity of lindane in the setting of readily available, safer, and more effective alternatives, should limit its use. Prescription products shown to be safe and effective with a single application, without nit combing, are topical ivermectin, malathion, and spinosad, whereas benzyl alcohol requires two applications. Home remedies such as mayonnaise, and essential oils, have not been demonstrated to be safe or effective, and may carry potential for severe adverse events. The high risk of failure of over-the-counter treatments in eliminating head louse infestations drives a need for health care provider recognition of the limitations of current treatments and for judicious use of treatments that remain effective. © 2016 Wiley Periodicals, Inc.
Hazan, Lydie; Berg, Jeffrey E; Bowman, James P; Murray, John V; Ryan, William G
The safety of a novel 0.5% ivermectin lotion (IVL) and potential for ivermectin absorption after application was investigated in an open-label study in young children, and a human repeat insult patch test (HRIPT) and cumulative irritation test (CIT) assessed any potential for cumulative dermal irritation and contact sensitization. In the pharmacokinetic and safety study, 30 head louse-infested children ages 6 months to 3 years received a 10-minute application of IVL on day 1. Blood was collected before application; 0.5, 1, and 6 hours after rinsing; and on days 2 and 8. Samples from 20 subjects were assayed for ivermectin (test sensitivity 0.05 ng/mL). Liver panel and complete blood counts were completed for all subjects. For the HRIPT/CIT, occlusive patches containing IVL or vehicle control lotion (CL) were repeatedly applied to 220 healthy adult subjects to assess contact sensitization; for cumulative dermal irritation testing, additional patches with normal saline and sodium dodecyl sulfate (SDS) were applied to 36 subjects. In the open-label study, all detected ivermectin plasma concentrations were <1 ng/mL. No safety signals emerged, and treatment was well tolerated. In the HRIPT/CIT, IVL was significantly less irritating than normal saline and SDS, with no evidence of dermal irritation or sensitization in human skin. IVL was safe when applied topically, absorption was de minimus, there was no evidence of irritation or sensitization from repeated exposures, and results support the safety of topical IVL use in children as young as 6 months. © 2012 Wiley Periodicals, Inc.
Background Tocopheryl acetate is viscous oily fluid used in a range of preparations for skin and scalp care in Italy. Observational and in vitro data have suggested a high level of efficacy against head louse infestation. The purpose of this investigation was to confirm the activity of tocopheryl acetate in a clinical setting in comparison with a standard widely used preparation. Methods A spray formulation containing tocopheryl acetate 20% in cyclomethicone was compared with permethrin 1% creme rinse for treatment of head louse infestation in a randomised, assessor blind, trial. Forty-five people were treated on two occasions 7 days apart. The spray was applied to dry hair for 20 minutes then washed. Participants treated with permethrin washed their hair and towel dried it before treatment for 10 minutes. Assessments were made by dry detection combing 1, 6, 9, and 14 days after first treatment. Results The tocopheryl acetate 20% spray was significantly (p = 0.033) more effective than permethrin 1%, using intention to treat worst case analysis, in which there were 13/23 (56.5%) successful treatments for tocopheryl acetate compared with 5/22 (22.7%) for permethrin. After unprecedented issues of re-infestation within households had been taken into account the underlying cure rate was 17/23 (73.9%) for tocopheryl acetate compared with 5/22 (22.7%), Odds Ratio 9.63 (95% CI, 2.46 to 37.68) (p < 0.001). Conclusions The tocopheryl acetate spray was significantly more effective than the permethrin product, was cosmetically acceptable, and not affected by current problems with resistance. Trial registration Current Controlled Trials ISRCTN45553737. PMID:24004959
Fan, P C; Chao, D; Lee, K M; Chan, C H; Liu, H Y
In order to evaluate the effectiveness of 1% gamma-BHC emulsion against head louse infestation, 1,527 school children were examined using observation by ocular and combing methods were used and infested children were treated with three regimes of 1% gamma-BHC emulsion. An overall infestation rate of 40% was found. The infestation rate was highest in Tung-Kuang Primary School (59%) and lowest in Chien-Hua Primary Schools (7%). The rate was highest among school children grade 2 (45%) and lowest in grade 3 (35%). The rate of girls (65%) was much higher than that of boys (9%). A total of 443 lice were collected from 78 infested school girls: 56 males, 59 females, and 328 nymph. The average number of head lice in each infested girl was 5.7. Follow-up examination was conducted one week after treatment. The cure rates for dosages of 10.0 ml, 5.0 ml, and 2.5 ml 1% gamma-BHC emulsion were 96%, 88%, 68% for girls and 100%, 92%, and 33% for boys, respectively. Only mild and transient itching and burn sensation of scalp were reported by a few children. The overall infestation rate 5 months (April-September 1981) after treatment was 23% (286/1,245). The rate of girls decreased from 65% to 40% and that of boys from 9% to 3%. Results of the present study indicates that 1% gamma-BHC emulsion is an effective pediculicide at a dosage of 5 ml or 10 ml. However, the overall infestation rate remained high (23%) 5 months after treatment. These findings suggest that treatment of head louse infestation must be conducted continuously.
Elston, D M
Head lice remain a common problem worldwide. As resistance to available therapeutic agents can emerge rapidly, there is a need for continued research to find new and better agents. Until better agents are available, clinicians may find that rotational therapy, using different agents, may help to slow the emergence of resistance. Physical modalities, such as mechanical nit and louse removal and occlusive agents to asphyxiate the lice, should not be ignored, especially in light of our limited therapeutic armamentarium. All therapeutic agents are doomed to failure if infestation is allowed to recur. Classmates, playmates, and family members of infested children should be inspected for head lice. Efforts should be directed at fomite control and nit removal. Louse infestation must be addressed as a community-wide problem. Body lice remain important vectors of disease. War, natural disaster, and poverty favor the spread of body lice. As we work to solve these seemingly eternal problems, we must develop better agents to treat infestation and prevent the spread of body lice.
Burgess, Ian F.; Lee, Peter N.; Kay, Katrina; Jones, Ruth; Brunton, Elizabeth R.
Background Interest in developing physically active pediculicides has identified new active substances. The objective was to evaluate a new treatment for clinical efficacy. Methods and Findings We describe the selection of 1,2-octanediol as a potential pediculicide. Clinical studies were community based. The main outcome measure was no live lice, after two treatments, with follow up visits over 14 days. Study 1 was a proof of concept with 18/20 (90%) participants cured. Study 2 was a multicentre, parallel, randomised, observer-blind study (520 participants) that compared 0.5% malathion liquid with 1,2-octanediol lotion (20% alcohol) applied 2–2.5 hours or 8 hours/overnight. 1,2-octanediol lotion was significantly (p<0.0005) more effective with success for 124/175 (70.9%) RR = 1.50 (97.5% CI, 1.22 to 1.85) for 2–2.5 hours, and 153/174 (87.9%) RR = 1.86 (97.5% CI, 1.54 to 2.26) for 8 hours/overnight compared with 81/171 (47.4%) for malathion. Study 3, a two centre, parallel, randomised, observer-blind study (121 participants), compared 1,2-octanediol lotion, 2–2.5 hours with 1,2-octanediol alcohol free mousse applied for 2–2.5 hours or 8 hours/overnight. The mousse applied for 8 hours/overnight cured 31/40 (77.5%), compared with 24/40 (60.0%) for lotion (RR = 1.29, 95% CI, 0.95 to 1.75; NNT = 5.7) but mousse applied for 2–2.5 hours 17/41 (41.5%) was less effective than lotion (RR = 0.69, 95% CI, 0.44 to 1.08). Adverse events were more common using 1,2-octanediol lotion at both 2–2.5 hours (12.0%, p = 0.001) and 8 hours/overnight (14.9%, p<0.0005), compared with 0.5% malathion (2.3%). Similar reactions were more frequent (p<0.045) using lotion compared with mousse. Conclusions 1,2-octanediol was found to eliminate head louse infestation. It is believed to disrupt the insect's cuticular lipid, resulting in dehydration. The alcohol free mousse is more acceptable exhibiting significantly fewer adverse reactions. Trial registrations
Burgess, Ian F; Brunton, Elizabeth R; Burgess, Nazma A
Permethrin is the most widely used pediculicide, but evidence of resistance from several countries and anecdotal reports from Germany suggest that permethrin lotion is now less effective. We designed a randomized, controlled, parallel group trial involving 100 participants with active head louse infestation to investigate the activity of a coconut and anise spray and to see whether permethrin lotion is still effective, using two applications of product 9 days apart. The spray was significantly more successful (41/50, 82.0%) cures compared with permethrin (21/50, 42.0%; p < 0.0001, difference 40.0%, 95% confidence interval of 22.5% to 57.5%). Per-protocol success was 83.3% and 44.7%, respectively. Thirty-three people reported irritant reactions following alcohol contact with excoriated skin. We concluded that, although permethrin lotion is still effective for some people, the coconut and anise spray can be a significantly more effective alternative treatment.
Ward, M P; Armstrong, R T
Information provided by wool growers in Queensland, Australia between 1995 and 1997 was used to assess the prevalence and spatial distribution of louse (Bovicola ovis) infestation in sheep flocks. The estimated prevalence of louse-infested flocks was 40% (95% confidence interval, 35-46%). Although the prevalence of infestation was higher in western regions (41-50%) compared to the south region of Queensland (31%), the difference was not statistically significant (P > 0.05). Significant (P = 0.02) clustering of infested flocks was detected in the south region where two foci were apparent. We conclude that Queensland sheep flocks have a moderate prevalence of louse infestation, and that clustering of infestation is not strong. The control of lice is an industry-wide issue that needs to be addressed by most wool growers in Queensland.
Dehghani, R; Limoee, M; Ahaki, A R
The sucking lice including the head, body and pubic louse infest humans and so they are of high hygienic importance. Pubic lice are transmitted during sexual contact in adults. Thus, infestation of children with pubis louse is very rare. A case of infestation with pubic louse (Pthirus pubis) in a family in Kashan was seen. On examination of family members, the parasites were collected and observed under the light microscope. Infestation of eyelashes with P. pubis lice was confirmed. Since this parasite can be observed on the skin, infestation with this louse has always been one of the concerns of human communities. Pthiriasis has frequently been reported in many parts of the world; however, there are few reports on this infestation in Iran, especially familial infestation with this louse. Hence, this article could be the first report on the familial infestation with P. pubis in Iran and it can be suggested that infestation with pubic lice occurs in sporadic form in all over the country.
When children return to school after the summer holiday, cases of head lice appear to increase. Ian Burgess describes the life cycle of the head louse and dispels some of the myths about transmission of this insect. A second article discusses the detection and treatment of head lice.
Brown, Christine M.; Burgess, Nazma A.; Kaufman, Judith
Background. Many families find regular checking of children’s heads for head louse infestation too onerous and would prefer to be able to prevent infestation by use of a topical application that deters lice from infesting the head. Identification in the laboratory of a repellent activity for piperonal provided the basis for developing a spray product to repel lice. Methods. A proof of principle field study in Dhaka, Bangladesh, compared the effect of using 2% piperonal spray with that of a placebo in 105 children and adults from three communities with infestation levels close to 100%. All participants were treated for infestation and subsequent incidence of reinfestation monitored daily by investigators. A second randomised, controlled, double blind, study in North London, UK, evaluated the effect of the product in normal use. One hundred and sixty-three children from schools with a high level (20–25%) of infestation were treated and confirmed louse free and randomly divided between 2% piperonal, a placebo spray, and a control group for up to 22 weeks. Parents applied the spray and monitored for infestation. Regular investigator visits confirmed the parental monitoring and replenished supplies of spray. Results. In Dhaka, over 18 days there were only 4 infestations in the piperonal group and 8 in the placebo group. This difference was not significant (p = 0.312). In North London, there were 41 cases of infestation over the course of the study. Although there were fewer infestations in the piperonal group, analysis of time to first infestation showed a no significant (p = 0.4368) difference between groups. Conclusion. Routine use of 2% piperonal spray in communities with a high prevalence of head louse infestation may provide some protection from infestation. However, the difference between use of the product and no active intervention was sufficiently small that regular checking for presence of lice is likely to be a more practical and cost effective approach
Mumcuoglu, Kosta Y
Of the pediculicides on the market, most are not 100% ovicidal and don't have a residual activity of more than 2 days. Therefore, at least 2 treatments are necessary to control the entire louse population. In order for a pediculicide to be effective it should kill all active stages of the louse after a single treatment. Otherwise remaining lice will continue laying eggs and the following treatments will not be fully effective, at least against the eggs. However, there is no general consensus as to when the second treatment should be conducted. Taking into consideration that head louse eggs hatch between 5 to 11 days, it is suggested that a second treatment should be administered 10 days after the beginning of the treatment. This might also explain why most of the clinical trials that were conducted by treating the patients twice with an interval of 6, 7, or 8 days showed a poor efficacy, and clinical trials where the pediculicide was applied with an interval of 10 days showed an efficacy level of more than 90%.
Li, Wenjun; Ortiz, Gabriel; Fournier, Pierre-Edouard; Gimenez, Gregory; Reed, David L; Pittendrigh, Barry; Raoult, Didier
Genetic analyses of human lice have shown that the current taxonomic classification of head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus) does not reflect their phylogenetic organization. Three phylotypes of head lice A, B and C exist but body lice have been observed only in phylotype A. Head and body lice have different behaviours and only the latter have been involved in outbreaks of infectious diseases including epidemic typhus, trench fever and louse borne recurrent fever. Recent studies suggest that body lice arose several times from head louse populations. By introducing a new genotyping technique, sequencing variable intergenic spacers which were selected from louse genomic sequence, we were able to evaluate the genotypic distribution of 207 human lice. Sequence variation of two intergenic spacers, S2 and S5, discriminated the 207 lice into 148 genotypes and sequence variation of another two intergenic spacers, PM1 and PM2, discriminated 174 lice into 77 genotypes. Concatenation of the four intergenic spacers discriminated a panel of 97 lice into 96 genotypes. These intergenic spacer sequence types were relatively specific geographically, and enabled us to identify two clusters in France, one cluster in Central Africa (where a large body louse outbreak has been observed) and one cluster in Russia. Interestingly, head and body lice were not genetically differentiated. We propose a hypothesis for the emergence of body lice, and suggest that humans with both low hygiene and head louse infestations provide an opportunity for head louse variants, able to ingest a larger blood meal (a required characteristic of body lice), to colonize clothing. If this hypothesis is ultimately supported, it would help to explain why poor human hygiene often coincides with outbreaks of body lice. Additionally, if head lice act as a reservoir for body lice, and that any social degradation in human populations may allow the formation of new populations of
Burgess, Ian F.; Brown, Christine M.; Nair, Pat
In this investigation of effectiveness of an alternative pediculicide dosage form, we recruited 228 children and 50 adult participants from Bedfordshire, UK, to a randomised, controlled, assessor blind trial comparing two insecticide products with mechanical removal of lice as a control group. Participants using insecticide were treated with either the investigative 0.5% phenothrin mousse, for 30 minutes, or 0.2% phenothrin lotion, for 2 hours as the reference product. Both treatments were applied only once, followed by shampoo washing. Those treated by wet-combing with conditioner were combed 4 times over 12 days. Parents/carers carried out the treatments to mimic normal consumer use. The outcome measure was the absence of lice, 14 days after treatment for the insecticides, and up to 14 days after completion of combing. Intention to treat analysis of the outcomes for 275 participants showed success for phenothrin mousse in 21/105 (20.0%), in 23/107 (21.5%) for phenothrin lotion, and in 12/63 (19.1%) for wet-combing. People receiving mousse were 1.07 (95% CI, 0.63 to 1.81) times more likely to still have lice after treatment compared with those treated with lotion. The group of participants who received the wet combing treatment were 1.13 (95% CI, 0.61 to 2.11) times more likely to still have lice after the treatment. None of the treatments was significantly (p < 0.05) more effective than any other. This study was carried out in an area where moderate resistance to phenothrin was demonstrated after the study by using a bioassay. Analysis of post treatment assessments found that failure of insecticides to kill louse eggs had influenced the outcome. PMID:25254106
Li, Wenjun; Ortiz, Gabriel; Fournier, Pierre-Edouard; Gimenez, Gregory; Reed, David L.; Pittendrigh, Barry; Raoult, Didier
Background Genetic analyses of human lice have shown that the current taxonomic classification of head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus) does not reflect their phylogenetic organization. Three phylotypes of head lice A, B and C exist but body lice have been observed only in phylotype A. Head and body lice have different behaviours and only the latter have been involved in outbreaks of infectious diseases including epidemic typhus, trench fever and louse borne recurrent fever. Recent studies suggest that body lice arose several times from head louse populations. Methods and Findings By introducing a new genotyping technique, sequencing variable intergenic spacers which were selected from louse genomic sequence, we were able to evaluate the genotypic distribution of 207 human lice. Sequence variation of two intergenic spacers, S2 and S5, discriminated the 207 lice into 148 genotypes and sequence variation of another two intergenic spacers, PM1 and PM2, discriminated 174 lice into 77 genotypes. Concatenation of the four intergenic spacers discriminated a panel of 97 lice into 96 genotypes. These intergenic spacer sequence types were relatively specific geographically, and enabled us to identify two clusters in France, one cluster in Central Africa (where a large body louse outbreak has been observed) and one cluster in Russia. Interestingly, head and body lice were not genetically differentiated. Conclusions We propose a hypothesis for the emergence of body lice, and suggest that humans with both low hygiene and head louse infestations provide an opportunity for head louse variants, able to ingest a larger blood meal (a required characteristic of body lice), to colonize clothing. If this hypothesis is ultimately supported, it would help to explain why poor human hygiene often coincides with outbreaks of body lice. Additionally, if head lice act as a reservoir for body lice, and that any social degradation in human populations
Veneziano, Vincenzo; Galietti, Alfredo; Mariani, Ugo; Di Loria, Antonio; Piantedosi, Diego; Neola, Benedetto; Guccione, Jacopo; Gokbulut, Cengiz
A trial was conducted to assess the efficacy of eprinomectin (EPR) against the sucking louse Haematopinus asini on naturally infested donkeys. Parasitological investigations were performed on fifteen animals. On day 0, donkeys received EPR pour-on at the manufacturer's recommended cattle dose. Louse counts were performed on days -1, 7, 14, 21, 28, 35, 42, 49 and 56 at seven predilection sites on the skin of each donkey. EPR was completely effective (100%) from day 7, until the end of the study. Clinically no adverse reactions were observed in any of donkeys treated. EPR was considered to be 100% effective against H. asini. This is the first trial to evaluate the efficacy of EPR against a natural louse infestation in donkeys.
Burgess, I F
Eggs of the head louse, Pediculus capitis De Geer (Phthiraptera: Pediculidae), are difficult to remove because the female louse fixes them to hairs using a proteinaceous secretion that hardens within seconds. The persistent eggshells are harmless but unsightly and are often mistaken for an active infestation. Combing with a fine comb (nit comb) does not readily remove the eggs or empty eggshells because of the resilience of the fixative and both folk remedies and medical products have claimed to facilitate their removal. Measurement of the force required to initiate sliding of the egg fixative using a slip-peel tester was unable to detect evidence that any of three products which claimed to have egg-loosening properties (Step 2 Nit Removal System, Clear Lice Egg Remover, RID Lice Egg Loosener Gel) had any activity or exerted any effect on the egg fixative beyond the lubricating effects conveyed by water or conventional hair conditioner.
Bush, Sarah E; Rock, Alex N; Jones, Sherri L; Malenke, Jael R; Clayton, Dale H
Human head lice (Pediculus humanus capitis De Geer) occur worldwide and infest millions of children and adults every year. Head lice infestations, which are known as pediculosis capitis, are psychologically stressful, physically irritating, and are one of the leading causes of K-6 school absence. The prevalence of head lice in many countries is increasing rapidly because of resistance to chemicals used in many head lice treatments. We tested the efficacy of an alternative method for controlling head lice, the LouseBuster, a custom-built medical device designed to kill head lice and their eggs using controlled, heated air. A total of 56 infested subjects was treated with the LouseBuster, and the efficacy of the treatment was evaluated by comparing the viability of lice and eggs on randomly assigned pre- and posttreatment sides of each subject's scalp. We evaluate treatment efficacy in the hands of novice versus experienced operators. We also evaluate treatment efficacy on different hair types and at different ambient humidities. Overall mortality of lice and eggs was 94.8% after treatment by experienced operators. Novice operators also achieved good results after a short training session; their results did not differ significantly from those of experienced operators. No adverse events were associated with the LouseBuster treatment. The LouseBuster is efficacious for killing head lice and their eggs. The use of heated air is appealing because it is a fast, safe, nonchemical treatment. Head lice are also unlikely to evolve resistance to desiccation, which is the apparent mode of action.
Agarwal, G P; Ahmad, Aftab; Rashmi, Archna; Arya, Gaurav; Bansal, Nayanci; Saxena, A K
Abstract The population characteristics of the louse, Upupicola upupae (Shrank) (Mallophaga: Philopteridae: Ishnocera), infesting the Common Hoopae, Upupa epops L. (Aves: Upupiformes), were recorded during 2007-08 in District Rampur, Uttar Pradesh India. The pattern of frequency distribution of the louse conformed to the negative binomial model. The lice and its nits were reared in vitro at 35 ± 1° C, 75-82 % RH, on a feather diet. The data obtained was used to construct the life table and to determine the intrinsic rate of natural increase (0.035 female/day), the net reproductive rate was 3.67 female eggs/female, the generation time was 37 days, and the doubling time of the population was 19 days. The chaetotaxy of the three nymphal instars has also been noted to record their diagnostic characteristics. Information on egg morphology and antennal sensilla is also presented.
Agarwal, G. P; Ahmad, Aftab; Rashmi, Archna; Arya, Gaurav; Bansal, Nayanci; Saxena, A.K.
The population characteristics of the louse, Upupicola upupae (Shrank) (Mallophaga: Philopteridae: Ishnocera), infesting the Common Hoopae, Upupa epops L. (Aves: Upupiformes), were recorded during 2007–08 in District Rampur, Uttar Pradesh India. The pattern of frequency distribution of the louse conformed to the negative binomial model. The lice and its nits were reared in vitro at 35 ± 1° C, 75–82 % RH, on a feather diet. The data obtained was used to construct the life table and to determine the intrinsic rate of natural increase (0.035 female/day), the net reproductive rate was 3.67 female eggs/female, the generation time was 37 days, and the doubling time of the population was 19 days. The chaetotaxy of the three nymphal instars has also been noted to record their diagnostic characteristics. Information on egg morphology and antennal sensilla is also presented. PMID:21861650
Ortega-Insaurralde, Isabel; Ceferino Toloza, Ariel; Gonzalez-Audino, Paola; Inés Picollo, María
Relevant evidence has shown that parasites process host-related information using chemical, visual, tactile, or auditory cues. However, the cues that are involved in the host-parasite interaction between Pediculus humanus capitis (De Geer 1767) and humans have not been identified yet. In this work, we studied the effect of human scalp components on the behavior of adult head lice. Filter paper segments were rubbed on volunteers' scalps and then placed in the experimental arena, where adult head lice were individually tested. The movement of the insects was recorded for each arena using the software EthoVision. Average movement parameters were calculated for the treatments in the bioassays such as total distance, velocity, number of times a head louse crossed between zones of the arena, and time in each zone of the arena. We found that scalp components induced head lice to decrease average locomotor activity and to remain arrested on the treated paper. The effect of the ageing of human scalp samples in the response of head lice was not statistically significant (i.e., human scalp samples of 4, 18, 40, and 60 h of ageing did not elicit a significant change in head louse behavior). When we analyzed the effect of the sex in the response of head lice to human scalp samples, males demonstrated significant differences. Our results showed for the first time the effect of host components conditioning head lice behavior. We discuss the role of these components in the dynamic of head lice infestation. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Sunantaraporn, Sakone; Sanprasert, Vivornpun; Pengsakul, Theerakamol; Phumee, Atchara; Boonserm, Rungfar; Tawatsin, Apiwat; Thavara, Usavadee; Siriyasatien, Padet
Head louse infestation, which is caused by Pediculus humanus capitis, occurs throughout the world. With the advent of molecular techniques, head lice have been classified into three clades. Recent reports have demonstrated that pathogenic organisms could be found in head lice. Head lice and their pathogenic bacteria in Thailand have never been investigated. In this study, we determined the genetic diversity of head lice collected from various areas of Thailand and demonstrated the presence of Acinetobacter spp. in head lice. Total DNA was extracted from 275 head louse samples that were collected from several geographic regions of Thailand. PCR was used to amplify the head louse COI gene and for detection of Bartonella spp. and Acinetobacter spp. The amplified PCR amplicons were cloned and sequenced. The DNA sequences were analyzed via the neighbor-joining method using Kimura's 2-parameter model. The phylogenetic tree based on the COI gene revealed that head lice in Thailand are clearly classified into two clades (A and C). Bartonella spp. was not detected in all the samples, whereas Acinetobacter spp. was detected in 10 samples (3.62%), which consisted of A. baumannii (1.45%), A. radioresistens (1.45%), and A. schindleri (0.72%). The relationship of Acinetobacter spp. and the head lice clades showed that Acinetobacter spp. was found in clade A and C. Head lice in Thailand are classified into clade A and B based on the COI gene sequences. Pathogenic Acinetobacter spp. was detected in both clades. The data obtained from the study might assist in the development of effective strategies for head lice control in the future. Detection of pathogenic bacteria in head lice could raise awareness of head lice as a source of nosocomial bacterial infections.
Takano-Lee, Miwa; Edman, John D; Mullens, Bradley A; Clark, John M
As the frequency and level of pediculicide resistance increases throughout the world, the need for novel solutions to control pediculosis has intensified. The development and registration of new pesticides has become so costly that many chemical companies are unwilling to pursue it and health-care providers now face a serious lack of new commercial pediculicides. Many infested people resort to using "home-remedy" approaches that have not been scientifically tested. In this article, we examined the potential value of six purportedly effective "home remedies" (vinegar, isopropyl alcohol, olive oil, mayonnaise, melted butter, and petroleum jelly) to treat head louse infestations and the likelihood of drowning lice by water submersion. Results indicated that only the application of petroleum jelly caused significant louse mortality but no treatment prevented lice from laying eggs. Most home remedy products did little to kill eggs, despite prolonged exposure. Petroleum jelly caused the greatest egg mortality, allowing only 6% to hatch. It was extremely difficult to drown lice, despite extended periods (i.e., 8 hr) of water submersion, suggesting that killing lice by depriving them of oxygen is inefficient. None of the home remedy products we surveyed was an effective means of louse control. This suggests that when treatment failure occurs, an increased amount of time and effort should be focused on alternative chemical pediculicides and/or manual louse removal (i.e., combing) rather than using any of these products.
Leo, N P; Hughes, J M; Yang, X; Poudel, S K S; Brogdon, W G; Barker, S C
Little is known about the population genetics of the louse infestations of humans. We used microsatellite DNA to study 11 double infestations, that is, hosts infested with head lice and body lice simultaneously. We tested for population structure on a host, and for population structure among seven hosts that shared sleeping quarters. We also sought evidence of migration among louse populations. Our results showed that: (i) the head and body lice on these individual hosts were two genetically distinct populations; (ii) each host had their own populations of head and body lice that were genetically distinct to those on other hosts; and (iii) lice had migrated from head to head, and from body to body, but not between heads and bodies. Our results indicate that head and body lice are separate species.
Rózsa, Lajos; Apari, Péter
Head lice transmit to new hosts when people lean their heads together. Humans frequently touch their heads to express friendship or love, while this behaviour is absent in apes. We hypothesize that this behaviour was adaptive because it enabled people to acquire head lice infestations as early as possible to provoke an immune response effective against both head lice and body lice throughout the subsequent periods of their life. This cross-immunity could provide some defence against the body-louse-borne lethal diseases like epidemic typhus, trench fever, relapsing fever and the classical plague. Thus the human 'touching heads' behaviour probably acts as an inherent and unconscious 'vaccination' against body lice to reduce the threat exposed by the pathogens they may transmit. Recently, the eradication of body-louse-borne diseases rendered the transmission of head lice a maladaptive, though still widespread, behaviour in developed societies.
Perotti, M Alejandra; Catalá, Silvia S; Ormeño, Analía del V; Żelazowska, Monika; Biliński, Szczepan M; Braig, Henk R
Background At the turn of the 19th century the first observations of a female-biased sex ratio in broods and populations of the head louse, Pediculus humanus capitis, had been reported. A study by Buxton in 1940 on the sex ratio of lice on prisoners in Ceylon is still today the subject of reanalyses. This sex ratio distortion had been detected in ten different countries. In the last sixty years no new data have been collected, especially on scalp infestations under economically and socially more developed conditions. Results Here we report a female bias of head lice in a survey of 480 school children in Argentina. This bias is independent of the intensity of the pediculosis, which makes local mate competition highly unlikely as the source of the aberrant sex ratio; however, other possible adaptive mechanisms cannot be discounted. These lice as well as lice from pupils in Britain were carrying several strains of the endosymbiotic bacterium Wolbachia pipientis, one of the most wide spread intracellular sex ratio distorters. Similar Wolbachia strains are also present in the pig louse, Haematopinus suis, suggesting that this endosymbiont might have a marked influence on the biology of the whole order. The presence of a related obligate nutritional bacterium in lice prevents the investigation of a causal link between sex ratio and endosymbionts. Conclusions Regardless of its origin, this sex ratio distortion in head lice that has been reported world wide, is stable over time and is a remarkable deviation from the stability of frequency-dependent selection of Fisher's sex ratio. A female bias first reported in 1898 is still present over a hundred years and a thousand generations later. PMID:15140268
Lowden, Stewart; Gray, Stephen; Dawson, Kim
The horse biting louse (Werneckiella equi) is a common global equine ectoparasite. To our knowledge, benzoyl(phenyl)urea insecticides (triflumuron, diflubenzuron) commonly used as sheep lousicides, have not been evaluated for efficacy against W. equi. The aim of this study was to determine louse control efficacy, general wellness and dermal safety following triflumuron application as a backline pour-on to horses. Two efficacy trials using 25 adult naturally infested lousy horses, and a dermal safety trial using 10 adult louse-free horses were conducted over a 14-month period. Lousy animals were selected by assessment of their lice status prior to treatment. For the efficacy trial, the triflumuron product was applied at a dose of 2.5mg triflumuron per kg bodyweight (1 mL product per 10 kg bodyweight). For the safety study, triflumuron was applied at a 3x clinical dose of 7.5 mg triflumuron per kg bodyweight (3 mL product per 10 kg bodyweight). In our first efficacy trial, 100% lousicidal efficacy was achieved by day 44 post-treatment. In our second trial, no lice were identified on horses by day 71 post-treatment. In the safety trial, no adverse effects were seen. Results of this study demonstrate that the off-label, experimental pour-on application of triflumuron at 2.5 mg/kg bodyweight is convenient, highly effective and safe (at 3x the clinical dose) for the treatment of the horse biting louse, W. equi.
Boev, B V; Barabash, V K; Tarasevich, I V
Methods of mathematical modelling and prediction of louse propagation processes in the natural habitation medium are presented. Theoretical and experimental data on head louse ecology served the basis for the elaboration of a mathematical model predicting the population dynamics. The model structure corresponds to 3 stages of louse development cycle (eggs, larva, lice) and parameters corresponding to natural characteristics of louse propagation process: mean lifespan of each individual during each phase of the cycle, age, fertility and so forth. The model helped to study some properties of the population, assess maximum rate of head louse population growth, detect threshold effects, establish the effects of coefficients, limiting the number of louse per unit of the body surface. The model made it possible to formulate necessary data (distribution functions) for the creation of the mathematical model of Pediculosis.
Yoon, Kyong Sup; Previte, Domenic J.; Hodgdon, Hilliary E.; Poole, Bryan C.; Kwon, Deok Ho; El-Ghar, Gamal E. Abo; Lee, Si Hyeock; Clark, J. Marshall
The study examines the extent and frequency of a knockdown-type resistance allele (kdr type) in North American populations of human head lice. Lice were collected from 32 locations in Canada and the United States. DNA was extracted from individual lice and used to determine their zygosity using the serial invasive signal amplification technique to detect the kdr-type T917I (TI) mutation, which is most responsible for nerve insensitivity that results in the kdr phenotype and permethrin resistance. Previously sampled sites were resampled to determine if the frequency of the TI mutation was changing. The TI frequency was also reevaluated using a quantitative sequencing method on pooled DNA samples from selected sites to validate this population genotyping method. Genotyping substantiated that TI occurs at high levels in North American lice (88.4%). Overall, the TI frequency in U.S. lice was 84.4% from 1999 to 2009, increased to 99.6% from 2007 to 2009, and was 97.1% in Canadian lice in 2008. Genotyping results using the serial invasive signal amplification reaction (99.54%) and quantitative sequencing (99.45%) techniques were highly correlated. Thus, the frequencies of TI in North American head louse populations were found to be uniformly high, which may be due to the high selection pressure from the intensive and widespread use of the pyrethrins- or pyrethroid-based pediculicides over many years, and is likely a main cause of increased pediculosis and failure of pyrethrins- or permethrin-based products in Canada and the United States. Alternative approaches to treatment of head lice infestations are critically needed. PMID:24724296
Müller, G H
Cosmus Conrad Cuno, a less well known optician and inventor of microscopes from the second half of the 17th century, published in 1734 at Augsburg his Observationes durch dessen verfertigte Microscopia where along with various observations he communicated salient details pertaining to the biology of the head louse.
Abdel-Ghaffar, Fathy; Al-Quraishy, Saleh; Sobhy, Hassan; Semmler, Margit
In the present study, the efficacy of water-free neem seed extract shampoo Wash Away Louse, provided by Alpha-Biocare GmbH, Düsseldorf (Germany), was investigated against Sarcoptes scabiei infesting dogs in Egypt. Ten naturally infested dogs were collected from different areas in the Nile delta. The occurrence of lesions, hair loss, and skin inflammation were regarded as signs of infestation and proved by detection of adult parasites and their developmental stages in scrapings of infested lesions. Adequate amount of the provided shampoo was applied topically and spread on the infested areas daily for 14 successive days. Scraping examinations were used to follow up the healing process. At day 7 of application, four dogs were completely free of mites as was proven by the disappearance of adults and/or any developmental stages of mites. The remaining six dogs showed a clear decrease in mite counts. By the end of the treatment (after 14 days), only a small number of mites were found in two dogs, while eight dogs were completely cured as was proven by mite counts and disappearance of clinical signs. No remarkable signs of side effects or adverse reactions were observed throughout the study.
The prevalence of infestation with the head louse, Pediculus capitis, was assessed among the child population, from birth to 10 years old inclusive, of the rapidly expanding Saudi Arabian city of Jeddah. Over a period of two months, 300 consecutive children attending the general practitioner for any reason were examined specifically to identify those infested with head lice: 37 cases of active infestation were found, which is an overall prevalence of 12%. An interesting distribution, however, was noted in respect of age, ranging from less than 2% in the first year of life, rising rapidly to around 30% in ages six to eight years, thereafter declining steadily to about 16% by age 10 years. The distribution of infestation among males and females was broadly similar. These results show a high head lice infestation, particularly in the early school years, where presumably interpersonal contacts are most frequent, facilitating contagious spread. As the head lice is known to spread several viral and rickettsial diseases, such as relapsing fever and typhus, greater efforts should be made towards patient education in hygiene, and towards identifying and treating the disease when found.
Volcsik, R; Preuss, P; Knaus, B
670 children of infant-schools and 109 children of schools were examined for head-lice. Also the existence of nits was valued. The identified infestation of 9.9% is to stimulate examinations in other districts of GDR and measures to form the search and the control of these ectoparasites with more effects.
Sosnina, E F; Davydov, G S
2213 lice of Neohaematopinus palaearctcus Ols. were collected from 152 of 865 examined specimens of Marmota caudata Geoffr. from different vertical zones of Tadjikistan. The long-tailed marmot is characterized by a moderate or poor infestation with lice. In the subalpine zone, where the number and density of these animals in rather high, the infestation rate is greater than that in the brushwood zone. In spring after hibernation the infestation of M. caudata is very low. Within the reporoduction period the infestation with lice increases, the latter begin to reproduce intensively. During the preparation for hibernation the infestation rate falls due to a less intensive reproduction of lice. There are no distinct differences in the infestation rate of long-tailed marmots belonging to different age groups since there are constant contacts between the individuals of the colony. Only reproducing females live together with brood by themselves, differ in moulting periods and in a greater intensity of invasion during reproduction.
Pfeffer, A; Morris, C A; Green, R S; Wheeler, M; Shu, D; Bisset, S A; Vlassoff, A
The inheritance of resistance to louse infestation and the related allergic skin disease, cockle, was examined in Romney lambs. The lambs used in the study were the 2001- and 2004-born progeny of four experimental breeding lines ("Resistant", "Susceptible", "Resilient" and "Control") developed as part of a long-term study of the genetics of host resistance (maintenance of low faecal egg count (FEC) under nematode challenge) or resilience (maintenance of health and productivity under nematode challenge irrespective of FEC) to nematode parasites in sheep. Between 13 and 22 progeny (equally distributed between males and females, where possible) from each of five sires in each line were selected each year for this trial. All lambs (n=701) were examined for lice (Bovicola ovis) before artificial infestation; in 2001 the lambs were free of natural infestation, whilst in 2004 naturally acquired infestation was evident. In November 2001 and May 2002, approximately 60 B. ovis were transferred to each lamb, followed by monitoring at approximately 2-monthly intervals until August 2002. Similar procedures, but with fewer monitoring times, were repeated on the 2004 lambs. Overall, lambs in the Control line were significantly more susceptible to louse infestation and cockle compared with those in the other three lines (P<0.001). Least squares-means (SEM) of log-transformed louse score for the control, resistant, susceptible and resilient lines, respectively, were 2.178 (0.045), 1.499 (0.050), 1.618 (0.050) and 1.587 (0.044), and for cockle score were 1.36 (0.05), 0.76 (0.05), 0.95 (0.05) and 0.78 (0.05). From all progeny together, the heritability of log-transformed louse score was 0.22 (Standard Error (SE) 0.06) in autumn and 0.34 (SE 0.08) in winter, with a value of 0.44 (SE 0.09) when these data were combined. These estimates were similar to those obtained for resistance to gastro-intestinal nematodes in these breeding lines, using log-transformed FECs. Heritability estimates
Shayeghi, M; Paksa, A; Salim abadi, Y; Sanei dehkoordi, A; Ahmadi, A; Eshaghi, M; Bazrafkan, S
Background: Pediculus capitis (Anoplura: Pediculidae) or head louse is an obligate ectoparasite transmitted mainly through physical contact. This study was conducted to survey the prevalence of head lice infestation rate and some risk factors in Primary School pupils, in Khajeh City East Azerbaijan Province, Iran Methods: We selected 20 primary schools of Khajeh City during 2008 and 2009. Totally 500 pupils including 200 boys and 300 girls from all grade 1–5 were selected by multistage, systematic random sampling in rural areas of Khajeh City and were examined for lice. In addition, a standard questionnaire recorded information about demographic features of each pupil. Results were analyzed by SPSS software. Results: The total prevalence of head lice infestation in this study was 4.8%. and the prevalence rate was significantly higher in girls (6.66%) than in boys (2%). Epidemiological factors such as: sex, school grade, family size, parent's education, type of house, hair washing (per week), number of using comb per day, were evaluated and results showed significant difference in head lice infestation and sex, school grade, family size, father education, and type of house (P< 0.05). Conclusion: Pediculosis is a public health problem in many parts of the world, and due to the higher prevalence of pediculosis in crowded families, family by lower levels of father's education and socioeconomic status in our study and rural area, it is necessary to give health education for families to prevent of pediculosis in this area. PMID:22808387
Hodgdon, Hilliary E.; Yoon, Kyong Sup; Previte, Domenic J.; Kim, Hyo Jeong; Aboelghar, Gamal E.; Lee, Si Hyeock; Clark, J. Marshall
BACKGROUND Pediculosis is the most prevalent parasitic infestation of humans. Resistance to pyrethrin- and pyrethroid-based pediculicides is due to knockdown (kdr)-type point mutations in the voltage-sensitive sodium channel α-subunit gene. Early detection of resistance is crucial for the selection of effective management strategies. RESULTS Kdr allele frequencies of lice from 14 countries were determined using serial invasive signal amplification reaction. Lice collected from Uruguay, UK and Australia had kdr allele frequencies of 100% while lice from Ecuador, Papua New Guinea, South Korea and Thailand had kdr allele frequencies of 0%. The remaining 7 countries investigated, including seven US populations, two Argentina, Brazil, Denmark, Czech Republic, Egypt and Israel, displayed variable kdr allele frequencies, ranging from 11% to 97%. CONCLUSION The newly developed and validated SISAR method is suitable for accurate monitoring of kdr allele frequencies in head lice. Proactive management is needed where kdr-type resistance is not yet saturated. Based on sodium channel insensitivity and its occurrence in louse populations resistant to pyrethrin- and pyrethroid-based pediculicides, the T917I mutation appears a key marker for resistance. Results from the Egyptian population, however, indicate that phenotypic resistance of lice with single or double mutations (M815I and/or L920F) should also be determined. PMID:20564731
Ascunce, Marina S; Fane, Jackie; Kassu, Gebreyes; Toloza, Ariel C; Picollo, Maria I; González-Oliver, Angélica; Reed, David L
Anthropological studies suggest that the genetic makeup of human populations in the Americas is the result of diverse processes including the initial colonization of the continent by the first people plus post-1492 European migrations. Because of the recent nature of some of these events, understanding the geographical origin of American human diversity is challenging. However, human parasites have faster evolutionary rates and larger population sizes allowing them to maintain greater levels of genetic diversity than their hosts. Thus, we can use human parasites to provide insights into some aspects of human evolution that may be unclear from direct evidence. In this study, we analyzed mitochondrial DNA (mtDNA) sequences from 450 head lice in the Americas. Haplotypes clustered into two well-supported haplogroups, known as A and B. Haplogroup frequencies differ significantly among North, Central and South America. Within each haplogroup, we found evidence of demographic expansions around 16,000 and 20,000 years ago, which correspond broadly with those estimated for Native Americans. The parallel timing of demographic expansions of human lice and Native Americans plus the contrasting pattern between the distribution of haplogroups A and B through the Americas suggests that human lice can provide additional evidence about the human colonization of the New World. Copyright © 2013 Wiley Periodicals, Inc.
Cole, Sabrina W; Lundquist, Lisa M
To review the pharmacology, pharmacokinetics, clinical trials, and safety profile of spinosad 0.9% topical lotion, a recently approved pediculicide for treatment of head lice infestation. English-language articles indexed in MEDLINE (1948-May 2011), Toxline, Google Scholar, International Pharmaceutical Abstracts (1970-May 2011), and Cumulative Index to Nursing and Allied Health Literature (1981-May 2011) were identified, using the search terms spinosad, head lice, and pediculosis capitis. Available English-language articles were reviewed. In the studies that were reviewed, the percentage of patients who were lice free 14 days after the last treatment was significantly higher in the spinosad groups compared to the permethrin groups (84.6% vs 44.9% and 86.7% vs 42.9%, respectively; p < 0.001 for both studies). Additionally, the proportion of all primary and nonprimary participants determined to be lice free following only 1 treatment with the study medication was higher among patients in the spinosad groups compared with those in the permethrin groups. Application-site erythema was observed in patients in both treatment groups; however, it was more common in patients in the permethrin groups compared with those receiving spinosad (6.8% vs 3.1%, respectively; p = 0.007). No serious adverse effects were reported by patients receiving spinosad. Adherence was higher in the spinosad groups compared with the permethrin groups, although adherence overall was high in both studies. These data suggest that spinosad is a safe and effective treatment for the eradication of head lice, and the ease of administration and improved adherence with spinosad could offer an advantage over currently available treatment options. Because of its established efficacy, favorable safety profile, and ease of application, spinosad can be considered a convenient and effective treatment for head lice in patients aged 4 years and older.
Sharma, Divyesh; Kaliaperumal, Chandrasekaran; Choudhari, Kishor A
Head lice or pediculosis is recognized as an increasing problem in medical practice (Down et al, 1999). Secondary bacterial infections can occur in patients with infestation. In neurosurgical patients, head lice infestation may be a potential risk factor for peri-operative complications. Secondary infection could further complicate neurosurgical wounds with subsequent complications. The authors discuss epidemiology, pathogenesis of potential peri-operative complications resulting from pediculosis and methodology of treatment of this common condition. The importance of early recognition and prompt treatment in patients with neurological diseases is highlighted. A simple algorithm to treat scalp pediculosis is suggested.
Suleman, M; Jabeen, N
The prevalence of head lice infestation was estimated among the general population of four urban localities in the North West Frontier Province of Pakistan during 1986. Altogether 1002 persons (656 females, 346 males) were screened by visual inspection and combing of the head. The overall infestation rate was 36.7%, with females showing a higher prevalence (41.5%) than males (27.7%). The prevalence did not differ significantly with locality, and exhibited only a slight seasonal variation. Pediculosis was high in the five to 19 year old age-group, beyond which it decreased, gradually in females and abruptly in males. Higher rate of infestation in females could be attributed to their long hair. A significant negative association between pediculosis and dandruff was noticed in males but not in females. Crowding and low level of education, which reflect poor socio-economic status, apparently contributed to higher rate of infestation. Prevalence was directly related to the number of children per family, suggesting that school children perhaps play an important role in the distribution of lice. Intensity of infestation, like prevalence, was higher in females than males, and decreased with age in both sexes.
Doulgeraki, Artemis; Valari, Manthoula
Pediculosis capitis constitutes a growing problem worldwide and is usually considered as an inconvenience. Parents often handle this infestation on their own initiative. We conducted a survey in order to depict the parental attitudes towards head lice infestation in Greece. Parents of children aged 3-14 years, attending a dermatology outpatient clinic at a children's hospital, were given a questionnaire regarding head lice. Demographic data, management, and prevention strategies were included in the questionnaire. Three-hundred and seventy-two complete questionnaires were analyzed (response rate: 89%). Pediculosis capitis was more prevalent in the age groups 3-5 years and 6-8 years. The percentage of parents of infested children who sought advice on treatment from the pharmacist was 73%, and only 15% consulted their doctor. Chemical agents to treat head lice were used by 59% of them, products containing natural oils by 38%, and wet combing in parallel was employed by 79% of them. Preventive measures were employed by 66% of the respondents, and 54% applied botanical and synthetic products commercially available for this purpose. There is a trend towards the use of natural oils for either prevention or treatment. More needs to be done to promote public education and rational use of either pediculicides or non-pharmacological agents for pediculosis capitis infestation. © 2011 The International Society of Dermatology.
Villegas, S C
Head lice infestations continue to be an issue in today's society, with an increase in economic cost and resistance. Spinosad 0.9% topical suspension was recently introduced in the U.S. market as a novel agent with both pediculicidal and ovicidal activity, approved in children 4 years of age and older for the treatment of head lice infestations. In clinical trials, it has demonstrated effectiveness against head lice with permethrin resistance. In two clinical trials comparing spinosad to permethrin, efficacy was observed in the spinosad-treated groups at 84.6% and 86.7%, respectively, when compared to the permethrin-treated groups (respective values of 44.9% and 42.9%; P < 0.001). Overall, spinosad was well tolerated in clinical trials.
Birkemoe, Tone; Lindstedt, Heidi Heggen; Ottesen, Preben; Soleng, Arnulf; Næss, Øyvind; Rukke, Bjørn Arne
Background. Health providers need to know which measures to take and children to prioritize in order to decrease costs associated with head lice infestations. Objective. Our aim was to determine the most important predictors for head lice and identify the major drivers of an infestation outbreak in a low-prevalence area. Methods. The study was based on three datasets of head lice prevalence (retrospective, point prevalence and prospective approach) from primary school children (ages 6–12) at 12 schools in Oslo, Norway. The tested predictors were siblings with lice, individual and household characteristics as well as class and school affiliation. Self-reported monthly incidences (prospective approach) of head lice were used to evaluate infestation dynamics. Results. Infested siblings strongly increased the odds of head lice infestation of school children (odds ratio 36, 26 and 7 in the three datasets) whereas having short hair halved the odds. Household characteristics were of minor importance, and class affiliation proved more important than school affiliation. Having head lice in one school term increased the odds of an infestation in the next, but this effect diminished over time. About 97% of all self-reported infestations were noted in two consecutive months or less. Conclusions. With the exception of hair length, we have found that individual and household characteristics are of minor importance to predict head lice infestations in a low-prevalence country and that unnoticed transmissions in school classes and families are likely to be the major driver upon outbreaks. PMID:26511728
Bachok, Norsa'adah; Nordin, Rusli Bin; Awang, Che Wil; Ibrahim, Noor Aini; Naing, Lin
Head lice infestation contributes a significant morbidity among schoolchildren in Malaysia. A cross-sectional study was designed to determine the prevalence and associated factors of head lice infestation among primary schoolchildren in Kelantan, Malaysia. Six schools were randomly selected from three sub-districts of Kuala Krai, Kelantan. A total of 463 eleven-year-old pupils were screened by visual scalp examination and fine-toothed combing. Self-administered questionnaire was used to collect data on socio-demography and associated factors of head lice infestation. The prevalence of head lice infestation was 35.0% (95% Cl: 30.6, 39.3) with 11.9% inactive, 23.1% active, 18.2% light and 16.8% heavy infestations. The associated factors were girls; family income of RM247 or less; head lice infestation of family member and having four or more siblings. The high prevalence of head lice infestation in this study indicates the need for regular school health program that emphasis on the eradication of head lice. The significant associated factors identified in this study reconfirm the importance of controlling the transmissibility of head lice. Pupils and parents should be informed regarding factors that may facilitate the transmission of head lice.
Rassami, Watcharawit; Soonwera, Mayura
Head lice infestation, a worldwide head infestation caused Pediculus humanus capitis De Geer, is an important public health problem in Thailand. Several chemical pediculicides have lost in efficacy due to increasing resistance of lice against insecticide. Therefore, non-toxic alternative products, such as natural products from plants, e.g. plant extract pediculicides, are needed for head lice control. The aims of this study were to evaluate the potential of pediculicidal activity of herbal shampoo base on three species of Thai local plants (Accacia concinna (Willd.) DC, Averrhoa bilimbi Linn. and Tamarindus indica Linn.) against head lice and to compare them with carbaryl shampoo (Hafif shampoo®; 0.6% w/v carbaryl) and non-treatment control in order to assess their in vitro. Doses of 0.12 and 0.25 ml/cm2 of each herbal shampoo were applied to filter paper, and ten head lice were place on the filter paper. The mortalities of head lice on the filter paper were recorded at 1, 5, 10, 30 and 60 min by sterio-microscope. All herbal shampoos at 0.25 ml/cm2 were more effective pediculicide than carbaryl shampoo with 100% mortality at 5 min. The median lethal time (LT50) of all herbal shampoos at 0.25 ml/cm2 showed no significant differences over at 0.12 ml/cm2 (P<0.01). The most effective pediculicide was T. indica extract shampoo, followed by Av. bilimbi extract shampoo and Ac. concinna extract shampoo, with LT50 values<1.0 min. Our data showed that all herbal shampoos have high potential of pediculicide to head lice treatments for schoolchildren.
Strycharz, Joseph P; Lao, Alice R; Alves, Anna-Maria; Clark, J Marshall
Using the in vitro rearing system in conjunction with the hair tuft bioassay, NYDA and NYDA without fragrances formulations (92% wt:wt dimeticones) were 100% ovicidal (0% of treated eggs hatched) after an 8-h exposure of the eggs of the human head louse (Pediculus humanus capitis De Geer) following the manufacturer's instructions. Comparatively, 78 and 66% of eggs similarly exposed hatched after distilled deionized water or Nix (1% permethrin) treatments, respectively. NYDA and NYDA without fragrances formulations were also statistically and substantially more ovicidal than either distilled deionized water or Nix treatments after 10, 30 min, and 1 h exposures. Only the 10 min exposure of eggs to NYDA and NYDA without fragrances formulations resulted in hatched lice that survived to adulthood (5-8% survival). Of the lice that hatched from eggs exposed to NYDA formulations for 10 min, there were no significant differences in the time it took them to become adults, female fecundity or the viability of eggs laid by surviving females. The longevity of adults, however, was reduced after the 10 min treatments of eggs with NYDA and NYDA without fragrances formulations compared with either the distilled deionized water or Nix treatments.
Bauer, Eline; Jahnke, Claudia; Feldmeier, Hermann
Pediculosis capitis is one of the most frequent infectious diseases in childhood. If not diagnosed and treated rapidly, considerable clinical pathology may develop. The ubiquitous parasitic skin disease is characterized by a lack of sound epidemiological data, and factors which influence disease occurrence are still enigmatic. To investigate whether, in Germany, head lice infestation follows a seasonal pattern, we analyzed the weekly head lice consultations at the Health Department of Braunschweig City, Lower Saxony, for a period of 5 years, and compared the data with the units of pediculocides sold by two wholesalers to German pharmacies during a period of 2 and 3 years, respectively. The number of consultations did not show a clear seasonality, although there was a tendency of fewer consultations during school holidays, and an increase when schools opened again after Christmas, Easter, summer, and autumn holidays. In contrast, the number of packages of pediculocides sold followed a distinct seasonal rhythm with a maximum between calendar week 34 and 40, i.e., from mid September to end of October. In Germany, occurrence of pediculosis capitis varies according to the season of the year with a maximum in late summer and early autumn.
Karakuş, Mehmet; Arıcı, Aylin; Töz, Seray Özensoy; Özbel, Yusuf
The well-known and common infestation caused by Pediculus humanus capitis is an important public health and a social issue in many communities in the world. The aim of this study was to compare the head louse infestation rate in two schools having pupils from different socio-economic levels in the city center of Izmir. The pupils aged between 6 and 11 years, were screened for the presence of eggs and nymph/adult lice using a fine-tooth head louse comb. A total of 88 and 126 pupils from the schools with low and medium socio-economic level were screened and 24 (27.2%) and 5 (3.96%) of them were found to be positive for head lice, respectively. Overall, the infestation rate among girls was 3.14 times higher than in boys. Head louse infestation is a significant public health problem among primary schools. Increasing the knowledge about pediculosis and self-hygiene would be helpful in successfully reducing head louse infestation in the school setting. School authorities must encourage the parents to look for head lice routinely and a "school nurse" system is needed for effective head louse control in the schools.
Robinson, D; Leo, N; Prociv, P; Barker, S C
Since the pioneering work of Charles Nicolle in 1909 [see Gross (1996) Proc Natl Acad Sci USA 93:10539-10540] most medical officers and scientists have assumed that body lice are the sole vectors of Rickettsia prowazekii, the aetiological agent of louse-borne epidemic typhus (LBET). Here we review the evidence for the axiom that head lice are not involved in epidemics of LBET. Laboratory experiments demonstrate the ability of head lice to transmit R. prowazekii, but evidence for this in the field has not been reported. However, the assumption that head lice do not transmit R. prowazekii has meant that head lice have not been examined for R. prowazekii during epidemics of LBET. The strong association between obvious (high) infestations of body lice and LBET has contributed to this perception, but this association does not preclude head lice as vectors of R. prowazekii. Indeed, where the prevalence and intensity of body louse infections may be high (e.g. during epidemics of LBET), the prevalence and intensity of head louse infestations is generally high as well. This review of the epidemiology of head louse and body louse infestations, and of LBET, indicates that head lice are potential vectors of R. prowazekii in the field. Simple observations in the field would reveal whether or not head lice are natural vectors of this major human pathogen.
Munirathinam, Arumugam; Sunish, Ittoop Pulikkottil; Rajendran, Rathinasamy; Tyagi, Brij Kishore
Antifilarial drug combinations including ivermectin provide antifilarial activity with ancillary benefits on intestinal helminths and ectoparasites, such as chiggers and lice. The impact of single oral dose of antifilarial drugs, viz; (1) diethylcarbamazine (DEC) alone, (ii) DEC + albendazole (ALB), (iii) ivermectin (IVR) + DEC and (iv) IVR + ALB, was determined, on the head louse (Pediculus humanus capitis) in primary school children in a rural community in south India. Primary school children (n = 534) of age 6-10 years from four villages of South India were examined for the presence of head lice before and after single dose of DEC + ivermectin drug combination. The effectiveness and the duration of cure sustained by these drugs were quantified. The head louse was examined by "combing method" during post-treatment periods at 15, 45, 60 and 75 days interval. The antifilarial drug consumption rate was similar (96-98%) in all treatment arms. In pre-treatment survey the prevalence of head lice in children administered with DEC, DEC + ALB, IVR + DEC and IVR + ALB arm was 86%, 80%, 87% and 80%, respectively, with the latter two arms demonstrating significant reduction in louse infestation (P < 0.05) for 60 days. Single dose with IVR combination demonstrates a greater impact in reducing head louse infestation in the endemic rural communities for nearly 60 days. Therefore, in regions such as Africa where ivermectin is part of the antifilariasis campaign, this drug will have an additional benefit in reducing head lice infestation.
Kurt, Özgür; Balcıoğlu, I Cüneyt; Limoncu, M Emin; Girginkardeşler, Nogay; Arserim, Süha K; Görgün, Serhan; Oyur, Tuba; Karakuş, Mehmet; Düzyol, Didem; Gökmen, Aysegül Aksoy; Kitapçıoğlu, Gül; Özbel, Yusuf
Head lice infestation (HLI) caused by Pediculus humanus capitis has been a public health problem worldwide. Specially designed combs are used to identify head lice, while anti-lice products are applied on the scalp for treatment. In the present study, we aimed to test whether combing only by precision detection comb (PDC) or metal pin comb (MPC) could be effective alternatives to the use of anti-lice products in children. A total of 560 children from two rural schools in Turkey were screened. In the PDC trial, children were combed every second day for 14 days, while in the MPC trial, combing was performed once in every four days for 15 days. Children were divided into two groups (dry combing and wet combing) for both trials and results were compared. The results showed no significant differences between dry and wet combing strategies for both combs for the removal of head lice (p > 0.05). The number of adult head lice declined significantly on each subsequent combing day in both approaches, except on day 15 in the MPC trial. In the end, no louse was found in 54.1 and 48.9% of children in the PDC and MPC trials, respectively. Since family members of infested children were not available, they were not checked for HLI. Four times combing within 2 weeks with MPC combs was found effective for both treatment of low HLI and prevention of heavy HLI. In conclusion, regular combing by special combs decreases HLI level in children and is safely applicable as long-term treatment.
Magenwirth, Jessica; Nemeth, Nicole M; Yabsley, Michael J; Munk, Brandon A; Keel, M Kevin; Brown, Justin D
A recently described North American mite, Harpirhynchus quasimodo (Acariformes: Harpirhynchidae), was identified in a wild brown-headed cowbird (Molothrus ater) from Tennessee and another from Arkansas, U. S. A., during 2010 and 2011, respectively. Consistent with a single previous report of H. quasimodo infestation, both cowbirds had multiple skin masses composed of epidermal cysts filled with harpirhynchid mites, keratin, and cellular debris. Although very little is currently known about this avian mite, these three reports suggest that H. quasimodo infestation is a rare source of overt disease in free-ranging brown-headed cowbirds from the southeastern United States; however, further research and surveillance efforts are needed.
Bosely, Hanan Aboalkasem; El-Alfy, Nadia M
The prevalence and human risk factors associated with head lice infestation was studied. A total of 860 children, 474 (55.1%) boys and 386 (44.9%) girls, with ages ranged from 6-13 years were critically examined. They were randomly selected from two schoolchildren (one for boys and one for girls) in Jazan Province. The children or their parents were subjected to questionnaire and physical examination by visual inspections of scalp and hair for the presence of adult lice, nymphs, and/or eggs (nits). A total of 114 children (13.3%) were infested with head lice, 73 (18.9%) girls and 41 (8.6%) boys. The highest infestation rate was recorded in rural area (20.5%). Pediculosis had a negative association with father's education level and frequency of hair washing (p > 0.01). The results indicated that rural residence, sex, long hair, age- group 6- < 8 years old, positive history of previous infestation, sharing of beds and combs, uneducated mother and family overcrowding might be the risk factors for the head lice infestation.
Arriaza, Bernardo; Orellana, Nancy C; Barbosa, Helene S; Menna-Barreto, Rubem F S; Araújo, Adauto; Standen, Vivien
Pediculus humanus capitis is an ancient human parasite, probably inherited from pre-hominid times. Infestation appears as a recurrent health problem throughout history, including in pre-Columbian populations. Here, we describe and discuss the occurrence of pre-Columbian pediculosis in the Andean region of the Atacama Desert. Using a light microscope and scanning electron microscopy, we studied a highly infested Maitas Chiribaya mummy from Arica in northern Chile dating to 670-990 calibrated years A.D. The scalp and hair of the mummy were almost completely covered by nits and adult head lice. Low- and high-vacuum scanning electron microscopy revealed a well-preserved morphology of the eggs. In addition, the excellent preservation of the nearly 1,000-yr-old adult head lice allowed us to observe and characterize the head, antennae, thorax, abdomen, and legs. Leg segmentation, abdominal spiracles, and sexual dimorphism also were clearly observed. The preservation of the ectoparasites allowed us to examine the micromorphology using scanning electron microscopy; the opercula, aeropyles, and spiracles were clearly visible. This case study provides strong evidence that head lice were a common nuisance for Andean farmers and herders. Head lice are transmitted by direct head-to-head contact; thus, this ancient farmer and herder was potentially infesting other people. The present study contributes to the body of research focusing on lice in ancient populations.
Mohammed, A L Bashtawy
Little is known about the effect of socioeconomic status on the infestation by head lice in schoolchildren in Jordan. A cross-sectional school-based study was conducted from December 2009 to February 2010. A list of all primary schools in Mafraq governorate was obtained (394 primary schools). Eight primary schools were randomly selected (four male schools and four female schools). Data were collected by five well-trained nurses. Hair was examined for head lice as well as for eggs/nits. Analysis of data was conducted by using SPSS software version 16. The chi-square test was used to assess statistical significance of subgroup differences in the prevalence of infestation, and multivariate logistic regression was used to control for potential confounding. Out of 1550 primary schoolchildren screened, 412 (26.6%) were infected with lice, 163 (19.6%) boys and 249 (34.7%) girls. The results showed significant variations in head lice infestation by factors such as gender, age, and socioeconomic variables (family income, father's education, mother's education, number of rooms, number of siblings younger than 15 years, frequency of hair washing per week, and bathing per week). There was no significant variation in lice infestation with parents' occupation (P > 0.05). Socioeconomic status is a major factor influencing the occurrence of pediculosis capitis among schoolchildren in both sexes. Improving standards of living and personal hygiene might significantly reduce pediculosis capitis in schoolchildren in Jordan. © 2012 The International Society of Dermatology.
Tebruegge, Marc; Pantazidou, Anastasia; Curtis, Nigel
Head lice infestation (pediculosis capitis) is a common problem in paediatric practice. It can cause considerable distress to children and their families and may lead to bullying and social stigmatisation. Therapy with "conventional" topical pediculicides with neurotoxic mode of action-such as malathion, permethrin, phenothrin and carbaryl-is increasingly associated with treatment failure as a result of the emergence of resistance within the parasite population. This review provides an overview of the natural history, clinical symptoms and diagnosis of head lice infestation. It also discusses general management principles and summarises the current data on novel treatment strategies, including wet combing, dimeticone, isopropyl myristate, benzyl alcohol, plant-based compounds and oral medication.
Doroodgar, Abbas; Sadr, Fakhraddin; Doroodgar, Masoud; Doroodgar, Moein; Sayyah, Mansour
Objective To determine the prevalence rate of head louse infestation among elementary students, and examine the associated factors with infection in the city of Aran and Bidgol. Methods A total of 19 boys' and girls' primary schools were selected by multistage, systematic random sampling. Overall, 3 590 students were examined for head lice infestation in urban areas of Aran and Bidgol during 2008. The diagnosis was based on live louse or nit on the scalp of students. The students were screened by standard questionnaire and demographic data in addition to related information were obtained by interview and observation. The data were analyzed by SPSS software using chi-square and Fisher's exact tests. Results The mean age of students was (8.68±1.58) years ranging between 6-12 years. The total prevalence of head louse infestation was 0.47%. This rate was 0.42% and 0.05% in female and male, respectively. There was a significant association between pediculosis and sex, father's job, mother's education, access to bathroom in home, prior infection, drug use and nationality, respectively (P<0.05). Conclusions The results showed that pediculosis was not a major health priority among primary school in city of Aran and Bidgol. However, enhancing the knowledge of students about head lice infestation and the existence of health teachers in schools can play a significant role in disease control.
Mumcuoglu, K Y
Head louse infestations (pediculosis) are prevalent worldwide. In developed countries, the infestation rate of 4- to 13-year-old children remains high despite preventive efforts. This is due to the existence of numerous ineffective pediculicides, the incorrect use of the effective agents, toxicological concerns and the development of louse strains resistant to insecticides. One of the most effective tools for the prevention and control of lice is the louse comb, which should be used regularly for the detection of living lice at an early stage of infestation, and as an accessory to any treatment method to remove living and dead lice. The louse comb can also be used systematically for the treatment of infestations, for confirmation that treatment with pediculicides has been successful, and for the removal of nits (dead eggs or egg shells). Most pediculicides are only partially ovicidal. Therefore, 10 days after beginning treatment with any antilouse product, the scalp of the child should be examined. If no living lice are found, the treatment should be discontinued. If living lice are still present, treatment should be continued with a product containing a different active ingredient. Suffocating agents such as olive, soya, sunflower and corn oils, hair gels and mayonnaise are able to kill a significant number of lice only if they are applied in liberal quantities for more than 12 hours. However, they lubricate the hair and therefore may facilitate combing and removing lice and eggs from the scalp. Nits may remain glued on the hair for at least 6 months, even after a successful treatment, and lead to a false positive diagnosis of louse infestation. If nits are seen on the hair, the child should be examined, but treatment should be initiated only if living lice are found. Formulations containing 5% acetic acid or 8% formic acid, as well as acid shampoos (pH 4.5 to 5.5) and conditioners, in combination with a louse comb, can be helpful for removing nits. There is no
Militão de Sousa, F; Vasconcelos, A W; de Nadon, J; Duhot, P-Y
To evaluate the efficiency and safety of a new galenic meta-emulsion for the treatment of human head lice (Pediculus capitis) in a single application. A controlled clinical study was conducted comparing lice infestation and nit hatching observed before and after a treatment in a single application. Eighty-two of the 87 children included completed the study. An infestation control was performed on 36 and 46 children, 8 and 24 h respectively after application. Five days later, a meticulous hair examination was carried out to check that the lice infestation was completely cured. After a single application of the lotion being tested, an examination of the scalp with a head lice detection comb, as well as an examination of the rinsing water and the towel used for drying after washing, showed that out of the total 1285 lice, there were no live lice. The percentage of nits hatching before treatment was close to 70%. In comparison, after an 8-h treatment (t(+8)), the percentage of nits hatching was 2.1%, with only 0.35% of living nymphs. After a 24-h treatment (t(+24)), 1.9% hatched with 0.38% living nymphs. Nymphs were revealed to be non-viable. After 5 days (t(+120)), no living adult or immature lice were found on the subjects tested. Moreover, observation of tolerance levels to this treatment at days 1, 5 and 12 showed no side effects. The specific galenic lotion completely cured head lice infestation in the population studied in a single application. The lotion, a patented meta-emulsion, has a mechanical action that asphyxiates lice and nits. Considering the advantages of the single application, the possibility of complete concomitant therapeutics for a whole school population within only 1 day and the high level of tolerance to this treatment, this approach seems simple and promising.
Dzul-Cauich, José F.; Hernández-Ortiz, Vicente; Parra-Tabla, Victor; Rico-Gray, Victor
Seasonal dynamics of the capitula infested by Dictyotrypeta sp. and Rhynencina spilogaster (Steyskal) (Diptera: Tephritidae) was evaluated throughout the flowering cycle of their host plant the sunflower, Smallanthus maculatus (Cavanilles) Robinson (Asterales: Asteraceae). In central Veracruz, Mexico, along 16 consecutive weeks, a total of 1,017 mature capitula were collected, recording the presence and abundance of immature stages (larvae and pupae) and their related parasitoids. Both fly species were present throughout the entire season, with overall infestation of 51.5% of the capitula examined. However, Dictyotrypeta sp. infested 11.3%, representing about one-fifth of them, and R. spilogaster was most abundant infesting four times as many capitula (42.9%), whereas both species were found together in only 2.6% of the capitula examined. Based on the temporal occurrence of larvae and pupae into flower heads as well as their associated parasitoids and times of emergence, Dictyotrypeta sp. had two yearly generations, and it seems that the second generation could enter a seasonal diapause; in contrast, R. spilogaster was a univoltine species that entered diapause that lasted until the next year. PMID:25368091
Dzul-Cauich, José F; Hernández-Ortiz, Vicente; Parra-Tabla, Victor; Rico-Gray, Victor
Seasonal dynamics of the capitula infested by Dictyotrypeta sp. and Rhynencina spilogaster (Steyskal) (Diptera: Tephritidae) was evaluated throughout the flowering cycle of their host plant the sunflower, Smallanthus maculatus (Cavanilles) Robinson (Asterales: Asteraceae). In central Veracruz, Mexico, along 16 consecutive weeks, a total of 1,017 mature capitula were collected, recording the presence and abundance of immature stages (larvae and pupae) and their related parasitoids. Both fly species were present throughout the entire season, with overall infestation of 51.5% of the capitula examined. However, Dictyotrypeta sp. infested 11.3%, representing about one-fifth of them, and R. spilogaster was most abundant infesting four times as many capitula (42.9%), whereas both species were found together in only 2.6% of the capitula examined. Based on the temporal occurrence of larvae and pupae into flower heads as well as their associated parasitoids and times of emergence, Dictyotrypeta sp. had two yearly generations, and it seems that the second generation could enter a seasonal diapause; in contrast, R. spilogaster was a univoltine species that entered diapause that lasted until the next year. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.
Pilger, Daniel; Khakban, Adak; Heukelbach, Jorg; Feldmeier, Hermann
To compare sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of self-diagnosis for head lice infestation with visual inspection, we conducted a study in an urban slum in Brazil. Individuals were asked about active head lice infestation (self-diagnosis); we performed visual inspection and thereafter wet combing (gold standard). Of the 175 individuals included, 77 (44%) had an active head lice infestation. For self-diagnosis, sensitivity (80.5%), specificity (91.8%), PPV (88.6%) and NPV (85.7%) were high. Sensitivity of visual inspection was 35.1%. Public health professionals can use self-diagnosis as a diagnostic tool, to estimate accurately prevalence of pediculosis in a community, and to monitor ongoing intervention strategies.
Background In Spain, head lice are considered a therapeutic resource for the treatment of jaundice. All folk remedies based on the ingestion of these insects meet in the present document, previously dispersed among a large number of references. Methods An overview of the Spanish literature has been carried out. The most important databases have been consulted. All related works have been examined. Results Although the method of preparation is diverse and the dose varies, the primary recommendation is a transference ritual consisting of taking nine live lice for nine days on an empty stomach without the patient’s knowledge. This traditional knowledge survives in Spanish society, and constitutes an example of the interrelation between Spanish and Latin American folk medicines. Conclusions The survival of this therapy in the worldview of certain rural communities suggests the need to take into account the beliefs, ideas and behaviour patterns of popular culture in relation to health and disease. PMID:23876126
Morsy, T A; el-Ela, R G; Mawla, M Y; Khalaf, S A
Human lice (head and body) are among the arthropod-ectoparasites of worldwide distribution. Examining students in primary, preparatory and secondary schools recorded prevalence rates of 21.86%, 30.38% and 12.94% respectively. The overall rate of the lice infestation in the three schools was 384 out of 1772 or 21.67%. The prevalence rate of lice infestation among males and females were 17.02% & 37.8% (primary school), 27.8% & 33.1% (preparatory school), and 12.0% & 13.9% (secondary school). These totaled 17.7% (males) and 30.26% (females). The overall ratio of head to body lice was 18.2:1. Consequently, lice mainly the head louse, are still a public health problem particularly among female students in the primary and preparatory schools. In the secondary school prevalence rate of the lice infestation was low. So human lice is still a community health problem.
Gutiérrez, María Mercedes; González, Jorge Werdin; Stefanazzi, Natalia; Serralunga, Gabriela; Yañez, Loreto; Ferrero, Adriana Alicia
The human head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), is a worldwide public health concern. This human obligate ectoparasite usually infests school age children. The aim of this work was to investigate the prevalence of head lice in kindergarten children from Bahia Blanca. In addition, the influence of risk factors for pediculosis infestation, such as gender, hair characteristics, and socioeconomic class, was studied in relation to the prevalence of this ectoparasite. From a total of 220 pupils examined (125 girls and 95 boys), 94 showed pediculosis. The overall prevalence of head lice infestation was 42.7 %. Pediculosis was more frequent in girls (53.6 %) than in boys (28.4 %) and in medium, long, and very long hairs. No differences were found between socioeconomic classes. This indicated that head lice are relatively common in kindergarten children from Bahía Blanca.
Meinking, Terri L; Mertz-Rivera, Kamara; Villar, Maria Elena; Bell, Margie
Ivermectin is a broad-spectrum parasiticide in widespread systemic use, including as an off-label treatment for head lice infestation. The potential of the topical use of ivermectin as a treatment for head lice infestation was suggested by an in vitro report of a novel lotion formulation. This study investigated the relative effectiveness of three ivermectin lotion concentrations (0.15, 0.25, and 0.5%) compared with vehicle placebo in eliminating head lice infestation. In this randomized, blinded study, 78 head lice-infested subjects, aged 2-62 years, received a single, 10-minute application of product on day 1. Evaluations were completed at two and six hours post-application, and on days 2, 8 (±1), and 15 (+2). Safety was assessed according to the evaluations of trained observers and adverse event (AE) reports. Efficacy was assessed according to scalp and hair examinations. Compared with placebo, all ivermectin concentrations resulted in the statistically significant (P ≤ 0.003) eradication of head lice through to day 15, with the highest level of eradication (73.7%) in subjects who received the 0.5% concentration. The severity of pruritus decreased from baseline in all treatment groups, including the placebo group, from six hours post-treatment to day 15, with the greatest reduction in the 0.5% concentration group. No ocular irritation was observed. All three ivermectin treatment strengths and vehicle were well tolerated. A single application of a 0.5% concentration of this ivermectin lotion formulation shows promise as a safe and effective treatment for head lice infestation and the associated signs of pruritus. © 2013 The International Society of Dermatology.
Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult louse ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to ...
Yoon, Kyong Sup; Ketzis, Jennifer K; Andrewes, Samuel W; Wu, Christopher S; Honraet, Kris; Staljanssens, Dorien; Rossel, Bart; Marshall Clark, J
The human head louse is a cosmopolitan ectoparasite and frequently infests many people, particularly school-age children. Due to widespread pyrethroid resistance and the lack of efficient resistance management, there has been a considerable interest in the protection of uninfested people and prevention of reinfestation by disrupting lice transfer. In this study, two nonclinical model systems (in vitro and in vivo) were used to determine the efficacy of the infestation deterrents, Elimax lotion and Elimax shampoo, against human head lice or poultry chewing lice, respectively. With in vitro assessments, female head lice exhibited significantly higher avoidance responses to hair tufts treated with either of the test formulations, which led to significantly higher ovipositional avoidance when compared with female lice on control hair tufts. Additionally, both formulations were determined to be competent infestation deterrents in a competitive avoidance test in the presence of a known attractant (head louse feces extract). In in vivo assessments using a previously validated poultry model, Elimax shampoo was determined to be an efficacious deterrent against poultry chewing lice within Menopon spp. and Menacanthus spp. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America.
Yoon, Kyong Sup; Ketzis, Jennifer K.; Andrewes, Samuel W.; Wu, Christopher S.; Honraet, Kris; Staljanssens, Dorien; Rossel, Bart; Marshall Clark, J.
The human head louse is a cosmopolitan ectoparasite and frequently infests many people, particularly school-age children. Due to widespread pyrethroid resistance and the lack of efficient resistance management, there has been a considerable interest in the protection of uninfested people and prevention of reinfestation by disrupting lice transfer. In this study, two nonclinical model systems (in vitro and in vivo) were used to determine the efficacy of the infestation deterrents, Elimax lotion and Elimax shampoo, against human head lice or poultry chewing lice, respectively. With in vitro assessments, female head lice exhibited significantly higher avoidance responses to hair tufts treated with either of the test formulations, which led to significantly higher ovipositional avoidance when compared with female lice on control hair tufts. Additionally, both formulations were determined to be competent infestation deterrents in a competitive avoidance test in the presence of a known attractant (head louse feces extract). In in vivo assessments using a previously validated poultry model, Elimax shampoo was determined to be an efficacious deterrent against poultry chewing lice within Menopon spp. and Menacanthus spp. PMID:26336209
Smith, Christine H; Goldman, Ran D
Head lice infestations continue to be seen frequently in many communities. Some of these children require multiple treatments before eradication. What are the current treatment recommendations for head lice? Head lice (Pediculus humanus capitis) infestations are common, particularly among school-aged children. In order to minimize louse resistance, insecticide usage, and social stigmatization, diagnosis and treatment should be limited to those with live lice on the scalp. Options for management are predominantly topical therapies or physical removal. Large studies comparing the efficacy of these treatments are lacking. Treatment should be repeated in approximately 7 days if topical insecticides are used or every 2 to 3 days for 2 weeks if wet combing is used. Lice resistance patterns vary widely geographically, and resistance is now the most common cause of treatment failure.
Rupes, V; Vlcková, J; Mazánek, L; Chmela, J; Ledvinka, J
Based on the current knowledge, head louse (Pediculus capitis) and body louse (Pediculus humanus) are two different species that infest specific parts of the human body and do not interbreed in vivo. In 1991-2002, 6 257 cases of pediculosis were reported in the Czech Republic while 3 138 000 pediculicide packagings, i.e. about 500 times as many as the number of cases, were marketed. Between October 2004 and February 2005, a total of 531 children aged between 6 and 15 years from 16 selected schools in the Zlín and Olomouc regions were screened by dry hair combing. Living lice were detected in 14.1% of the enrolled children and dead nits alone were observed in other 9.8% of the subjects. In vitro tests revealed that the collected head lice were highly resistant to malathion, the active ingredient of Diffusil H 92 M. The number of reported cases of pediculosis roughly doubled in 2005.
Nazari, Mansour; Fakoorziba, Mohammad Reza; Shobeiri, Fatemeh
Pediculus capitis or head-louse infestation has been a worldwide public-health problem, especially among school-aged children. To determine the intensity of infestation (abundance) among schoolchildren, children's sex and social factors were analyzed as modifiers of the general prevalence of parasitism. The study included 847 schoolchildren (407 girls, 440 boys) aged 6-12 years, from 12 public rural primary schools of Hamedan, Hamedan Province, Iran. Classic prevalence was obtained as the percentage of children with nits and/or lice. The general prevalence was 6.85% (girls: 13.5%; boys: 0.7%, p<0.001), head lice were much more common in girls than boys. The results showed significant variations in head lice infestation, and factors such as parents' literacy, type of hair, previous infestation, sharing of bed and comb, and care centers, while there was no significant variation between school grade, parents' job, members of family, and pediculosis in the studied areas (p>0.05). Sex and social factors are important modifiers of P. capitis general prevalence and degree of infestation. The classification of children by intensity of infestation allowed a more precise delimitation of this condition, which is especially important for disease surveillance and application of control measures.
Burkhart, Craig N; Burkhart, Craig G
Head lice, like many insects, produce a protective coating for their newly laid eggs that is essential to the survival of the species. Knowledge of the composition of the sheath, which is the glue by which the egg is attached to human hair, and the nit laying process could lead to production of agents that could be used to attack louse infestations by interfering with the normally protected environment of nymph development within the egg. The physical removal of nits has become an important part of treatment of head louse infestations given the "no-nit" policy in schools. Biochemical analysis has revealed that the nit sheath of the head louse is composed of 4 bands of protein, possibly cross-linked to aliphatic components with a tertiary structure of beta sheeting. Nature has protected the louse by making the nit sheath similar in composition to the hair; thereby, agents designed to unravel the nit sheath may also damage human hair. Possible targets to destroy the nit sheath include proteases, denaturants, beta sheet breaker proteins, and small protein inhibitors of sheath formation. Better understanding of insect glues may allow us to develop compounds so that the liquid secretions of the collateral glands of the female louse, which becomes the nit sheath, do not solidify by oxidation when placed with the louse egg onto human hair. Knowledge of insect behavior, such as oviposition, may also suggest methods for repelling female lice from laying eggs onto hair. Alternatively, agents that coat the nits and restrict the oxygen transfer to the developing larvae may prove beneficial.
Drali, Rezak; Boutellis, Amina; Raoult, Didier; Rolain, Jean Marc; Brouqui, Philippe
Background Body louse or head louse? Once removed from their environment, body and head lice are indistinguishable. Neither the morphological criteria used since the mid-18th century nor the various genetic studies conducted since the advent of molecular biology tools have allowed body lice and head lice to be differentiated. In this work, using a portion of the Phum_PHUM540560 gene from the body louse, we aimed to develop a multiplex real-time polymerase chain reaction (PCR) assay to differentiate between body and head lice in a single reaction. Materials and Methods A total of 142 human lice were collected from mono-infested hosts from 13 countries on five continents. We first identified the louse clade using a cytochrome b (CYTB) PCR sequence alignment. We then aligned a fragment of the Phum_PHUM540560 gene amplified from head and body lice to design-specific TaqMan© FAM- and VIC-labeled probes. Results All the analyzed lice were Clade A lice. A total of 22 polymorphisms between the body and head lice were characterized. The multiplex real-time PCR analysis enabled the body and head lice to be distinguished in two hours. This method is simple, with 100% specificity and sensitivity. Conclusions We confirmed that the Phum_PHUM540560 gene is a useful genetic marker for the study of lice. PMID:23469145
Guinea pigs (Cavia porcellus (L.)) (Rodentia: Caviidae) are pets and laboratory animals. They can be infested by a chewing louse, Gliricola porcelli (Schrank) (Phthiraptera: Gyropidae), which is fairly common in some animal rearing facilities, pet stores, and on wild guinea pigs. Infestation with G....
Ellse, L; Sands, B; Burden, F A; Wall, R
Chewing lice are widespread and clinically compromising parasites of livestock and equids. Their management is complicated by growing levels of resistance to commonly applied insecticides. Hence, the development of novel approaches to their control is of major clinical interest. To assess the effects of incorporating the essential oils of tea tree and lavender into a grooming programme for populations of donkeys with natural infestations of Bovicola ocellatus in the UK and Ireland when louse populations were at their winter seasonal peak. In vivo field trial. Suspensions of 5% (v/v) tea tree or lavender oil or an excipient only control were groomed into the coats of winter-housed donkeys (n = 198) on 2 occasions, 2 weeks apart. Louse counts were conducted before each application and 2 weeks later. After 2 applications, the groups groomed with lavender or tea tree oil suspensions had a significant reduction in louse intensity, with a mean decline in louse abundance of 78% (95% confidence interval 76-80%). Louse numbers in the groups groomed with excipient only either did not change or increased significantly. Donkey hair length had no effect on the decline in louse numbers. These results demonstrate that the inclusion of essential oil suspensions during grooming can be used to manage louse populations successfully. © 2015 EVJ Ltd.
Sultan, K; Khalafalla, R E
Heterodoxus spiniger is a rare chewing louse; infest dogs and occasionally cats with expanding geographical distribution. This preliminary report is aimed to record infestation of stray dogs in Kafr El-Sheikh city, Egypt by H. spiniger. Two dogs out of 10 were naturally infected with H. spiniger. This report is the first to demonstrate H. spiniger infestation on dogs in northern regions of Nile-delta of Egypt.
Ellse, L; Burden, F A; Wall, R
A longitudinal study was undertaken over a 21 months period to examine the seasonal abundance of lice infesting donkeys, the risk factors which predispose donkeys to infestation and the effectiveness of louse management. All the lice seen were Bovicola (Werneckiella) ocellatus. A strong seasonal pattern, which was correlated with mean monthly temperature, was observed with higher prevalence and intensity in the cooler, winter months (October-March). Overall infestation in these animals was over-dispersed, suggesting that some individuals are strongly predisposed to infestation. Donkey age and mean hair length were characteristics which affected louse prevalence: older and younger donkeys and donkeys with longer hair harboured the highest numbers of lice. However, the practice of coat-clipping, to reduce the infestation, resulted in a lower louse prevalence only in the summer, suggesting that clipping is not an effective form of louse control in cooler months. Higher louse burdens were associated with larger areas of visible excoriation and hair damage, suggesting that B. ocellatus does adversely impact animal welfare. However, the ability of animal carers to estimate louse presence or absence accurately on an individual donkey was not sufficiently high to allow targeted selective treatment of heavily infested animals to be employed effectively. As animals are housed in closed herds these findings suggest that clipping in the summer and treating all animals with insecticide in late autumn, prior to turn-in may be an effective louse management strategy.
Gholamnia Shirvani, Zeinab; Amin Shokravi, Farkhondeh; Ardestani, Mona Sadat
An important health problem in students is pediculosis capitis (head lice infestation) which causes physical, mental, and social complications. Social stigma induces feeling of shame, anger, and embarrassment for families and may prevent people from coming forward. This study was a quasi-experimental (case - control) study which was done during periods of 2008 - 2009. Data collection tools were questionnaire, checklist, and head examination. Two schools were randomly selected among female primary schools in Chabahar, where 153 students were divided into case and control groups. After collecting the data, an educational program was designed and performed in the experimental group and was evaluated after two months. The results showed a significant difference in knowledge, attitude, and practice of the students in the case group, before and after the intervention (P < 0.0001), but in the control group it was not significant (P > 0.05) .The infestation rate was 69.3% in the case group before the intervention, and 82.1 % in the control group, which decreased to 26.7% in the case group after the education (P < 0.0001), but there was no significant difference in the control group (P < 0.05). The health education program had a positive effect on the reduction of pediculosis capitis among students; thus, it is suggested to perform and evaluate educational programs in students and their parents.
Barnett, Eric; Palma, Kathleen G; Clayton, Bert; Ballard, Timothy
In the treatment of human head lice infestation, healthcare providers are increasingly concerned about lice becoming resistant to existing pesticide treatments. Traditional pesticides, used to control these pests, have a neurological mechanism of action. This publication describes a topical solution with a non-traditional mechanism of action, based on physical disruption of the wax layer that covers the cuticle of the louse exoskeleton. This topical solution has been shown clinically to cure 82% of patients with only a 10-minute treatment time, repeated once after 7 days. All insects, including human head lice, have a wax-covered exoskeleton. This wax, composed of hydrocarbons, provides the insect with protection against water loss and is therefore critical to its survival. When the protective wax is disrupted, water loss becomes uncontrollable and irreversible, leading to dehydration and death. A specific pattern of hydrocarbons has been found in all of the head louse cuticular wax studied. Iso-octane effectively removes these hydrocarbons from human head lice's cuticular wax. A method of head louse cuticle wax extraction and analysis by gas chromatography was developed. Human head lice (Pediculus humanus capitis) were collected from infested patients and subjected to any of three extraction solvents comprising either the test product or one of two solvents introduced as controls. A gas chromatograph equipped with a flame ionization detector (GC/FID) was used to determine the presence of hydrocarbons in the three head lice extracts. In the study reported herein, the test product isopropyl myristate/cyclomethicone D5 (IPM/D5) was shown to perform comparably with iso-octane, effectively extracting the target hydrocarbons from the cuticular wax that coats the human head louse exoskeleton. Disruption of the integrity of the insect cuticle by removal of specific hydrocarbons found in the cuticular wax appears to offer a mechanism for killing lice without the
Background In the treatment of human head lice infestation, healthcare providers are increasingly concerned about lice becoming resistant to existing pesticide treatments. Traditional pesticides, used to control these pests, have a neurological mechanism of action. This publication describes a topical solution with a non-traditional mechanism of action, based on physical disruption of the wax layer that covers the cuticle of the louse exoskeleton. This topical solution has been shown clinically to cure 82% of patients with only a 10-minute treatment time, repeated once after 7 days. All insects, including human head lice, have a wax-covered exoskeleton. This wax, composed of hydrocarbons, provides the insect with protection against water loss and is therefore critical to its survival. When the protective wax is disrupted, water loss becomes uncontrollable and irreversible, leading to dehydration and death. A specific pattern of hydrocarbons has been found in all of the head louse cuticular wax studied. Iso-octane effectively removes these hydrocarbons from human head lice’s cuticular wax. Methods A method of head louse cuticle wax extraction and analysis by gas chromatography was developed. Human head lice (Pediculus humanus capitis) were collected from infested patients and subjected to any of three extraction solvents comprising either the test product or one of two solvents introduced as controls. A gas chromatograph equipped with a flame ionization detector (GC/FID) was used to determine the presence of hydrocarbons in the three head lice extracts. Results In the study reported herein, the test product isopropyl myristate/cyclomethicone D5 (IPM/D5) was shown to perform comparably with iso-octane, effectively extracting the target hydrocarbons from the cuticular wax that coats the human head louse exoskeleton. Conclusions Disruption of the integrity of the insect cuticle by removal of specific hydrocarbons found in the cuticular wax appears to offer a
Al-Shahrani, Sarah A; Alajmi, Reem A; Ayaad, Tahany H; Al-Shahrani, Mohammed A; Shaurub, El-Sayed H
The present work aimed at investigating the genetic diversity of the head louse Pediculus humanus capitis (P. humanus capitis) among infested primary school girls at Bisha governorate, Saudi Arabia, based on the sequence of mitochondrial cytochrome b (mt cyt b) gene of 121 P. humanus capitis adults. Additionally, the prevalence of pediculosis capitis was surveyed. The results of sequencing were compared with the sequence of human head lice that are genotyped previously. Phylogenetic tree analysis showed the presence of 100% identity (n = 26) of louse specimens with clade A (prevalent worldwide) of the GenBank data base. Louse individuals (n = 50) showed 99.8% similarity with the same clade A reference having a single base pair difference. Also, a number of 22 louse individuals revealed 99.8% identity with clade B reference (prevalent in North and Central Americas, Europe, and Australia) with individual diversity in two base pairs. Moreover, 14 louse individual sequences revealed 99.4% identity with three base pair differences. It was concluded that moderate pediculosis (~13%) prevailed among the female students of the primary schools. It was age-and hair texture (straight or curly)-dependent. P. humanus capitis prevalence diversity is of clades A and B genotyping.
Tella, J L; Rodríguez-Estrella, R; Blanco, G
Louse flies were collected from 401 birds of 32 species captured in autumn of 1996 in Baja California Sur (Mexico). Only one louse fly species (Microlynchia pusilla) was found. It occurred in four of the 164 common ground doves (Columbina passerina) collected. This is a new a host species for this louse fly.
Toloza, Ariel Ceferino; Ascunce, Marina S; Reed, David; Picollo, María Inés
The human head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae), is an obligate ectoparasite that causes pediculosis capitis and has parasitized humans since the beginning of humankind. Head louse infestations are widespread throughout the world and have been increasing since the early 1990s partially because of ineffective pediculicides. In Argentina, the overuse of products containing pyrethroids has led to the development of resistant louse populations. Pyrethroid insecticides act on the nervous system affecting voltage-sensitive sodium channels. Three point mutations at the corresponding amino acid sequence positions M815I, T917I, and L920F in the voltage-gated sodium channel gene are responsible for contributing to knockdown resistance (kdr). The management of pyrethroid resistance requires either early detection or the characterization of the mechanisms involved in head louse populations. In the current study, we estimated the distribution of kdr alleles in 154 head lice from six geographical regions of Argentina. Pyrethroid resistance kdr alleles were found in high frequencies ranging from 67 to 100%. Of these, 131 (85.1%) were homozygous resistant, 13 (8.4%) were homozygous susceptible, and 10 (6.5%) were heterozygous. Exact tests for the Hardy-Weinberg equilibrium for each location showed that genotype frequencies differed significantly from expectation in four of the six sites studied. These results show that pyrethroid resistance is well established reaching an overall frequency of 88%, thus close to fixation. With 30 yr of pyrethroid-based pediculicides use in Argentina, kdr resistance has evolved rapidly among these head louse populations.
James, P J; Moon, R D
The spatial distribution of chewing lice (Bovicola ovis) on their hosts was examined in Polypay and Columbia ewes initially artificially infested on the midside or the neck. Densities of lice were determined at 69 body sites in eight body regions at approximately monthly intervals for 2 years. In the second year, half of the ewes were mated and lice were counted at 26 body sites on the resulting lambs. Polypay ewes had higher densities of lice than Columbias at most inspections but there was little effect of infestation point or mating on either numbers or the distribution of lice. During periods of high louse numbers densities were generally greatest on the sides or the back. Densities on the head were also high at times and peaked later than overall louse densities. Shearing markedly reduced density but increased the proportion of lice found on the neck, belly and lowleg sites. The distribution of lice on the lambs was similar to that on the ewes except that fewer lice were found on the head. Comparisons of lice per part with the numbers of lice extracted from clipped patches indicated that a sheep with wool bearing area of 1 m2 and a mean count of one louse per 10 cm fleece parting carried approximately 2000 lice. At most times of the year inspections for sheep lice should be concentrated on the sides and back, but in recently shorn sheep greater attention should be paid to the lower neck and ventral regions. Implications of the observed distributions of lice for the efficacy of chemical treatments are discussed.
Shmidt, Eugenia; Levitt, Jacob
Head lice are transmitted by head to head contact. Optimal therapy includes malathion lotion 0.5% repeated in one week left on for 30 minutes to 8 hours. Spinosad topical suspension 0.9% repeated in one week left on for 10 minutes is another option. Scabies is transmitted mainly by direct contact but also via heavily infested fomites due to crusted scabies. Permethrin 5% cream to the body repeated in four days is often sufficient; however, scalp treatment with malathion lotion 0.5% is helpful in crusted scabies and in infested children. Oral ivermectin 200 mcg/kg is another option, repeated in four days. For scabies more than lice, fomites should be placed in a drier at 60 °C for 10 minutes to kill the arthropods. Treatment of close contacts in both cases will control outbreaks and repeated infestations. Both have been associated with methicillin-resistant Staphylococcus aureus infection. Bed bugs are a common cause for papular urticaria. Identification of the insect in the mattress or bedding confirms the diagnosis. Prevention involves encasing the mattress in a sealed plastic cover and extermination. Delusions of parasitosis is a diagnosis of exclusion that is best treated with an antipsychotic.
Karabela, Yunus; Yardimci, Gurkan; Yildirim, Isik; Atalay, Eray; Karabela, Semsi Nur
Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. A 45-year-old man presented with conjunctival hyperaemia and moderate itching associated with irritation, and crusty excretions of the eyelashes in the left eye. Careful slit-lamp examination revealed many lice and nits in left eye and mild conjunctival hyperaemia. No abnormality was found in the right eye. On dermatologic examination, only one louse was found at the pubic area. The patient was treated effectively with petrolatum jelly (Vaseline) and 1% permethrin shampoo (Kwellada 1% shampoo). At the end of the first week no louse or nit was present on eyelashes and pubic area.
Karabela, Yunus; Yardimci, Gurkan; Yildirim, Isik; Atalay, Eray; Karabela, Semsi Nur
Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. A 45-year-old man presented with conjunctival hyperaemia and moderate itching associated with irritation, and crusty excretions of the eyelashes in the left eye. Careful slit-lamp examination revealed many lice and nits in left eye and mild conjunctival hyperaemia. No abnormality was found in the right eye. On dermatologic examination, only one louse was found at the pubic area. The patient was treated effectively with petrolatum jelly (Vaseline) and 1% permethrin shampoo (Kwellada 1% shampoo). At the end of the first week no louse or nit was present on eyelashes and pubic area. PMID:26451147
Pariser, David M; Meinking, Terri Lynn; Bell, Margie; Ryan, William G
The emergence of resistance to treatment complicates the public health problem of head-louse infestations and drives the need for continuing development of new treatments. There are limited data on the activity of ivermectin as a topical lousicide. In two multisite, randomized, double-blind studies, we compared a single application of 0.5% ivermectin lotion with vehicle control for the elimination of infestations without nit combing in patients 6 months of age or older. A tube of topical ivermectin or vehicle control was dispensed on day 1, to be applied to dry hair, left for 10 minutes, then rinsed with water. The primary end point was the percentage of index patients (youngest household member with ≥3 live lice) in the intention-to-treat population who were louse-free 1 day after treatment (day 2) and remained so through days 8 and 15. A total of 765 patients completed the studies. In the intention-to-treat population, significantly more patients receiving ivermectin than patients receiving vehicle control were louse-free on day 2 (94.9% vs. 31.3%), day 8 (85.2% vs. 20.8%), and day 15 (73.8% vs. 17.6%) (P<0.001 for each comparison). The frequency and severity of adverse events were similar in the two groups. A single, 10-minute, at-home application of ivermectin was more effective than vehicle control in eliminating head-louse infestations at 1, 7, and 14 days after treatment. (Funded by Topaz Pharmaceuticals [now Sanofi Pasteur]; ClinicalTrials.gov numbers, NCT01066585 and NCT01068158.).
Ellse, L; Burden, F A; Wall, R
Infestations by lice can be a significant clinical and welfare issue in the management of large animals. The limited range of commercial pediculicides available and the development of resistance have led to the need to explore alternative louse management approaches. The results of in vitro and in vivo trials undertaken to control populations of the donkey chewing louse, Bovicola ocellatus (Piaget) (Phthiraptera: Trichodectidae) using the essential oils of tea tree (Melaleuca alternifolia) and lavender (Lavandula angustifolia) are reported here. Results of contact and vapour bioassays showed that 5% (v/v) tea tree and lavender oils resulted in > 80% louse mortality after 2 h of exposure. On farms, separate groups of 10 donkeys sprayed with 5% (v/v) tea tree and lavender oil as part of their usual grooming regime showed significant reductions in louse numbers compared with a control group (0.2% polysorbate 80 in water). These findings indicate that tea tree and lavender essential oils can provide clinically useful levels of control of B. ocellatus when used as part of a grooming routine and suggest that with further development could form the basis of an easy to apply and valuable component of a louse management programme for donkeys.
Introduction Head louse infection is diagnosed by finding live lice, as eggs take 7 days to hatch (but a few may take longer, up to 13 days) and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings or of lower socioeconomic group. Factors such as longer hair make diagnosis and treatment more difficult. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of physically acting treatments for head lice? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found six studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: 1,2-octanediol, dimeticone, herbal and essential oils, and isopropyl myristate. PMID:25587918
Marcoux, Danielle; Palma, Kathleen G; Kaul, Nalini; Hodgdon, Hilliary; Van Geest, Andrea; Previte, Dominic J; Abou-Elghar, Gamal Elsayed; Yoon, Kyong Sup; Clark, J Marshall
Most people in the United States and Canada with pediculosis will be treated with neurotoxic pediculicides containing pyrethrins or pyrethroids. Their widespread use led to significant resistance reported from various countries. Although treatment failures are frequently observed in Canada, the resistance frequency to pyrethroid pediculicide of human head lice (Pediculus humanus capitis) has not been determined. To determine the knockdown resistance (kdr) allele frequency in human head louse populations in Canada. Patients infested with Pediculus humanus capitis, aged 4 to 65 years, residents of Ontario, Quebec, and British Columbia, were participants. Head lice were collected by combing and picking the enrolled subjects' hair. Lice were analyzed by serial invasive signal amplification reaction (SISAR) for genotyping the T917I mutation of lice indicating permethrin resistance. The permethrin-resistant kdr allele (R allele) frequency could then be evaluated in the head lice collected in Canada. Of the head louse populations analyzed, 133 of 137 (97.1%) had a resistant (R) allele frequency, whereas only 4 of 137 (2.9%) had a susceptible (S) allele frequency. The 97.1% resistant (R) allele frequency in head lice from Canada could explain the treatment failures encountered with pyrethrin and pyrethroid pediculicide treatments in Canadian populations infested with Pediculus humanus capitis as the latter will not be eliminated by those pediculicides.
Head lice infestation is common, and mainly affects children of primary school age. Treatments include conventional chemical insecticides; fine tooth louse combs; and fluid preparations that work by a physical rather than chemical mode of action. However, each of these fails to eradicate head lice in some patients. Other disadvantages include the long contact time required for certain preparations e.g. 8 hours and the time commitment for combing regimens. Isopropyl myristate 50% in cyclomethicone solution (Full Marks Solution - SSL International) is a new fluid treatment with a physical mode of action that uses a 10-minute contact time. Here, we consider this product in the context of updating advice we gave in 2007 on treatments for head lice.
Vander Stichele, R H; Gyssels, L; Bracke, C; Meersschaut, F; Blokland, I; Wittouck, E; Willems, S; De Maeseneer, J
There is no scientific consensus on the best way to control head louse infestation in schoolchildren. A study was conducted to test the feasibility and acceptability of a screening campaign by wet combing and a community approach to head-louse control with home visits, and to explore parents' treatment preferences and treatment outcomes. A non-controlled intervention (advice on treatment options offered to all positive children) was nested within an epidemiological prevalence study. All children in three primary schools in Ghent, Belgium, were invited to take part in screening by wet combing (n=677, 3-11 years). Positive children were offered structural treatment advice, a home visit on day 7, and a check by wet combing on day 14. 83% of the children were screened. The prevalence of active infestation (living moving lice) was 13.0% in school 1 and 19.5% in school 3. In school 2, prevalence of signs of active and past infestation was 40.7%. A home visit was made to 58% of the positive children. 85% of the positive children were screened again on day 14. Wet combing was the most widely used treatment, followed by chemical treatment and a combination of the two. In school 1 and 3 51% were cured, and in school 2 24% became nit-free. A wet combing screening campaign and a community-oriented approach to head-louse control is feasible though resource-intensive. The prevalence of head lice was high and the cure rate was low, with either topical treatments or wet combing.
Fan, P C; Chung, W C; Fan, C K; Huang, P; Yen, C W
In the present study, pediculosis was investigated among a total of 2,725 children from 35 primary schools in Hsiulin District of Hualien County, Jenai District of Nantou County, Wulai District of Taipei County, Chienshih District of Hsinchu County, Fushing District of Taoyuan County, and Nanao District of Ilan County. The overall infestation rate was 12.8%. The rates by districts were 19.7%, 17.3%, 16.7%, 15.1%, 7.9%, and 3.0%, respectively. The pediculicides including Nix (permethrin 1%) 56 gm/tube, Para aerosol (bioallethrin 0.66%) 90 gm/tube, and Perioderm (malathion 1%) cream shampoo 40 gm/tube were used to treat the head louse infestation in 83, 91, and 103 children; the cure rates were 97.3%, 94.1%, and 93.4%, respectively. No significant differences were found in these rates. The reactions were slight and transitory. A total of 636 lice was collected from the hair using fine-toothed combs before treatment and from the used towels after treatment of children in Wulai, Chienshih, Hsiulin, and Jenai Districts. Each child was found infested with a mean of 7.7 lice. The mean intensity of infestation was highest in Jenai (9.3) and Chienshih (8.7) came next. Wulai (3.7) and Hsiulin (3.6) had lower intensities.
Johnson, Lee F.
During the 1993 growing season, leaf reflectance and chlorophyll concentrations were monitored with respect to phylloxera (root-louse) infestation in a Napa Valley (California) vineyard. Study plots were established in areas of severely infested, mildly infested, and uninfested sections of the vineyard. A handheld chlorophyll meter, measuring leaf transmittance of near-infrared and red light, confirmed that reduced foliar chlorophyll concentrations were symptomatic of phylloxera stress in the sample vines. Bidirectional reflectance measurements of green and near-infrared light, taken on fresh leaves with a laboratory spectrophotometer, were related to chlorophyll concentration but did not allow discrimination of mildly infested from uninfested vines.
Núñez-Acuña, Gustavo; Gonçalves, Ana Teresa; Valenzuela-Muñoz, Valentina; Pino-Marambio, Jorge; Wadsworth, Simon; Gallardo-Escárate, Cristian
One of the most significant threats to the Chilean salmon aquaculture industry is the ectoparasitic sea louse Caligus rogercresseyi. To cope with sea lice infestations, functional diets have become an important component in strengthening the host immune response. The aim of this study was to evaluate molecular mechanisms activated through immunostimulation by in-feed plant-derived additives in Atlantic salmon infected with sea lice. Herein, a transcriptome-wide sequencing analysis was performed from skin and head kidney tissues, evidencing that the immune response genes were the most variable after the challenge, especially in the head kidney, while other genes involved in metabolism were highly expressed individuals fed with the immunostimulants. Interestingly, defensive enzymes such as Cytochrome p450 and serpins were down-regulated in infested individuals, especially in skin tissue. Additionally, MHC-I and MHC-II genes were differentially expressed after the incorporation of the in-feed additives, giving some cues about the protection mechanisms of plant-derived compound as immunostimulants for infested salmons. This is the first published study that evaluates the transcriptomic response of sea lice-infested Atlantic salmon fed with in-feed additives.
Valenzuela-Muñoz, V; Boltaña, S; Gallardo-Escárate, C
Salmon species cultured in Chile evidence different levels of susceptibility to the sea louse Caligus rogercresseyi. These differences have mainly been associated with specific immune responses. Moreover, iron regulation seems to be an important mechanism to confer immunity during the host infestation. This response called nutritional immunity has been described in bacterial infections, despite that no comprehensive studies involving in marine ectoparasites infestation have been reported. With this aim, we analysed the transcriptome profiles of Atlantic and coho salmon infected with C. rogercresseyi to evidence modulation of the iron metabolism as a proxy of nutritional immune responses. Whole transcriptome sequencing was performed in samples of skin and head kidney from Atlantic and coho salmon infected with sea lice. RNA-seq analyses revealed significant upregulation of transcripts in both salmon species at 7 and 14 dpi in skin and head kidney, respectively. However, iron regulation transcripts were differentially modulated, evidencing species-specific expression profiles. Genes related to heme degradation and iron transport such as hepcidin, transferrin and haptoglobin were primary upregulated in Atlantic salmon; meanwhile, in coho salmon, genes associated with heme biosynthesis were strongly transcribed. In summary, Atlantic salmon, which are more susceptible to infestation, presented molecular mechanisms to deplete cellular iron availability, suggesting putative mechanisms of nutritional immunity. In contrast, resistant coho salmon were less affected by sea lice, mainly activating pro-inflammatory mechanisms to cope with infestation.
Bonilla, Denise L; Kabeya, Hidenori; Henn, Jennifer; Kramer, Vicki L; Kosoy, Michael Y
Bartonella quintana is a bacterium that causes trench fever in humans. Past reports have shown Bartonella spp. infections in homeless populations in San Francisco, California, USA. The California Department of Public Health in collaboration with San Francisco Project Homeless Connect initiated a program in 2007 to collect lice from the homeless to test for B. quintana and to educate the homeless and their caregivers on prevention and control of louse-borne disease. During 2007-2008, 33.3% of body lice-infested persons and 25% of head lice-infested persons had lice pools infected with B. quintana strain Fuller. Further work is needed to examine how homeless persons acquire lice and determine the risk for illness to persons infested with B. quintana-infected lice.
Mumcuoglu, Kosta Y; Mumcuoglu, Michael; Danilevich, Maria; Gilead, Leon
Health providers such as physicians, nurses and pharmacists should be knowledgeable about the biology of head lice and the ways to control them effectively, in order to reduce the proportion of children infested with head lice. To evaluate the knowledge of physicians in Israel on the biology and epidemiology of lice, as well as their experience with infested individuals and their preferences for diagnosis, prophylaxis and control. An anonymous questionnaire with 37 questions was used. The first 20 questions addressed the general knowledge of physicians on lice biology and control, while the remaining 17 questions were related to their personal experience with lice and louse treatment. Out of 273 physicians interviewed 66.8% had good knowledge of lice, while the remaining 33.2% had some knowledge on lice. The difference between the groups of physicians with medium and good knowledge on lice was borderline significant (P=0.0722), with the dermatologists borderline significantly less knowledgeable than the rest (P=0.0765). Significant differences were found between those physicians with 4-6 or 11-20 years of professional experience and the remaining groups (twice P<0.001). Although the percentage of female physicians who had a good knowledge on louse biology and control was higher than male physicians (39.4% and 29.4%, respectively), the differences were borderline significant (P=0.09). Pediatricians and dermatologists examined significantly more children than family physicians and general practitioners (P <0.001). The results of this study suggest that healthcare professionals' knowledge is of paramount importance for the correct diagnosis and control of head louse infestations.
Di Campli, Emanuela; Di Bartolomeo, Soraya; Delli Pizzi, Patricia; Di Giulio, Mara; Grande, Rossella; Nostro, Antonia; Cellini, Luigina
Head lice infestation is an emerging social problem in undeveloped and developed countries. Because of louse resistance increasing, several long-used insecticidal compounds have lost their efficacy, and alternatives, such as essential oils, have been proposed to treat this parasitic infestation. The present study investigated the efficacy of two natural substances: tea tree (Melaleuca alternifolia) oil and nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol) against lice and its eggs. Products were used alone and in combination (ratio 1:1 and 1:2) from 8 % dilution. The in vitro effect of natural substances at different concentrations were evaluated against 69 head lice (adults and nymphs) and 187 louse eggs collected from school children in Chieti-Pescara (Central Italy) over a 6-month period. The lice mortality was evaluated for 24 h by a stereo light microscope. The ovicidal activity was monitored by microscopic inspections for 15 days. Tea tree oil was more effective than nerolidol against head lice with 100 % mortality at 30 min and 1 % concentration. On the contrary, nerolidol expressed a more pronounced ovicidal activity inducing the failure of 50 % of the eggs to hatch at 1 % concentration after 4 days; the same effect was achieved by using a twice concentration of tea tree oil. The association of the two substances both in ratios 1:1 and 1:2 combined efficaciously their insecticidal and ovicidal effect; in particular, the ratio 1:2 (tea tree oil 0.5 % plus nerolidol 1 %) acted producing both the death of all head lice at 30 min and the abortive effect of louse eggs after 5 days. These results offer new potential application of natural compounds and display a promising scenario in the treatment of pediculosis resistant cases. The development of novel pediculicides containing essential oils could be, in fact, an important tool to control the parasitic infestation.
Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian
Sea lice are copepodid ectoparasites that produce high economic losses and environmental issues, thus impacting the salmon aquaculture worldwide. Atlantic salmon (Salmo salar) from Northern and Southern Hemispheres are primarily parasitized by Lepeophtheirus salmonis and Caligus rogercresseyi, respectively. To cope L. salmonis infestation, studies suggest that Atlantic salmon can restrict iron availability as a mechanism of nutritional immunity. However, no molecular studies of iron regulation from salmonids infected with C. rogercresseyi have been reported. The aim of this study was to determine if there are differences in the regulation of iron metabolism in Atlantic salmon infested with L. salmonis or C. rogercresseyi. For comparisons, skin and head kidney were profiled using qPCR of 15 genes related to iron regulation in Atlantic salmons infected with each sea louse species in Norway and Chile, respectively. Prior to infestation, no significant differences were observed between fish group. However, genes involved in iron transport and Heme biosynthesis were highly upregulated in Atlantic salmon infested with L. salmonis. Interestingly, hepcidin and Heme oxygenase, a component of the Heme degradation pathway, were upregulated during C. rogercresseyi infestation. Oxidative stress related genes were also evaluated, showing higher transcription activity in the head kidney than in the skin of Atlantic salmon infested with L. salmonis. These comparative results suggest pathogen-specific responses in infected Atlantic salmon, where iron metabolism is primarily regulated during the infestation with L. salmonis than C. rogercresseyi. Feeding behavior, for instance haematophagy, of the infesting sea lice species in relation to iron modulation is discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.
Shobrak, Mohammed; Alahmed, Azzam; Palma, Ricardo; Almalki, Mohammed; Nasser, Mohamed Gamal El-Den
Six species of terns, which breed on the Arabian Peninsula, were examined for head chewing lice of the genus Saemundssonia in four different islands around the coasts of Saudi Arabia, both in the Red Sea and in the Arabian Gulf. Four louse species were collected: Saemundssonia laticaudata, Saemundssonia melanocephalus, Saemundssonia meridiana and Saemundssonia sternae, of which three are recorded for the first time from this region. Also, we record three new host-louse associations for the world-Saemundssonia laticaudata and Saemundssonia sternae from white-cheeked terns and Saemundssonia melanocephalus from Saunders's terns-including a host-switch event of Saemundssonia laticaudata on white-cheeked terns in the Karan Island population. Gene bank data for the COI gene from seven species of Saemundssonia that infest marine birds were used to propose evolutionary trees using two different statistical methods: maximum parsimony (MP) and neighbour joining (NJ). The result indicated that the tree which was produced by NJ is likely to be more accurate as it appeared more compatible with hosts' phylogeny. The trees indicate relationships between tern Saemundssonia and congeneric species from other marine birds, especially from gulls. An ANOVA was also conducted to test the mean parasite load for each tern species studied, and results indicate that there is a relation between louse loads and colonization behaviour of the hosts. Data from lice examined and illustrations of lice and their hosts are also included.
Boutellis, Amina; Mediannikov, Oleg; Bilcha, Kassahun Desalegn; Ali, Jemal; Campelo, Dayana; Barker, Stephen C.
Since the 1800s, the only known vector of Borrelia recurrentis has been the body louse. In 2011, we found B. recurrentis DNA in 23% of head lice from patients with louse-borne relapsing fever in Ethiopia. Whether head lice can transmit these bacteria from one person to another remains to be determined. PMID:23648147
Boutellis, Amina; Mediannikov, Oleg; Bilcha, Kassahun Desalegn; Ali, Jemal; Campelo, Dayana; Barker, Stephen C; Raoult, Didier
Since the 1800s, the only known vector of Borrelia recurrentis has been the body louse. In 2011, we found B. recurrentis DNA in 23% of head lice from patients with louse-borne relapsing fever in Ethiopia. Whether head lice can transmit these bacteria from one person to another remains to be determined.
Ponce-Garcia, Gustavo; Villanueva-Segura, Karina; Trujillo-Rodriguez, Gerardo; Rodriguez-Sanchez, Iram P; Lopez-Monroy, Beatriz; Flores, Adriana E
The head louse Pediculus humanus capitis (De Geer) is a hematophagous ectoparasite that inhabits the human scalp. Infestations by this insect are commonly known as pediculosis, which is more common in younger groups. These infestations are asymptomatic; however, skin irritation from scratching occasionally may cause secondary bacterial infections. In recent years, the prevalence of pediculosis has increased in children; this increase has been attributed to louse resistance to the insecticides used as a control measure for infestation. The aim of the present study was to determine the presence and frequency of the knockdown resistance mutation (kdr) T929I in 468 head lice collected from 32 elementary schools in the metropolitan area of Nuevo Leon (24) and Yucatan (8), Mexico. This is the first report of a knockdown resistance (kdr) mechanism in head lice from Mexico. The T929I mutation was present in all of the sampled schools, with variability observed in its allelic and genotypic frequencies. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Khan, M A; Schaalje, G B
Two groups (A and C) of range cows were treated in February with chlorpyrifos (16 mL Dursban 44/cow) for the control of heavy infestations of the short-nosed cattle louse. Group A was treated in 1977 and group C in 1979 and each treated group was compared with a separate untreated group. Some of the treated cows were identified as carriers of louse infestation (subgroups A1 and C1), while others were noncarriers (subgroups A2 and C2). The maximum level of reduction in louse populations was 99% at week 4 posttreatment in subgroup A1, 99% from weeks 2-16 posttreatment in subgroup A2, 92% at week 3 posttreatment in subgroup C1 and 100% at weeks 15-17 in subgroup C2. Clinically, the treated cows, which were anemic at the time of treatment, recovered from anemia during the posttreatment period of 25 weeks for group A and 17 weeks for group C. Remission of anemia also occurred in the two untreated groups, possibly because of natural summer decline in louse population. The treatment had no effect on the whole blood cholinesterase of the cows and the treated cows showed no signs of organophosphorous toxicity. PMID:2416414
Burkhart, Craig N; Burkhart, Craig G
Control of various infestations requires an accurate understanding of transmission. After thousands of years of lice infestation, scientific documentation of indirect contact transmission has been substantiated. Lice can be transferred in the egg, instar, and adult stages. Lice have now been shown in the laboratory to be readily dislodged by air movements such as blow-drying one's hair, combing, and toweling. Moreover, passive transfer to adjoining fabric is also frequently observed. Louse transmission by fomites occurs more frequently than has been commonly believed. Close proximity suffices to increase the likeliness of a new infestation. Thus louse control measures should take account of fomite transmission and include screening of all individuals within an infested person's immediate circle of contact, laundering of everything within the infested individuals' bed or quarantining of such material for 10 days, thorough vacuuming of floors, carpets, upholstery, with a standard vacuum cleaner.
Lindh, Johan; Magnusson, Måns; Grünewald, Maria; Hulth, Anette
The head louse, Pediculus humanus capitis, is an obligate ectoparasite that causes infestations of humans. Studies have demonstrated a correlation between sales figures for over-the-counter (OTC) treatment products and the number of humans with head lice. The deregulation of the Swedish pharmacy market on July 1, 2009, decreased the possibility to obtain complete sale figures and thereby the possibility to obtain yearly trends of head lice infestations. In the presented study we wanted to investigate whether web queries on head lice can be used as substitute for OTC sales figures. Via Google Insights for Search and Vårdguiden medical web site, the number of queries on “huvudlöss” (head lice) and “hårlöss” (lice in hair) were obtained. The analysis showed that both the Vårdguiden series and the Google series were statistically significant (p<0.001) when added separately, but if the Google series were already included in the model, the Vårdguiden series were not statistically significant (p = 0.5689). In conclusion, web queries can detect if there is an increase or decrease of head lice infested humans in Sweden over a period of years, and be as reliable a proxy as the OTC-sales figures. PMID:23144923
Lindh, Johan; Magnusson, Måns; Grünewald, Maria; Hulth, Anette
The head louse, Pediculus humanus capitis, is an obligate ectoparasite that causes infestations of humans. Studies have demonstrated a correlation between sales figures for over-the-counter (OTC) treatment products and the number of humans with head lice. The deregulation of the Swedish pharmacy market on July 1, 2009, decreased the possibility to obtain complete sale figures and thereby the possibility to obtain yearly trends of head lice infestations. In the presented study we wanted to investigate whether web queries on head lice can be used as substitute for OTC sales figures. Via Google Insights for Search and Vårdguiden medical web site, the number of queries on "huvudlöss" (head lice) and "hårlöss" (lice in hair) were obtained. The analysis showed that both the Vårdguiden series and the Google series were statistically significant (p<0.001) when added separately, but if the Google series were already included in the model, the Vårdguiden series were not statistically significant (p = 0.5689). In conclusion, web queries can detect if there is an increase or decrease of head lice infested humans in Sweden over a period of years, and be as reliable a proxy as the OTC-sales figures.
Toloza, Ariel C; Zygadlo, Julio; Biurrun, Fernando; Rotman, Alicia; Picollo, María I
Infestation with the head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae), is one of the most common parasitic infestation of humans worldwide. Traditionally, the main treatment for control of head lice is chemical control that is based in a wide variety of neurotoxic synthetic insecticides. The repeated overuse of these products has resulted in the selection of resistant populations of head lice. Thus, plant-derived insecticides, such as the essential oils seem to be good viable alternatives as some have low toxicity to mammals and are biodegradable. We determined the insecticidal activity of 25 essential oils belonging to several botanical families present in Argentina against permethrin-resistant head lice. Significant differences in fumigant activity against head lice were found among the essential oils from the native and exotic plant species. The most effective essential oils were Cinnamomum porphyrium, followed by Aloysia citriodora (chemotype 2) and Myrcianthes pseudomato, with KT(50) values of 1.12, 3.02 and 4.09; respectively. The results indicate that these essential oils are effective and could be incorporated into pediculicide formulations to control head lice infestations once proper formulation and toxicological tests are performed.
Toloza, Ariel C; Zygadlo, Julio; Biurrun, Fernando; Rotman, Alicia; Picollo, María I
Infestation with the head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae), is one of the most common parasitic infestation of humans worldwide. Traditionally, the main treatment for control of head lice is chemical control that is based in a wide variety of neurotoxic synthetic insecticides. The repeated overuse of these products has resulted in the selection of resistant populations of head lice. Thus, plant-derived insecticides, such as the essential oils seem to be good viable alternatives as some have low toxicity to mammals and are biodegradable. We determined the insecticidal activity of 25 essential oils belonging to several botanical families present in Argentina against permethrin-resistant head lice. Significant differences in fumigant activity against head lice were found among the essential oils from the native and exotic plant species. The most effective essential oils were Cinnamomum porphyrium, followed by Aloysia citriodora (chemotype 2) and Myrcianthes pseudomato, with KT50 values of 1.12, 3.02 and 4.09; respectively. The results indicate that these essential oils are effective and could be incorporated into pediculicide formulations to control head lice infestations once proper formulation and toxicological tests are performed. PMID:21062140
Sawyer Mac Productions, Weston, MA.
Head lice affect over 10 million Americans each year. Noting that head lice are becoming resistant to conventional pediculicide (insecticide) treatments, this video combines live action and animation to education parents, children, and health professionals about the use of olive oil for successfully preventing and getting rid of head lice. The…
Sawyer Mac Productions, Weston, MA.
Head lice affect over 10 million Americans each year. Noting that head lice are becoming resistant to conventional pediculicide (insecticide) treatments, this video combines live action and animation to education parents, children, and health professionals about the use of olive oil for successfully preventing and getting rid of head lice. The…
Ellse, L; Burden, F; Wall, R
Equine pediculosis is a significant health and welfare issue, particularly in elderly and chronically debilitated animals. Currently infestation is controlled predominantly using topically applied pyrethroid insecticides, allowing limited scope for the rotation of drugs and increasing the risk of selection for resistance. Here the insecticidal efficacies of two pyrethroid-based products against the louse Bovicola (Werneckiella) ocellatus collected from donkeys were examined in vitro. The products were cypermethrin (Deosect™, Pfizer Ltd., 5% (w/v) cypermethrin, cutaneous spray) and permethrin (Switch™, VetPlus Ltd., 4% (w/v) permethrin, pour-on). The pyrethroid efficacy was contrasted with that of the organophosphate diazinon, since the louse populations examined were unlikely to have had prior exposure to this compound. The efficacy of diluted pure permethrin, the excipient, butyl dioxitol and the synergist piperonyl butoxide in the presence of the pyrethroids, were also considered. At the concentrations recommended for animal application, neither 4% (w/v) permethrin, nor 0.1% (w/v) cypermethrin had any significant effect on the mortality of B. ocellatus and neither induced significantly more mortality than an acetone-only control. In contrast, 0.04% diazinon caused 70% mortality within 4h and 100% mortality after 24h exposure. The addition of a potential pyrethroid synergist, piperonyl butoxide, in combination with cypermethrin and permethrin, resulted in no significant increase in mortality. It is concluded that the population of lice tested display a high level of pyrethroid tolerance which is likely to reflect the development of resistance. Twenty-four hours after routine treatment of 10 donkeys with a pour-on permethrin product (Switch™, VetPlus Ltd., 4% (w/v) permethrin, pour-on) hair tufts taken from their flanks were not significantly insecticidal compared with hair from the midline application site, implying a low level of insecticide distribution
Brunton, Elizabeth R.; Brown, Christine M.
Context. During the late 1990s, insecticide resistance had rendered a number of treatment products ineffective; some companies saw this as an opportunity to develop alternative types of treatment. We investigated the possibility that a surfactant-based lotion containing 10% cocamide diethanolamine (cocamide DEA) was effective to eliminate head louse infestation. Settings and Design. Initial in vitro testing of the lotion formulation versus laboratory reared body/clothing lice, followed by two randomised, controlled, community-based, assessor blinded, clinical studies. Materials and Methods. Preliminary laboratory tests were performed by exposing lice or louse eggs to the product using a method that mimicked the intended use. Clinical Study 1: Children and adults with confirmed head louse infestation were treated by investigators using a single application of aqueous 10% cocamide DEA lotion applied for 60 min followed by shampooing or a single 1% permethrin creme rinse treatment applied to pre-washed hair for 10 min. Clinical Study 2: Compared two treatment regimens using 10% cocamide DEA lotion that was concentrated by hair drying. A single application left on for 8 h/overnight was compared with two applications 7 days apart of 2 h duration, followed by a shampoo wash. Results. The initial laboratory tests showed a pediculicidal effect for a 60 min application but limited ovicidal effect. A longer application time of 8 h or overnight was found capable of killing all eggs but this differed between batches of test material. Clinical Study 1: Both treatments performed badly with only 3/23 (13%) successful treatments using cocamide DEA and 5/25 (23.8%) using permethrin. Clinical Study 2: The single overnight application of cocamide DEA concentrated by hair drying gave 10/56 (17.9%) successes compared with 19/56 (33.9%) for the 2 h application regimen repeated after 1 week. Intention to treat analysis showed no significant difference (p = 0.0523) between the treatments
Borges, Raquel; Mendes, Júlio
From November 1996 to March 2000, a total of 884 children between 0 and 15 years, from 11 institutions including day care centres, public urban and public rural schools in Uberlândia, State of Minas Gerais, central Brazil, were examined for head louse infestation. Children's sex, race, age and some hairs characteristics were shown to be associated to parasite infestation. A prevalence rate of 35% was found and the highest rates were observed in black, female children, with long, dark, wavy hairs. Hairs density and thickness did not seem to influence significantly the distribution of this pediculosis in Uberlândia's schoolchildren. Differences observed between the prevalence rates of head lice in children from the urban institutions suggest there is a greater epidemiological heterogeneity in this group when compared to the rural schoolchildren.
Rogers, Luke A.; Bateman, Andrew W.; Connors, Brendan M.; Frazer, L. Neil; Godwin, Sean C.; Krkošek, Martin; Lewis, Mark A.; Peacock, Stephanie J.; Rees, Erin E.; Revie, Crawford W.; Schlägel, Ulrike E.
Effective disease management can benefit from mathematical models that identify drivers of epidemiological change and guide decision-making. This is well illustrated in the host–parasite system of sea lice and salmon, which has been modelled extensively due to the economic costs associated with sea louse infections on salmon farms and the conservation concerns associated with sea louse infections on wild salmon. Consequently, a rich modelling literature devoted to sea louse and salmon epidemiology has been developed. We provide a synthesis of the mathematical and statistical models that have been used to study the epidemiology of sea lice and salmon. These studies span both conceptual and tactical models to quantify the effects of infections on host populations and communities, describe and predict patterns of transmission and dispersal, and guide evidence-based management of wild and farmed salmon. As aquaculture production continues to increase, advances made in modelling sea louse and salmon epidemiology should inform the sustainable management of marine resources. PMID:26880836
Sim, Seobo; Lee, In-Yong; Lee, Kyu-Jae; Seo, Jang-Hoon; Im, Kyung-Il; Shin, Myeong Heon
Total of 7,495 children including 3,908 boys and 3,587 girls from a kindergarten and 15 primary schools were examined for head lice infestation (HLI). The overall prevalence of HLI in this study was found to be 5.8%. Head lice were much more commonly detected in girls than in boys with prevalence of 11.2% and 0.9%, respectively. Sixty-nine children with HLI were treated with 1% lindane shampoo alone (group 1), and 45 children with HLI were treated with 1% lindane shampoo and oral trimethoprim/sulfamethoxazole (group 2), and follow-up visits were conducted 2 and 4 weeks later. The children who still had HLI 2 weeks after the primary treatment were treated again. At the 2-week follow-up visit, the treatment success rates of groups 1 and 2 were 76.8% and 86.7%, respectively, and at the 4-week follow-up visit, the rates were 91.3% and 97.8%, respectively. No statistically significant synergistic effect was observed for the combination of a 1% lindane shampoo and oral trimethoprim/sulfamethoxazole. PMID:12666731
Sim, Seobo; Lee, In-Yong; Lee, Kyu-Jae; Seo, Jang-Hoon; Im, Kyung-Il; Shin, Myeong Heon; Yong, Tai-Soon
Total of 7,495 children including 3,908 boys and 3,587 girls from a kindergarten and 15 primary schools were examined for head lice infestation (HLI). The overall prevalence of HLI in this study was found to be 5.8%. Head lice were much more commonly detected in girls than in boys with prevalence of 11.2% and 0.9%, respectively. Sixty-nine children with HLI were treated with 1% lindane shampoo alone (group 1), and 45 children with HLI were treated with 1% lindane shampoo and oral trimethoprim/sulfamethoxazole (group 2), and follow-up visits were conducted 2 and 4 weeks later. The children who still had HLI 2 weeks after the primary treatment were treated again. At the 2-week follow-up visit, the treatment success rates of groups 1 and 2 were 76.8% and 86.7%, respectively, and at the 4-week follow-up visit, the rates were 91.3% and 97.8%, respectively. No statistically significant synergistic effect was observed for the combination of a 1% lindane shampoo and oral trimethoprim/sulfamethoxazole.
Salehi, Shayesteh; Ban, Maryam; Motaghi, Minoo
Head lice contamination has a global distribution and it is regarded as a main health problem throughout the world. Given the importance of physical health of students and head lice prevalence at school age, we aimed to examine the rate of head lice contamination among primary school students in the villages of Abadan in 2012. In this descriptive study, 624 students were randomly selected from primary schools. The hair of all students under the study was examined by the researcher (community health nurse) and the result was registered in the checklist confidentially. Moreover, one questionnaire including personal and family information was filled out for each student. The obtained data were later analyzed in SPSS software, version 18, using statistical test Chi-square and central qualitative and distribution statistics. The frequency of lice contamination was 27 cases (4.33%) in total, all of whom were girls. Although the difference between the head lice contamination and gender was statistically significant (P=0.00), the difference between this contamination type and grade of students and their parents’ education and fathers’ occupation was not significance. The highest rate of contamination (6.73%) was, however, observed in fifth graders. All contaminations were seen in girls, which could be due to their longer hair or wearing scarf as compared with boys. Unfavorable health condition and regional hot weather can be effective as well. Therefore, it is essential to provide the students, especially girls, with health training. PMID:25349862
Salehi, Shayesteh; Ban, Maryam; Motaghi, Minoo
Head lice contamination has a global distribution and it is regarded as a main health problem throughout the world. Given the importance of physical health of students and head lice prevalence at school age, we aimed to examine the rate of head lice contamination among primary school students in the villages of Abadan in 2012. In this descriptive study, 624 students were randomly selected from primary schools. The hair of all students under the study was examined by the researcher (community health nurse) and the result was registered in the checklist confidentially. Moreover, one questionnaire including personal and family information was filled out for each student. The obtained data were later analyzed in SPSS software, version 18, using statistical test Chi-square and central qualitative and distribution statistics. The frequency of lice contamination was 27 cases (4.33%) in total, all of whom were girls. Although the difference between the head lice contamination and gender was statistically significant (P=0.00), the difference between this contamination type and grade of students and their parents' education and fathers' occupation was not significance. The highest rate of contamination (6.73%) was, however, observed in fifth graders. All contaminations were seen in girls, which could be due to their longer hair or wearing scarf as compared with boys. Unfavorable health condition and regional hot weather can be effective as well. Therefore, it is essential to provide the students, especially girls, with health training.
Semmler, Margit; Abdel-Ghaffar, Fathy; Gestmann, Falk; Abdel-Aty, Mohammed; Rizk, Ibrahim; Al-Quraishy, Saleh; Lehmacher, Walter; Hoff, Norman-Philipp
The present clinical trial was conducted to obtain additional data for the safety and efficacy of a head lice shampoo that is free of silicone compared with an anti-head lice product containing dimethicone. Both products act by a physical mode of action. This randomized, investigator-blinded, controlled clinical study was conducted between July and November 2016 in households of two villages (Abou Rawash and Shandalat) in Egypt. Children older than 2 years with an active head lice infestation were treated with either a shampoo-based head lice treatment containing neem extract (Licener®) or dimethicone (Jacutin® Pedicul Fluid) on day 1 and additionally on day 9. Assessment for living lice by combing was conducted before and 1-2 h after treatment and on days 5 and 13. The main objective was to demonstrate a cure rate of the test product of at least 85% after a single application (day 5 and 9). Secondary objectives were to scrutinize patient safety and satisfaction as well as cure rates on day 13 after two treatments and the evaluation of ovicidal and licicidal efficacies of the products. Sixty-one children in the test-group (Licener®) and 58 children in the reference group (Jacutin® Pedicul Fluid) were included in this study. The test product and the reference product were very well tolerated. Both products exceeded the objective of cure rates of over 85% after single treatment (test group 60/60 = 100%; 95% CI = 94.04-100.00%; reference group 54/57 = 94.74%; 95% CI = 85.38-98.90%; p = 0.112; CI by Clopper-Pearson) and after two treatments (test group 58/58 = 100%; 95% CI = 93.84-100.00%; reference group 52/54 = 96.30%; 95% CI = 87.25-99.55%; p = 0.230) with higher cure rates and non-inferiority for the test product. The combined success rate shows significant superiority of the test product against the reference product (test group 58/58 = 100%; 95% CI = 93.84-100.00%; reference group 49/54 = 90.7%; 95% CI = 79.70-96.92%; p = 0
Leulmi, Hamza; Diatta, Georges; Sokhna, Cheikh; Rolain, Jean-Marc; Raoult, Didier
Reports of treatment failure and the emergence of resistance to topical head lice treatments have become increasingly common, driving the need for continued development of new therapeutic options for pediculosis. Ivermectin has been proposed as a potential alternative for the treatment of pediculosis but has not been sufficiently evaluated. In this study, the effectiveness of oral ivermectin versus shampoo in the treatment of pediculosis in Senegal was compared. The study was conducted in two neighbouring villages of Sine-Saloum, Senegal: Dielmo (ivermectin trial group; 201 female participants) and Ndiop (shampoo trial group; 239 female participants). In the ivermectin group, patients received two doses of oral ivermectin (400 µg/kg body weight; Mectizan(®)) 7 days apart. In contrast, the shampoo group received a shampoo treatment based on d-phenothrin (0.23%; Hégor(®)). At the beginning of the study, 70 (34.8%) of 201 participants in the ivermectin group were infested by head lice versus 145 (60.7%) of 239 participants in the shampoo group. At Day 15 post-treatment, the efficacy of the treatment against head lice reached 41/53 (77.4%) in the ivermectin group (53 patients were tested in this group) versus 42/130 (32.3%) in the shampoo group (130 patients were tested in this group) (P <10(-7)). However, 4 (7.5%) of the 53 females in the ivermectin group exhibited probable ivermectin treatment failure, suggesting the emergence of ivermectin-resistant lice. This study demonstrates that oral ivermectin is highly effective for the treatment of pediculosis compared with shampoo, but also suggests that ivermectin resistance may emerge during treatment. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
Laupland, Kevin B.; Valiquette, Louis
Although the practice of infectious diseases involves a broad range of surgical and medical disciplines, interactions with psychiatry are infrequent. Delusional infestation is a condition where an individual has a firmly fixed false belief that they have an infection. Delusional infestation challenges the infectious diseases specialist who must diligently rule out the presence of a true infection. However, perhaps, more importantly, we may need to initiate therapy with neuroleptic medications for which we may have little specific knowledge and experience. In this note we review the diagnosis and management of patients with delusional infestation. PMID:27366186
Peacock, Stephanie J; Connors, Brendan M; Krkosek, Martin; Irvine, James R; Lewis, Mark A
The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host-parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations.
Peacock, Stephanie J.; Connors, Brendan M.; Krkošek, Martin; Irvine, James R.; Lewis, Mark A.
The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host–parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations. PMID:24352951
Akkaş, Önder; Cengiz, Zeynep Taş
This study was carried out to detect the prevalence and evaluate risk factors of Pediculus capitis infestation in four primary schools in Iğdır in April and May, 2010. The study was performed on 2222 students (6-15 years old), 1116 female and 1106 male. The hair of the students, especially from the neck and back of the head, were examined for egg, nymph and imago of P. capitis. The samples taken from the students were brought to the Medical Laboratory of Health Services Vocational School of Iğdır University for examination. Each student answered a questionnaire containing some questions related to the infestation. The imago, nymph or eggs of the parasite were encountered in 22.9% of females and in 3.2% of males. Prevalence of infestation in all students was 13.1%. It was determined that there was a significant relation between head louse infestation and gender, socioeconomic status of the schools, hair length, number of people living in the home and the number of rooms in the house. In most comparisons, relations between prevalence of pediculosis capitis and education level, income level and job of the children's father and education level of the children's mother were found significant at different levels.
... of a sesame seed, and are tan to gray in color. Lice need to suck a tiny bit of blood to survive, and they sometimes live on people's heads and lay eggs in the hair , on the back of the neck, or behind ...
Meleney, W P; Roberts, I H
Insect juvenile hormone mimics (IJH) at 0.1 and 0.01% were used as sprays for control of the short-nosed cattle louse, Haematopinus eurysternus Denny, on 11 heavily infested Hereford cows. A significant reduction of lice occurred although eradication was achieved in only one case. Severe reactions, apparently associated with the death or failure of complete development of cattle grub larvae, Hypoderma sp. Latr., were seen in the IJH-treated cows.
Costa, Andrea P; Silva, Arannadia B; Costa, Francisco B; Xavier, Gabriel S; Martins, Thiago F; Labruna, Marcelo B; Guerra, Rita M S N C
This study evaluated for the first time, ectoparasite infestations on dogs from urban and rural areas of the continental land of the state of Maranhão, northeastern Brazil. In total, 622 dogs were examined for ectoparasite infestations. Overall, 392 (63.0%) were infested with ectoparasites, 154 (51.3%) of 300 urban dogs and 238 (73.9%) of 322 rural dogs. Five species of ectoparasites were found, three ticks [Rhipicephalus sanguineus (Latreille), Amblyomma ovale Koch, and Amblyomma cajennense (F.)], one flea [Ctenocephalides felis (Bouché)], and one louse [(Heterodoxus spininger (Enderlein)]. The frequency of infestation by R. sanguineus tended to be higher in urban than in rural areas, whereas infestations by Amblyomma ticks and C. felis fleas tended to be higher among rural dogs. Louse (H. spininger) infestations were similarly low among all areas. Mixed infestations by at least two species of ectoparasites on the same dog were significantly more frequent on rural than on urban dogs. The most frequent mixed infestation was by R. sanguineus and C. felis, found on 11.4% of the dogs. Further studies are warranted to evaluate canine vector-borne agents in Maranhão, especially because most of the ectoparasites here reported are vectors of major vector-borne diseases, including zoonoses of continental importance.
Delaplane, Keith S; Pietravalle, Stéphane; Brown, Mike A; Budge, Giles E
A honey bee queen mates on wing with an average of 12 males and stores their sperm to produce progeny of mixed paternity. The degree of a queen's polyandry is positively associated with measures of her colony's fitness, and observed distributions of mating number are evolutionary optima balancing risks of mating flights against benefits to the colony. Effective mating numbers as high as 40 have been documented, begging the question of the upper bounds of this behavior that can be expected to confer colony benefit. In this study we used instrumental insemination to create three classes of queens with exaggerated range of polyandry--15, 30, or 60 drones. Colonies headed by queens inseminated with 30 or 60 drones produced more brood per bee and had a lower proportion of samples positive for Varroa destructor mites than colonies whose queens were inseminated with 15 drones, suggesting benefits of polyandry at rates higher than those normally obtaining in nature. Our results are consistent with two hypotheses that posit conditions that reward such high expressions of polyandry: (1) a queen may mate with many males in order to promote beneficial non-additive genetic interactions among subfamilies, and (2) a queen may mate with many males in order to capture a large number of rare alleles that regulate resistance to pathogens and parasites in a breeding population. Our results are unique for identifying the highest levels of polyandry yet detected that confer colony-level benefit and for showing a benefit of polyandry in particular toward the parasitic mite V. destructor.
Delaplane, Keith S.; Pietravalle, Stéphane; Brown, Mike A.; Budge, Giles E.
A honey bee queen mates on wing with an average of 12 males and stores their sperm to produce progeny of mixed paternity. The degree of a queen’s polyandry is positively associated with measures of her colony’s fitness, and observed distributions of mating number are evolutionary optima balancing risks of mating flights against benefits to the colony. Effective mating numbers as high as 40 have been documented, begging the question of the upper bounds of this behavior that can be expected to confer colony benefit. In this study we used instrumental insemination to create three classes of queens with exaggerated range of polyandry– 15, 30, or 60 drones. Colonies headed by queens inseminated with 30 or 60 drones produced more brood per bee and had a lower proportion of samples positive for Varroa destructor mites than colonies whose queens were inseminated with 15 drones, suggesting benefits of polyandry at rates higher than those normally obtaining in nature. Our results are consistent with two hypotheses that posit conditions that reward such high expressions of polyandry: (1) a queen may mate with many males in order to promote beneficial non-additive genetic interactions among subfamilies, and (2) a queen may mate with many males in order to capture a large number of rare alleles that regulate resistance to pathogens and parasites in a breeding population. Our results are unique for identifying the highest levels of polyandry yet detected that confer colony-level benefit and for showing a benefit of polyandry in particular toward the parasitic mite V. destructor. PMID:26691845
Laguna, María Fabiana; Laguna, Mara Fabiana; Risau-Gusman, Sebastián
In this paper we use detailed data about the biology of the head louse (pediculus humanus capitis) to build a model of the evolution of head lice colonies. Using theory and computer simulations, we show that the model can be used to assess the impact of the various strategies usually applied to eradicate head lice, both conscious (treatments) and unconscious (grooming). In the case of treatments, we study the difference in performance that arises when they are applied in systematic and non-systematic ways. Using some reasonable simplifying assumptions (as random mixing of human groups and the same mobility for all life stages of head lice other than eggs) we model the contagion of pediculosis using only one additional parameter. It is shown that this parameter can be tuned to obtain collective infestations whose characteristics are compatible with what is given in the literature on real infestations. We analyze two scenarios: One where group members begin treatment when a similar number of lice are present in each head, and another where there is one individual who starts treatment with a much larger threshold ("superspreader"). For both cases we assess the impact of several collective strategies of treatment.
Laguna, Mara Fabiana; Risau-Gusman, Sebastián
In this paper we use detailed data about the biology of the head louse (pediculus humanus capitis) to build a model of the evolution of head lice colonies. Using theory and computer simulations, we show that the model can be used to assess the impact of the various strategies usually applied to eradicate head lice, both conscious (treatments) and unconscious (grooming). In the case of treatments, we study the difference in performance that arises when they are applied in systematic and non-systematic ways. Using some reasonable simplifying assumptions (as random mixing of human groups and the same mobility for all life stages of head lice other than eggs) we model the contagion of pediculosis using only one additional parameter. It is shown that this parameter can be tuned to obtain collective infestations whose characteristics are compatible with what is given in the literature on real infestations. We analyze two scenarios: One where group members begin treatment when a similar number of lice are present in each head, and another where there is one individual who starts treatment with a much larger threshold (“superspreader”). For both cases we assess the impact of several collective strategies of treatment. PMID:21799752
Sawicka, Bozena; Mikulak, Ewa; Gliniewicz, Aleksandra
Despite civilisation development and the easy access to pediculicides, head pediculosis remains still the social, hygienic and medical problem. In the years 2007 - 2009 in children's homes in selected provinces of Poland the questionnaire survey on the occurrence of head pediculosis and its control have been conducted. From 127 orphanages 61 (48.03%) sent back fulfilled questionnaire. The infestation level ranged from 4.63% (Swietokrzyskie Province, 2009) until 17.63% (Mazowieckie Province 2007) in the surveyed children's homes. The most head pediculosis cases were observed among girls 6 - 12 years old in children's homes from all regions investigated. The profile of pediculicides used had been changed during our study: in the first year the most often pediculicides with the insecticide permethrin were used. In the next years their use decreased, but the use of herbal and silicone pediculicides increased. The efficacy of anti-louse product was the most important factor for the respondents when they choose an pediculicide.
Poudel, S K S; Barker, S C
The prevalence of infestation with head lice and body lice, Pediculus spp. (Phthiraptera: Pediculidae) and pubic (crab) lice Pthirus pubis (L.) (Phthiraptera: Pthiridae), was recorded from 484 people in Nepal. The prevalence of head lice varied from 16% in a sample of people aged 10-39 years of age, to 59% in street children. Simultaneous infestations with head and body lice (double infestations) varied from 18% in slum children to 59% in street children.
James, P J; Garrett, J A; Moon, R D
The sampling distribution of Bovicola ovis (Schrank) on sheep was examined in two flocks, one with a light and one with a heavy infestation of lice. The derived distributions were used to calculate the sensitivity of detecting lice on individual sheep and in flocks by fleece parting regimes that varied in number of parts per animal and number of sheep per flock, different scenarios of flock sizes, proportion infested and louse density were examined. Lice were aggregated among fleece partings in the heavily infested flock and described by a negative binomial distribution with k values between 0.3 and 1.92. The distribution was indistinguishable from Poisson in the lightly infested flock. The assumed distribution had little effect on sensitivity, except when only one fleece part per animal was examined. On individual sheep where louse density was 0.5 per 10 cm part or greater, there were only marginal gains from inspecting more than 10 parts per animal. Increasing the number of sheep inspected always increased sensitivity more than increasing number of parts per sheep by an equivalent amount. This advantage was greatest in situations where a low proportion of sheep in the flock were infested with a high density of lice, and less where a low proportion of sheep were infested with a low density of lice, or a high proportion of sheep were infested with a high density of lice.
Badiaga, S; Brouqui, P
Several of the infectious diseases associated with human lice are life-threatening, including epidemic typhus, relapsing fever, and trench fever, which are caused by Rickettsia prowazekii, Borrelia recurrentis, and Bartonella quintana, respectively. Although these diseases have been known for several centuries, they remain a major public health concern in populations living in poor-hygiene conditions because of war, social disruption, severe poverty, or gaps in public health management. Poor-hygiene conditions favour a higher prevalence of body lice, which are the main vectors for these diseases. Trench fever has been reported in both developing and developed countries in populations living in poor conditions, such as homeless individuals. In contrast, outbreaks of epidemic typhus and epidemic relapsing fever have occurred in jails and refugee camps in developing countries. However, reports of a significantly high seroprevalence for epidemic typhus and epidemic relapsing fever in the homeless populations of developed countries suggest that these populations remain at high risk for outbreaks of these diseases. Additionally, experimental laboratory studies have demonstrated that the body louse can transmit other emerging or re-emerging pathogens, such as Acinetobacter baumannii and Yersinia pestis. Therefore, a strict survey of louse-borne diseases and the implementation of efficient delousing strategies in these populations should be public health priorities.
Studdiford, James S; Conniff, Kathryn M; Trayes, Kathryn P; Tully, Amber S
The significant resurgence of bedbugs in the past decade has been attributed to pesticide resistance, more frequent travel, lack of public awareness, and inadequate pest control programs. Bedbugs are obligate blood parasites (insect family Cimicidae). They can withstand a large range of temperatures but are attracted to warmth and carbon dioxide. They typically feed just before dawn. Cutaneous reactions to bedbug bites can include macules, papules, wheals, vesicles, bullae, and nodules. Bites may be confused with other skin conditions. Bedbug bite reactions are typically self-limited and resolve within one to two weeks without treatment. Bedbug infestation may cause significant psychological distress. The diagnosis of a bedbug infestation is based on history, appearance of bites, and inspection of sleeping quarters. Although there is no evidence that bedbugs transmit disease, systemic reactions may include asthma, angioedema, generalized urticaria, iron deficiency anemia, and, rarely, anaphylaxis. An integrated pest management strategy should be employed to eliminate infestation. Tactics include vacuuming, heat or cold treatment, trapping devices, and pesticides.
Freudenmann, Roland W; Lepping, Peter
This papers aims at familiarizing psychiatric and nonpsychiatric readers with delusional infestation (DI), also known as delusional parasitosis. It is characterized by the fixed belief of being infested with pathogens against all medical evidence. DI is no single disorder but can occur as a delusional disorder of the somatic type (primary DI) or secondary to numerous other conditions. A set of minimal diagnostic criteria and a classification are provided. Patients with DI pose a truly interdisciplinary problem to the medical system. They avoid psychiatrists and consult dermatologists, microbiologists, or general practitioners but often lose faith in professional medicine. Epidemiology and history suggest that the imaginary pathogens change constantly, while the delusional theme "infestation" is stable and ubiquitous. Patients with self-diagnosed "Morgellons disease" can be seen as a variation of this delusional theme. For clinicians, clinical pathways for efficient diagnostics and etiology-specific treatment are provided. Specialized outpatient clinics in dermatology with a liaison psychiatrist are theoretically best placed to provide care. The most intricate problem is to engage patients in psychiatric therapy. In primary DI, antipsychotics are the treatment of choice, according to limited but sufficient evidence. Pimozide is no longer the treatment of choice for reasons of drug safety. Future research should focus on pathophysiology and the neural basis of DI, as well as on conclusive clinical trials, which are widely lacking. Innovative approaches will be needed, since otherwise patients are unlikely to adhere to any study protocol.
Combescot-Lang, Catherine; Vander Stichele, Robert H; Toubate, Berthine; Veirron, Emilie; Mumcuoglu, Kosta Y
Head lice infestation is still a public health problem worldwide, with an intracountry and intercountry prevalence variation of 0.7 to 59%. There is a large variety of over-the-counter anti-louse products, but their efficacy is not always well assessed. Our objective was to test the pediculicidal and ovicidal efficacy of 21 over-the-counter head louse products, available in France during the period of 2008 to 2012. We tested children living in Tours City in central France and visiting preschools, primary schools, kindergarten, camps, and child care facilities, as well as children in their family houses, and were examined for the presence of lice. The products were collected from randomly selected pharmacies by covert investigators and then tested in the laboratory on an ex vivo sample of head lice and their eggs, collected from the hair of infested children. Living lice and unharmed eggs were collected from the scalps of 3-12 years old. The laboratory conditions for ex vivo testing mimicked the manufacturers' instructions for exposure time and application method. In 21 runs, 3919 living lice and 4321 undamaged living eggs were collected from the scalp of over 400 children. The 21 products were classified in three groups: 6 products in a group of potentially 100% pediculicidal activity and potentially 100% ovicidal activity, 8 products in a group of potentially 100% pediculicidal activity but insufficient ovicidal activity (including 2 products with claims of single application treatment), and 7 products in a group of insufficient pediculicidal activity and ovicidal activity. The pharmaceutical market for head lice products in France is swamped with poorly tested and ineffective products. Rigorous efficacy testing preregistration and periodic screening and testing of effectiveness in the post-registration period should be endorsed by the health authorities.
Li, Hu; Barker, Stephen C.
Fragmented mitochondrial (mt) genomes have been reported in 11 species of sucking lice (suborder Anoplura) that infest humans, chimpanzees, pigs, horses, and rodents. There is substantial variation among these lice in mt karyotype: the number of minichromosomes of a species ranges from 9 to 20; the number of genes in a minichromosome ranges from 1 to 8; gene arrangement in a minichromosome differs between species, even in the same genus. We sequenced the mt genome of the guanaco louse, Microthoracius praelongiceps, to help establish the ancestral mt karyotype for sucking lice and understand how fragmented mt genomes evolved. The guanaco louse has 12 mt minichromosomes; each minichromosome has 2–5 genes and a non-coding region. The guanaco louse shares many features with rodent lice in mt karyotype, more than with other sucking lice. The guanaco louse, however, is more closely related phylogenetically to human lice, chimpanzee lice, pig lice, and horse lice than to rodent lice. By parsimony analysis of shared features in mt karyotype, we infer that the most recent common ancestor of sucking lice, which lived ∼75 Ma, had 11 minichromosomes; each minichromosome had 1–6 genes and a non-coding region. As sucking lice diverged, split of mt minichromosomes occurred many times in the lineages leading to the lice of humans, chimpanzees, and rodents whereas merger of minichromosomes occurred in the lineage leading to the lice of pigs and horses. Together, splits and mergers of minichromosomes created a very complex and dynamic mt genome organization in the sucking lice. PMID:28164215
Frankowski, Barbara L; Weiner, Leonard B
Head lice infestation is associated with little morbidity but causes a high level of anxiety among parents of school-aged children. This statement attempts to clarify issues of diagnosis and treatment of head lice and makes recommendations for dealing with head lice in the school setting.
Freudenmann, Roland W.; Lepping, Peter
Summary: This papers aims at familiarizing psychiatric and nonpsychiatric readers with delusional infestation (DI), also known as delusional parasitosis. It is characterized by the fixed belief of being infested with pathogens against all medical evidence. DI is no single disorder but can occur as a delusional disorder of the somatic type (primary DI) or secondary to numerous other conditions. A set of minimal diagnostic criteria and a classification are provided. Patients with DI pose a truly interdisciplinary problem to the medical system. They avoid psychiatrists and consult dermatologists, microbiologists, or general practitioners but often lose faith in professional medicine. Epidemiology and history suggest that the imaginary pathogens change constantly, while the delusional theme “infestation” is stable and ubiquitous. Patients with self-diagnosed “Morgellons disease” can be seen as a variation of this delusional theme. For clinicians, clinical pathways for efficient diagnostics and etiology-specific treatment are provided. Specialized outpatient clinics in dermatology with a liaison psychiatrist are theoretically best placed to provide care. The most intricate problem is to engage patients in psychiatric therapy. In primary DI, antipsychotics are the treatment of choice, according to limited but sufficient evidence. Pimozide is no longer the treatment of choice for reasons of drug safety. Future research should focus on pathophysiology and the neural basis of DI, as well as on conclusive clinical trials, which are widely lacking. Innovative approaches will be needed, since otherwise patients are unlikely to adhere to any study protocol. PMID:19822895
Veneziano, Vincenzo; Neglia, Gianluca; Galietti, Alfredo; Rufrano, Domenico; Bassini, Andrea; Mariani, Ugo; Gokbulut, Cengiz
The chewing louse Werneckiella equi is an ectoparasite of donkeys and other equids. Alphacypermethrin (ACYP) is a pyrethroid insecticide commonly used for the control of insects of veterinary and public health concerns. A trial was conducted to assess the efficacy of ACYP against W. equi on naturally infested donkeys. Parasitological investigations were performed on 13 animals. On day 0, the donkeys received ACYP pour-on at the manufacturer's recommended dose rate for cattle. Louse counts were performed on days -1, 7, 14, 21, 28, 35, 42, 49, and 56 at seven predilection sites on the skin of each donkey. ACYP was completely effective (100 %) from day 7, until the end of the study. ACYP was well tolerated by all animals as there were no observed clinical adverse reactions. ACYP was highly effective, safe, user-friendly, and considered to be suitable for the treatment of donkeys for W. equi infestation.
Coles, G C; Hadley, P J; Milnes, A S; Green, L E; Stosic, P J; Garnsworthy, P C
The relationship between lice infestation and leather damage was investigated in a trial involving 61 cattle, half of which were treated with ectoparasiticides for lice control either in their first or second year. Hides from the lice-free and lousy calves were removed manually at an abattoir, tanned and inspected for lice-related damage, commercially referred to as light spot and/or fleck. In both the first- and second-year animals there was a significant difference between the hides of the lousy and lice-free animals, confirming that the chewing louse Bovicola bovis is a cause of winter light spot. There was also a difference between the two groups in the levels of scratch damage. After the infested animals had been treated with fenvalerate and eprinomectin to kill all the lice, the damage to the hides had not been fully reversed 13 weeks later.
Wappler, Torsten; Smith, Vincent S; Dalgleish, Robert C
Out of the 30 extant orders of insects, all but one, the parasitic lice (Insecta: Phthiraptera), have a confirmed fossil record. Here, we report the discovery of what appears to be the first bird louse fossil: an exceptionally well-preserved specimen collected from the crater of the Eckfeld maar near Manderscheid, Germany. The 44-million-year-old specimen shows close phylogenetic affinities with modern feather louse ectoparasites of aquatic birds. Preservation of feather remnants in the specimen's foregut confirms its association as a bird ectoparasite. Based on a phylogenetic analysis of the specimen and palaeoecological data, we suggest that this louse was the parasite of a large ancestor to modern Anseriformes (swans, geese and ducks) or Charadriiformes (shorebirds). The crown group position of this fossil in the phylogeny of lice confirms the group's long coevolutionary history with birds and points to an early origin for lice, perhaps inherited from early-feathered theropod dinosaurs. PMID:15503987
Habluetzel, Annette; Carnevali, Fiorella; Lucantoni, Leonardo; Grana, Lucia; Attili, Anna Rita; Archilei, Francesca; Antonini, Marco; Valbonesi, Alessandro; Abbadessa, Valerio; Esposito, Fulvio; van der Esch, Stephen Andrew
Secondary metabolites present in the neem tree (Azadirachta indica A. Juss, Meliaceae), exhibit a wide range of biological activities in insects. However, few studies have been undertaken to assess the potential of neem products as insecticides for the control of ectoparasites of domestic animals. This study was undertaken to estimate the efficacy of Neem Azal, an azadirachtin-rich extract of neem seeds, in controlling Damalinia limbata (Phthiraptera) louse infestation of angora goats. The study was conducted on a fibre animal farm situated in Central Italy. Groups of 11-12 goats were treated with Neem Azal at an azadirachtin concentration of 650ppm or 125ppm, with Neguvon or were left untreated. Their louse burden was assessed fortnightly to monthly for 22 weeks. A reduction in louse densities of 76-96% was observed from week 2 to week 18 after treatment with the neem solution containing azadirachtin at a concentration of 650ppm. At the lower test concentration (125ppm) a reduction of 60-92% could be recorded from week 2 to week 14. Neem Azal was found to reduce the survival of both adult and nymph stages of D. limbata and to interfere with oviposition and oogenesis of female lice. A decrease in oviposition was observed in neem exposed female lice and the examination of their ovaries revealed morphological alterations in both vitellogenic and previtellogenic ovarioles at the follicular and germinal level. Since neem compounds target different life stages and physiological processes of D. limbata, the development of insecticide resistance by biting lice exposed to neem-based insecticides appears unlikely. For this reason and for its prolonged activity, which in principle allows angora goats to be protected for a large part of the mohair production cycle, neem-based insecticides may have a potential interest for mohair producing breeders.
González, Margarita P; Vargas-Chacoff, Luis; Marín, Sandra L
The year-round presence of ovigerous females of the parasite Caligus rogercresseyi in the fish farms of southern Chile results in a continuous source of the copepodid (infestive) stage of this louse. The short generation time in spring-summer could lead to high abundances of this copepodid, potentially leading to high infestation levels for fish. Knowing how heavy lice infestations affect Salmo salar can help determine how to time antiparasitic treatments so as to both minimize the treatment impact and reduce lice infestation levels for fish. This study aimed to describe the effects of high infestations of the copepodid stage of C. rogercresseyi on the physiology of S. salar. Two groups of S. salar were used: an infested group (75 copepodids per fish) and a control group (not infested). Sixty-five days after the first infestation, the infested fish group was re-infested at an infestation pressure of 200 copepodids per fish. Sampling was done prior to and following the second infestation, at 56 and 67 days (the latter 2 days following the second infestation). Several physiological variables were measured: cortisol (primary stress response) and glucose, proteins, amino acids, triglycerides, lactate, osmolality levels, and number and diameter of skin mucous cells (secondary stress responses). The plasma cortisol, glucose, and triglyceride levels were altered in the heavily infested fish, as was the diameter of skin mucous cells. These results suggest that heavy infestations of C. rogercresseyi lead to an acute stress response, metabolic reorganization, and increased mucus production in S. salar under heavy infestation conditions.
Yamagishi, Ayaka; Yao, Izumi; Johnson, Kevin P; Yoshizawa, Kazunori
Data from gene sequences and morphological structures were collected for the gull feather lice, Saemundssonia lari, Quadraceps punctatus, and Q. ornatus, parasitizing Larus crassirostris and L. schistisagus. Saemundssonia lari was collected from both gull species, and no detectable morphological and genetic differences were found between lice collected from the two different hosts. In contrast, Q. punctatus was only collected from L. crassirostris, whereas Q. ornatus was only collected from L. schistisagus. The two Quadraceps species were genetically highly divergent, and body-size differences corresponding to the gull's body size (Harrison's rule) were also detected between them. Both Quadraceps species were collected from the interbarb of the remex or rectrix, and a match in body size between the louse and the interbarb space may be important in escape from host preening defenses. In contrast, Saemundssonia is a head louse, inhabiting the finer feathers of the head and neck, which the bird cannot preen. A close match to host body size may be less important for lice in the head microhabitat. The differences in the pattern of host-specificity between Saemundssonia and Quadraceps on the two focal host species of this study were probably due to their different microhabitat preferences. More broadly, comparisons of the gene sequences of S. lari and Q. punctatus to those from other gull hosts showed that genetically almost undifferentiated populations of both species were distributed on wide range of gull species. Frequent interspecific hybridization of gulls is one possible factor that may allow these lice to maintain gene flow across multiple host species.
Veneziano, Vincenzo; Neglia, Gianluca; Cimmino, Roberta; Balestrieri, Anna; Rufrano, Domenico; Bastianetto, Eduardo; Santoro, Mario; Gokbulut, Cengiz
The sucking louse Haematopinus tuberculatus (Burmeister 1839) is an ectoparasite of buffaloes, cattle, camels, and American bison. Alphacypermethrin (ACYP) is a pyrethroid insecticide commonly used to control arthropods of veterinary and public health interest. Therapeutics, such as antiparasitic compounds, is often administered to buffaloes based on dosage and intervals recommended for cattle because very few drugs have buffalo-specific label indications. A trial was conducted on 20 louse-infested buffaloes at a farm to assess the efficacy and safety of ACYP pour-on, at the manufacturer's recommended dose for cattle, on buffaloes naturally infested by H. tuberculatus. Ten animals were assigned to ACYP-treated group (ACYP-group) and ten to untreated control group (C-group). On day 0, all ACYP-group buffaloes received alphacypermethrin pour-on. Louse counts were performed on days -1, 7, 14, 21, 28, 35, 42, 49, and 56 at eight predilection sites on the skin of each buffalo. ACYP was completely effective (100%) at day 7, highly effective (99.8%) at day 14, and completely effective (100%) from day 21 until the end of the study (day 56 post-treatment). During the trial, ACYP was well tolerated by all animals as there were no observed clinically adverse reactions. The results of this trial suggest that ACYP is an effective, safe, and user-friendly compound suitable for treatment of buffaloes with natural louse infestations.
Damriyasa, I M; Failing, K; Volmer, R; Zahner, H; Bauer, C
A cross-sectional survey was performed in 110 randomly selected pig-breeding farms of southern Hesse, Germany to estimate the prevalence of ectoparasite infestations and to find possible risk factors. Ear scrapings of, if available, 10 sows per farm were examined for Sarcoptes scabiei var. suis (De Geer) (Acaridida: Sarcoptidae) by the potassium hydroxide digestion method, and a total of 2754 sows was inspected for skin lesions and infestations with Haematopinus suis (L.) (Anoplurida: Haematopinidae). Data on farm profiles and sows were collected by a questionnaire. In total, 19.1% and 2.5% of the sows were found to be infested with S. scabiei or H. suis, respectively. The percentage of mite or louse infestation was significantly higher in sows showing pruritus than in those without skin lesions. Both ectoparasite infestations were related neither to the age of sows nor their reproduction status, nor to the time interval to last ectoparasite treatment. Using farms as the unit of analysis, the estimated prevalence of mange mite and louse infestations was 45.4% and 14.5%, respectively. There was no significant association between the presence of S. scabiei and H. suis in the farms. Risk factors for S. scabiei infestation were mixed housing of dry and nursing sows in the same unit (vs. separate housing) and straw bedding (vs. strawless). For louse infestation, only mechanical cleaning of stable units (vs. additional use of disinfection methods) and pasturing of gilts and dry sows were identified as risk factors. The economic loss by S. scabiei infestation in the study population was assessed at euro 4200 per affected farm and year on average.
Diamantis, Stephanie A; Morrell, Dean S; Burkhart, Craig N
Pediculosis capitis, or head lice, is a common infestation among children worldwide. Multiple therapies exist for the treatment of this condition, including topical pediculicides and oral medications. When used in combination with environmental decontamination, these drugs can be very effective in eradicating head lice infestation without significant adverse events. The present study discusses the use of available over-the-counter and prescription treatments, including pyrethroids and permethrin, lindane, malathion, ivermectin, and trimethoprim-sulfamethoxazole, in the treatment of head lice.
Zamani-Alavijeh, Fereshteh; Mojadam, Mehdi
Background Pediculosis is a common parasitic infestation in students worldwide, including Iran. This condition is more prevalent in populous and deprived communities with poor personal hygiene. This study sought to assess the efficacy of peer education for adopting preventive behaviors against pediculosis in female elementary school students based on the Health Belief Model (HBM). Methods A total of 179 female fifth grade students were selected using multistage random sampling and were randomly allocated to control and intervention groups. A standard questionnaire was designed and administered to collect baseline information. An educational intervention was then designed based on the conducted needs assessment. The educational program consisted of three sessions, held by peers for the intervention group. The questionnaire was re-administered one month after the intervention. Independent and paired t-test, Pearson’s correlation coefficient, and regression analysis were applied as appropriate. Results The two groups had no significant differences in the scores of knowledge, HBM constructs, or behavior before the intervention. After the intervention, however, the mean scores of all parameters significantly improved in the intervention group. Conclusion Peer education based on HBM is an effective strategy to promote preventive behaviors against pediculosis in among fifth grade female elementary school students in Iran. PMID:28072852
Trout, R T; Steelman, C D; Szalanski, A L
Louse flies, also known as deer keds (Lipoptena mazamae Rondani), infest cervids such as white-tailed deer, Odocoileus virginianus and vector pathogens such as Anaplasma and Bartonella schoenbuchensis to cattle and humans, respectively. The population genetic structure of 30 L. mazamae collected from white-tailed deer in four regions of Arkansas, U.S.A., designated by county boundaries, was examined using DNA sequences of a 259-bp region of the mitochondrial DNA rRNA 16S gene. Of the 259 nucleotide characters, 33 were variable and 6 haplotypes were identified. Two haplotypes occurred only once (haplotype 3 and 4), whereas two other haplotypes occurred in 43% (haplotype 1 in two regions) and 40% (haplotype 6 in three regions) of the samples. Phylogenetic relationships of the six L. mazamae haplotypes were constructed with other Hippoboscid and Glossinid samples and two clades resulted. Clade 1 was located in the north and western Ozarks whereas clade 2 was found in the northern and eastern Ozarks. Results from the present study indicate that Lipoptena may be a polyphyletic genus; consequently, more research into genetic variation within this genus is necessary.
Valenzuela-Muñoz, V; Gallardo-Escárate, C
Controlling infestations of copepodid ectoparasites in the salmon industry is increasingly problematic given higher instances of drug resistance or loss of sensitivity. Despite the importance of this issue, the molecular mechanisms and genes implicated in resistance/susceptibility are only scarcely understood. The objective of the present study was to identify and evaluate the expression levels of candidate genes associated with delousing drug response in the sea louse Caligus rogercresseyi. From RNA-seq data obtained for adult male and female sea lice, 62.48 M reads were assembled in 70,349 high-quality contigs. BLASTX analysis against UniprotKB/Swiss-Prot and the ESTs available for crustaceans in the NCBI database identified 870 transcripts previously related to genes associated with delousing drug response. Furthermore, 14 candidate genes were validated through RT-qPCR and were evaluated with deltamethrin and azamethiphos bioassays. The results evidenced an overregulation of genes involved in ion transport in salmon lice treated with deltamethrin, while those treated with azamethiphos evidenced an overregulation of genes such as cytochrome P450, Carboxylesterase, and acetylcholine receptors. The present study provides a multigene panel to test delousing drug response to pyrethroids and organophosphates in a highly prevalent pathogen of the Chilean salmon industry. Copyright © 2015 Elsevier B.V. All rights reserved.
Kynkäänniemi, Sanna-Mari; Kettu, Maria; Kortet, Raine; Härkönen, Laura; Kaitala, Arja; Paakkonen, Tommi; Mustonen, Anne-Mari; Nieminen, Petteri; Härkönen, Sauli; Ylönen, Hannu; Laaksonen, Sauli
Blood-sucking ectoparasites have often a strong impact on the behaviour of their hosts. The annual insect harassment of reindeer (Rangifer tarandus tarandus) has increased in the southern part of the Finnish reindeer herding area because of the recent invasion of a blood-feeding ectoparasitic louse-fly, the deer ked (Lipoptena cervi). We studied the impact of the deer ked on the behaviour of reindeer. Twelve reindeer were infested with a total of 300 keds/reindeer on six occasions in a 5-week period during the deer ked flight season in autumn, while six non-infested reindeer were used as controls. Behavioural patterns indicating potential stress were monitored by visual observation from August to December. The infested reindeer displayed more incidences of restless behaviour than the controls. Shaking and scratching were the most common forms of restless behaviour after infestation of deer keds. Increased grooming was also observed after the transplantation and also later, 1 month after the infestation. Based on the results, the deer ked infestation can cause acute behavioural disturbance in reindeer and, thus, could pose a potential threat to reindeer welfare. Antiparasitic treatment with, e.g. ivermectin, may increase the welfare of parasitized reindeer by reducing deer keds. If the deer ked infestation intensity on the reindeer herding area increases and restless behaviour of reindeer becomes more common, the present results can help in further evaluation of the duration and magnitude of behavioural changes.
Firooziyan, Samira; Sadaghianifar, Ali; Taghilou, Behrooz; Galavani, Hossein; Ghaffari, Eslam; Gholizadeh, Saber
In recent years, the increase of head louse infestation in Iran (7.4%) and especially in West-Azerbaijan Province (248%) has raised the hypothesis of insecticide resistance development. There are different mechanisms of resistance to various groups of insecticides, and knockdown resistance (kdr) is a prominent mechanism of resistance to pyrethroids, an insecticide group which is used conventionally for pediculosis control. For detection of kdr-type well-known amino acid substitutions (M815I-T917I-L920F) and additional sodium channel mutations potentially associated with kdr resistance in head and body lice, louse populations were collected from West-Azerbaijan and Zanjan Provinces of Iran. Six novel mutations were found to be located in the IIS1-2 extracellular loop (H813P) and IIS5 (I927F, L928A, R929V, L930M, and L932M) of the α-subunit. Genotyping results showed that all specimens (100%) have at least one of these or the well-known mutations. Therefore, the presence of kdr-related and novel mutations in the sodium channel is likely to be the reason for the frequent use of pyrethroid insecticides due to treatment failure against lice. Further studies are now required to evaluate the prevalence of the kdr-like mutant allele for monitoring of insecticide resistance and the management of head and body lice in other provinces of the country. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Gallardo, Anabella; Mougabure-Cueto, Gastón; Vassena, Claudia; Picollo, María Inés; Toloza, Ariel Ceferino
The use of pyrethroids to control head louse infestations have suffered considerable loss of efficacy due to the development of resistance. In the last past years, several new alternative products to synthetic pyrethroids have been developed and are sold in the Argentinean market against head lice. The present study investigated the efficacy of two new Argentinean products Nopucid Qubit® and Nopucid Bio Citrus® and its comparison with two reference products Nyda® and Hedrin®. Nopucid Qubit® is a two-phase lotion containing geraniol and citronellol (phase 1) and ciclopentaxiloxane (phase 2); while Nopucid Bio Citrus® contains dimethicone, ciclopentaxiloxane, and bergamot essential oil. These products are physically acting compounds. The sensitivity of two laboratory assays for testing insecticide activity of new formulations was also compared. Mortality (100%) of motile forms occurred after they were exposed to any product for 1 and 2 min, either by in vitro or ex vivo test. Concerning ovicidal activity, the most effective pediculicides were Nopucid Bio Citrus® and Nyda®, followed by Hedrin® and Nopucid Qubit®. The present study revealed, for the first time, the efficacy of over-the-counter commercial pediculicides available in Argentine (Nopucid Bio Citrus® and Nopucid Qubit®) on either motile stages or eggs against head lice.
James, P J; Meade, R J; Powell, D
Polymer matrix ear tags containing 13.7% w/w tetrachlorvinphos or 8.5% w/w cypermethrin were applied to Merino wethers infested with lice and carrying two months wool. The cypermethrin tags reduced louse numbers by a maximum of 89% in comparison to controls at 16 weeks after treatment and by 85% at the conclusion of the experiment 38 weeks after application. Lice were not eradicated from any sheep. The number of lice counted on sheep treated with tetrachlorvinphos-impregnated tags was not significantly different from controls.
Clark, J. Marshall; Yoon, Kyong Sup; Kim, Ju Hyeon; Lee, Si Hyeock; Pittendrigh, Barry R.
Since sequencing the human body louse genome, substantial advances have occurred in the utilization of the information gathered from louse genomes and transcriptomes. Comparatively, the body louse genome contains far fewer genes involved in environmental response, such as xenobiotic detoxification and innate immune response. Additionally, the body louse maintains a primary bacterial endosymbiont, Candidatus Riesia pediculicola, and a number of bacterial pathogens that it vectors, which have genomes that are also reduced in size. Thus, human louse genomes offer unique information and tools for use in advancing our understanding of coevolution among vectors, endosymbionts and pathogens. In this review, we summarize the current literature on the extent of pediculicide resistance, the availability of new pediculicides and information establishing this organism as an efficient model to study how xenobiotic metabolism, which is involved in insecticide resistance, is induced and how insects modify their innate immune response upon bacterial challenge resulting in enhanced vector competence. PMID:25987230
Ono, Jill C; Navin, James J; Glamb, Roman W; Hardman, John M
Myiasis, the infestation of humans and animals with fly larvae, is observed in tropical, lowland areas. Dermatobia hominis is a common cause of cutaneous human infestation in these areas. Patients often present with a furuncular lesion on the extremities, back, or scalp. We report a case of furuncular myiasis in a patient returning from a trip to South America. We will discuss the life-cycle of D. hominis and the clinical findings important in the diagnosis of myiasis.
Guha, Arun; Aditya, Gautam; Saha, Samar Kumar
The life history traits like fecundity and body size are useful predictors of life history strategies of organisms. The information on these aspects provided necessary input for control measures for ectoparasites. In view of this, the variations in the life history traits of the fish louse Argulus bengalensis Ramakrishna (1951) were assessed using age as an explanatory factor. The analyses revealed that the body weight (BW) is related to age in males as: y (BW) = 0.03 × (Age)-2.58: and in females as: y (BW) = 0.89 + 0.13x (Age). The body length and age relationship in males is observed as: y (BL) = 2.94 + 0.01x (Age) and in females as: y (BL) = 2.89 + 0.06x (Age). The degree of sexual dimorphism (DD) for BL is positively correlated (r = -0.358; df = 43; P < 0.001) with age while DD for BW is negatively correlated (r = -0.525; df = 43; P < 0.001) with age. The eggs/clutch remained between 02 and 43 for the 21st and 38th day old females. The fecundity as a function of age could be represented as: y (Eggs) = 1.62x (Age)-27.92. The increase in BW with age in female A. bengalensis favoured greater resource allocation for egg production, while in males it likely favours dispersal ability. Since body size and fecundity varied with age, the relative abundance and extent of infestation in fish host would vary with age composition of the population and recruitment of juveniles. The impacts of host specific variations on these features need to be tested further.
Salant, H; Mumcuoglu, K Y; Baneth, G
In a period cross-sectional study performed to examine ectoparasites on 340 stray cats in Jerusalem, Israel, 186 (54.7%) were infested with the cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae), 49 (14.4%) with the cat louse, Felicola subrostratus (Phthiraptera: Trichodectidae), 41 (12.0%) with the ear mite, Otodectes cynotis (Astigmata: Psoroptidae), three (0.9%) with the fur mite, Cheyletiella blakei (Trobidiformes: Cheyletidae), two (0.6%) with the itch mite Notoedres cati (Astigmata: Sarcoptidae), and 25 (7.3%) with ticks of the species Rhipicephalus sanguineus sensu lato (Ixodida: Ixodidae), Rhipicephalus turanicus or Haemaphysalis adleri (Ixodida: Ixodidae). A higher number of flea infestations was observed in apparently sick cats (P < 0.05) and in cats aged < 6 months (P < 0.05). The proportion of flea-infested cats (P < 0.01), as well as the number of fleas per infested cat (P < 0.01), was higher in autumn than in other seasons. By contrast with findings in cats with flea infestations, rates of infestation with ticks were higher amongst cats with clinical signs (P < 0.01) and cats aged ≥ 6 months (P < 0.05). The high rates of ectoparasite infestation in the cats studied constitute a risk for the spread of vector-borne infections of zoonotic and veterinary importance. © 2013 The Royal Entomological Society.
Head lice infestation is common and mainly affects children of primary school age. Treatments include licensed topical preparations containing conventional chemical insecticides and medical devices. Each of these fail to eradicate head lice in some patients and resistance is a problem with chemical insecticides. Dimeticone 4% lotion (Hedrin - Thornton & Ross) is a new treatment licensed "for the eradication of head lice infestations". Here we consider its place in the context of other options.
Raoult, D; Birtles, R J; Montoya, M; Perez, E; Tissot-Dupont, H; Roux, V; Guerra, H
Typhus and other louse-transmitted bacterial infections in Peruvian sierra communities are known to occur but have not recently been assessed. In this study, 194 of 1,280 inhabitants of four villages in Calca Province in the Urubamba Valley were included. Thirty-nine (20%) of the 194 volunteers had antibodies to Rickettsia prowazekii, whereas 24 (12%) had antibodies to Bartonella quintana and 2 against Borrelia recurrentis. There was a significant correlation between the presence of infesting ectoparasites and antibodies to R. prowazekii, as well as between antibodies to R. prowazekii and ectoparasite infestation and fever in the previous 6 months. The proportion of inhabitants infested with ectoparasites was significantly higher in the highest-altitude village than in the other three villages. Two volunteers' antibody levels suggested a recent typhus infection, but only B. quintana DNA was amplified from lice. Epidemic typhus remains extant in the area, and B. quintana infections were encountered and documented for the first time in South America.
Nasser, Mohamed Gamal El-Den; Alahmed, Azzam; Shobrak, Mohamed
The endemic avifauna of Arabia is unique and characteristic through the whole region. Little is known about these birds and their ectoparasites. The Arabian partridge Alectoris melanocephala (Rüppell, 1835) and Philby's partridge Alectoris philbyi Lowe, 1934 are two endemic species which are distributed through the Sarawat Mountains in Saudi Arabia and Yemen. Captive breeding population of these birds were examined for chewing lice at the National Wildlife Research Center (NWRC) near Ta'if. Only one rare species of louse, Cuculotogaster arabicus (Clay 1938), was found to infest these birds. The occurrence of such species is considered a first record of the genus Cuculotogaster from Saudi Arabia, and the association of C. arabicus with Philby's partridge is considered a new host/parasite association. The clear diagnostic characters, high definition photos, and drawing of male genitalia are available through this paper.
Leonardi, M S; Crespo, E A; Raga, J A; Aznar, F J
In this study, we document patterns of vertical transmission of the amphibious louse Antarctophthirus microchir (Echinophthiriidae) in pups of South American sea lion, Otaria flavescens, from Patagonia. Vertical transmission is fundamental for the long-term stability of A. microchir populations because only pups stay long enough (1 month) on land for the louse to reproduce. A total of 72 pups ≤7 days old from a single rookery were captured and examined for lice. Infection parameters and population structure of A. microchir did not differ among pups collected at the beginning, middle, and end of the reproductive season, suggesting that patterns of early vertical transmission are not affected by the increase of rookery size during this period. Over 60% of 1-day-old pups were infected with A. microchir, and recruitment increased in pups up to 3 days old and then leveled off. In 1-day-old pups, significantly more adults than nymphs were found, but the pattern was reversed in older pups. The number of first-stage nymphs was significantly smaller than that of second- and third-stage nymphs, as it was the number of males vs. females, particularly in 1-day-old pups. Three non-exclusive hypotheses could account for these patterns, i.e., recruitment merely reflects the population structure of A. microchir is cows; the relative ability of lice to pass from cows onto pups increases in advanced instars; and/or natural selection favors transmission of adults, especially females, because they accrue greater fitness. The importance of latter hypothesis should not be underestimated in a species with a tight reproductive schedule.
Farlora, Rodolfo; Valenzuela-Muñoz, Valentina; Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian
Aquaporins are small integral membrane proteins that function as pore channels for the transport of water and other small solutes across the cell membrane. Considering the important roles of these proteins in several biological processes, including host-parasite interactions, there has been increased research on aquaporin proteins recently. The present study expands on the knowledge of aquaporin family genes in parasitic copepods, examining diversity and expression during the ontogeny of the sea louse Caligus rogercresseyi. Furthermore, aquaporin expression was evaluated during the early infestation of Atlantic (Salmo salar) and Coho salmon (Oncorhynchus kisutch). Deep transcriptome sequencing data revealed eight full length and two partial open reading frames belonging to the aquaporin protein family. Clustering analyses with identified Caligidae sequences revealed three major clades of aquaglyceroporins (Cr-Glp), classical aquaporin channels (Cr-Bib and Cr-PripL), and unorthodox aquaporins (Cr-Aqp12-like). In silico analysis revealed differential expression of aquaporin genes between developmental stages and between sexes. Male-biased expression of Cr-Glp1_v1 and female-biased expression of Cr-Bib were further confirmed in adults by RT-qPCR. Additionally, gene expressions were measured for seven aquaporins during the early infestation stage. The majority of aquaporin genes showed significant differential transcription expressions between sea lice parasitizing different hosts, with Atlantic salmon sea lice exhibiting overall reduced expression as compared to Coho salmon. The observed differences in the regulation of aquaporin genes may reveal osmoregulatory adaptations associated with nutrient ingestion and metabolite waste export, exposing complex host-parasite relationships in C. rogercresseyi. Copyright © 2016 Elsevier B.V. All rights reserved.
SHORT COMMUNICATIONS New Record of Lipoptena cervi and Updated Checklist of the Louse Flies (Diptera: Hippoboscidae) of the Republic of Korea HEUNG...Republic of Korea. A total of Þve females and 10 males was collected from eight of 29 Korean water deer ,Hydropotes inermis argyropus Swinhoe, from...collection records, and repositories are also noted. KEY WORDS louse ßy, Lipoptena cervi, Hippoboscidae, water deer , Korea Both sexes of louse ßies or
Abd El Bagi, Mohamed E; Sammak, Bassam M; Mohamed, Abdulrahman E; Al Karawi, Mohamed A; Al Shahed, Mona; Al Thagafi, Mohamed A
Twenty-five percent of the world's population could be suffering parasitic infestation. Highest prevalence is in underdeveloped agricultural and rural areas in the tropical and subtropical regions. In some areas incidence may reach 90% of the population. In contrast, some major economic projects intended to promote local development have, paradoxically, caused parasitic proliferation, e.g. bilharziasis in Egypt and Sudan and Chagas disease in Brazil. The commonest cosmopolitan gastrointestinal parasite is Entamoeba histolytica. Some intestinal parasite are endemic in temperate climates, e.g. Entrobius vermicularis. The AIDS epidemic has increased the prevalence and severity of parasitic disease, particularly Strongyloides stercolaris. Tropical parasites are seen in Western people who travel to tropical countries. Radiology has acquired a major role in diagnosis and management of gastrointestinal parasite infestations and their complications.
Chaves, I S; Luvizzotto-Santos, R; Sampaio, L A N; Bianchini, A; Martínez, P E
Fish have developed protective strategies against monogeneans through immunological responses. In this study, immune adaptive response to parasites was analysed in the pompano Trachinotus marginatus infested by Bicotylophora trachinoti. Hosts were pre-treated with formalin and after 10 days assigned to one of the following experimental treatments: (1) fish infested with remaining eggs of B. trachinoti; (2) fish infested with remaining eggs of B. trachinoti and experimentally re-infested by exposure to T. marginatus heavily infested with B. trachinoti. Samples were collected at 0, 15, and 30 days. Gills were dissected to check the presence of B. trachinoti. Blood was collected for haematological and biochemical assays. Spleen and head-kidney were dissected for phagocytosis assay. The spleen-somatic index was also calculated. Re-infested fish showed a faster and higher parasite infestation than infested ones. The parasite mean abundance at 15 days was 24.86+/-13.32 and 11.67+/-8.57 for re-infested and infested fish, respectively. In both groups, hosts showed an immune adaptive response to parasite infestation that was marked by an increased number of leukocytes. Also, phagocytosis (%) in spleen and head-kidney cells was stimulated after parasite infestation (92.50+/-3.73 and 66.00+/-9.54, respectively), becoming later depressed (77.39+/-6.69 and 53.23+/-9.14, respectively). These results support the hypothesis that monogenean infestation induces a biphasic response of the non-specific defence mechanisms in the pompano T. marginatus. This response is marked by an initial stimulation followed by a later depression of the non-specific defence mechanisms.
Gillespie, Joseph J.; Ammerman, Nicole C.; Beier-Sexton, Magda; Sobral, Bruno S.; Azad, Abdu F.
In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed. PMID:19036234
Dalvin, Sussie T.; Bron, James E.; Nilsen, Frank; Boxshall, Geoff; Skern-Mauritzen, Rasmus
Each year the salmon louse (Lepeophtheirussalmonis Krøyer, 1838) causes multi-million dollar commercial losses to the salmon farming industry world-wide, and strict lice control regimes have been put in place to reduce the release of salmon louse larvae from aquaculture facilities into the environment. For half a century, the Lepeophtheirus life cycle has been regarded as the only copepod life cycle including 8 post-nauplius instars as confirmed in four different species, including L. salmonis. Here we prove that the accepted life cycle of the salmon louse is wrong. By observations of chalimus larvae molting in incubators and by morphometric cluster analysis, we show that there are only two chalimus instars: chalimus 1 (comprising the former chalimus I and II stages which are not separated by a molt) and chalimus 2 (the former chalimus III and IV stages which are not separated by a molt). Consequently the salmon louse life cycle has only six post-nauplius instars, as in other genera of caligid sea lice and copepods in general. These findings are of fundamental importance in experimental studies as well as for interpretation of salmon louse biology and for control and management of this economically important parasite. PMID:24069203
Kirkness, Ewen F.; Haas, Brian J.; Sun, Weilin; Braig, Henk R.; Perotti, M. Alejandra; Clark, John M.; Lee, Si Hyeock; Robertson, Hugh M.; Kennedy, Ryan C.; Elhaik, Eran; Gerlach, Daniel; Kriventseva, Evgenia V.; Elsik, Christine G.; Graur, Dan; Hill, Catherine A.; Veenstra, Jan A.; Walenz, Brian; Tubío, José Manuel C.; Ribeiro, José M. C.; Rozas, Julio; Johnston, J. Spencer; Reese, Justin T.; Popadic, Aleksandar; Tojo, Marta; Raoult, Didier; Reed, David L.; Tomoyasu, Yoshinori; Kraus, Emily; Mittapalli, Omprakash; Margam, Venu M.; Li, Hong-Mei; Meyer, Jason M.; Johnson, Reed M.; Romero-Severson, Jeanne; VanZee, Janice Pagel; Alvarez-Ponce, David; Vieira, Filipe G.; Aguadé, Montserrat; Guirao-Rico, Sara; Anzola, Juan M.; Yoon, Kyong S.; Strycharz, Joseph P.; Unger, Maria F.; Christley, Scott; Lobo, Neil F.; Seufferheld, Manfredo J.; Wang, NaiKuan; Dasch, Gregory A.; Struchiner, Claudio J.; Madey, Greg; Hannick, Linda I.; Bidwell, Shelby; Joardar, Vinita; Caler, Elisabet; Shao, Renfu; Barker, Stephen C.; Cameron, Stephen; Bruggner, Robert V.; Regier, Allison; Johnson, Justin; Viswanathan, Lakshmi; Utterback, Terry R.; Sutton, Granger G.; Lawson, Daniel; Waterhouse, Robert M.; Venter, J. Craig; Strausberg, Robert L.; Collins, Frank H.; Zdobnov, Evgeny M.; Pittendrigh, Barry R.
As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens. PMID:20566863
Kirkness, Ewen F; Haas, Brian J; Sun, Weilin; Braig, Henk R; Perotti, M Alejandra; Clark, John M; Lee, Si Hyeock; Robertson, Hugh M; Kennedy, Ryan C; Elhaik, Eran; Gerlach, Daniel; Kriventseva, Evgenia V; Elsik, Christine G; Graur, Dan; Hill, Catherine A; Veenstra, Jan A; Walenz, Brian; Tubío, José Manuel C; Ribeiro, José M C; Rozas, Julio; Johnston, J Spencer; Reese, Justin T; Popadic, Aleksandar; Tojo, Marta; Raoult, Didier; Reed, David L; Tomoyasu, Yoshinori; Kraus, Emily; Krause, Emily; Mittapalli, Omprakash; Margam, Venu M; Li, Hong-Mei; Meyer, Jason M; Johnson, Reed M; Romero-Severson, Jeanne; Vanzee, Janice Pagel; Alvarez-Ponce, David; Vieira, Filipe G; Aguadé, Montserrat; Guirao-Rico, Sara; Anzola, Juan M; Yoon, Kyong S; Strycharz, Joseph P; Unger, Maria F; Christley, Scott; Lobo, Neil F; Seufferheld, Manfredo J; Wang, Naikuan; Dasch, Gregory A; Struchiner, Claudio J; Madey, Greg; Hannick, Linda I; Bidwell, Shelby; Joardar, Vinita; Caler, Elisabet; Shao, Renfu; Barker, Stephen C; Cameron, Stephen; Bruggner, Robert V; Regier, Allison; Johnson, Justin; Viswanathan, Lakshmi; Utterback, Terry R; Sutton, Granger G; Lawson, Daniel; Waterhouse, Robert M; Venter, J Craig; Strausberg, Robert L; Berenbaum, May R; Collins, Frank H; Zdobnov, Evgeny M; Pittendrigh, Barry R
As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens.
Leonardi, Maria Soledad; Aznar, F Javier; Crespo, Enrique A; Lazzari, Claudio R
Despite the incredible success of insects in colonizing almost every habitat, they remain virtually absent in one major environment--the open sea. A variety of hypotheses have been raised to explain why just a few insect species are present in the ocean, but none of them appears to be fully explanatory. Lice belonging to the family Echinophthiriidae are ectoparasites on different species of pinnipeds and river otters, i.e. they have amphibious hosts, who regularly perform long excursions into the open sea reaching depths of hundreds of meters (thousands of feets). Consequently, lice must be able to support not only changes in their surrounding media, but also extreme variations in hydrostatic pressure as well as breathing in a low oxygen atmosphere. In order to shed some light on the way lice can survive during the diving excursions of their hosts, we have performed a series of experiments to test the survival capability of different instars of Antarctophthirus microchir (Phthiraptera: Anoplura) from South American sea lions Otaria flavescens, when submerged into seawater. These experiments were aimed at analyzing: (a) immersion tolerance along the louse life; (b) lice's ability to obtain oxygen from seawater; (c) physiological responses and mechanisms involved in survival underwater. Our experiments showed that the forms present in non-diving pups--i.e. eggs and first-instar nymphs--were unable to tolerate immersion in water, while following instars and adults, all usually found in diving hosts, supported it very well. Furthermore, as long as the level of oxygen dissolved in water was higher, the lice survival capability underwater increased, and the recovery period after returning to air declined. These results are discussed in relation to host ecology, host exploitation and lice functional morphology.
Di Marco, L; Berghenti, M; Cocuzza, C; Manfredini, A; Sciascia, V; Salmi, R
The Authors present 2 cases of enterobiasis of appendix observed on a total of 186 appendicectomies. Enterobius infestation is an uncommon cause of acute appendicitis. Preoperative diagnosis of pinworm infestation is almost impossible without clinical suspect. Parasites may produce symptoms which resemble acute appendicitis but parasitic infection rarely causes it. It is also important considered in the differential diagnosis cases that mimic Crohn's disease.
Lee, Yueh-Chang; Chiu, Cheng-Jen
This case report describes a female toddler with manifestations of ocular leech infestation. A 2-year-old girl was brought to our outpatient clinic with a complaint of irritable crying after being taken to a stream in Hualien 1 day previous, where she played in the water. The parents noticed that she rubbed her right eye a lot. Upon examination, the girl had good fix and follow in either eye. Slit-lamp examination showed conjunctival injection with a moving dark black–brown foreign body partly attached in the lower conjunctiva. After applying topical anesthetics, the leech, measuring 1 cm in length, was extracted under a microscope. The patient began using topical antibiotic and corticosteroid agents. By 1 week after extraction, the patient had no obvious symptoms or signs, except for a limited subconjunctival hemorrhage, and no corneal/scleral involvement was observed. PMID:25784786
Manual removal (using conditioner and comb or a wet comb) can be used in the treatment of head lice. Head lice infestation (Pediculosis humanus capitis) is a common problem. It is diagnosed by visualising the lice. As half of people infested with head lice will not scratch, all people in contact with a person affected with head lice should be manually checked for infestations. Wet combing is easily and safely performed at home, but persistence is needed. This article describes the process of head lice removal using a wet comb. It has NHMRC Level 2 evidence of efficacy and no serious adverse effects have been reported.
Cornejo, Isabel; Andrini, Olga; Niemeyer, María Isabel; Marabolí, Vanessa; González-Nilo, F Danilo; Teulon, Jacques; Sepúlveda, Francisco V; Cid, L Pablo
Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs) ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl) and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC(50) value of around 200 nM, being cooperative (n(H) = 2) for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new, more efficient
Niemeyer, María Isabel; Marabolí, Vanessa; González-Nilo, F. Danilo; Teulon, Jacques; Sepúlveda, Francisco V.; Cid, L. Pablo
Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs) ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl) and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC50 value of around 200 nM, being cooperative (nH = 2) for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new, more efficient
Yamauchi, Takeo; Tsuda, Yoshio; Sato, Yukita; Murata, Koichi
During a mosquito collection, a female of the pigeon louse fly, Pseudolynchia canariensis (Diptera: Hippoboscidae), was collected by a mosquito trap baited with dry ice in Ishigaki-jima, Yaeyama Islands, Japan. This is the 1st record of P. canariensis from Yaeyama Islands.
Darcis, Gilles; Hayette, Marie-Pierre; Bontems, Sebastien; Sauvage, Anne-Sophie; Meuris, Christelle; Van Esbroeck, Marjan; Leonard, Philippe
We report a case of louse-borne relapsing fever (LBRF) in a refugee from Somalia who had arrived in Belgium a few days earlier. He complained of myalgia and secondarily presented fever. Blood smears revealed spirochetes later identified as Borrelia recurrentis. LBRF should be considered in countries hosting refugees, particularly those who transit through endemic regions.
Souza, Ugo; Dall'Agnol, Bruno; Michel, Thais; Webster, Anelise; Klafke, Guilherme; Martins, João Ricardo; Kasper, Carlos Benhur; Trigo, Tatiane Campos; Ott, Ricardo; Maria de Assis Jardim, Márcia; Reck, José
Louse flies or deer keds, Lipoptena spp., are widespread in Neotropical cervids, but the vector-borne pathogens of louse flies had only been previously reported in the Northern hemisphere. This is the first report of Bartonella spp. in deer louse flies (Lipoptena mazamae) in the neotropics collected from gray brocket deer ( Mazama gouazoubira ) in Southern Brazil. DNA from Bartonella sp. was detected in all 429 L. mazamae collected from 11 road-killed gray brocket deer. The same sequences of DNA of Bartonella spp. were identified in samples. Gray brocket deer are abundant in Brazil, so Bartonella-infected Lipoptena spp. may be widely distributed in the neotropics.
Hanson, Shari K; Hill, Jeffrey E; Watson, Craig A; Yanong, Roy P E; Endris, Richard
The effect of 0.2% emamectin benzoate (SLICE; Intervet/ Schering-Plough Animal Health, Roseland, New Jersey) administered in top-dressed, pelleted commercial fish feed was evaluated for control of freshwater Argulus sp. in goldfish Carassius auratus and koi carp, a variant of common carp Cyprinus carpio, in freshwater aquaria at 24-25 degrees C. Sixteen individually housed goldfish were each exposed to 37 Argulus. The number of fish lice attached to each fish at the start of the experiment was not determined; however, the total number of motile fish lice in each aquarium (on fish and in the water) was determined at the start and end of each experiment. Eight goldfish were fed the control diet (0 microg x kg fish biomass(-1) x d(-1)) and eight were fed the medicated diet (50 microg x kg fish biomass(-1) x d(-1)) for seven consecutive days. After treatment, fish louse infestation in controls was 20.5 +/- 1.5 (mean +/- SE) lice per fish. No Argulus were found on fish in the treated group. In a separate experiment, 10 individually housed koi were each exposed to 128 Argulus. Five koi were fed the control diet and five were fed a low-dose medicated diet (5 microg x kg fish biomass(-1) x d(-1)) for 7 d. After treatment, fish louse infestation among the controls was 14.6 +/- 3.8 lice per koi. No Argulus were found on koi in the treated group. Hence, a 7-d regimen of oral emamectin benzoate controlled experimental infestation of Argulus when administered to goldfish at 50 microg x kg fish biomass(-1) x d(-1) and to koi at 5 microg x kg fish biomass(-1) x d(-1).
Mazigo, Humphrey D; Behamana, Emmanuel; Zinga, Maria; Heukelbach, Jorg
Tungiasis is caused by the jigger flea Tunga penetrans. We describe a case of severe infestation from Kigoma region, Western Tanzania. A 19-year-old male with epilepsy and mental disability presented with ulcerated and inflamed toes. Clinical examination revealed the presence of approximately 810 embedded jigger fleas on the feet, and another 60 lesions on the hands. The patient presented with fissures on the feet, hands and soles. He had difficulty walking and erythematous, oedematous, ulcerated and inflamed skin around the feet. Living conditions were precarious. The patient was assisted to extract the embedded fleas and his feet were washed with disinfectants. Oral antibiotics were given. The case shows that the disease may reach high parasite loads in Tanzanian individuals, with consequently severe pathology. There have been single reports of returning tourists from Tanzania with tungiasis, but the epidemiological situation and the geographic occurrence of the disease in this country are not known. Systematic studies are needed to increase knowledge on the epidemiological situation of tungasis in Tanzania and to identify endemic areas.
Gordon, Shirley C.
Head lice infestation is a worldwide phenomenon that affects persons of all ages. For reasons that are not entirely clear, a number of children experience persistent head lice infestations lasting weeks, months, or years. Little is known about the impact of caring for children with persistent head lice on parents/caregivers. The purpose of this…
Gordon, Shirley C.
Head lice infestation is a worldwide phenomenon that affects persons of all ages. For reasons that are not entirely clear, a number of children experience persistent head lice infestations lasting weeks, months, or years. Little is known about the impact of caring for children with persistent head lice on parents/caregivers. The purpose of this…
Balashov, Iu S
Long term observations of the abundance fluctuations of the deer louse-fly Lipoptena cervi were carried out in forest areas of the Leningrad, Novgorod and Pskov provinces in 1988-1995. The registration of the winged individuals was held in the period of the mass flight in August by the number of deer louse-flies attacking a collector man during 1 km of the pathway. The abundance of deer louse-flies was being high everywhere up to 1993, while it decreased by 8-29 times in 1994-1995. The reason of the abundance decrease of deer louse-flies is the abrupt abundance decrease of the main host, the elk Alces alces.
Veracx, Aurélie; Raoult, Didier
Head lice and body lice have distinct ecologies and differ slightly in morphology and biology, questioning their taxonomic status. Over the past 10 years many genetic studies have been undertaken. Controversial data suggest that not only body lice but also head lice can serve as vectors of Bartonella quintana, and a better understanding of louse epidemiology is crucial. Here, we review taxonomic studies based on biology and genetics, including genomic data on lice, lice endosymbionts, and louse-transmitted bacteria. We recommend that studies of human lice employ morphological and biological characteristics in conjunction with transcriptomic date because lice seem to differ mainly in gene expression (and not in gene content), leading to different phenotypes.
Althomali, Sarah Ali; Alzubaidi, Lamya Mohammed; Alkhaldi, Dhelal Musleh
Lice feed on human blood, and heavy and chronic lice infestation can lead to chronic blood loss with resultant iron deficiency anaemia. Although no definite relationship between lice infestation and iron deficiency anaemia has been described, the concurrent presence of these two conditions has been reported in children and adults, as well as in cattle. We present a case of a young woman with severe iron deficiency anaemia that could not be explained by the known causes of iron deficiency anaemia. However, the patient was found to have heavy and chronic head lice infestation.
Ashfaq, Muhammad; Prosser, Sean; Nasir, Saima; Masood, Mariyam; Ratnasingham, Sujeevan; Hebert, Paul D. N.
The study analyzes sequence variation of two mitochondrial genes (COI, cytb) in Pediculus humanus from three countries (Egypt, Pakistan, South Africa) that have received little prior attention, and integrates these results with prior data. Analysis indicates a maximum K2P distance of 10.3% among 960 COI sequences and 13.8% among 479 cytb sequences. Three analytical methods (BIN, PTP, ABGD) reveal five concordant OTUs for COI and cytb. Neighbor-Joining analysis of the COI sequences confirm five clusters; three corresponding to previously recognized mitochondrial clades A, B, C and two new clades, “D” and “E”, showing 2.3% and 2.8% divergence from their nearest neighbors (NN). Cytb data corroborate five clusters showing that clades “D” and “E” are both 4.6% divergent from their respective NN clades. Phylogenetic analysis supports the monophyly of all clusters recovered by NJ analysis. Divergence time estimates suggest that the earliest split of P. humanus clades occured slightly more than one million years ago (MYa) and the latest about 0.3 MYa. Sequence divergences in COI and cytb among the five clades of P. humanus are 10X those in their human host, a difference that likely reflects both rate acceleration and the acquisition of lice clades from several archaic hominid lineages. PMID:26373806
Ashfaq, Muhammad; Prosser, Sean; Nasir, Saima; Masood, Mariyam; Ratnasingham, Sujeevan; Hebert, Paul D N
The study analyzes sequence variation of two mitochondrial genes (COI, cytb) in Pediculus humanus from three countries (Egypt, Pakistan, South Africa) that have received little prior attention, and integrates these results with prior data. Analysis indicates a maximum K2P distance of 10.3% among 960 COI sequences and 13.8% among 479 cytb sequences. Three analytical methods (BIN, PTP, ABGD) reveal five concordant OTUs for COI and cytb. Neighbor-Joining analysis of the COI sequences confirm five clusters; three corresponding to previously recognized mitochondrial clades A, B, C and two new clades, "D" and "E", showing 2.3% and 2.8% divergence from their nearest neighbors (NN). Cytb data corroborate five clusters showing that clades "D" and "E" are both 4.6% divergent from their respective NN clades. Phylogenetic analysis supports the monophyly of all clusters recovered by NJ analysis. Divergence time estimates suggest that the earliest split of P. humanus clades occurred slightly more than one million years ago (MYa) and the latest about 0.3 MYa. Sequence divergences in COI and cytb among the five clades of P. humanus are 10X those in their human host, a difference that likely reflects both rate acceleration and the acquisition of lice clades from several archaic hominid lineages.
Davies, Charlotte E; Thomas, Gethin R; Maffeis, Thierry G G; Wootton, Emma C; Penny, Mark W; Rowley, Andrew F
The ectoparasitic copepod, Nicothoë astaci (the 'lobster louse'), infests the gills of the European lobster, Homarus gammarus. There have been limited studies on this haematophagous species; therefore knowledge of this parasite is rudimentary. The current study examines the surface morphology of this parasitic copepod, detached from the host, concentrating on adaptations of the suctorial mouthpart, the oral disc. Cryo-scanning electron microscopy revealed structural adaptations that facilitate attachment of these parasites to the gill filaments of their lobster host. The aperture of the feeding channel, through which host haemolymph is drawn, is only ca. 5μm in diameter. The edge of the oral disc is lined with numerous setae, whilst the surface of the disc is covered with large numbers of small (<1μm in diameter) teeth-like structures, which presumably pierce through, and grip, the cuticle lining of the host's gill. Overall, these structures are thought to provide a 'vacuum seal' to assist in pumping of blood, via peristalsis, into the alimentary canal of the copepod host.
Despite successful eradication techniques and specific effective therapies, insect bites and infestations remain a source of great human misery. The current scabies pandemic shows no signs of abating. Bed bugs, which through the ages have been second only to the malarial mosquito as an insect vector of fatal infection, have now been implicated in the transmission of Hepatitis B and possibly African acquired immune deficiency syndrome (AIDS). The incidence of head- and pubic lice is on the rise, the latter paralleling, and often co-existing with, other sexually transmitted diseases. Black widow spiders are native to many populous areas in southern Canada, and the brown recluse spider's range now encompasses Canada, thanks to moving vans and central heating. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:21263961
Riabi, H Ramezani Awal; Atarodi, Ar
Pediculosis (head lice) is considered as one of the most common health problems of the students in primary schools. The purpose of this study was to survey the prevalence rate of the infestation in the schools of Gonabad City (south of Khorasan-e-Razavi Province) to prevent its outbreak by on-time planning. In this retrospective-descriptive study, data were collected from the files of recorded health examinations of 55,997 female and male students of Gonabad City. We surveyed the infested cases to Pediculus capitis and P. corporis during 2006-2010. We used schools health unit of the city health center and review reports of infestation to head lice and body lice in cumulative centers. The reports showed 398 cases of P. capitis and 3 P. corporis infestations, which 91.5% were female (P <0.05). Generally 46.4% were from rural and 63.6% were from urban areas (P <0.05). 71.3% of the infestation to head lice was from the last month and the rest had recently been infested. The most age group being infested were students of 6-10 years old and the lowest were >17 yr. Pediculosis infestation has become a major health problem in primary school students in south of Khorasan-e-Razavi.
Riabi, H Ramezani Awal; Atarodi, AR
Background Pediculosis (head lice) is considered as one of the most common health problems of the students in primary schools. The purpose of this study was to survey the prevalence rate of the infestation in the schools of Gonabad City (south of Khorasan-e-Razavi Province) to prevent its outbreak by on-time planning. Methods In this retrospective-descriptive study, data were collected from the files of recorded health examinations of 55,997 female and male students of Gonabad City. We surveyed the infested cases to Pediculus capitis and P. corporis during 2006-2010. We used schools health unit of the city health center and review reports of infestation to head lice and body lice in cumulative centers. Results The reports showed 398 cases of P. capitis and 3 P. corporis infestations, which 91.5% were female (P <0.05). Generally 46.4% were from rural and 63.6% were from urban areas (P <0.05). 71.3% of the infestation to head lice was from the last month and the rest had recently been infested. The most age group being infested were students of 6-10 years old and the lowest were >17 yr. Conclusion Pediculosis infestation has become a major health problem in primary school students in south of Khorasan-e-Razavi. PMID:23133477
Harper, Sheree E; Spradling, Theresa A; Demastes, James W; Calhoun, Courtney S
Pocket gophers and their symbiotic chewing lice form a host-parasite assemblage known for a high degree of cophylogeny, thought to be driven by life history parameters of both host and parasite that make host switching difficult. However, little work to date has focused on determining whether these life histories actually impact louse populations at the very fine scale of louse infrapopulations (individuals on a single host) at the same or at nearby host localities. We used microsatellite and mtDNA sequence data to make comparisons of chewing-louse (Thomomydoecus minor) population subdivision over time and over geographic space where there are different potential amounts of host interaction surrounding a zone of contact between two hybridizing pocket-gopher subspecies. We found that chewing lice had high levels of population isolation consistent with a paucity of horizontal transmission even at the very fine geographic scale of a single alfalfa field. We also found marked genetic discontinuity in louse populations corresponding with host subspecies and little, if any, admixture in the louse genetic groups even though the lice are closely related. The correlation of louse infrapopulation differentiation with host interaction at multiple scales, including across a discontinuity in pocket-gopher habitat, suggests that host behaviour is the primary driver of parasite genetics. This observation makes sense in light of the life histories of both chewing lice and pocket gophers and provides a powerful explanation for the well-documented pattern of parallel cladogenesis in pocket gophers and chewing lice.
Oldenburg, Marcus; Baur, Xaver
Cockroaches are detected ashore worldwide. At present, little is known about cockroach infestation on ships. The authors' objective in this study was to assess the current prevalence of cockroach infestation on seagoing vessels. In August 2005, port officials investigated cockroach infestation on 59 ships in Hamburg's port via standardized procedures (ie, illuminating hiding places and using pyrethrum spray). About 3 minutes after illumination or chemical provocation, the inspectors counted the number of insects escaping from their hiding places. The examination revealed cockroach presence in the galley or mess room of 6 ships (10.2%). These ships were bigger than 10,000 gross register tons (GRT) and older than 7 years. Inspectors detected the cockroach species Blattella germanica on 5 ships and Blatta orientalis on 1 ship. The standardized use of pyrethrum spray more frequently detected cockroaches than did inspection or illumination of their hiding places.
Durden, L A
A new species of sucking louse, Neohaematopinus sundasciuri, collected from the tree squirrel, Sundasciurus juvencus, is described from Palawan Island, Philippines. An updated world list of the genus Neohaematopinus is presented; this documents descriptive citations, known hosts, and geographical distributions with interpretive annotations for each of the 32 species now included in the genus. The geographical distributions of Neohaematopinus sciuri and N. sciurinus are discussed.
Morsy, T A; el-Ela, R G; Morsy, A T; Nassar, M M; Khalaf, S A
Lice and scabies are the main ectoparasites transmitted by contagious, particularly among children living in crowded areas. Examination of an orphanage children (both sex, 2-6 years old), showed infestation with head louse (64.1%), body louse (53.8%) and scabies (26.9%). The results were discussed on the light of the work done before.
Massey, Robert L; Rodriguez, Gabriel
Cutaneous infestation of the scrotum with botfly larva from the order Dioptera, family Cuterebridae, species Dermatobia hominis is extremely rare. The first reported case of scrotal myiasis in the United States of America is described here. There is increased potential for human infestation with botfly larva (Dermatobia hominis), due to a more affluent and mobile population traveling to tropical areas for exotic vacations where the botfly is endemic. Urology nurses in a clinical setting should be aware of patients with unusual clinical presentations involving the genitourinary system.
Heukelbach, Jörg; Oliveira, Fabíola A S; Speare, Richard
Because topical compounds based on insecticidal chemicals are the mainstay of head lice treatment, but resistance is increasing, alternatives, such as herbs and oils are being sold to treat head lice. To test a commercial shampoo based on seed extract of Azadirachta indica (neem tree) for its in vitro effect, head lice (n=17) were collected from school children in Australia and immersed in Wash-Away Louse shampoo (Alpha-Biocare GmbH, Germany). Vitality was evaluated for more than 3 h by examination under a dissecting microscope. Positive and negative controls were a commercially available head lice treatment containing permethrin 1% (n=19) and no treatment (n=14). All lice treated with the neem shampoo did not show any vital signs from the initial examination after immersion at 5-30 min; after 3 h, only a single louse showed minor signs of life, indicated by gut movements, a mortality of 94%. In the permethrin group, mortality was 20% at 5 min, 50% at 15 min, and 74% after 3 h. All 14 head lice of the negative control group survived during the observation period. Our data show that Wash-Away Louse is highly effective in vitro against head lice. The neem shampoo was more effective than the permethrin-based product. We speculate that complex plant-based compounds will replace the well-defined chemical pediculicides if resistance to the commonly used products further increases.
Wells, Konstans; Beaucournu, Jean-Claude; Durden, Lance A; Petney, Trevor N; Lakim, Maklarin B; O'Hara, Robert B
Domestic dogs, Canis lupus, have been one of the longest companions of humans and have introduced their own menagerie of parasites and pathogens into this relationship. Here, we investigate the parasitic load of 212 domestic dogs with fleas (Siphonaptera) chewing lice (Phthiraptera), and ticks (Acarina) along a gradient from rural areas with near-natural forest cover to suburban areas in Northern Borneo (Sabah, Malaysia). We used a spatially-explicit hierarchical Bayesian model that allowed us to impute missing data and to consider spatial structure in modelling dog infestation probability and parasite density. We collected a total of 1,968 fleas of two species, Ctenocephalides orientis and Ctenocephalides felis felis, from 195 dogs (prevalence, 92 %). Flea density was higher on dogs residing in houses made of bamboo or corrugated metal (increase of 40 % from the average) compared to timber or stone/compound houses. Host-dependent and landscape-level environmental variables and spatial structure only had a weak explanatory power. We found adults of the invasive chewing louse Heterodoxus spiniger on 42 dogs (20 %). The effect of housing conditions was opposite to those for fleas; lice were only found on dogs residing in stone or timber houses. We found ticks of the species Rhipicephalus sanguineus as well as Haemaphysalis bispinosa gp., Haemaphysalis cornigera, Haemaphysalis koenigsbergi, and Haemaphysalis semermis on 36 dogs (17 %). The most common tick species was R. sanguineus, recorded from 23 dogs. Tick infestations were highest on dogs using both plantation and forest areas (282 % increase in overall tick density of dogs using all habitat types). The infestation probability of dogs with lice and ticks decreased with elevation, most infestations occurred below 800 m above sea level. However, the density of lice and ticks revealed no spatial structure; infestation probability of dogs with these two groups revealed considerable autocorrelation. Our study shows
Cluster tarweed(Madia glomerata) infests many livestock ranges in eastern Oregon, using soil moisture and nutrients that should be producing plants more valuable as forage and more effective in stabilizing watersheds. No completely satisfactory method of eliminating this obnoxious plant and replacing it, with forage has yet been found. Recent...
Peock, S; Maunder, J W
Piperonal, once used to kill lice in Australian hospitals, was acclaimed as an effective pediculicide (Corlette, 1925) by the standards of the day. It is unusual in also exhibiting a repellent action against lice, a property only recently realised. A new, easy to use, low-fragrance, pump action spray, which incorporates 2% piperonal, was tested in the laboratory using clothing lice in an arena test and was found to exhibit consistently high repellency after half an hour, dropping only slightly after 24 hours. A well known multi-purpose insect repellent, diethyltoluamide (DEET), was then tested against piperonal. A 2% solution of piperonal was found to be almost twice as effective as a 50% solution of DEET. In arena tests using lice with the tip segments of both antennae removed, no behavioural differences or statistically significant differences from a random distribution could be found between untreated and Rappell-treated areas. This strongly suggests that sense organ(s) on the tip of the antenna are necessary for detection of the repellent. Although there can be no strict correlation between results in the laboratory and potential efficacy in the field, materials such as insecticides found to be effective in the laboratory have been found to be equally effective in the field. Furthermore, what with the threat of resistance to head lice insecticides, ineffectual treatment and the lack of contact tracing, a repellent would be of obvious use in the control of head lice.
Burrows, Stephanie; Perron, Stéphane; Susser, Stephanie
Patient: Male, 62 Final Diagnosis: Bipolar disorder Symptoms: Bordeline personality disorder Medication: — Clinical Procedure: Bed bug infestation Specialty: Psychiatry Objective: Unusual clinical course Background: In the past decade, bed bug infestations have been increasingly common in high income countries. Psychological consequences of these infestations are rarely examined in the scientific literature. Case Report: We present a case, based on a coroner’s investigation report, of a woman with previous psychiatric morbidity who jumped to her death following repeated bed bug infestations in her apartment. Our case report shows that the bed bug infestations were the likely trigger for the onset a negative psychological state that ultimately led to suicide. Conclusions: Given the recent surge in infestations, rapid action needs to be taken not only in an attempt to control and eradicate the bed bugs but also to adequately care for those infested by bed bugs. PMID:23826461
Burrows, Stephanie; Perron, Stéphane; Susser, Stephanie
Male, 62. Bipolar disorder. Bordeline personality disorder. - Bed bug infestation. Psychiatry. Unusual clinical course. In the past decade, bed bug infestations have been increasingly common in high income countries. Psychological consequences of these infestations are rarely examined in the scientific literature. We present a case, based on a coroner's investigation report, of a woman with previous psychiatric morbidity who jumped to her death following repeated bed bug infestations in her apartment. Our case report shows that the bed bug infestations were the likely trigger for the onset a negative psychological state that ultimately led to suicide. Given the recent surge in infestations, rapid action needs to be taken not only in an attempt to control and eradicate the bed bugs but also to adequately care for those infested by bed bugs.
Stefka, Jan; Hypsa, Václav
The genealogy, population structure and population dynamics of the sucking louse Polyplax serrata were analysed across four host species of the genus Apodemus. An analysis of 126 sequences of cytochrome c oxidase subunit I using phylogenetic approaches and haplotype networking revealed a clear structure of European samples, forming three distinct and genetically distant clades with different host specificities. Although a clear connection was detected between the host and parasite genealogies/phylogenies, a uniform pattern of co-speciation was not found. For example, a dramatic shift in the degree of host specificity was demonstrated for two related louse lineages living in sympatry and sharing one of their host species. While one of the louse lineages frequently parasitised two different host taxa (Apodemus sylvaticus and Apodemus flavicollis), the other louse lineage was strictly specific to A. flavicollis. The estimate of divergence time between the two louse lineages indicates that they may have arisen due to parasite duplication on A. flavicollis.
Burgess, Ian F
Head lice can only be diagnosed by finding live lice, as eggs take 7 days to hatch and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings, longer hair, and of lower socioeconomic group. We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for head lice? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 26 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review, we present information relating to the effectiveness and safety of the following interventions: benzyl alcohol, dimeticone, herbal and essential oils, insecticide combinations, isopropyl myristate, ivermectin, lindane, malathion, mechanical removal by combing ("bug busting"), oral trimethoprim-sulfamethoxazole (co-trimoxazole, TMP-SMX), permethrin, phenothrin, pyrethrum, and spinosad.
Introduction Head lice can only be diagnosed by finding live lice, as eggs take 7 days to hatch and may appear viable for weeks after death of the egg. Infestation may be more likely in school children, with risks increased in children with more siblings, longer hair, and of lower socioeconomic group. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for head lice? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 26 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: benzyl alcohol, dimeticone, herbal and essential oils, insecticide combinations, isopropyl myristate, ivermectin, lindane, malathion, mechanical removal by combing ("bug busting"), oral trimethoprim–sulfamethoxazole (co-trimoxazole, TMP-SMX), permethrin, phenothrin, pyrethrum, and spinosad. PMID:21575285
Carmichael, Stephen N; Bekaert, Michaël; Taggart, John B; Christie, Hayden R L; Bassett, David I; Bron, James E; Skuce, Philip J; Gharbi, Karim; Skern-Mauritzen, Rasmus; Sturm, Armin
The salmon louse (Lepeophtheirus salmonis (Krøyer, 1837)) is a parasitic copepod that can, if untreated, cause considerable damage to Atlantic salmon (Salmo salar Linnaeus, 1758) and incurs significant costs to the Atlantic salmon mariculture industry. Salmon lice are gonochoristic and normally show sex ratios close to 1:1. While this observation suggests that sex determination in salmon lice is genetic, with only minor environmental influences, the mechanism of sex determination in the salmon louse is unknown. This paper describes the identification of a sex-linked Single Nucleotide Polymorphism (SNP) marker, providing the first evidence for a genetic mechanism of sex determination in the salmon louse. Restriction site-associated DNA sequencing (RAD-seq) was used to isolate SNP markers in a laboratory-maintained salmon louse strain. A total of 85 million raw Illumina 100 base paired-end reads produced 281,838 unique RAD-tags across 24 unrelated individuals. RAD marker Lsa101901 showed complete association with phenotypic sex for all individuals analysed, being heterozygous in females and homozygous in males. Using an allele-specific PCR assay for genotyping, this SNP association pattern was further confirmed for three unrelated salmon louse strains, displaying complete association with phenotypic sex in a total of 96 genotyped individuals. The marker Lsa101901 was located in the coding region of the prohibitin-2 gene, which showed a sex-dependent differential expression, with mRNA levels determined by RT-qPCR about 1.8-fold higher in adult female than adult male salmon lice. This study's observations of a novel sex-linked SNP marker are consistent with sex determination in the salmon louse being genetic and following a female heterozygous system. Marker Lsa101901 provides a tool to determine the genetic sex of salmon lice, and could be useful in the development of control strategies.
Taggart, John B.; Christie, Hayden R. L.; Bassett, David I.; Bron, James E.; Skuce, Philip J.; Gharbi, Karim; Skern-Mauritzen, Rasmus; Sturm, Armin
The salmon louse (Lepeophtheirus salmonis (Krøyer, 1837)) is a parasitic copepod that can, if untreated, cause considerable damage to Atlantic salmon (Salmo salar Linnaeus, 1758) and incurs significant costs to the Atlantic salmon mariculture industry. Salmon lice are gonochoristic and normally show sex ratios close to 1:1. While this observation suggests that sex determination in salmon lice is genetic, with only minor environmental influences, the mechanism of sex determination in the salmon louse is unknown. This paper describes the identification of a sex-linked Single Nucleotide Polymorphism (SNP) marker, providing the first evidence for a genetic mechanism of sex determination in the salmon louse. Restriction site-associated DNA sequencing (RAD-seq) was used to isolate SNP markers in a laboratory-maintained salmon louse strain. A total of 85 million raw Illumina 100 base paired-end reads produced 281,838 unique RAD-tags across 24 unrelated individuals. RAD marker Lsa101901 showed complete association with phenotypic sex for all individuals analysed, being heterozygous in females and homozygous in males. Using an allele-specific PCR assay for genotyping, this SNP association pattern was further confirmed for three unrelated salmon louse strains, displaying complete association with phenotypic sex in a total of 96 genotyped individuals. The marker Lsa101901 was located in the coding region of the prohibitin-2 gene, which showed a sex-dependent differential expression, with mRNA levels determined by RT-qPCR about 1.8-fold higher in adult female than adult male salmon lice. This study’s observations of a novel sex-linked SNP marker are consistent with sex determination in the salmon louse being genetic and following a female heterozygous system. Marker Lsa101901 provides a tool to determine the genetic sex of salmon lice, and could be useful in the development of control strategies. PMID:24147087
Discusses the five major concerns that govern a school nurse's thinking in managing head louse infestations, including dispelling misconceptions about head lice; ensuring that infestations are not missed; ensuring that parents understand instructions for effective treatment; educating the community about the correct use of pediculicides; and…
Discusses the five major concerns that govern a school nurse's thinking in managing head louse infestations, including dispelling misconceptions about head lice; ensuring that infestations are not missed; ensuring that parents understand instructions for effective treatment; educating the community about the correct use of pediculicides; and…
Allen, Julie M.; Koga, Ryuichi; Fukatsu, Takema; Sweet, Andrew D.; Johnson, Kevin P.; Reed, David L.
ABSTRACT Roughly 10% to 15% of insect species host heritable symbiotic bacteria known as endosymbionts. The lice parasitizing mammals rely on endosymbionts to provide essential vitamins absent in their blood meals. Here, we describe two bacterial associates from a louse, Proechinophthirus fluctus, which is an obligate ectoparasite of a marine mammal. One of these is a heritable endosymbiont that is not closely related to endosymbionts of other mammalian lice. Rather, it is more closely related to endosymbionts of the genus Sodalis associated with spittlebugs and feather-chewing bird lice. Localization and vertical transmission of this endosymbiont are also more similar to those of bird lice than to those of other mammalian lice. The endosymbiont genome appears to be degrading in symbiosis; however, it is considerably larger than the genomes of other mammalian louse endosymbionts. These patterns suggest the possibility that this Sodalis endosymbiont might be recently acquired, replacing a now-extinct, ancient endosymbiont. From the same lice, we also identified an abundant bacterium belonging to the genus Rickettsia that is closely related to Rickettsia ricketsii, a human pathogen vectored by ticks. No obvious masses of the Rickettsia bacterium were observed in louse tissues, nor did we find any evidence of vertical transmission, so the nature of its association remains unclear. IMPORTANCE Many insects are host to heritable symbiotic bacteria. These heritable bacteria have been identified from numerous species of parasitic lice. It appears that novel symbioses have formed between lice and bacteria many times, with new bacterial symbionts potentially replacing existing ones. However, little was known about the symbionts of lice parasitizing marine mammals. Here, we identified a heritable bacterial symbiont in lice parasitizing northern fur seals. This bacterial symbiont appears to have been recently acquired by the lice. The findings reported here provide insights
Reeves, Will K; Szumlas, Daniel E; Moriarity, John R; Loftis, Amanda D; Abbassy, Magda M; Helmy, Ibrahim M; Dasch, Gregory A
We collected 1,023 lice, representing 5 species, from rats and domestic cattle throughout 13 governorates in Egypt and tested these lice for Anaplasma marginale, Bartonella spp., Brucella spp., Borrelia recurrentis, Coxiella burnetii, Francisella tularensis, and Rickettsia spp. by PCR amplification and sequencing. Five different louse-borne bacterial agents were detected in lice from rodents or cattle, including "Bartonella rattimassiliensis", "B. phoceensis", and Bartonella sp. near Bartonella tribocorum, Coxiella burnetii, and Rickettsia typhi. More lice from governorates bordering the Mediterranean and Red Seas contained pathogens. Our data indicate that lice of urban and domestic animals harbor pathogenic or potentially pathogenic bacterial agents throughout Egypt.
Hytönen, Jukka; Khawaja, Tamim; Grönroos, Juha O; Jalava, Anna; Meri, Seppo; Oksi, Jarmo
We report two cases of louse-borne relapsing fever (LBRF) in young Somali asylum seekers having recently arrived to Finland. They had sought medical attention for a febrile illness. Blood smears were examined for suspected malaria, but instead, spirochete shaped bacteria were observed. The bacteria were confirmed as Borrelia recurrentis by PCR and sequencing. The patients survived, but their treatment was complicated by Jarisch-Herxheimer reaction. We conclude that LBRF must be considered as a diagnostic option in febrile refugees also in the northernmost parts of Europe.
Eremeeva, Marina E; Capps, Danielle; Winful, Emmanuel B; Warang, Shamta S; Braswell, Sarah E; Tokarevich, Nikolay K; Bonilla, Denise L; Durden, Lance A
Although the head louse, Pediculus humanus capitis De Geer, and body louse, Pediculus humanus humanus L., both have a worldwide distribution, the occurrence of head louse pediculosis appears to be more prevalent in modern societies despite systematic use of various pediculicides. This study tested head lice collected in rural Georgia and body lice collected in Russia for the prevalence of a kdr-biomarker that is associated with permethrin resistance. This study also screened lice for the presence of DNA from Bartonella quintana and Acinetobacter species. The kdr-permethrin resistance biomarker for the T917I mutation was detected by RFLP and PCR in 99.9% of head lice tested from Georgia, whereas only 2.9% of body lice from Russia tested positive for this kdr biomarker. DNA of B. quintana was detected in 10.3% of head lice from Georgia, whereas 84.8% of body lice from Russia tested positive. Acinetobacter DNA was detected in 80.8% (95% CI, 68-89%) of head lice from Georgia and all body lice from Russia tested. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
Infestations of head lice, body lice, scabies, and chiggers are common causes of rash and pruritus in children. Concern has arisen about development of resistance to often-used treatments, but a comprehensive approach to eradication is usually very effective. In this article, Dr Potts describes the presentation of ectoparasites and discusses conservative treatment and the safe use of pediculicides.
Skugor, Stanko; Glover, Kevin Alan; Nilsen, Frank; Krasnov, Aleksei
Background The salmon louse (SL) is an ectoparasitic caligid crustacean infecting salmonid fishes in the marine environment. SL represents one of the major challenges for farming of salmonids, and veterinary intervention is necessary to combat infection. This study addressed gene expression responses of Atlantic salmon infected with SL, which may account for its high susceptibility. Results The effects of SL infection on gene expression in Atlantic salmon were studied throughout the infection period from copepodids at 3 days post infection (dpi) to adult lice (33 dpi). Gene expression was analyzed at three developmental stages in damaged and intact skin, spleen, head kidney and liver, using real-time qPCR and a salmonid cDNA microarray (SFA2). Rapid detection of parasites was indicated by the up-regulation of immunoglobulins in the spleen and head kidney and IL-1 receptor type 1, CD4, beta-2-microglobulin, IL-12β, CD8α and arginase 1 in the intact skin of infected fish. Most immune responses decreased at 22 dpi, however, a second activation was observed at 33 dpi. The observed pattern of gene expression in damaged skin suggested the development of inflammation with signs of Th2-like responses. Involvement of T cells in responses to SL was witnessed with up-regulation of CD4, CD8α and programmed death ligand 1. Signs of hyporesponsive immune cells were seen. Cellular stress was prevalent in damaged skin as seen by highly significant up-regulation of heat shock proteins, other chaperones and mitochondrial proteins. Induction of the major components of extracellular matrix, TGF-β and IL-10 was observed only at the adult stage of SL. Taken together with up-regulation of matrix metalloproteinases (MMP), this classifies the wounds afflicted by SL as chronic. Overall, the gene expression changes suggest a combination of chronic stress, impaired healing and immunomodulation. Steady increase of MMP expression in all tissues except liver was a remarkable feature of SL
Amanzougaghene, Nadia; Akiana, Jean; Mongo Ndombe, Géor; Davoust, Bernard; Nsana, Nardiouf Sjelin; Parra, Henri-Joseph; Fenollar, Florence; Raoult, Didier; Mediannikov, Oleg
Background Head lice, Pediculus humanus capitis, occur in four divergent mitochondrial clades (A, B, C and D), each having particular geographical distributions. Recent studies suggest that head lice, as is the case of body lice, can act as a vector for louse-borne diseases. Therefore, understanding the genetic diversity of lice worldwide is of critical importance to our understanding of the risk of louse-borne diseases. Methodology/Principal Findings Here, we report the results of the first molecular screening of pygmies’ head lice in the Republic of Congo for seven pathogens and an analysis of lice mitochondrial clades. We developed two duplex clade-specific real-time PCRs and identified three major mitochondrial clades: A, C, and D indicating high diversity among the head lice studied. We identified the presence of a dangerous human pathogen, Borrelia recurrentis, the causative agent of relapsing fever, in ten clade A head lice, which was not reported in the Republic of Congo, and B. theileri in one head louse. The results also show widespread infection among head lice with several species of Acinetobacter. A. junii was the most prevalent, followed by A. ursingii, A. baumannii, A. johnsonii, A. schindleri, A. lwoffii, A. nosocomialis and A. towneri. Conclusions/Significance Our study is the first to show the presence of B. recurrentis in African pygmies’ head lice in the Republic of Congo. This study is also the first to report the presence of DNAs of B. theileri and several species of Acinetobacter in human head lice. Further studies are needed to determine whether the head lice can transmit these pathogenic bacteria from person to another. PMID:27911894
Amanzougaghene, Nadia; Akiana, Jean; Mongo Ndombe, Géor; Davoust, Bernard; Nsana, Nardiouf Sjelin; Parra, Henri-Joseph; Fenollar, Florence; Raoult, Didier; Mediannikov, Oleg
Head lice, Pediculus humanus capitis, occur in four divergent mitochondrial clades (A, B, C and D), each having particular geographical distributions. Recent studies suggest that head lice, as is the case of body lice, can act as a vector for louse-borne diseases. Therefore, understanding the genetic diversity of lice worldwide is of critical importance to our understanding of the risk of louse-borne diseases. Here, we report the results of the first molecular screening of pygmies' head lice in the Republic of Congo for seven pathogens and an analysis of lice mitochondrial clades. We developed two duplex clade-specific real-time PCRs and identified three major mitochondrial clades: A, C, and D indicating high diversity among the head lice studied. We identified the presence of a dangerous human pathogen, Borrelia recurrentis, the causative agent of relapsing fever, in ten clade A head lice, which was not reported in the Republic of Congo, and B. theileri in one head louse. The results also show widespread infection among head lice with several species of Acinetobacter. A. junii was the most prevalent, followed by A. ursingii, A. baumannii, A. johnsonii, A. schindleri, A. lwoffii, A. nosocomialis and A. towneri. Our study is the first to show the presence of B. recurrentis in African pygmies' head lice in the Republic of Congo. This study is also the first to report the presence of DNAs of B. theileri and several species of Acinetobacter in human head lice. Further studies are needed to determine whether the head lice can transmit these pathogenic bacteria from person to another.
Education Digest: Essential Readings Condensed for Quick Review, 2004
Pediculosis, or head lice infestation, has been a public health nuisance for thousands of years. Since most affected children are under 12 years of age, head lice is an elementary school issue. The question then becomes how schools should handle cases of head lice. Some organizations advocate immediately sending children home from school, while…
Education Digest: Essential Readings Condensed for Quick Review, 2004
Pediculosis, or head lice infestation, has been a public health nuisance for thousands of years. Since most affected children are under 12 years of age, head lice is an elementary school issue. The question then becomes how schools should handle cases of head lice. Some organizations advocate immediately sending children home from school, while…
Burgess, Ian F
Background Treatment of head lice using physically acting preparations based on silicones is currently replacing insecticide use due to widespread resistance to neurotoxic agents. It has been postulated that some products act by asphyxiation, although the limited experimental evidence and the anatomy of the louse respiratory system suggest this is unlikely. Results Observation over several hours of lice treated using 4% high molecular weight dimeticone in a volatile silicone base showed that, although rapidly immobilised initially, the insects still exhibited small movements of extremities and death was delayed. One common effect of treatment is inhibition of the louse's ability to excrete water by transpiration through the spiracles. Inability to excrete water that is ingested as part of the louse blood meal appears to subject the louse gut to osmotic stress resulting in rupture. Scanning electron microscopy coupled with X-ray microanalysis to detect silicon showed dimeticone lotion is deposited in the spiracles and distal region of the tracheae of lice and in some cases blocks the lumen or opening entirely. Conclusion This work raises doubts that lice treated using dimeticone preparations die from anoxia despite blockage of the outer respiratory tract because movements can be observed for hours after exposure. However, the blockage inhibits water excretion, which causes physiological stress that leads to death either through prolonged immobilisation or, in some cases, disruption of internal organs such as the gut. PMID:19232080
Louse-borne relapsing fever is an acute febrile illness caused by the spirochete Borrelia recurrentis and transmitted to man by infected body lice...shown to contain lipopolysaccharide (46), but extracted spirochetal lipopolysaccharides contained no pyrogenic activity for rabbits (47). Borreliae have...investigators. Mergenhagen et al extracted lipopolysaccharides from Borrelia vincentii, B. buccalis, and small oral treponemes and found them to be
Nazari, Mansour; Saidijam, Massoud
To determine the intensity of Pediculus capitis infestation (abundance) among school children, children's sex and social factors were analyzed as modifiers of the general prevalence of parasitism. The study included 847 school children (407 girls, 440 boys) between 6 and 12 years, from 12 in public rural primary schools of Hamedan, Province of Hamedan, Iran. Classic prevalence was obtained as the percentage of children with nits and/or lice. The general prevalence was 6.85% (girls: 13.5%; boys: 0.7%, p < 0.001), head lice were much more commonly detected in girls than in boys. The obtained results showed that there was significant variations between head lice infestation and the factors such as parents' literacy, type of hair, previous infestation, sharing of bed and comb and care centers, while there was no significant variation between school grade, parents' job, members of family and pediculosis in the studied areas (p > 0.05). Sex and social factor are important modifiers of P. capitis general prevalence and degree of infestation. The classification of children by intensity of infestation allowed a more precise delimitation of this condition, which is especially important for disease surveillance and application of control measures.
Gutiérrez, Ricardo; Cohen, Liron; Morick, Danny; Mumcuoglu, Kosta Y.; Harrus, Shimon
Bartonella spp. are worldwide-distributed facultative intracellular bacteria that exhibit an immense genomic diversity across mammal and arthropod hosts. The occurrence of cattle-associated Bartonella species was investigated in the cattle tail louse Haematopinus quadripertusus and in dairy cattle blood from Israel. Lice were collected from cattle from two dairy farms during summer 2011, and both lice and cow blood samples were collected from additional seven farms during the successive winter. The lice were identified morphologically and molecularly using 18S rRNA sequencing. Thereafter, they were screened for Bartonella DNA by conventional and real-time PCR assays using four partial genetic loci (gltA, rpoB, ssrA, and internal transcribed spacer [ITS]). A potentially novel Bartonella variant, closely related to other ruminant bartonellae, was identified in 11 of 13 louse pools collected in summer. In the cattle blood, the prevalence of Bartonella infection was 38%, identified as B. bovis and B. henselae (24 and 12%, respectively). A third genotype, closely related to Bartonella melophagi and Bartonella chomelii (based on the ssrA gene) and to B. bovis (based on the ITS sequence) was identified in a single cow. The relatively high prevalence of these Bartonella species in cattle and the occurrence of phylogenetically diverse Bartonella variants in both cattle and their lice suggest the potential role of this animal system in the generation of Bartonella species diversity. PMID:24973066
Grotmol, Sindre; Nilsen, Frank
A remarkable feature of many parasites is a high degree of host specificity but the mechanisms behind are poorly understood. A major challenge for parasites is to identify and infect a suitable host. Many species show a high degree of host specificity, being able to survive only on one or a few related host species. To facilitate transmission, parasite’s behavior and reproduction has been fine tuned to maximize the likelihood of infection of a suitable host. For some species chemical cues that trigger or attract the parasite in question have been identified but how metazoan parasites themselves receive these signals remains unknown. In the present study we show that ionotropic receptors (IRs) in the salmon louse are likely responsible for identification of a specific host. By using RNAi to knock down the expression level of different co-receptors, a significant change of infectivity and settlement of lice larvae was achieved on Atlantic salmon. More remarkably, knock down of the IRs changed the host specificity of the salmon louse and lice larvae settled at a significant rate on host that the wild type lice rejected within minutes. To our knowledge, this has never before been demonstrated for any metazoan parasite. Our results show that the parasites are able to identify the host quickly upon settlement, settle and initiate the parasitic life style if they are on the right host. This novel discovery opens up for utilizing the host recognition system for future parasite control. PMID:28582411
Kimsey, Lynn S
The literature on chronic pruritus, paresthesia and delusional infestation indicates that a wide variety of conditions ranging from AIDS to vitamin deficiencies may cause these symptoms. In many, or perhaps most of these cases, activation of itch pathways seems to be the underlying cause of the skin sensations and perhaps even the visual hallucinations characteristic of delusional infestation. The principle difference between diagnoses of chronic pruritus and delusional infestation appears to lie in the patient's interpretation of the cause of the symptoms, rather than underlying physiological differences. Delusional infestation, paresthesia and chronic pruritus must be considered symptoms of underlying conditions.
El-Azazy, Osama M E; Al-Behbehani, Bahja; Abdou, Nadra-Elwgoud M I
Bedbug, Cimex lectularius, human infestations were reported in the State of Kuwait in the last 2 years. Eleven separate infestations from different localities were received at the Veterinary Laboratories indicating that bedbug is widespread in the State of Kuwait. There was circumstantial evidence to suggest the transfer of bugs with recent immigrants or used furniture. The spread of infestation can be attributed to the increase in migrant labor and their mobility inside the country. The increase in reported cases appears also consistent with a worldwide increase in bedbug infestations.
Samaha, A; Green, W R; Traboulsi, E I; Ma'luf, R
To report the rare occurrence of tick infestation of the eyelid margin. A 58-year-old woman was initially examined with a small yellow lesion of the left upper eyelid margin that appeared after she felt a sting near her eye. Close examination disclosed an insect body attached to the eyelid margin. En bloc excision of the insect with part of the eyelid was performed. Gross examination of the specimen identified the organism as the nymph stage of a bloated tick of the genus Hyalomma but of an uncertain species. Ticks (Hyalomma) can become embedded in the meibomian gland orifice and manifest as a mass at the eyelid margin.
Mech, L.D.; Thiel, R.P.; Fritts, S.H.; Berg, W.E.
The dog louse was found on 19 wolves (Canis lupus) and six coyotes (C. latrans) from Minnesota and Wisconsin during the July-February, 1973 through 1983, period. No evidence was found that lice had any serious effect on wolf survival.
Muhammad Zayyid, M; Saidatul Saadah, R; Adil, A R; Rohela, M; Jamaiah, I
This is a survey of 120 children for scabies and head lice infestations in a welfare home in Pulau Pinang. Children from this welfare home (Rumah Kanak-Kanak Taman Bakti, Kepala Batas, Pulau Pinang) were randomly selected. Majority of them were Malays (72.5%) and the rest were Indians. The infestation rates were highest in the 10-12 years age group with 46% and 70% for scabies and head lice respectively. Head lice was more commonly seen in girls (65%) than boys (29%). Scabies was more commonly seen in boys (50%) than girls (16%). Overall prevalence rate for scabies was 31% and for head lice infestation was 49%.
Slonka, G F; McKinley, T W; McCroan, J E; Sinclair, S P; Schultz, M G; Hicks, F; Hill, N
An outbreak of head lice infestation (pediculosis) occurred in elementary school children in Barrow County, Georgia, in January 1974. An investigation was initiated to define the magnitude of the outbreak, determine factors that contribute to transmission, and disseminate information on control. All elementary school children in the county were examined for head lice and answered a questionnaire. Fifty-three (3%) of 1,783 white pupils were infested, but none of the 500 black pupils was infested. Distribution of infestation in the white pupils was influenced by grade, bed-sharing, socioeconomic status, infestation of other family members, crowding in the home, and family size; distribution was not influenced by hair length or the sex of the pupil. Recommendations for control based on the results of the investigation included procedures for identifying and processing cases, distributing free pediculicides, continuing surveillance, educating school personnel and parents on how to control the parasite.
Svoboda, Tomislav J.; De Jong, Iain J.; Kabasele, Karl J.; Gogosis, Evie
Until recently, bed bugs have been considered uncommon in the industrialized world. This study determined the extent of reemerging bed bug infestations in homeless shelters and other locations in Toronto, Canada. Toronto Public Health documented complaints of bed bug infestations from 46 locations in 2003, most commonly apartments (63%), shelters (15%), and rooming houses (11%). Pest control operators in Toronto (N = 34) reported treating bed bug infestations at 847 locations in 2003, most commonly single-family dwellings (70%), apartments (18%), and shelters (8%). Bed bug infestations were reported at 20 (31%) of 65 homeless shelters. At 1 affected shelter, 4% of residents reported having bed bug bites. Bed bug infestations can have an adverse effect on health and quality of life in the general population, particularly among homeless persons living in shelters. PMID:15829190
Hart, Sarah J; Veblen, Thomas T; Mietkiewicz, Nathan; Kulakowski, Dominik
Understanding disturbance interactions and their ecological consequences remains a major challenge for research on the response of forests to a changing climate. When, where, and how one disturbance may alter the severity, extent, or occurrence probability of a subsequent disturbance is encapsulated by the concept of linked disturbances. Here, we evaluated 1) how climate and forest habitat variables, including disturbance history, interact to drive 2000s spruce beetle (Dendroctonus rufipennis) infestation of Engelmann spruce (Picea engelmannii) across the Southern Rocky Mountains; and 2) how previous spruce beetle infestation affects subsequent infestation across the Flat Tops Wilderness in northwestern Colorado, which experienced a severe landscape-scale spruce beetle infestation in the 1940s. We hypothesized that drought and warm temperatures would promote infestation, whereas small diameter and non-host trees, which may reflect past disturbance by spruce beetles, would inhibit infestation. Across the Southern Rocky Mountains, we found that climate and forest structure interacted to drive the 2000s infestation. Within the Flat Tops study area we found that stands infested in the 1940s were composed of higher proportions of small diameter and non-host trees ca. 60 years later. In this area, the 2000s infestation was constrained by a paucity of large diameter host trees (> 23 cm at diameter breast height), not climate. This suggests that there has not been sufficient time for trees to grow large enough to become susceptible to infestation. Concordantly, we found no overlap between areas affected by the 1940s infestation and the current infestation. These results show a severe spruce beetle infestation, which results in the depletion of susceptible hosts, can create a landscape template reducing the potential for future infestations.
Hart, Sarah J.; Veblen, Thomas T.; Mietkiewicz, Nathan; Kulakowski, Dominik
Understanding disturbance interactions and their ecological consequences remains a major challenge for research on the response of forests to a changing climate. When, where, and how one disturbance may alter the severity, extent, or occurrence probability of a subsequent disturbance is encapsulated by the concept of linked disturbances. Here, we evaluated 1) how climate and forest habitat variables, including disturbance history, interact to drive 2000s spruce beetle (Dendroctonus rufipennis) infestation of Engelmann spruce (Picea engelmannii) across the Southern Rocky Mountains; and 2) how previous spruce beetle infestation affects subsequent infestation across the Flat Tops Wilderness in northwestern Colorado, which experienced a severe landscape-scale spruce beetle infestation in the 1940s. We hypothesized that drought and warm temperatures would promote infestation, whereas small diameter and non-host trees, which may reflect past disturbance by spruce beetles, would inhibit infestation. Across the Southern Rocky Mountains, we found that climate and forest structure interacted to drive the 2000s infestation. Within the Flat Tops study area we found that stands infested in the 1940s were composed of higher proportions of small diameter and non-host trees ca. 60 years later. In this area, the 2000s infestation was constrained by a paucity of large diameter host trees (> 23 cm at diameter breast height), not climate. This suggests that there has not been sufficient time for trees to grow large enough to become susceptible to infestation. Concordantly, we found no overlap between areas affected by the 1940s infestation and the current infestation. These results show a severe spruce beetle infestation, which results in the depletion of susceptible hosts, can create a landscape template reducing the potential for future infestations. PMID:26000906
Valim, Michel P.; Cicchino, Armando C.
Abstract A new genus of chewing louse as Bobdalgleishia, and its type species Bobdalgleishia stephanophallus sp. n. (Phthiraptera) belonging to the Brueelia-complex (Ischnocera: Philopteridae) are described. Adults of the new species are fully described, illustrated and compared morphologically with the type species of Motmotnirmus Mey & Barker, 2014, which is its closest relative. The type host of Bobdalgleishia stephanophallus is a subspecies of the great jacamar Jacamerops aureus ridgwayi Todd, 1943, an endemic Amazonian bird distributed in northern Brazil, and the type locality is the State of Pará. Bobdalgleishia is a remarkable genus with unique morphological and chaetotaxic characters which readily separate it from other members of the Brueelia-complex, in particular by having the first two marginal temporal and ocular setae very long. PMID:26798280
Walker, Mark D.; Rotherham, Ian D.
Little is known of the life-history of many parasitic species. This hinders a full understanding of host-parasitic interactions. The common swift louse fly, Crataerina pallida Latreille (Diptera: Hippoboscidae), an obligate haematophagous parasite of the Common Swift, Apus apus Linnaeus 1758, is one such species. No detrimental effect of its parasitism upon the host has been found. This may be because too little is known about C. pallida ecology, and therefore detrimental effects are also unknown. This is a review of what is known about the life-history of this parasite, with the aim of promoting understanding of its ecology. New, previously unreported observations about C. pallida made from personal observations at a nesting swift colony are described. Unanswered questions are highlighted, which may aid understanding of this host-parasite system. C. pallida may prove a suitable model species for the study of other host-parasite relationships. PMID:21268705
Valim, Michel P; Cicchino, Armando C
A new genus of chewing louse as Bobdalgleishia, and its type species Bobdalgleishia stephanophallus sp. n. (Phthiraptera) belonging to the Brueelia-complex (Ischnocera: Philopteridae) are described. Adults of the new species are fully described, illustrated and compared morphologically with the type species of Motmotnirmus Mey & Barker, 2014, which is its closest relative. The type host of Bobdalgleishia stephanophallus is a subspecies of the great jacamar Jacamerops aureus ridgwayi Todd, 1943, an endemic Amazonian bird distributed in northern Brazil, and the type locality is the State of Pará. Bobdalgleishia is a remarkable genus with unique morphological and chaetotaxic characters which readily separate it from other members of the Brueelia-complex, in particular by having the first two marginal temporal and ocular setae very long.
La Linn, May; Gardner, Joy; Warrilow, David; Darnell, Grant A.; McMahon, Clive R.; Field, Ian; Hyatt, Alex D.; Slade, Robert W.; Suhrbier, Andreas
A novel alphavirus was isolated from the louse Lepidophthirus macrorhini, collected from southern elephant seals, Mirounga leonina, on Macquarie Island, Australia. The virus displayed classic alphavirus ultrastructure and appeared to be serologically different from known Australasian alphaviruses. Nearly all Macquarie Island elephant seals tested had neutralizing antibodies against the virus, but no virus-associated pathology has been identified. Antarctic Division personnel who have worked extensively with elephant seals showed no serological evidence of exposure to the virus. Sequence analysis illustrated that the southern elephant seal (SES) virus segregates with the Semliki Forest group of Australasian alphaviruses. Phylogenetic analysis of known alphaviruses suggests that alphaviruses might be grouped according to their enzootic vertebrate host class. The SES virus represents the first arbovirus of marine mammals and illustrates that alphaviruses can inhabit Antarctica and that alphaviruses can be transmitted by lice. PMID:11287559
McMeniman, C J; Barker, S C
We studied inheritance at three microsatellite loci in eight F, and two F2 families of the body (clothes) louse of humans, Pediculus humanus. The alleles of heterozygous female-parents were always inherited in a Mendelian fashion in these families. Alleles from heterozygous male-parents, however, were inherited in two different ways: (i) in a Mendelian fashion and (ii) in a non-Mendelian fashion, where males passed to their offspring only one of their two alleles, that is, 100% nonrandom transmission. In male body lice, where there was non-Mendelian inheritance, the paternally inherited set of alleles was eliminated. We interpret this pattern of inheritance as evidence for extreme transmission ratio distortion of paternal alleles in this species.
Dutra, Juliana M.F.; Alves, Arthur Daniel; Pessanha, Thaila; Rachid, Rachel; de Souza, Wanderley; Linardi, Pedro Marcos; Ferreira, Luiz Fernando; de Souza, Sheila Mendonça; Araujo, Adauto
A pre-Columbian Peruvian scalp was examined decades ago by a researcher from the Oswaldo Cruz Foundation. Professor Olympio da Fonseca Filho described nits and adult lice attached to hair shafts and commented about the origin of head lice infestations on mankind. This same scalp was sent to our laboratory and is the subject of the present paper. Analysis showed a massive infestation with nine eggs/cm2 and an impressive number of very well preserved adult lice. The infestation age was roughly estimated as nine months before death based on the distance of nits from the hair root and the medium rate of hair growth. A small traditional textile was associated with the scalp, possibly part of the funerary belongings. Other morphological aspects visualized by low-vacuum scanning electron microscopy are also presented here for adults and nits. PMID:24626412
Dutra, Juliana M F; Alves, Arthur Daniel; Pessanha, Thaila; Rachid, Rachel; Souza, Wanderley de; Linardi, Pedro Marcos; Ferreira, Luiz Fernando; Souza, Sheila Mendonça de; Araujo, Adauto
A pre-Columbian Peruvian scalp was examined decades ago by a researcher from the Oswaldo Cruz Foundation. Professor Olympio da Fonseca Filho described nits and adult lice attached to hair shafts and commented about the origin of head lice infestations on mankind. This same scalp was sent to our laboratory and is the subject of the present paper. Analysis showed a massive infestation with nine eggs/cm2 and an impressive number of very well preserved adult lice. The infestation age was roughly estimated as nine months before death based on the distance of nits from the hair root and the medium rate of hair growth. A small traditional textile was associated with the scalp, possibly part of the funerary belongings. Other morphological aspects visualized by low-vacuum scanning electron microscopy are also presented here for adults and nits.
Mertins, James W; Mortenson, Jack A; Bernatowicz, Jeffrey A; Hall, P Briggs
Through a recent (2003-2007) survey of ectoparasites on hoofed mammals in western North America, a literature review, and examination of archived museum specimens, we found that the exotic deer-chewing louse, Bovicola tibialis (Piaget), is a long-term, widespread resident in the region. The earliest known collection was from Salt Spring Island, Canada, in 1941. We found these lice on the typical host, that is, introduced European fallow deer (Dama dama L.), and on Asian chital (Axis axis [Erxleben] ), native Columbian black-tailed deer (Odocoileus hemionus columbianus [Richardson] ), and Rocky Mountain mule deer (O. h. hemionus [Rafinesque]) x black-tailed deer hybrids. Chital and the hybrid deer are new host records. All identified hosts were known to be or probably were exposed to fallow deer. Geographic records include southwestern British Columbia, Canada; Marin and Mendocino Counties, California; Deschutes, Lincoln, and Linn Counties, Oregon; Yakima and Kittitas Counties, Washington; Curry County, New Mexico; and circumstantially, at least, Kerr County, Texas. All but the Canadian and Mendocino County records are new. Bovicola tibialis displays a number of noteworthy similarities to another exotic deer-chewing louse already established in the region, that is, Damalinia (Cervicola) sp., which is associated with a severe hair-loss syndrome in black-tailed deer. We discuss longstanding problems with proper identification of B. tibialis, the probability that it occurs even more widely in the United States, and the prospects for it to cause health problems for North American deer. Additional information gathered since our active survey establishes further new distribution and host records for B. tibialis.
Weaver, Haylee J
Three new species of the rodent louse genus Hoplopleura (Anoplura: Hoplopleuridae) are described and illustrated from Australia: H. melomydis new species from Melomys burtoni (Muridae: Hydromyini, grassland melomys) and M. capensis (Muridae: Hydromyini, Cape York melomys) from Queensland; H. notomydis new species and H. setosa new species from Notomys alexis (Muridae: Hydromyini, spinifex hopping mouse) from the Northern Territory. These new louse species are the first lice recorded from each of the three host rodent species.
Heuch, P A; Mo, T A
Salmon lice Lepeophtheirus salmonis Krøyer have caused disease problems in farmed Atlantic salmon Salmo salar L. since the mid-1970s in Norway. High infection intensities and premature return of wild sea trout Salmo trutta L. were first reported in 1992. Later emaciated wild Atlantic salmon smolts carrying large amounts of lice have been observed both in fjords and offshore. The Norwegian Animal Health Authority regulations to control the problem, which came into operation in 1998, included compulsory louse level monitoring in farms and maximum legal numbers of lice per fish. Here, we present a model of salmon louse egg production in Norway and show that the effect of the current public management strategy is critically dependent on the yearly increase in salmon production. This is because the infection pressure is the product of the number of fish in the system, and the number of lice per fish. Due to the much larger number of farmed than wild salmonids, it is highly likely that lice originating from farmed salmon infect wild stock. Estimated tolerance limits for wild salmonids vary widely, and the level of louse egg production in farms which would be needed to decimate wild populations is not known. Two possible thresholds for total lice egg production are investigated: (1) 1986 to 1987 level (i.e. before adverse effects on sea trout were recorded), and (2) a level corresponding to a doubling of the estimated natural infection pressure. The farm lice per fish limits that would have to be observed to keep louse production within the 2 thresholds are calculated for the period 1986 to 2005. A steady decrease in the permitted number of lice per fish may keep the total louse production stable, but the number of salmon required for verification of lice numbers will increase as the prevalence to be verified is decreased. At threshold (2), the model estimated that lice limits should have been 0.05 louse per fish in 1999. This would require 60 fish from each pen to be
Larsen, K S; Eydal, M; Mencke, N; Sigurdsson, H
Lice infestations on horses caused by the lice Werneckiella (Damalinia) equi and Haematopinus equi are observed worldwide. In this study, the distribution and clinical manifestations of lice on Icelandic horses were examined. Thirty-eight out of 93 animals (40.86%) were identified as infested with W. equi. Sixty-eight animals (73.12%) presented dermatological lesions associated with lice infestation, while only 32 of these animals presented lice. Six animals had no clinical signs although of being lice-positive, and 19 animals (20.43%) showed neither lice nor clinical manifestations. Lice burdens varied from animal to animal, and clinical manifestations occurred at all levels of infestation. Focal alopecia was the main clinical sign (83.78%) on lice-positive horses, while scaling and crusts occurred in 10.81% and 9.68% of the cases, respectively. Clinical signs present in the head and the neck/mane area were found to be an indication of lice infestation in horses.
Pandit, Pranav; Bandivdekar, Ruta; Geevarghese, G; Pande, Satish; Mandke, Omkar
In total, 167 individuals of 30 species of snakes belonging to 22 genera and five families were examined for tick infestation from November 2008 to March 2010. Only two species of snakes, Ptyas mucosa (L., 1758) (Indian rat snake) and Naja naja (L., 1758) (spectacled cobra), were found infested by ticks. All ticks collected were identified to be Amblyomma gervaisi [previously Aponomma gervaisi (Lucas, 1847) 1. The average prevalence of these ticks on Indian rat snakes (n=48) was 29.16%, with abundance of 7.02 ticks per individual; on spectacled cobras (n=20), average prevalence was 30.00%, with abundance of 6.9 ticks per individual. The nymphs and males were predominant. All the ticks were found on the dorsal aspect of the body of the snake, and no ticks were recorded on the head, tail, or ventral body. The rate of tick infestation was highest in scrubland and was lowest in evergreen forests. Female Indian rat snakes showed higher tick infestation rates than male Indian rat snakes. Using Mann-Whitney U test, we found that longer snakes of both species had significantly higher rate of tick infestation in both the species of snakes.
Sblendorio, R.P.; Malinchock, J.C. ); Claudi, R. )
U.S. and Canadian utilities in the great lakes area have adopted techniques to temporarily prevent infestation of the zebra mussel in their hydro facilities, but are still looking for more permanent solutions.
Populations of phytopathogenic bacteria representing five host-pathogen combinations were assessed to determine if there was a mathematical relationship common across seedborne bacterial diseases. Bacterial populations were estimated from naturally-infested seeds of cowpea (Vigna unguiculata), peppe...
Kaufman, P E; Rutz, D A; Doscher, M E; Albright, R
The four chlorfenapyr formulations examined provided 100% control of both the nymphal and adult stages of naturally acquired Bovicola bovis (L.) on cattle up to 35 days after application. Treatment with 6mg chlorfenapyr per kg BW in a 0.12ml per kg BW formulation was as effective as treatment with CyLence (cyfluthrin) in controlling naturally acquired Solenopotes capillatus (Enderlein) on cattle for 35 days. Percent reduction was never greater than 90% with any chlorfenapyr application against Linognathus vituli (L.). However, percent reduction was greater than 90% with CyLence from day 21 through 35. No adverse effects were noted on cattle from any of the chlorfenapyr dosages used.
Skilbrei, O T; Finstad, B; Urdal, K; Bakke, G; Kroglund, F; Strand, R
The impact of salmon lice on the survival of migrating Atlantic salmon smolts was studied by comparing the adult returns of sea-ranched smolts treated for sea lice using emamectin benzoate or substance EX with untreated control groups in the River Dale in western Norway. A total of 143 500 smolts were released in 35 release groups in freshwater from 1997 to 2009 and in the fjord system from 2007 to 2009. The adult recaptures declined gradually with release year and reached minimum levels in 2007. This development corresponded with poor marine growth and increased age at maturity of ranched salmon and in three monitored salmon populations and indicated unfavourable conditions in the Norwegian Sea. The recapture rate of treated smolts was significantly higher than the controls in three of the releases performed: the only release in 1997, one of three in 2002 and the only group released in sea water in 2007. The effect of treating the smolts against salmon lice was smaller than the variability in return rates between release groups, and much smaller that variability between release years, but its overall contribution was still significant (P < 0.05) and equivalent to an odds ratio of the probability of being recaptured of 1.17 in favour of the treated smolts. Control fish also tended to be smaller as grilse (P = 0.057), possibly due to a sublethal effect of salmon lice. PMID:23311746
Skilbrei, O T; Finstad, B; Urdal, K; Bakke, G; Kroglund, F; Strand, R
The impact of salmon lice on the survival of migrating Atlantic salmon smolts was studied by comparing the adult returns of sea-ranched smolts treated for sea lice using emamectin benzoate or substance EX with untreated control groups in the River Dale in western Norway. A total of 143 500 smolts were released in 35 release groups in freshwater from 1997 to 2009 and in the fjord system from 2007 to 2009. The adult recaptures declined gradually with release year and reached minimum levels in 2007. This development corresponded with poor marine growth and increased age at maturity of ranched salmon and in three monitored salmon populations and indicated unfavourable conditions in the Norwegian Sea. The recapture rate of treated smolts was significantly higher than the controls in three of the releases performed: the only release in 1997, one of three in 2002 and the only group released in sea water in 2007. The effect of treating the smolts against salmon lice was smaller than the variability in return rates between release groups, and much smaller that variability between release years, but its overall contribution was still significant (P < 0.05) and equivalent to an odds ratio of the probability of being recaptured of 1.17 in favour of the treated smolts. Control fish also tended to be smaller as grilse (P = 0.057), possibly due to a sublethal effect of salmon lice.
Økland, Arnfinn Lodden; Nylund, Are; Øvergård, Aina-Cathrine; Blindheim, Steffen; Watanabe, Kuninori; Grotmol, Sindre; Arnesen, Carl-Erik; Plarre, Heidrun
Several new viruses have emerged during farming of salmonids in the North Atlantic causing large losses to the industry. Still the blood feeding copepod parasite, Lepeophtheirus salmonis, remains the major challenge for the industry. Histological examinations of this parasite have revealed the presence of several virus-like particles including some with morphologies similar to rhabdoviruses. This study is the first description of the genome and target tissues of two new species of rhabdoviruses associated with pathology in the salmon louse. Salmon lice were collected at different Atlantic salmon (Salmo salar) farming sites on the west coast of Norway and prepared for histology, transmission electron microscopy and Illumina sequencing of the complete RNA extracted from these lice. The nearly complete genomes, around 11 600 nucleotides encoding the five typical rhabdovirus genes N, P, M, G and L, of two new species were obtained. The genome sequences, the putative protein sequences, and predicted transcription strategies for the two viruses are presented. Phylogenetic analyses of the putative N and L proteins indicated closest similarity to the Sigmavirus/Dimarhabdoviruses cluster, however, the genomes of both new viruses are significantly diverged with no close affinity to any of the existing rhabdovirus genera. In situ hybridization, targeting the N protein genes, showed that the viruses were present in the same glandular tissues as the observed rhabdovirus-like particles. Both viruses were present in all developmental stages of the salmon louse, and associated with necrosis of glandular tissues in adult lice. As the two viruses were present in eggs and free-living planktonic stages of the salmon louse vertical, transmission of the viruses are suggested. The tissues of the lice host, Atlantic salmon, with the exception of skin at the attachment site for the salmon louse chalimi stages, were negative for these two viruses. PMID:25402203
Økland, Arnfinn Lodden; Nylund, Are; Øvergård, Aina-Cathrine; Blindheim, Steffen; Watanabe, Kuninori; Grotmol, Sindre; Arnesen, Carl-Erik; Plarre, Heidrun
Several new viruses have emerged during farming of salmonids in the North Atlantic causing large losses to the industry. Still the blood feeding copepod parasite, Lepeophtheirus salmonis, remains the major challenge for the industry. Histological examinations of this parasite have revealed the presence of several virus-like particles including some with morphologies similar to rhabdoviruses. This study is the first description of the genome and target tissues of two new species of rhabdoviruses associated with pathology in the salmon louse. Salmon lice were collected at different Atlantic salmon (Salmo salar) farming sites on the west coast of Norway and prepared for histology, transmission electron microscopy and Illumina sequencing of the complete RNA extracted from these lice. The nearly complete genomes, around 11,600 nucleotides encoding the five typical rhabdovirus genes N, P, M, G and L, of two new species were obtained. The genome sequences, the putative protein sequences, and predicted transcription strategies for the two viruses are presented. Phylogenetic analyses of the putative N and L proteins indicated closest similarity to the Sigmavirus/Dimarhabdoviruses cluster, however, the genomes of both new viruses are significantly diverged with no close affinity to any of the existing rhabdovirus genera. In situ hybridization, targeting the N protein genes, showed that the viruses were present in the same glandular tissues as the observed rhabdovirus-like particles. Both viruses were present in all developmental stages of the salmon louse, and associated with necrosis of glandular tissues in adult lice. As the two viruses were present in eggs and free-living planktonic stages of the salmon louse vertical, transmission of the viruses are suggested. The tissues of the lice host, Atlantic salmon, with the exception of skin at the attachment site for the salmon louse chalimi stages, were negative for these two viruses.
Ibrahim, Omer; Syed, Usama Mohammad; Tomecki, Kenneth J
Bedbugs--hematophagous parasitic arthropods of the genus Cimex--have been unwelcome bedfellows for humans for thousands of years. With increases in population density, ease of travel, and insecticide resistance, bedbugs have reemerged. As a result, physicians are often at the forefront in the diagnosis and treatment of bedbug infestation. This review summarizes the biology and epidemiology of bedbugs and provides details on the diagnosis and treatment of bedbug infestation.
Uzun, Aslıhan; Gök, Mustafa; İşcanlı, Murat Doğan
Tick infestation of the eyelid is a rare but serious condition that can lead to Crimean-Congo hemorrhagic fever. In this report, we describe two cases who presented with tick infestation of the eyelid. Neither patient developed systemic disease or adverse sequelae after tick extraction. Complete mechanical removal of ticks located on the eyelid with blunt forceps is a safe and effective treatment method. PMID:28058170
Mougabure Cueto, G; Zerba, E N; Picollo, M I
The insecticidal activity of spinosad was evaluated against susceptible and permethrin-resistant human lice. In a permethrin-susceptible strain of the body louse, Pediculus humanus humanus L. (Anoplura: Pediculidae), the toxicity of spinosad was similar to that established for permethrin, with an LD50 value of 1.2 ng/insect and 2.4 ng/insect, respectively. Topical application of spinosad to populations of permethrin-resistant head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), showed that susceptibility to spinosad was independent of resistance to permethrin. The effectiveness of spinosad against human lice and the low mammalian toxicity reported in the literature suggest that spinosad could be useful for the management of permethrin-resistant human lice.
Bowles, Vernon M; Yoon, Kyong Sup; Barker, Stephen C; Tran, Christopher; Rhodes, Christopher; Clark, Marshall J
Studies were undertaken to determine the ovicidal efficacy of 5,5'-dimethyl-2,2'-bipyridyl (abametapir) against eggs of both human head and body lice. Head lice eggs of different ages (0-2, 3-5, and 6-8-d-old eggs) were exposed to varying concentrations of abametapir in isopropanol and concentration-dependent response relationships established based on egg hatch. One hundred percent of all abametapir-treated eggs failed to hatch at the 0.74 and 0.55% concentrations, whereas 100% of 6-8-d-old head louse eggs failed to hatch only at the 0.74% concentration. The LC50 value for abametapir varied, depending on the age of the head lice eggs, from ∼0.10% recorded for 0-2-d-old eggs and increasing to ∼0.15% for 6-8-d-old eggs. Abametapir was also evaluated once formulated into a lotion referred to as Xeglyze (0.74% abametapir) and serial dilutions made. Ovicidal efficacies were determined against head lice eggs 0-8-d-old. Results indicated 100% ovicidal activity at the 0.74, 0.55, 0.37, and 0.18% concentrations. Additional studies undertaken using body lice eggs also demonstrated that abametapir was 100% ovicidal against eggs of all ages when evaluated at a concentration of 0.37 and 0.55%. Given that ovicidal activity is a critical component of any effective treatment regime for louse control, the data presented in this study clearly demonstrate the ability of abametapir to inhibit hatching of both head and body louse eggs as assessed in vitro.
Bowles, Vernon M; Yoon, Kyong Sup; Barker, Stephen C; Tran, Christopher; Rhodes, Christopher; Clark, Marshall J
Studies were undertaken to determine the ovicidal efficacy of 5,5'-dimethyl-2,2'-bipyridyl (abametapir) against eggs of both human head and body lice. Head lice eggs of different ages (0-2, 3-5, and 6-8-d-old eggs) were exposed to varying concentrations of abametapir in isopropanol and concentration-dependent response relationships established based on egg hatch. One hundred percent of all abametapir-treated eggs failed to hatch at the 0.74 and 0.55% concentrations, whereas 100% of 6-8-d-old head louse eggs failed to hatch only at the 0.74% concentration. The LC50 value for abametapir varied, depending on the age of the head lice eggs, from ∼0.10% recorded for 0-2-d-old eggs and increasing to ∼0.15% for 6-8-d-old eggs. Abametapir was also evaluated once formulated into a lotion referred to as Xeglyze (0.74% abametapir) and serial dilutions made. Ovicidal efficacies were determined against head lice eggs 0-8-d-old. Results indicated 100% ovicidal activity at the 0.74, 0.55, 0.37, and 0.18% concentrations. Additional studies undertaken using body lice eggs also demonstrated that abametapir was 100% ovicidal against eggs of all ages when evaluated at a concentration of 0.37 and 0.55%. Given that ovicidal activity is a critical component of any effective treatment regime for louse control, the data presented in this study clearly demonstrate the ability of abametapir to inhibit hatching of both head and body louse eggs as assessed in vitro.
Colomba, C; Scarlata, F; Di Carlo, P; Giammanco, A; Fasciana, T; Trizzino, M; Cascio, A
Currently louse-borne relapsing fever (LBRF) is primarily found in limited endemic foci in Ethiopia, Somalia and Sudan; no case of imported LBRF has been reported in Europe in the 9 years prior to 2015. The aim of our paper is to describe a new case of imported LBRF detected in Sicily, Italy, and to review all cases reported in migrants arrived in Europe in the last 10 years. Mini review of all published cases of louse-borne relapsing fever in Europe in the last 10 years. A computerized search without language restriction was conducted using PubMed combining the terms '(louse-borne relapsing fever or LBRF or recurrentis) and (refugee or Europe or migrant)' without limits. Furthermore, the 'Ahead-of-Print Articles' of the top 10 journals (ranked by Impact factor - Web of Science) of Infectious diseases and of Epidemiology were checked. Our search identified 26 cases of LBRF between July and October 2015 in migrants recently arrived in Europe: 8 had been described in Italy; 1 in Switzerland; 2 in the Netherlands; 15 in Germany. We describe data regarding the clinical characteristics, diagnostic methods, therapy and outcome of these patients and of the new case. LBRF by Borrelia recurrentis should be considered among the clinical hypotheses in migrants presenting with fever, headache, chills, sweating, arthralgia, myalgia, dizziness, nausea and vomiting. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Gutiérrez-López, Rafael; Martínez-de la Puente, Josué; Gangoso, Laura; Soriguer, Ramón C; Figuerola, Jordi
The barcoding of life initiative provides a universal molecular tool to distinguish animal species based on the amplification and sequencing of a fragment of the subunit 1 of the cytochrome oxidase (COI) gene. Obtaining good quality DNA for barcoding purposes is a limiting factor, especially in studies conducted on small-sized samples or those requiring the maintenance of the organism as a voucher. In this study, we compared the number of positive amplifications and the quality of the sequences obtained using DNA extraction methods that also differ in their economic costs and time requirements and we applied them for the genetic characterization of louse flies. Four DNA extraction methods were studied: chloroform/isoamyl alcohol, HotShot procedure, Qiagen DNeasy(®) Tissue and Blood Kit and DNA Kit Maxwell(®) 16LEV. All the louse flies were morphologically identified as Ornithophila gestroi and a single COI-based haplotype was identified. The number of positive amplifications did not differ significantly among DNA extraction procedures. However, the quality of the sequences was significantly lower for the case of the chloroform/isoamyl alcohol procedure with respect to the rest of methods tested here. These results may be useful for the genetic characterization of louse flies, leaving most of the remaining insect as a voucher. © 2015 The Society for Vector Ecology.
Shao, Renfu; Kirkness, Ewen F; Barker, Stephen C
The mitochondrial (mt) genomes of animals typically consist of a single circular chromosome that is approximately 16-kb long and has 37 genes. Our analyses of the sequence reads from the Human Body Louse Genome Project and the patterns of gel electrophoresis and Southern hybridization revealed a novel type of mt genome in the sucking louse, Pediculus humanus. Instead of having all mt genes on a single chromosome, the 37 mt genes of this louse are on 18 minicircular chromosomes. Each minicircular chromosome is 3-4 kb long and has one to three genes. Minicircular mt chromosomes are also present in the four other species of sucking lice that we investigated, but not in chewing lice nor in the Psocoptera, to which sucking lice are most closely related. We also report unequivocal evidence for recombination between minicircular mt chromosomes in P. humanus and for sequence variation in mt genes generated by recombination. The advantages of a fragmented mt genome, if any, are currently unknown. Fragmentation of mt genome, however, has coevolved with blood feeding in the sucking lice. It will be of interest to explore whether or not life history features are associated with the evolution of fragmented chromosomes.
Shao, Renfu; Kirkness, Ewen F.; Barker, Stephen C.
The mitochondrial (mt) genomes of animals typically consist of a single circular chromosome that is ∼16-kb long and has 37 genes. Our analyses of the sequence reads from the Human Body Louse Genome Project and the patterns of gel electrophoresis and Southern hybridization revealed a novel type of mt genome in the sucking louse, Pediculus humanus. Instead of having all mt genes on a single chromosome, the 37 mt genes of this louse are on 18 minicircular chromosomes. Each minicircular chromosome is 3–4 kb long and has one to three genes. Minicircular mt chromosomes are also present in the four other species of sucking lice that we investigated, but not in chewing lice nor in the Psocoptera, to which sucking lice are most closely related. We also report unequivocal evidence for recombination between minicircular mt chromosomes in P. humanus and for sequence variation in mt genes generated by recombination. The advantages of a fragmented mt genome, if any, are currently unknown. Fragmentation of mt genome, however, has coevolved with blood feeding in the sucking lice. It will be of interest to explore whether or not life history features are associated with the evolution of fragmented chromosomes. PMID:19336451
Boruk, Marina; Rosenfeld, Richard M; Alexis, Richard
To report a new cause of peri-auricular mass in children: cutaneous myiasis-botfly infestation. Case report. The human botfly (Dermatobia hominis) is found in the tropics of Central and South America. However, cases of infestation are uncommon in the United States. We present the case of a 5-year-old girl with cutaneous myiasis in order to expand the differential diagnosis for a peri-auricular mass in children. In our report, the parasite was initially identified as sparganum, but was later reclassified by the center for disease control and prevention (CDC) as a botfly larva. Parasitic infection should be considered with a newly noted head and neck mass, and cutaneous myiasis should be included in the differential diagnosis. Cutaneous myiasis has not been previously reported in the literature describing the peri-auricular region as the site of occurrence. Furthermore, when an unusual parasite is extracted from a lesion, it should be confirmed by an authority such as CDC for definitive diagnosis, so appropriate plan of care and follow up can be instituted.
Hau, Veronica; Muhi-Iddin, Nadia
An 11-year-old child presented with poor school attendance, and signs and symptoms of severe anaemia. He was heavily covered in lice. He was investigated for other causes of anaemia. Following treatment for head lice and also iron supplementation, he was back in full-time education. This case highlights the link between head lice (pediculosis capitis) infestation and iron-deficiency anaemia. PMID:25527684
Hau, Veronica; Muhi-Iddin, Nadia
An 11-year-old child presented with poor school attendance, and signs and symptoms of severe anaemia. He was heavily covered in lice. He was investigated for other causes of anaemia. Following treatment for head lice and also iron supplementation, he was back in full-time education. This case highlights the link between head lice (pediculosis capitis) infestation and iron-deficiency anaemia. 2014 BMJ Publishing Group Ltd.
Pittendrigh, B R; Clark, J M; Johnston, J S; Lee, S H; Romero-Severson, J; Dasch, G A
The human body louse, Pediculus humanus humanus (L.), and the human head louse, Pediculus humanus capitis, belong to the hemimetabolous order Phthiraptera. The body louse is the primary vector that transmits the bacterial agents of louse-borne relapsing fever, trench fever, and epidemic typhus. The genomes of the bacterial causative agents of several of these aforementioned diseases have been sequenced. Thus, determining the body louse genome will enhance studies of host-vector-pathogen interactions. Although not important as a major disease vector, head lice are of major social concern. Resistance to traditional pesticides used to control head and body lice have developed. It is imperative that new molecular targets be discovered for the development of novel compounds to control these insects. No complete genome sequence exists for a hemimetabolous insect species primarily because hemimetabolous insects often have large (2000 Mb) to very large (up to 16,300 Mb) genomes. Fortuitously, we determined that the human body louse has one of the smallest genome sizes known in insects, suggesting it may be a suitable choice as a minimal hemimetabolous genome in which many genes have been eliminated during its adaptation to human parasitism. Because many louse species infest birds and mammals, the body louse genome-sequencing project will facilitate studies of their comparative genomics. A 6-8X coverage of the body louse genome, plus sequenced expressed sequence tags, should provide the entomological, evolutionary biology, medical, and public health communities with useful genetic information.
Rukke, Bjørn Arne; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben; Birkemoe, Tone
How head lice infestations are managed by households is an important but generally neglected issue in head lice research. In the present study, we investigate actions taken against head lice by Norwegian households in association with socioeconomic status, family background, school-related variables and other key factors. Repeat questionnaires distributed to caretakers of the same elementary school children during a 2-year period enabled us to study both previous head lice management and any changes in this management through time. Households from 12 schools spanning the main socioeconomic variation found in Norway participated in the study. All students with active head lice infestation were treated in the four investigated periods. Most caretakers used a thorough head lice checking technique and informed others of own infestation. Checking frequency was low as most children were inspected less than monthly. The best determinant of increased checking frequency and thoroughness was personal experience with head lice. The increased awareness, however, seemed to be somewhat short-lived, as there was a decrease in checking frequency and thoroughness within 1 year after infestation. Personal experience with head lice also increased general knowledge related to the parasite. Parents born in developing countries checked their children for head lice more frequently, although less thoroughly, informed fewer contacts when infested, used pediculicides preventively more often and knew less about head lice than parents born in developed countries. Households with highly educated mothers had a lower checking frequency, but their knowledge and willingness to inform others was high. Single parents were more concerned about economic costs and kept children home from school longer while infested than other parents. As head lice management varied among socioeconomic groups and with parental background, differentiated advice should be considered in the control of head lice. The
... PA: Elsevier Saunders; 2015:chap 294. Elston DM. Arthropods and leeches. In: Goldman L, Schafer AI, eds. ... 15. Kliegman RM, Stanton BF, St Geme JW. Arthropods bites and infestations. In: Kliegman RM, Stanton BF, ...
van Dooremalen, C; Stam, E; Gerritsen, L; Cornelissen, B; van der Steen, J; van Langevelde, F; Blacquière, T
Varroa destructor in combination with one or more stressors, such as low food availability or chemical exposure, is considered to be one of the main causes for honey bee colony losses. We examined the interactive effect of pollen availability on the protein content and body weight of young bees that emerged with and without V. destructor infestation. With reduced pollen availability, and the coherent reduced nutritional protein, we expected that V. destructor infestation during the pupal stage would have a larger negative effect on bee development than without infestation. Moreover, when raised with ample pollen available after emergence, infested pupae were expected not to be able to compensate for early losses due to V. destructor. We found that both V. destructor infestation and reduced pollen availability reduced body weight, abdominal protein level, and increased the head to abdomen protein ratio. The availability of pollen did indeed not result in compensation for reduced mass and protein content caused by V. destructor infestation in young bees after 1 week of their adult life. Both V. destructor and nutrition are top concerns for those studying honey bee health and this study demonstrates that both have substantial effects on young bees and that ample available pollen cannot compensate for reduced mass and protein content caused by V. destructor parasitism. Copyright © 2013 Elsevier Ltd. All rights reserved.
FERRARA, Pietro; DEL BUFALO, Francesca; ROMANO, Valerio; TIBERI, Eloisa; BOTTARO, Giorgia; ROMANI, Lorenza; MALAMISURA, Monica; IANNIELLO, Francesca; CENI, Laura; MOTTINI, Giovanni; GATTO, Antonio
Background We conducted a study to evaluate efficacy and safety of dimeticone 4%, a lotion with no conventional insecticide activity, to cure lice infection and to prevent spread of infestation/reinfestation by prophylaxis of classmates. Methods: The study is carried out between April 2008 and June 2008 in Petranova International Institute in Rome. A total of 131 children, aged 3 to 13 years (median age: 7 years) were included in the study. All participants received treatment with dimeticone 4% that was applied both to children with the infestation, to cure it, and to all classmates, to prevent the spreading of the infestation. They have been controlled after 7 and 30 days from the application of dimeticone. Results: At baseline we found a positivity of lice infestation in 23/131 children (17.6%), whereas 108/131 (82.4%) children were free from lice. After 7 days of treatment with dimeticone 4%, 7/23 (30.4%) positive children still had lice infestation, with a cure rate of 69.6% (16/23). At 30 days 26/131 children (19.9%) were infested: 15 children were lice free at baseline whereas 11 had lice at both evaluations; the cure rate amounted to 52.2% (12/23). The reinfestation rate (percentage of positive children that showed negativity at baseline) was 5.3% (7/131) at 7 days and 11.5% (15/131) at 30 days. Conclusion: The lower reinfestation rate showed in our trial suggests that this approach could be effective in reducing spreading of head lice in small communities. More studies are needed to confirm our findings. PMID:24427749
Schoessler, Sally Z
School nurses often are the first healthcare professionals to diagnose lice infestations in children. Although lice do not transmit disease, many schools send children home if they detect live head lice. It is the position of the National Association of School Nurses that children who have been treated for lice infestations should not be excluded from school because of the presence of residual nits. The primary goals of the school nurse in controlling infestations are to identify children with head lice and to break the cycle of reinfestation. Routine screening of children for head lice is often part of infestation management policies in school districts. A thorough screening of a child's head can take several minutes. If a school's policy is to screen all students, the total time for examination adds significantly to the school nurse's caseload. The use of the school nurse's time for universal screening must be measured against other responsibilities, including health problem management, medication management, health assessments, and vision and hearing screening. Once a child is identified as having lice, the school nurse can play a key role in working with the child's family to eradicate the infestation. Education about treatment options and environmental cleaning are topics the nurse can address with the family. The school nurse also can function as a case manager who coordinates various aspects of treatment for an affected child. Because infestations can be very upsetting to students and to their families, the nurse can provide support and reassurance to the family as the child is treated. Participation of school nurses in developing appropriate and consistent policies and procedures within the school district is vital to the overall management of infestations. Their efforts to control and reduce infestations are necessary for the overall health of the school population.
Mumcuoglu, K Y; Friger, M; Cohen, R
Physical methods such as high and low temperatures were used in the past for the control of human body louse, Pediculus humanus humanus L. (Anoplura: Pediculidae). In the current study, the minimum time necessary to kill all lice after exposing them to temperatures other than those described in the literature, the mortality of lice after immersing them in water, and the survival of lice whose legs were amputated were studied. All lice died after 6 d at 6 degrees C, after 11 d at 24 degrees C, and after 9 d at 31 degrees C. At -17 degrees C, all lice were dead after 35 min, whereas at -70 degrees C, all lice were dead after 1 min. All lice died after immersion in water within 19 h. The differences in mortality were significant but borderline between controls and lice whose two legs were amputated immediately or 24 h after feeding (3.3 versus 13.3% and 8.3 versus 21.7%). For lice whose leg was amputated 48 h after feeding, significant differences were found between controls and lice with one amputated leg (13.3 versus 48.3%), between controls and lice with two amputated legs (13.3 versus 68.3%), and between lice with one and two amputated legs (48.3 versus 68.3%).
Douglas, H D; Malenke, J R
Distortions of sex ratios and sexual traits from synthetic chemicals have been well documented; however, there is little evidence for such phenomena associated with naturally occurring chemical exposures. We reasoned that chemical secretions of vertebrates could contribute to skewed sex ratios in ectoparasitic insects due to differences in susceptibility among the sexes. For example, among ectoparasitic lice the female is generally the larger sex. Smaller males may be more susceptible to chemical effects. We studied sex ratios of lice on two sympatric species of colonial seabirds. Crested auklets (Aethia cristatella) secrete a strong smelling citrus-like odorant composed of aldehydes while a closely related congener the least auklet (Aethia pusilla) lacks these compounds. Each auklet hosts three species of lice, two of which are shared in common. We found that the sex ratio of one louse species, Quadraceps aethereus (Giebel), was highly skewed on crested auklets 1:69 (males: females), yet close to unity on least auklets (1:0.97). We suggest that a host-specific effect contributes to this difference, such as the crested auklet's chemical odorant.
Thakkar, Angeli; Ooi, Kenneth GJ; Assaad, Nagi; Coroneo, Minas
This case report documents a 58-year-old male who presented to the clinic with a 12-month history of a burrowing sensation in his eyelids that he attributed to a parasitic infestation. After being extensively investigated and reviewed by relevant specialties, no evidence of parasitic infestation was found. He was diagnosed with and treated for blepharitis. Psychiatric referral for presumed delusional infestation (DI) was recommended. Despite this, he remained insistent in his belief of infestation, and was inevitably lost to follow-up. DI, previously known as delusional parasitosis, is a rare delusional disorder where affected individuals have a fixed, false belief that they have a parasitic infestation. Diagnosis can be challenging. Practitioners need to evaluate between primary and secondary DI carefully, as management differs depending on the etiology. Despite this, patients diagnosed with primary DI tend to be resistant to psychiatric referral. This report aims to optimize management by giving the reader a guideline for appropriate investigations and advice on patient approach. It is important to recognize hallmark features of DI to minimize self-inflicted trauma and associated psychosocial consequences. Effective treatment for DI is available, and devastating consequences, including blindness, can be avoided. PMID:26082608
Madke, Bhushan; Khopkar, Uday
Head louse infestation, or pediculosis capitis, caused by Pediculus humanus var. capitis, is a common health concern in pediatric age group. An itching of the scalp is the chief symptom, whereas presence of viable nits confirms the diagnosis of head louse infestation. Secondary bacterial infection with impetignization with cervical and occipital lymphadenopathy can complicate the clinical scenario with physician misdiagnosing pediculosis to a primary bacterial infection. Screening and treatment of all close contacts is necessary for an adequate management of pediculosis. Medical management of head louse infestation requires proper application of topical pediculicidal agents', chiefly permethrin lotion and wet combing with a fine toothcomb. Severe cases with high parasitic load justify the use of either oral cotrimoxazole or Ivermectin. Other described technique involves a single application of hot air for 30 minutes. Radical but culturally unacceptable method would be shaving of scalp in resistant cases. Environmental fogging with insecticides is neither necessary nor recommended.
Kim, Jaehwan; Loh, Chee Hoou; Murrell, Dedee F
Epidermolysis bullosa pruriginosa (EB-Pr) is an unusual variant of dystrophic EB. Potential genetic disease modifiers and metabolic factors have been investigated, but thus far no specific insight into this phenotype has emerged. We report an in-depth description of three patients diagnosed as having EB-Pr in whom this particular phenotype developed after scabies infestation and dramatically improved after full treatment. This short communication suggests that scabies infestation could be one of the important triggering factors for the development of the EB-Pr phenotype. © 2013 Japanese Dermatological Association.
Sangaré, A K; Doumbo, S N; Koné, A K; Thera, M A; Dabo, A; Brouqui, P; Raoult, D; Doumbo, O K
Because lice-transmitted infections are a real public health problem, epidemiological studies in different ecoclimatic zones of Africa are useful. This article aims to describe the frequency of lice infestation, their genotypes, and their infection by pathogens in the regions of Koulikoro and Mopti. A cross-sectional survey allowed us to collect lice from rural populations. Techniques of molecular biology (real-time PCR, standard PCR, and genotyping) were used for analysis of lice samples. Infestation rates were 57% (12/21) among subjects in Diankabou, in the Sahelian zone; 91% (39/43) in Doneguebougou, and 86% (59/69) in Zorocoro, in a savanna zone. The overall lice infestation rate in the samples in the three localities was 83% (110/133). Real-time PCR showed 3% (4/92) of Acinetobacter baumanii but no B. quintana in Diankabou. Phylogenetic analysis of the mitochondrial gene (Cytb) showed that head lice in Mali belong to genotype C. The high frequency of lice infestation in the study population indicates that it would be useful to conduct national epidemiological surveys to estimate the magnitude of this public health problem.
Physiological consequences of the salmon louse (Lepeophtheirus salmonis) on juvenile pink salmon (Oncorhynchus gorbuscha): implications for wild salmon ecology and management, and for salmon aquaculture.
Brauner, C J; Sackville, M; Gallagher, Z; Tang, S; Nendick, L; Farrell, A P
Pink salmon, Oncorhynchus gorbuscha, are the most abundant wild salmon species and are thought of as an indicator of ecosystem health. The salmon louse, Lepeophtheirus salmonis, is endemic to pink salmon habitat but these ectoparasites have been implicated in reducing local pink salmon populations in the Broughton Archipelago, British Columbia. This allegation arose largely because juvenile pink salmon migrate past commercial open net salmon farms, which are known to incubate the salmon louse. Juvenile pink salmon are thought to be especially sensitive to this ectoparasite because they enter the sea at such a small size (approx. 0.2 g). Here, we describe how 'no effect' thresholds for salmon louse sublethal impacts on juvenile pink salmon were determined using physiological principles. These data were accepted by environmental managers and are being used to minimize the impact of salmon aquaculture on wild pink salmon populations.
Physiological consequences of the salmon louse (Lepeophtheirus salmonis) on juvenile pink salmon (Oncorhynchus gorbuscha): implications for wild salmon ecology and management, and for salmon aquaculture
Brauner, C. J.; Sackville, M.; Gallagher, Z.; Tang, S.; Nendick, L.; Farrell, A. P.
Pink salmon, Oncorhynchus gorbuscha, are the most abundant wild salmon species and are thought of as an indicator of ecosystem health. The salmon louse, Lepeophtheirus salmonis, is endemic to pink salmon habitat but these ectoparasites have been implicated in reducing local pink salmon populations in the Broughton Archipelago, British Columbia. This allegation arose largely because juvenile pink salmon migrate past commercial open net salmon farms, which are known to incubate the salmon louse. Juvenile pink salmon are thought to be especially sensitive to this ectoparasite because they enter the sea at such a small size (approx. 0.2 g). Here, we describe how ‘no effect’ thresholds for salmon louse sublethal impacts on juvenile pink salmon were determined using physiological principles. These data were accepted by environmental managers and are being used to minimize the impact of salmon aquaculture on wild pink salmon populations. PMID:22566682
Veracx, Aurélie; Rivet, Romain; McCoy, Karen D.; Brouqui, Philippe; Raoult, Didier
Human head lice and body lice are morphologically and biologically similar but have distinct ecologies. They were shown to have almost the same basic genetic content (one gene is absent in head lice), but differentially express certain genes, presumably responsible for the vector competence. They are now believed to be ecotypes of the same species (Pediculus humanus) and based on mitochondrial studies, body lice have been included with head lice in one of three clades of human head lice (Clade A). Here, we tested whether head and body lice collected from the same host belong to the same population by examining highly polymorphic intergenic spacers. This study was performed on lice collected from five homeless persons living in the same shelter in which Clade A lice are prevalent. Lice were individually genotyped at four spacer loci. The genetic identity and diversity of lice from head and body populations were compared for each homeless person. Population genetic structure was tested between lice from the two body regions and between the lice from different host individuals. We found two pairs of head and body lice on the same homeless person with identical multi locus genotypes. No difference in genetic diversity was found between head and body louse populations and no evidence of significant structure between the louse populations was found, even after controlling for a possible effect of the host individual. More surprisingly, no structure was obvious between lice of different homeless persons. We believe that the head and body lice collected from our five subjects belong to the same population and are shared between people living in the same shelter. These findings confirm that head and body lice are two ecotypes of the same species and show the importance of implementing measures to prevent lice transmission between homeless people in shelters. PMID:23049889
Veracx, Aurélie; Rivet, Romain; McCoy, Karen D; Brouqui, Philippe; Raoult, Didier
Human head lice and body lice are morphologically and biologically similar but have distinct ecologies. They were shown to have almost the same basic genetic content (one gene is absent in head lice), but differentially express certain genes, presumably responsible for the vector competence. They are now believed to be ecotypes of the same species (Pediculus humanus) and based on mitochondrial studies, body lice have been included with head lice in one of three clades of human head lice (Clade A). Here, we tested whether head and body lice collected from the same host belong to the same population by examining highly polymorphic intergenic spacers. This study was performed on lice collected from five homeless persons living in the same shelter in which Clade A lice are prevalent. Lice were individually genotyped at four spacer loci. The genetic identity and diversity of lice from head and body populations were compared for each homeless person. Population genetic structure was tested between lice from the two body regions and between the lice from different host individuals.We found two pairs of head and body lice on the same homeless person with identical multi locus genotypes. No difference in genetic diversity was found between head and body louse populations and no evidence of significant structure between the louse populations was found, even after controlling for a possible effect of the host individual. More surprisingly, no structure was obvious between lice of different homeless persons.We believe that the head and body lice collected from our five subjects belong to the same population and are shared between people living in the same shelter. These findings confirm that head and body lice are two ecotypes of the same species and show the importance of implementing measures to prevent lice transmission between homeless people in shelters.
Eric L. Smith; Andrew J. Storer; Bryan K. Roosien
The goal of this study was to obtain an estimate of the infestation rate of ash trees with emerald ash borer (EAB) (Agrilus planipennis, Fairmaire; Coleoptera; Buprestidae), across its primary infestation zone of...
Mumcuoglu, K Y; Miller, J; Manor, O; Ben-Yshai, F; Klaus, S
Newly arrived Ethiopian immigrants in Israel were screened for ectoparasitic insects and mites. Of 304 individuals examined 65.1% were infested with the head louse (Pediculus humanus capitis). The infestation rate among children varied between 65 and 100%. Children aged 6-11 years were the most infested group and no differences between girls and boys were found. The infestation rate in children was significantly higher than that found in adults. Approximately 39% of those examined were infested with the body louse (Pediculus humanus humanus). The rate of infestation with this parasite was higher in adults than in children and higher in females than males. Ten percent of the immigrants examined were infested with the scabies mite (Sarcoptes scabiei) and 4.3% with the human flea (Pulex irritans).
Lehnert, Kristina; Schwanke, Eva; Hahn, Kerstin; Wohlsein, Peter; Siebert, Ursula
The seal louse (Echinophthirius [E.] horridus) and the heartworm (Acanthocheilonema [A.] spirocauda) are parasites of harbour seal (Phoca vitulina). Little is known about the role of the seal louse as a potential vector and its role for the development and transmission of heartworm larvae to their final host, the harbour seal. The life-cycle of the heartworm is still not fully understood. For the presented study, findings of 1191 stranded harbour seals collected along the North- and Baltic Sea coast between 1996 and 2013 were examined. 4.4% (n = 53) of these harbour seals were infected with adult heartworms and 3.4% (n = 40) harbour seals carried seal lice. The highest prevalence and level of infection with adult heartworms (A. spirocauda) (9.3%) and seal lice (E. horridus) (8.9%) were found on yearling harbour seals (7-18 months) compared to neonate and adult seals. Investigating seal lice (n = 35) for larval heartworm stages one larvae was encountered in an ethanol-fixated seal louse. During a health monitoring survey of live harbour seals, 109 animals were captured and examined during spring and autumn between 2008 and 2014. Blood samples were taken and microfilariae were discovered in blood smears in 41% (n = 45) of the examined harbour seals. Yearling seals (n = 21) showed higher prevalence (86%) and level of infection with microfilariae than adults. Microfilariae were identified as A. spirocauda by sequencing the species-specific COI gene in 24 blood samples. The high prevalence of microfilariae of A. spirocauda in blood samples (41%) is in contrast to the low prevalence of mature infections/adult specimens in stranded seals (4.4%) investigated. Although rare parasites of seals, the recent increase in prevalence of heartworm and seal lice in stranded seals and the relatively high occurrence of microfilaria in the free-ranging population underscore the importance of further studies investigating the immunology of infections and their transmission pathways, as
... Schedules Nutrient Shortfall Questionnaire Home Diseases and Conditions Head Lice Head Lice Condition Family HealthKids and Teens Share Head Lice Table of Contents1. Overview2. Symptoms3. Causes4. Prevention5. ...
... a child's head circumference. Normal ranges for a child's sex and age (weeks, months), based on values that experts have obtained for normal growth rates of infants' and children's heads. Measurement of the head circumference is an ...
Larsson, Christer; Lundqvist, Jenny; van Rooijen, Nico; Bergström, Sven
Louse-borne relapsing fever (LBRF) borreliosis is caused by Borrelia recurrentis, and it is a deadly although treatable disease that is endemic in the Horn of Africa but has epidemic potential. Research on LBRF has been severely hampered because successful infection with B. recurrentis has been achieved only in primates (i.e., not in other laboratory or domestic animals). Here, we present the first non-primate animal model of LBRF, using SCID (-B, -T cells) and SCID BEIGE (-B, -T, -NK cells) immunocompromised mice. These animals were infected with B. recurrentis A11 or A17, or with B. duttonii 1120K3 as controls. B. recurrentis caused a relatively mild but persistent infection in SCID and SCID BEIGE mice, but did not proliferate in NUDE (-T) and BALB/c (wild-type) mice. B. duttonii was infectious but not lethal in all animals. These findings demonstrate that the immune response can limit relapsing fever even in the absence of humoral defense mechanisms. To study the significance of phagocytic cells in this context, we induced systemic depletion of such cells in the experimental mice by injecting them with clodronate liposomes, which resulted in uncontrolled B. duttonii growth and a one-hundred-fold increase in B. recurrentis titers in blood. This observation highlights the role of macrophages and other phagocytes in controlling relapsing fever infection. B. recurrentis evolved from B. duttonii to become a primate-specific pathogen that has lost the ability to infect immunocompetent rodents, probably through genetic degeneration. Here, we describe a novel animal model of B. recurrentis based on B- and T-cell-deficient mice, which we believe will be very valuable in future research on LBRF. Our study also reveals the importance of B-cells and phagocytes in controlling relapsing fever infection. PMID:19787030
Masetti, Massimo; Bruschi, Fabrizio
In summer 2003 two separate infestations due to the common bedbug (Cimex lectularius) occurred in Pisa, Italy. Cutaneous reaction was evident and one patient developed a severe bullous eruption. In both cases there was circumstantial evidence for association with international travel.
Levens, Afra M A; Schurink, Maarten; Koetse, Harma A; van Baren, Robertine
Gastrointestinal infestation with the parasite Enterobius vermicularis is common in humans and is usually harmless. Anal pruritus is the most characteristic symptom, but the parasites can cause severe abdominal pain mimicking appendicitis. Early recognition can prevent an unnecessary appendectomy. A six-year-old girl reported to the accident and emergency department with pain in the lower right abdominal region. She was admitted and treated for suspected perforated appendix, following physical examination supplemented with an abdominal CT scan. After antibiotic treatment the symptoms disappeared as did the abscess, apart from a minor amount of residual infiltrate. She was then readmitted twice with recurrent abdominal pain without radiological evidence of an abdominal focus. We decided to conduct a diagnostic laparoscopy and an elective appendectomy à froid. During this procedure living worms were found in the appendix. Treatment with the anthelminthicum mebendazol was effective. Gastro-intestinal infestation with E. vermicularis is very common, especially in young children. This infestation is usually harmless, but can mimic appendicitis. This infestation is easily treatable with mebendazol.
This is the final part of a three part series specifically addressing lessons learned concerning the management of rehabilitated cheatgrass-infested rangelands. Steve Novak and Richard Mack reported in 2003 that they found no evidence of outcrossing in 2,000 cheatgrass seedlings from 60 North Americ...
Alcaide, M; Reina, D; Frontera, E; Navarrete, I
This survey was conducted to determine the chronobiology and seroprevalence of nasal bot infestation (Oestrus ovis) in Spain and to identify the risk factors associated with this disease in caprine herds. A total of 1590 sera from adult goats were collected at random on 175 farms in southwestern Spain. Sera were tested by ELISA, using crude protein from second stage larvae as antigen. The mean seroprevalence was 46.04% and mean percentage of optical densities was 41.83. These data indicate a high prevalence of this parasite in the investigated areas. The serological survey revealed that goats managed at higher altitudes, at meridians latitudes and on farms with small herds had a smaller probability of infestation. Eighty goat heads, obtained from abattoirs in the central region of Spain, were collected and examined for nasal botflies from February to October 2002. O. ovis larval stages were recovered from the nasal-sinus cavities of 23 goats, reaching a prevalence of 34.94%. The mean larval burden was 3.9 larvae per infested head. No first instars were found during February and March, when the second instar reached its larger count. The third instar was observed in very small number during the whole period of study, with one peak occurring in July--August. These data show the existence of a favourable period for the development of larval instars of O. ovis in goats that starts in February and finishes in September.
Mutlow, Adrian G; Dryden, Michael W; Payne, Patricia A
A pair of captive adult giant anteaters (Myrmecophaga tridactyla) presented heavily infested with a flea species (Pulex simulans) commonly found on Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor) in the central United States. In this case, the flea was demonstrated to have completed its entire life cycle with the anteaters as the host. A single treatment of topical imidacloprid, coupled with removal and replacement of infested bedding, was rapidly effective at controlling the infestation and no adverse effects of the drug were noted. Control of the anteater infestation also removed the flea infestation of aardvarks in the same building.
Koch, T; Brown, M; Selim, P; Isam, C
Head lice infestation is a public health issue. In the effort to compile an evidence-base about the physiology, detection, treatment, effects and management strategies of head lice infestations we reviewed current literature. This literature signalled significant evidence gaps and these gaps provide incentives for further research. Our conclusions from the literature are that parents of children are responsible for head lice detection and treatment but have varying access to advice about how best to treat this condition. Concern is exacerbated by misconceptions surrounding the circumstances of infestation. Head lice are a low priority for health professionals in Australia, whereas parents and teachers believe the problem necessitates greater attention. It is important to provide a unified evidence-based approach to good information. It is timely for health care professionals to re-examine and prioritize this public health issue. They should research and work collaboratively towards the eradication of head lice.
Shao, Renfu; Barker, Stephen C
The mitochondrial (mt) genome of the human body louse, Pediculus humanus, consists of 18 minichromosomes. Each minichromosome is 3 to 4 kb long and has 1 to 3 genes. There is unequivocal evidence for recombination between different mt minichromosomes in P. humanus. It is not known, however, how these minichromosomes recombine. Here, we report the discovery of eight chimeric mt minichromosomes in P. humanus. We classify these chimeric mt minichromosomes into two groups: Group I and Group II. Group I chimeric minichromosomes contain parts of two different protein-coding genes that are from different minichromosomes. The two parts of protein-coding genes in each Group I chimeric minichromosome are joined at a microhomologous nucleotide sequence; microhomologous nucleotide sequences are hallmarks of non-homologous recombination. Group II chimeric minichromosomes contain all of the genes and the non-coding regions of two different minichromosomes. The conserved sequence blocks in the non-coding regions of Group II chimeric minichromosomes resemble the "recombination repeats" in the non-coding regions of the mt genomes of higher plants. These repeats are essential to homologous recombination in higher plants. Our analyses of the nucleotide sequences of chimeric mt minichromosomes indicate both homologous and non-homologous recombination between minichromosomes in the mitochondria of the human body louse. Copyright © 2010 Elsevier B.V. All rights reserved.
Sands, B; Ellse, L; Wall, R
Essential oils have shown good experimental potential as novel veterinary ectoparasiticides. However, if they are to be used as veterinary products, they must be available in formulations that are suitable for practical application against specific ectoparasites. Here, the efficacies of formulations containing 5% (v/v) lavender or tea tree oil, in combination with two emulsifiers [a surfactant, 5% (w/v) N-lauroylsarcosine sodium salt (SLS), and a soluble polymer, 5% (w/v) polyvinylpyrrolidone (PVP)], with or without 10% coconut oil, were tested in contact bioassays against the donkey chewing louse Bovicola ocellatus (Piaget) (Phthiraptera: Trichodectidae). Residual activity was quantified in open and closed containers; ovicidal efficacy was also examined. Exposure to either of 5% (v/v) lavender or tea tree oils with SLS or PVP resulted in louse mortality of 100%, but when coconut oil was included as an excipient, significantly lower efficacy was recorded. However, the formulations became significantly less effective after 2 h in open containers and 40 h in closed containers. The results confirm that the residual activity of essential oils is relatively transitory and the addition of 10% coconut oil does not prolong the period of insecticidal activity by slowing essential oil evaporation. Too short a period of residual activity is likely to be a significant impediment to the effective practical use of essential oils. However, unlike many synthetic pediculicides, the essential oils tested here were highly ovicidal, which suggests that prolonged residual activity may not be essential to kill newly hatched nymphs after treatment.
In 1914, the third year of the Taisho era, a period of democracy and prosperity of Japan, Tokyo was attached by an outbreak of epidemic louse-borne typhus. The number of patients was 4,119 and number of deaths was 778 (mortality rate of 18.9%) in Tokyo and 7,309 patients had been suffering from typhus fever that year in Japan. Many possible causes of the outbreak were suspected by the Health Authority of the Home Office, but these were not confirmed. One of the most likely reasons is the poor and congested living conditions of seasonal construction workers. Laborers had moved from the northwest region of Japan where typhus fever had developed occasionally in those days. Some of the laborers probably brought pathogenic germs with lice. The main preventive method for epidemic louse-borne typhus was isolation of patients and disinfecting of the areas. Kitasato Shibasaburou proposed the improvement of residential conditions of workers to prevent the prevalence of disease, but the proposal was not accepted because of financial reasons of the government. Recurrence of the outbreak did not occur in the following years. However, a huge outbreak of typhus fever with 32,366 patients and 3,351 deaths, was documented in 1946, amidst the disordered conditions of Japan after World War II.
Wootton, Emma C; Pope, Edward C; Vogan, Claire L; Roberts, Emily C; Davies, Charlotte E; Rowley, Andrew F
Ectoparasitic copepods have been reported in a wide range of aquatic animals, including crustacean shellfish. However, with the exception of the salmon louse, Lepeophtheirus salmonis, our knowledge of such parasites in commercial species is rudimentary. The current study examines the morphology and pathology of the parasitic copepod, Nicothoë astaci (the 'lobster louse') in its host, the European lobster, Homarus gammarus. Lobsters were sampled from waters surrounding Lundy Island (Bristol Channel, UK) and all individuals collected were found to harbour female adult N. astaci in their gills, with a mean of 47·3 parasites/lobster. The majority of N. astaci were found in the basal region of pleurobranch gills. The parasite was found to attach to gill filaments via its oral sucker, maxillae and maxillipeds, and to feed on host haemolymph (blood) through a funnel-like feeding channel. It caused varying degrees of damage to the host gill, including occlusion of gill filaments and disruption to the vascular system in the central axis. Although there was evidence of extensive host response (haemocytic infiltration) to the parasite, it was displaced from the parasite attachment site and thus was observed in the central gill axis below. The region of gill filament immediately underlying the parasite feeding channel was devoid of such activity suggesting that the parasite interferes with the cellular defence and haemostatic mechanisms of the lobster in order to maintain invasion of the host.
Braden, Laura M; Koop, Ben F; Jones, Simon R M
Disease outbreaks with the salmon louse Lepeophtheirus salmonis cause significant economic losses in mariculture operations worldwide. Variable innate immune responses at the louse-attachment site contribute to differences in susceptibility among species such that members of Salmo spp. are more susceptible to infection than those of some Oncorhynchus spp. Relatively little is known about the mechanisms that contribute to disease resistance or susceptibility to L. salmonis in salmon. Here, we utilize histochemistry and transcriptomics in a comparative infection model with susceptible (Atlantic, sockeye) and resistant (coho) salmon. At least three cell populations (MHIIβ+, IL1β+, TNFα+) were activated in coho salmon skin during L. salmonis infection. Locally elevated expression of several pro-inflammatory mediators (e.g. IL1β, IL8, TNFα, COX2, C/EBPβ), and tissue repair enzymes (MMP9, MMP13) were detected in susceptible and resistant species. However, responses specific to coho salmon (e.g. IL4, IL6, TGFβ) or responses shared among susceptible salmon (e.g. SAP, TRF, Cath in Atlantic and sockeye salmon) provide evidence for species-specific pathways contributing to resistance or susceptibility, respectively. Our results confirm the importance of an early pro-inflammatory TH1-type pathway as an initial host response during infection with Pacific sea lice, and demonstrate subsequent regulatory TH2-type processes as candidate defense mechanisms in the skin of resistant coho salmon. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.
Durden, L A; Webb, J P
Both sexes of Abrocomaphthirus hoplai, new genus and new species (Anoplura: Polyplacidae), are described and illustrated. The endemic Chilean chinchilla rat Abrocoma bennetti Waterhouse (Rodentia: Abrocomidae) is the type host. The definition of the family Polyplacidae is amended to accommodate the new genus. Polyplax longa (Werneck), also referred to in the literature as Neohaematopinus longus Werneck, is reassigned to Abrocomaphthirus. The host of A. longus comb.n., is Abrocoma cinerea Thomas, another chinchilla rat, which inhabits parts of Argentina, Bolivia, Chile and Peru. The erection of Abrocomaphthirus as a distinct genus has important zoogeographical and evolutionary implications. The tenuous anomaly of P. longa being the sole native representative of the genus Polyplax in South America, possibly with African affinities, is now refuted. Instead, partial colonization of the neotropics by native species of both Polyplax and Neohaematopinus appears to have been relatively recent and from North America. The phylogenetic affinities of Abrocomaphthirus are unknown, but it appears to be closely related to other, more ancient, native South American polyplacid louse genera, such as Cuyana, Eulinognathus, Galeophthirus, and Lagidiophthirus. Arguments are presented in support of an ancestral zoogeographical link to Africa for these louse genera.
Vulink, Nienke C
Patients with a delusional infestation (DI) have an overwhelming conviction that they are being infested with (non) pathogens without any medical proof. The patients need a systematic psychiatric and dermatological evaluation to assess any possible underlying cause that could be treated. Because they avoid psychiatrists, a close collaboration of dermatologists and psychiatrists, who examine the patient together, seems to be a promising solution. It helps to start a trustful doctor-patient relationship and motivates the patient for psychiatric treatment. We here review diagnostic criteria, classification of symptoms, pathophysiology and treatment options of DI. Antipsychotic medication is the treatment of choice when any other underlying cause or disorder is excluded. Further research is needed to assess the pathophysiology, and other treatment options for patients with DI.
Gupta, Sanjeev; Gupta, Sunita; Mittal, Amit; Mahendra, Aneet; Aggarwal, Anshu; Batra, Rohit; Jindal, Nidhi
There are many causes of urticaria, which may vary from infections to malignancy. Among the infections, infestations by cysticercosis (larval stage of the tapeworm called Taenia solium) is an important cause. The present report is of forty four years old female who presented with urticaria and swelling on face. The swelling was later diagnosed as cysticercosis by noninvasive ultrasonography. The urticaria subsided after the treatment of cysticercosis. We report this case for rarity of its presentation.
Gewirtzman, A; Rabinovitz, H
With air travel so prevalent, diseases endemic to certain regions may appear anywhere. The botfly (Dermatobia hominis) is not native to North America. We describe a case of a young boy and his father who presented with furunculosis secondary to infestation with the botfly. The infected patients live in South Florida and had been vacationing in Central America. Standard surgical treatment as well as multiple native remedies are described.
Gallardo, A; Mougabure Cueto, G; Picollo, M I
Human pediculosis is produced by Pediculus humanus humanus (Linnaeus 1758) and Pediculus humanus capitis (De Geer 1767). Laboratory-reared body lice, susceptible to insecticides, were used as reference in toxicological studies on head lice. In this work, we evaluated the survival of both subspecies at different temperatures and relative humidities and we propose the optimal conditions for comparative bioassays. Moreover, we used these conditions to test the activity of three monoterpenoids against both lice. The results showed differential response to changes in temperature and humidity between both organisms. The survival of body lice ranged between 83% and 100% and was not affected for the tested conditions. The survival of head lice depended on temperature, humidity, and exposure time. The optimal conditions for head lice were 18 masculineC and 97% relative humidity at 18 h of exposition. The insecticidal activity of three monoterpenoids (pulegone, linalool, and 1,8-cineole), evaluated according the selected conditions by topical application, showed no significant differences between males of body and head lice. To conclude, as head lice required more special laboratory conditions than body lice, the optimal head lice conditions should be used in both organisms in comparative bioassays. Body louse is an appropriate organism for testing products against of head louse.
Gamarra, J G P; He, F
1. The relationship between occupancy and spatial contagion during the spread of eruptive and invasive species demands greater study, as it could lead to improved prediction of ecosystem damage. 2. We applied a recently developed model that links occupancy and its fractal dimension to model the spatial distribution of mountain pine beetle infestations in British Columbia, Canada. We showed that the distribution of infestation was scale-invariant in at least 24 out of 37 years (mostly in epidemic years), and presented some degree of scale-invariance in the rest. There was a general logarithmic relationship between fractal dimension and infestation occupancy. Based on the scale-invariance assumption, we further assessed the interrelationships for several landscape metrics, such as correlation length, maximum cluster size, total edge length and total number of clusters. 3. The scale-invariance assumption allows fitting the above metrics, and provides a framework to establish the scaling relationship between occupancy and spatial contagion. 4. We concluded that scale-invariance dominates the spread of mountain pine beetle. In this context, spatial aggregation can be predicted from occupancy, hence occupancy is the only variable one needs to know in order to predict the spatial distributions of populations. This supports the hypothesis that fractal dispersal kernels may be abundant among outbreaks of pests and invasive species.
Smith, Peter C; Zeiss, Caroline J; Beck, Amanda P; Scholz, Jodi A
Demodex musculi, a prostigmatid mite that has been reported infrequently in laboratory mice, has been identified with increasing frequency in contemporary colonies of immunodeficient mice. Here we describe 2 episodes of D. musculi infestation with associated clinical signs in various genetically engineered mouse strains, as well as treatment strategies and an investigation into transmissibility and host susceptibility. The first case involved D. musculi associated with clinical signs and pathologic lesions in BALB/c-Tg(DO11.10)Il13tm mice, which have a defect in type 2 helper T cell (Th2) immunity. Subsequent investigation revealed mite transmission to both parental strains (BALB/c-Tg[DO11.10] and BALB/c-Il13tm), BALB/c-Il13/Il4tm, and wild-type BALB/c. All Tg(DO11.10)Il13tm mice remained infested throughout the investigation, and D. musculi were recovered from all strains when they were cohoused with BALB/c-Tg(DO11.10)Il13tm index mice. However, only Il13tm and Il13/Il4tm mice demonstrated persistent infestation after index mice were removed. Only BALB/c-Tg(DO11.10)Il13tm showed clinical signs, suggesting that the phenotypic dysfunction of Th2 immunity is sufficient for persistent infestation, whereas clinical disease associated with D. musculi appears to be genotype-specific. This pattern was further exemplified in the second case, which involved NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) and C;129S4 Rag2tm1.1Flv Il2rgtm1.1Flv/J mice with varying degrees of blepharitis, conjunctivitis, and facial pruritis. Topical amitraz decreased mite burden but did not eliminate infestation or markedly ameliorate clinical signs. Furthermore, mite burden began to increase by 1 mo posttreatment, suggesting that topical amitraz is an ineffective treatment for D. musculi. These experiences illustrate the need for vigilance regarding opportunistic and uncommon pathogens in rodent colonies, especially among mice with immunologic deficits. PMID:27538858
Smith, Peter C; Zeiss, Caroline J; Beck, Amanda P; Scholz, Jodi A
Demodex musculi, a prostigmatid mite that has been reported infrequently in laboratory mice, has been identified with increasing frequency in contemporary colonies of immunodeficient mice. Here we describe 2 episodes of D. musculi infestation with associated clinical signs in various genetically engineered mouse strains, as well as treatment strategies and an investigation into transmissibility and host susceptibility. The first case involved D. musculi associated with clinical signs and pathologic lesions in BALB/c-Tg(DO11.10)Il13(tm) mice, which have a defect in type 2 helper T cell (Th2) immunity. Subsequent investigation revealed mite transmission to both parental strains (BALB/c-Tg[DO11.10] and BALB/c-Il13(tm)), BALB/c-Il13/Il4(tm), and wild-type BALB/c. All Tg(DO11.10)Il13(tm) mice remained infested throughout the investigation, and D. musculi were recovered from all strains when they were cohoused with BALB/c-Tg(DO11.10)Il13(tm) index mice. However, only Il13(tm) and Il13/Il4(tm) mice demonstrated persistent infestation after index mice were removed. Only BALB/c-Tg(DO11.10)Il13(tm) showed clinical signs, suggesting that the phenotypic dysfunction of Th2 immunity is sufficient for persistent infestation, whereas clinical disease associated with D. musculi appears to be genotype-specific. This pattern was further exemplified in the second case, which involved NOD.Cg-Prkdc(scid)Il2r(tm1Wjl)/SzJ (NSG) and C;129S4 Rag2(tm1.1Flv) Il2rg(tm1.1Flv)/J mice with varying degrees of blepharitis, conjunctivitis, and facial pruritis. Topical amitraz decreased mite burden but did not eliminate infestation or markedly ameliorate clinical signs. Furthermore, mite burden began to increase by 1 mo posttreatment, suggesting that topical amitraz is an ineffective treatment for D. musculi. These experiences illustrate the need for vigilance regarding opportunistic and uncommon pathogens in rodent colonies, especially among mice with immunologic deficits.
Torbick, Nathan M.
Recent shifts in wetland ecosystem management goals have directed efforts toward measuring ecological integrity, rather than only using physical and chemical measures of ecosystems as health indicators. Invasive species pose one of the largest threats to wetlands integrity. Resource managers can benefit from improved methods for identifying invasive plant species, assessing infestation, and monitoring control measures. The utilization of advanced remote sensing tools for species-level mapping has been increasing and techniques need to be explored for identifying species of interest and characterizing infestation. The overarching goal of this research was to develop monitoring technologies to map invasive plants and quantify wetland infestation. The first field-level objective was to characterize absorption and reflectance features and assess processing techniques for separating wetland species. The second field-level objective was to evaluate the abilities of a shape filter to identify wetland invasive plant species. The first landscape-level objective was to classify hyperspectral imagery in order to identify invasives of interest. The second landscape-level objective was to quantify infestation within the study area. Field-level hyperspectral data (350-2500nm) were collected for twenty-two wetland plant species in a wetland located in the lower Muskegon River watershed in Michigan, USA. The Jeffries-Matusita distance measure, continuum removal, and a shape-filter were applied to hyperspectral species reflectance data to characterize spectral features. Generally, continuum removal decreased separation distance for the invasive species of interest. Using the shape-filter, Lythrum salicaria, Phragmites australis, and Typha latifolia possessed maximum separation (distinguished from other species) at the near-infrared edge (700nm) and water absorption region (1350nm), the near-infrared down slope (1000 and 1100nm), and the visible/chlorophyll absorption region (500nm
... Us HEADS UP Apps Reshaping the Culture Around Concussion in Sports Get HEADS UP on Your Web Site Concussion ... fit, and maintain the right helmet for specific sports. Concussion Laws Learn about Return to Play and other ...
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Catherine S. Wightman; Victoria A. Saab; Chris Forristal; Kim Mellen-Mclean; Amy Markus
Within forests susceptible to wildfire and insect infestations, land managers need to balance dead tree removal and habitat requirements for wildlife species associated with snags. We used Mahalanobis distance methods to develop predictive models of white-headed woodpecker (Picoides albolarvatus) nesting habitat in postfire ponderosa pine (Pinus ponderosa)-dominated...
Argandoña, V H; Chaman, M; Cardemil, L; Muñoz, O; Zúñiga, G E; Corcuera, L J
The purpose of this work was to investigate whether ethylene is involved in the oxidative and defensive responses of barley to the aphids Schizaphis graminum (biotype C) and Rhopalophum padi. The effect of aphid infestation on ethylene production was measured in two barley cultivars (Frontera and Aramir) that differ in their susceptibility to aphids. Ethylene evolution was higher in plants infested for 16 hr than in plants infested for 4 hr in both cultivars. Under aphid infestation, the production of ethylene was higher in cv. Frontera than in Aramir, the more aphid susceptible cultivar. Ethylene production also increases with the degree of infestation. Maximum ethylene evolution was detected after 16 hr when plants were infested with 10 or more aphids. Comparing the two species of aphids, Schizaphis graminum induced more ethylene evolution than Rhopalosiphum padi. Infestation with S. graminum increased hydrogen peroxide content and total soluble peroxidase activity in cv. Frontera, with a maximum level of H2O2 observed after 20 min of infestation and the maximum in soluble peroxidase activity after 30 min of infestation. When noninfested barley seedlings from cv. Frontera were exposed to ethylene, an increase in hydrogen peroxide and in total peroxidase activity was detected at levels similar to those of infested plants from cv. Frontera. When noninfested plants were treated with 40 ppm of ethylene, the maximum levels of H2O2 and soluble peroxidase activity were at 10 and 40 min, respectively. Ethylene also increased the activity of both cell-wall-bound peroxidases types (ionically and covalently bound), comparable with infestation. These results suggest that ethylene is involved in the oxidative responses of barley plants induced by infestation.
Noting that every year, 10 to 12 million children contract head lice, this book aims to demystify and provide information about the problem of head lice infestation of children. The first chapter gives statistical details about the problem and its effects on health. Chapter 2 provides factual information concerning the features, life-cycle,…
Noting that every year, 10 to 12 million children contract head lice, this book aims to demystify and provide information about the problem of head lice infestation of children. The first chapter gives statistical details about the problem and its effects on health. Chapter 2 provides factual information concerning the features, life-cycle,…
Braden, Laura M; Sutherland, Ben J G; Koop, Ben F; Jones, Simon R M
Outcomes of infections with the salmon louse Lepeophtheirus salmonis vary considerably among its natural hosts (Salmo, Oncorhynchus spp.). Host-parasite interactions range from weak to strong host responses accompanied by high to low parasite abundances, respectively. Parasite behavioral studies indicate that the louse prefers the host Atlantic Salmon (Salmo salar), which is characterized by a weak immune response, and that this results in enhanced parasite reproduction and growth rates. Furthermore, parasite-derived immunosuppressive molecules (e.g., proteases) have been detected at higher amounts in response to the mucus of Atlantic Salmon relative to Coho Salmon (Oncorhynchus kisutch). However, the host-specific responses of the salmon louse have not been well characterized in either of the genetically distinct sub-species that occur in the Atlantic and Pacific Oceans. We assessed and compared the transcriptomic feeding response of the Pacific salmon louse (L. salmonis oncorhynchi,) while parasitizing the highly susceptible Atlantic Salmon and Sockeye Salmon (Oncorhynchus nerka) or the more resistant Coho Salmon (Oncorhynchus kisutch) using a 38 K oligonucleotide microarray. The response of the louse was enhanced both in the number of overexpressed genes and in the magnitude of expression while feeding on the non-native Atlantic Salmon, compared to either Coho or Sockeye Salmon. For example, putative virulence factors (e.g., cathepsin L, trypsin, carboxypeptidase B), metabolic enzymes (e.g., cytochrome B, cytochrome C), protein synthesis enzymes (e.g., ribosomal protein P2, 60S ribosomal protein L7), and reproduction-related genes (e.g., estrogen sulfotransferase) were overexpressed in Atlantic-fed lice, indicating heightened parasite fitness with this host species. In contrast, responses in Coho- or Sockeye-fed lice were more similar to those of parasites deprived of a host. To test for host acclimation by the parasite, we performed a reciprocal host transfer
Dale, Colin; Beeton, Michael; Harbison, Christopher; Jones, Tait; Pontes, Mauricio
Members of the genus Arsenophonus comprise a large group of bacterial endosymbionts that are widely distributed in arthropods of medical, veterinary, and agricultural importance. At present, little is known about the role of these bacteria in arthropods, because few representatives have been isolated and cultured in the laboratory. In the current study, we describe the isolation and pure culture of an Arsenophonus endosymbiont from the hippoboscid louse fly Pseudolynchia canariensis. We propose provisional nomenclature for this bacterium in the genus Arsenophonus as "Candidatus Arsenophonus arthropodicus." Phylogenetic analyses indicate that "Candidatus Arsenophonus arthropodicus" is closely related to the Arsenophonus endosymbionts found in psyllids, whiteflies, aphids, and mealybugs. The pure culture of this endosymbiont offers new opportunities to examine the role of Arsenophonus in insects. To this end, we describe methods for the culture of "Candidatus Arsenophonus arthropodicus" in an insect cell line and the transformation of this bacterium with a broad-host-range plasmid.
Raja, K; Venmathi Maran, B A; Gopalakrishnan, A; Saravanakumar, A; Vijayakumar, R; Sinduja, K
A commercially important fish, wahoo Acanthocybium solandri (Cuvier, 1832) (Scombridae), was collected to study the infestation of parasites from Parangipettai landing center, Tamil Nadu, southeast coast of India for a period of one year from January to December 2011. A total of 644 fish were captured and screened for parasites. Off 644 fish, 270 were infested by a parasitic copepod Lernaeenicus seeri Kirtisinghe, 1934 (Siphonostomatoida: Pennellidae) on the body surface. It is a mesoparasite, since the head and neck are inserted and attached to the muscle by making a wound/hole on the body and the rest of the parasite body with the egg sacs hanging outside. Prevalence was recorded as 42.29% with mean and maximum intensity at 3.22 and 33, respectively. Seasonal study showed that the prevalence was highest (62.82 %) during postmonsoon. Simultaneously, some of the fish (n = 144) were internally observed for the presence of parasites and we found that 101 fish were infested with an endoparasite digenean Hirudinella ventricosa (Pallas, 1774) (Hirudinellidae) in the stomach. Prevalence was recorded as 70.9%, and mean intensity of 1.62 and maximum intensity of 3 were also noted. The overall percentage of both copepod and digenean infestation were recorded as 60.42%. The infestation was high in postmonsoon season for both parasites. This is the first record of L. seeri from Indian waters and the second record of occurrence worldwide. Significant interactions were observed between season and infestation of both parasites (P<0.05).
Bayhan, Gülsüm İclal; Çenesiz, Funda; Tanır, Gönül; Taylan Özkan, Ayşegül; Çınar, Gökçe
Ascariasis is a common soil-transmitted helminth infestation worldwide. Ascaris lumbricoides infestation is generally asymptomatic or cause nonspecific signs and symptoms. We report a 5-year-old male with hemophagocytic lymphohistiocytosis associated with A. lumbricoides infestation. The presented patient recovered completely after defecating an A. lumbricoides following intravenous immunoglobulin (IVIG) and mebendazole treatment. We wanted to emphasize that because helminth infestation is easily overlooked, the diagnosis of ascariasis should be considered in patients who live in endemic areas and treated timely to prevent severe complications.
Fukatsu, Takema; Koga, Ryuichi; Smith, Wendy A; Tanaka, Kohjiiro; Nikoh, Naruo; Sasaki-Fukatsu, Kayoko; Yoshizawa, Kazunori; Dale, Colin; Clayton, Dale H
The current study focuses on a symbiotic bacterium found in the slender pigeon louse, Columbicola columbae (Insecta: Phthiraptera). Molecular phylogenetic analyses indicated that the symbiont belongs to the gamma subdivision of the class Proteobacteria and is allied to Sodalis glossinidius, the secondary symbiont of tsetse flies (Glossina spp.) and also to the primary symbiont of grain weevils (Sitophilus spp.). Relative-rate tests revealed that the symbiont of C. columbae exhibits accelerated molecular evolution in comparison with the tsetse fly symbiont and the weevil symbiont. Whole-mount in situ hybridization was used to localize the symbiont and determine infection dynamics during host development. In first- and second-instar nymphs, the symbionts were localized in the cytoplasm of oval bacteriocytes that formed small aggregates on both sides of the body cavity. In third-instar nymphs, the bacteriocytes migrated to the central body and were finally located in the anterior region of the lateral oviducts, forming conspicuous tissue formations called ovarial ampullae. In adult females, the symbionts were transmitted from the ovarial ampullae to developing oocytes in the ovarioles. In adult males, the bacteriocytes often disappeared without migration. A diagnostic PCR survey of insects collected from Japan, the United States, Australia, and Argentina detected 96.5% (109/113) infection, with a few uninfected male insects. This study provides the first microbial characterization of a bacteriocyte-associated symbiont from a chewing louse. Possible biological roles of the symbiont are discussed in relation to the host nutritional physiology associated with the feather-feeding lifestyle.
Seilmaier, M; Guggemos, W; Wieser, A; Fingerle, V; Balzer, L; Fenzl, T; Hoch, M; von Both, U; Schmidt, H U; Wendtner, C M; Strobel, E
Background | Relapsing fever is divided into tick borne relapsing fever (TBRF) and louse borne relapsing fever (LBRF). This report describes 25 refugees from East Africa who were diagnosed to suffer from LBRF within a period of 6 month only at a single hospital in Munich / Germany. Material & Methods | The aim was to point out common clinical features as well as laboratory findings and clinical symptoms before and after initiation of treatment in 25 patients with louse borne relapsing fever (LBRF) who were diagnosed and treated at Klinikum München Schwabing from August 2015 to January 2016. To the best of our knowledge this is the largest case series of LBRF in the western world for decades. Main focus of the investigation was put on clinical aspects. Results | All 25 patients suffered from acute onset of high fever with chills, headache and severe prostration. Laboratory analysis showed high CRP and a marked thrombocytopenia. A Giemsa blood stain was procured immediately in order to look for malaria. In the blood smear spirochetes with typical shape and aspect of borrelia species could be detected.The further PCR analysis confirmed infection with Borrelia recurrentis. Treatment with Doxycycline was started forthwith. The condition improved already on the second day after treatment was started and all were restored to health in less than a week. Apart from a mild to moderate Jarisch-Herxheimer-reaction we didn`t see any side effects of the therapy. Conclusion | LBRF has to be taken into account in feverish patients who come as refugees from East-Africa. It seems that our patients belong to a cluster which probably has its origin in Libya and more patients are to be expected in the near future. As LBRF might cause outbreaks in refugee camps it is pivotal to be aware of this emerging infectious disease in refugees from East-Africa.
Kim, J H; Previte, D J; Yoon, K S; Murenzi, E; Koehler, J E; Pittendrigh, B R; Lee, S H; Clark, J M
Human body and head lice are highly related haematophagous ectoparasites but only the body louse has been shown to transmit Bartonella quintana, the causative agent of trench fever. The mechanisms by which body lice became a vector for B. quintana, however, are poorly understood. Following oral challenge, green fluorescent protein-expressing B. quintana proliferated over 9 days postchallenge with the number of bacteria being significantly higher in whole body vs. head lice. The numbers of B. quintana detected in faeces from infected lice, however, were approximately the same in both lice. Nevertheless, the viability of B. quintana was significantly higher in body louse faeces. Comparison of immune responses in alimentary tract tissues revealed that basal transcription levels of peptidoglycan recognition protein and defensins were lower in body lice and the transcription of defensin 1 was up-regulated by oral challenge with wild-type B. quintana in head but not in body lice. In addition, the level of cytotoxic reactive oxygen species generated by epithelial cells was significantly lower in body lice. Although speculative at this time, the reduced immune response is consistent with the higher vector competence seen in body vs. head lice in terms of B. quintana infection. © 2017 The Royal Entomological Society.
Sousa, A. O.; de Oliveira, S. Moss; Sá Martins, J. S.
The Penna model is used to simulate the competition between an asexual parthenogenetic and asexual population inhabiting the same environment represented by a square lattice. With a small probability, a newborn from the sexual population mutates into an asexual one and vice versa. Then, the asexual population rapidly dominates the sexual one, which all but disappears. However, when an infestation by mutating genetically coupled parasites, that mimic trematodes that feed on gonads, is introduced, the outcome may be one in which both populations coevolve or one in which one of the populations overcomes the other, depending on the density of parasites on the lattice.
Lamattina, Daniela; Nava, Santiago
This work presents records of ticks infesting humans in northern Misiones Province, Argentina. Also, notes on potential transmission of tick-borne pathogens are included. A total of 282 ticks attached to researchers were collected and identified by their morphological characters. Eight tick species were found: Amblyomma brasiliense, Amblyomma coelebs, Amblyomma dubitatum, Amblyomma incisum, Amblyomma ovale, Haemaphysalis juxtakochi, Rhipicephalus sanguineus and Rhipicephalus microplus. Some of these species as A. dubitatum, A. ovale and R. sanguineus have been found infected with spotted fever group rickettsiae pathogenic to humans in Brazil and Argentina. The potential role as vectors of humans pathogens of the ticks found attached to humans in this study is discussed.
Levy, Michael Z.; Quíspe-Machaca, Victor R.; Ylla-Velasquez, Jose L.; Waller, Lance A.; Richards, Jean M.; Rath, Bruno; Borrini-Mayori, Katty; del Carpio, Juan G. Cornejo; Cordova-Benzaquen, Eleazar; McKenzie, F. Ellis; Wirtz, Robert A.; Maguire, James H.; Gilman, Robert H.; Bern, Caryn
We used sentinel animal enclosures to measure the rate of infestation by the Chagas disease vector, Triatoma infestans, in an urban community of Arequipa, Peru, and to evaluate the effect of deltamethrin-impregnated netting on that rate. Impregnated netting decreased the rate of infestation of sentinel enclosures (rate ratio, 0.23; 95% confidence interval, 0.13–0.38; P < 0.001), controlling for the density of surrounding vector populations and the distance of these to the sentinel enclosures. Most migrant insects were early-stage nymphs, which are less likely to carry the parasitic agent of Chagas disease, Trypanosoma cruzi. Spread of the vector in the city therefore likely precedes spread of the parasite. Netting was particularly effective against adult insects and late-stage nymphs; taking into account population structure, netting decreased the reproductive value of migrant populations from 443.6 to 40.5. Impregnated netting can slow the spread of T. infestans and is a potentially valuable tool in the control of Chagas disease. PMID:18840739
Levy, Michael Z; Quíspe-Machaca, Victor R; Ylla-Velasquez, Jose L; Waller, Lance A; Richards, Jean M; Rath, Bruno; Borrini-Mayori, Katty; del Carpio, Juan G Cornejo; Cordova-Benzaquen, Eleazar; McKenzie, F Ellis; Wirtz, Robert A; Maguire, James H; Gilman, Robert H; Bern, Caryn
We used sentinel animal enclosures to measure the rate of infestation by the Chagas disease vector, Triatoma infestans, in an urban community of Arequipa, Peru, and to evaluate the effect of deltamethrin-impregnated netting on that rate. Impregnated netting decreased the rate of infestation of sentinel enclosures (rate ratio, 0.23; 95% confidence interval, 0.13-0.38; P < 0.001), controlling for the density of surrounding vector populations and the distance of these to the sentinel enclosures. Most migrant insects were early-stage nymphs, which are less likely to carry the parasitic agent of Chagas disease, Trypanosoma cruzi. Spread of the vector in the city therefore likely precedes spread of the parasite. Netting was particularly effective against adult insects and late-stage nymphs; taking into account population structure, netting decreased the reproductive value of migrant populations from 443.6 to 40.5. Impregnated netting can slow the spread of T. infestans and is a potentially valuable tool in the control of Chagas disease.
Roza-Gomes, Margarida F; Salvadori, José R; Schons, Jurema
Aphids are considered relevant pests on wheat either by direct damage through sap sucking or by indirect damage vectoring BYDV (Barley yellow dwarf virus). Rhopalosiphum padi L. has been observed infesting wheat fields with an increasing frequency. The knowledge and the available technology, besides being more related to other aphids species already recognized as pests, they are insufficient to control the specific problem of R. padi. Thus, this work evaluated the effects of feeding duration and infestation densities of R. padi on seedlings of wheat cv. Embrapa 16. Grain yield, yield components and the extent of symptoms were recorded. The experiment was carried out in the field under a completely randomized split-plot experimental design with four replications. The main plot was feeding duration (two and seven days) and the sub-plots were infestation densities (zero, two and 10 aphids per plant). Independent on feeding duration, 10 aphids per plant resulted in significant yield losses, reduction of number of heads and tillers per plant. Canopy dry matter was also reduced. Infestations of two and 10 aphids per plant resulted in continuous yellowing of wheat plants from tillering to the end of flowering stage. When aphids fed for seven days on wheat, more yellowing symptoms were observed at the flower stage in comparison with two days feeding.
Amin, Hardik S.; Russo, Rachel S.; Sive, Barkley; Richard Hoebeke, E.; Dodson, Craig; McCubbin, Ian B.; Gannet Hallar, A.; Huff Hartz, Kara E.
Bark beetle infestation impacts the health of coniferous forests, which are an important source of volatile organic compounds (VOCs) to the atmosphere. The types and amounts of VOCs emitted from forests can influence secondary organic aerosol (SOA) formation and impact overall air quality. In this initial work, the impact of bark beetle infestation on SOA precursors from Engelmann spruce is assessed. The VOCs emitted from the trunk of infested and healthy spruce trees were sampled using both sorbent traps and evacuated canisters that were analyzed by gas chromatography/mass spectroscopy. The samples from the infested spruce tree suggest a nine-fold enhancement in the total VOC emissions. The dominant VOCs in the infested spruce trees were 3-carene, β-pinene, and α-pinene. The increase observed in VOCs sampled at the trunk of the infested spruce was consistent with increases observed at infested lodgepole pine trunks. However, the types and amounts of VOCs emitted from Engelmann spruce and lodgepole pine are different, which suggests that additional measures of VOC emissions are needed to characterize the impact of bark beetle infestation on VOC emissions and SOA precursors.
... 7 Agriculture 5 2011-01-01 2011-01-01 false Generally infested areas. 301.45-3 Section 301.45-3 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Gypsy Moth § 301.45-3 Generally infested...
... 7 Agriculture 5 2013-01-01 2013-01-01 false Generally infested areas. 301.45-3 Section 301.45-3 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Gypsy Moth § 301.45-3 Generally infested...
... 7 Agriculture 5 2012-01-01 2012-01-01 false Generally infested areas. 301.45-3 Section 301.45-3 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Gypsy Moth § 301.45-3 Generally infested...
... 7 Agriculture 5 2014-01-01 2014-01-01 false Generally infested areas. 301.45-3 Section 301.45-3 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Gypsy Moth § 301.45-3 Generally infested...
... 7 Agriculture 5 2010-01-01 2010-01-01 false Generally infested areas. 301.45-3 Section 301.45-3 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Gypsy Moth § 301.45-3 Generally infested...
Tran, M M A; Iredell, J R; Packham, D R; O'Sullivan, M V N; Hudson, B J
Delusional infestation remains a debilitating condition that is therapeutically challenging for clinicians. This case series identifies 23 patients with delusional infestation in an Australian setting. The majority of patients are women and unlikely to have a psychiatric comorbid background. The use of unnecessary anti-parasitic medication is prevalent. © 2015 Royal Australasian College of Physicians.
Walter E. Cole; Gene D. Amman
Tree losses resulting from infestation by the mountain pine beetle (Dendroctonus ponderosae Hopkins) were measured in two stands of lodgepole pine (Pinus contorta Dougl.) where the beetle population had previously been epidemic. Measurement data showed that larger diameter trees were infested and killed first. Tree losses...
Individual animal variation occurs regarding external parasite infestation in beef cattle. Our objective was to determine if horn flies infestations present on beef cattle are associated with the single nucleotide polymorphism (SNP; T-318C) in the cytochrome P450 gene (CYP3A28) and the prolactin (PR...
Song, Geun Cheol; Lee, Soohyun; Hong, Jaehwa; Choi, Hye Kyung; Hong, Gun Hyong; Bae, Dong-Won; Mysore, Kirankumar S; Park, Yong-Soon; Ryu, Choong-Min
Agrobacterium tumefaciens causes crown gall disease. Although Agrobacterium can be popularly used for genetic engineering, the influence of aboveground insect infestation on Agrobacterium induced gall formation has not been investigated. Nicotiana benthamiana leaves were exposed to a sucking insect (whitefly) infestation and benzothiadiazole (BTH) for 7 d, and these exposed plants were inoculated with a tumorigenic Agrobacterium strain. We evaluated, both in planta and in vitro, how whitefly infestation affects crown gall disease. Whitefly-infested plants exhibited at least a two-fold reduction in gall formation on both stem and crown root. Silencing of isochorismate synthase 1 (ICS1), required for salicylic acid (SA) synthesis, compromised gall formation indicating an involvement of SA in whitefly-derived plant defence against Agrobacterium. Endogenous SA content was augmented in whitefly-infested plants upon Agrobacterium inoculation. In addition, SA concentration was three times higher in root exudates from whitefly-infested plants. As a consequence, Agrobacterium-mediated transformation of roots of whitefly-infested plants was clearly inhibited when compared to control plants. These results suggest that aboveground whitefly infestation elicits systemic defence responses throughout the plant. Our findings provide new insights into insect-mediated leaf-root intra-communication and a framework to understand interactions between three organisms: whitefly, N. benthamiana and Agrobacterium. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
Studies were conducted to evaluate treatments that reduce survival and attachment of Diaphorina citri nymphs on infested curry leaves (Bergera koenigii). Decontamination of curry leaves infested with D. citri in relation to disinfectant (none or Pro-San), temperature (0, 40, and 50°C), and treatment...
Griffith, G. S.; Cook, R.; Mizen, K. A.
Trifolium repens (white clover) stolons were inoculated with Ditylenchus dipsaci (stem nematode), and the development of resulting infestations was monitored. Nematodes initially remained confined to superficial locations, concentrating in petiole axils near inoculation points. They were able to migrate slowly from the inidal inoculation points and infest adjacent axils, especially in regions near the stolon tip. As time progressed, in some axils, nematodes migrated through the stolon epidermis and colonized slowly expanding subepidermal pockets of host tissue (ca. 0.2-mm length of stolon/day). In these loci nematodes established exponentially increasing populations, but the rates of locus expansion remained constant, indicating that locus expansion was limited by unidentified host-dependent factors. As a result of increasing population pressure within subepidermal loci, J4 entered a "diapause" state and the rate of egg production by adults declined, thereby reducing rate of population growth to more sustainable levels. Typically, these populations peaked at ca. 10,000 individuals in ca. 160 days occupying 3-cm lengths of stolon. Thereafter, heavily infested regions of stolons started to die, leading to the formation of longitudinal splits in their epidermis. In other axils, nematodes did not migrate into the stolons but remained confined to axils. Some of these populations increased a hundred-fold in 95 days, with population growth ending when petioles started to die. Host plant stolon morphology was affected only when subepidermal stolon populations developed high population levels (>100 nematodes) within close proximity (<2 cm) to active terminal meristems. This occurred either when axillary buds became active on previously infested nodes or when nematodes established endoparasitic populations at locations near the stolon tip during winter and spring, when the rate of stolon extension was limited by low light intensity. Affected stolon tips could "escape" from
Cordeiro, Quirino; Corbett, Carlos Eduardo Pereira; Cordeiro Jr, Quirino
Shared psychiatric disorder (folie deux) is a rare condition. But its prevalence can be 5-25% in patients with delusional parasitic infestation. We report the a case of a 62 years-old female with psychotic symptoms. For 15 years, she has lived with her younger sister. Since the patient was well-controled, her sister interrupted her antipsychotic drug administration. So, the patient initiated delusional parasitic infestation accompanied by visual hallucinations. Her sister, who did not have psychiatric history, initiated to believe that the patient was really infested. Moreover, she started to believe that was infested by the patient. This case report aims to discuss the relation between folie deux and delusional parasitic infestation.
Hoch, Martin; Wieser, Andreas; Löscher, Thomas; Margos, Gabriele; Pürner, Friedrich; Zühl, Jürgen; Seilmaier, Michael; Balzer, Lukas; Guggemos, Wolfgang; Rack-Hoch, Anita; von Both, Ulrich; Hauptvogel, Katja; Schönberger, Katharina; Hautmann, Wolfgang; Sing, Andreas; Fingerle, Volker
We report 15 imported louse-borne relapsing fever (LBRF) cases in refugees in Bavaria, Germany. One patient died. Epidemiological findings confirmed that all were young males from the Horn of Africa (12 from Somalia), who had similar migration routes converging in Sudan continuing through Libya and Italy. The majority likely acquired their infection during migration. Healthcare workers should be aware of LBRF in refugees passing through north Africa to ensure correct treatment and preventive measures.
Soliman, S; Marzouk, A S; Main, A J; Montasser, A A
The present study was carried out in the Bilbeis area, Sharqiya Governorate, Egypt. A total of 127 male and 115 female black rats Rattus rattus and 124 male and 153 female Norway rats R. norvegicus was collected during the study period. A total of 20,643 and 40,997 ectoparasites was recovered from R. rattus and R. norvegicus, respectively. Three common mite species were recovered from both rat hosts: Ornithonyssus bacoti, Radfordia ensifera, and Laelaps nuttalli. Three common flea species were also recovered from both rat hosts: Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis. Polyplax spinulosa was the only louse species that infested both rat hosts. Rats that lived more than 12 mo formed about 24 and 14% of the populations of the black and Norway rats, respectively. The prevalences and general indices of many ectoparasites were significantly higher on males than on females of both rat hosts. Seasonal differences in prevalences and general indices of many ectoparasites were recorded between the 2 sexes of both rat species. Prevalences and general indices of most ectoparasites on both rat species showed a tendency to increase with increasing size and age of rat hosts. The type and degree of correlation between prevalences and general indices on the one hand and each of body size and age on the other hand differed among the species of ectoparasites.
Wisseman, C L; Boese, J L; Waddell, A D; Silverman, D J
Evidence is presented to indicate that proteolytic and perhaps other enzymes of the louse midgut, essential to the nutrition of the louse, perform molecular dissection on the antirickettsial antibodies present in the blood of a typhus-immune host that selectively destroys, along with other functions, the portion of the antibody that determines the only known function by which antirickettsial antibodies may operate in host defense mechanisms, namely, opsonization of rickettsiae for enhanced ingestion by professional phagocytes and subsequent destruction. The epidemiologic significance of these findings is discussed in relation to the progressive destruction of cells that produce digestive enzymes of the louse midgut that occurs with progressive rickettsial infection, and the possibility of a negative feedback mechanism in transmission is introduced. Speculations that involve evolutionary concepts of both convergent and divergent varieties with respect to rickettsiae, potentially operational in a system that consists of an obligate blood-sucking arthropod vector and a vertebrate host capable of adaptive responses to both vector and rickettsial agent, are presented.
Braden, Laura M; Barker, Duane E; Koop, Ben F; Jones, Simon R M
Juvenile pink salmon larger than 0.7 g reject the sea louse, Lepeophtheirus salmonis, and are considered resistant to the infection. Robust innate defense responses in the skin contribute to the observed resistance. In contrast adult pink salmon captured at sea or shortly before spawning carry large numbers of the parasite, suggesting inability to control the infection. The purpose of this research is to better understand these apparently contradictory conclusions by comparing a suite of genetic and cellular markers of resistance to L. salmonis in the skin of juvenile and mature pink salmon. The expression of major histocompatibility factor II, C-reactive protein, interleukin-1β, interleukin-8 and cyclooxygenase-2 was down-regulated in mature but not juvenile pink salmon. Similarly, skin at the site of parasite attachment in juvenile salmon was highly populated with MHIIβ(+) and IL-1β(+) cells that were either absent, or at reduced levels at similar sites in mature salmon. In addition, mucocyte density was relatively low in the skin of mature salmon, irrespective of louse infection. In juveniles, the higher mucocyte density decreased following louse attachment. We show that in mature pink salmon, genetic and histological responses in skin are depressed and speculate that salmonid defense against L. salmonis is modulated by maturation.
Sangaré, Abdoul Karim; Boutellis, Amina; Drali, Rezak; Socolovschi, Cristina; Barker, Stephen C.; Diatta, Georges; Rogier, Christophe; Olive, Marie-Marie; Doumbo, Ogobara K.; Raoult, Didier
Currently, the body louse is the only recognized vector of Bartonella quintana, an organism that causes trench fever. In this work, we investigated the prevalence of this bacterium in human lice in different African countries. We tested 616 head lice and 424 body lice from nine African countries using real-time polymerase chain reaction targeting intergenic spacer region 2 and specific B. quintana genes. Overall, B. quintana DNA was found in 54% and 2% of body and head lice, respectively. Our results also show that there are more body lice positive for B. quintana in poor countries, which was determined by the gross domestic product, than in wealthy areas (228/403 versus 0/21, P < 0.001). A similar finding was obtained for head lice (8/226 versus 2/390, P = 0.007). Our findings suggest that head lice in Africa may be infected by B. quintana when patients live in poor economic conditions and are also exposed to body lice. PMID:24935950
Sangaré, Abdoul Karim; Boutellis, Amina; Drali, Rezak; Socolovschi, Cristina; Barker, Stephen C; Diatta, Georges; Rogier, Christophe; Olive, Marie-Marie; Doumbo, Ogobara K; Raoult, Didier
Currently, the body louse is the only recognized vector of Bartonella quintana, an organism that causes trench fever. In this work, we investigated the prevalence of this bacterium in human lice in different African countries. We tested 616 head lice and 424 body lice from nine African countries using real-time polymerase chain reaction targeting intergenic spacer region 2 and specific B. quintana genes. Overall, B. quintana DNA was found in 54% and 2% of body and head lice, respectively. Our results also show that there are more body lice positive for B. quintana in poor countries, which was determined by the gross domestic product, than in wealthy areas (228/403 versus 0/21, P < 0.001). A similar finding was obtained for head lice (8/226 versus 2/390, P = 0.007). Our findings suggest that head lice in Africa may be infected by B. quintana when patients live in poor economic conditions and are also exposed to body lice.
Christie, Andrew E
Copepods of the order Siphonostomatoida are a major concern for commercial aquaculture as many farmed fish serve as hosts for these parasitic crustaceans. Caligus rogercresseyi, a member of the Siphonostomatoida, is a significant problem for salmonid aquaculture in the Southern Hemisphere, and as such, a search for methods for controlling infestations of it is ongoing. One possibility for biological control of this and other copepod ectoparasites is endocrine manipulation. However, little is known about the native endocrine signaling systems in these animals. As part of an ongoing effort to characterize crustacean ectoparasite peptidergic systems, the publicly accessible C. rogercresseyi transcriptome shotgun assembly (TSA) was mined for peptide-encoding transcripts. Using the identified TSA sequences, precursor proteins were deduced and their mature peptides predicted. Thirty-three peptide-encoding transcripts were identified within the Caligus TSA dataset, with the structures of 131 distinct peptides characterized from the deduced pre/preprohormones. The predicted peptides included isoforms of allatostatin A, allatostatin B, bursicon α, bursicon β, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone, diuretic hormone 31, DXXRLamide, FLRFamide, FXGGXamide, GSEFLamide, insulin-like peptide (ILP), intocin, leucokinin, molt-inhibiting hormone, myosuppressin, neuroparsin, neuropeptide F (NPF), orcokinin and tachykinin-related peptide. The predicted ILPs are of particular note as they are the first members of this peptide family identified from a copepod. Similarly, the predicted complement of four distinct NPFs is larger than that known from other crustaceans. Taken collectively, these data greatly expand the known C. rogercresseyi peptidome and provide a foundation for initiating studies of peptidergic control in this species.
Eichner, Christiane; Frost, Petter; Dysvik, Bjarte; Jonassen, Inge; Kristiansen, Bjørn; Nilsen, Frank
Background Lepeophtheirus salmonis is an ectoparasitic copepod feeding on skin, mucus and blood from salmonid hosts. Initial analysis of EST sequences from pre adult and adult stages of L. salmonis revealed a large proportion of novel transcripts. In order to link unknown transcripts to biological functions we have combined EST sequencing and microarray analysis to characterize female salmon louse transcriptomes during post molting maturation and egg production. Results EST sequence analysis shows that 43% of the ESTs have no significant hits in GenBank. Sequenced ESTs assembled into 556 contigs and 1614 singletons and whenever homologous genes were identified no clear correlation with homologous genes from any specific animal group was evident. Sequence comparison of 27 L. salmonis proteins with homologous proteins in humans, zebrafish, insects and crustaceans revealed an almost identical sequence identity with all species. Microarray analysis of maturing female adult salmon lice revealed two major transcription patterns; up-regulation during the final molting followed by down regulation and female specific up regulation during post molting growth and egg production. For a third minor group of ESTs transcription decreased during molting from pre-adult II to immature adults. Genes regulated during molting typically gave hits with cuticula proteins whilst transcripts up regulated during post molting growth were female specific, including two vitellogenins. Conclusion The copepod L.salmonis contains high a level of novel genes. Among analyzed L.salmonis proteins, sequence identities with homologous proteins in crustaceans are no higher than to homologous proteins in humans. Three distinct processes, molting, post molting growth and egg production correlate with transcriptional regulation of three groups of transcripts; two including genes related to growth, one including genes related to egg production. The function of the regulated transcripts is discussed in
Diaz, James H; Nesbitt, Lee T
Physicians are not infrequently consulted by distraught patients with delusions of infestation who believe that they are infested with external or internal parasites and describe a crawling sensation of bugs or worms on or under their skin. Internet search engines were queried with the keywords as search terms to examine the latest articles on delusional infestations in order to describe presenting manifestations, differential diagnoses, and effective management strategies. The demographic and behavioral features of delusional infestations have remained constant and include: (1) onset in well-educated, middle-aged adults who are pet owners; (2) production of purported specimens of causative parasites; (3) pesticide overtreatment of themselves, their households, and pets; (4) excessive cleaning or vacuuming of households; (5) intense anger and resentment directed at physicians failing to confirm their self-diagnoses; and (6) sharing delusional symptoms with spouses or relatives. Although some reports have suggested that cases of delusional infestation are increasing today in the tropics, most studies have confirmed a stable incidence over time and similar disorder demographics worldwide. However, management strategies for delusional infestations have changed significantly over time with second generation, atypical antipsychotics offering safer adverse effect profiles and better prognoses than earlier therapies with first generation, typical antipsychotics. The most effective management strategies for delusional infestations include empathetic history-taking and active listening to the patient, careful exclusion of true parasitoses, and a therapeutic regimen that includes a second generation neuroleptic agent.
Muñoz-Leal, Sebastián; Eriksson, Alan; Santos, Carolina Ferreira; Fischer, Erich; de Almeida, Juliana Cardoso; Luz, Hermes R; Labruna, Marcelo B
Ticks associated with bats have been poorly documented in the Neotropical Zoogeographical Region. In this study, a total of 1028 bats were sampled for tick infestations in the southern portion of the Brazilian Pantanal. A total of 368 ticks, morphologically identified as Ornithodoros hasei (n = 364) and O. mimon (n = 4), were collected from the following bat species: Artibeus planirostris, Platyrrhinus lineatus, Phyllostomus hastatus, Mimon crenulatum and Noctilio albiventris. Morphological identification of O. hasei was confirmed by molecular analysis. Regarding the most abundant bat species, only 40 (6.2%) out of 650 A. planirostris were infested by O. hasei, with a mean intensity of 7.2 ticks per infested bat, or a mean abundance of 0.44 ticks per sampled bat. Noteworthy, one single P. hastatus was infested by 55 O. hasei larvae, in contrast to the 2.5-7.2 range of mean intensity values for the whole study. As a complement to the present study, a total of 8 museum bat specimens (6 Noctilio albiventris and 2 N. leporinus), collected in the northern region of Pantanal, were examined for tick infestations. These bats contained 176 ticks, which were all morphologically identified as O. hasei larvae. Mean intensity of infestation was 22, with a range of 1-46 ticks per infested bat. Our results suggest that A. planirostris might play an important role in the natural life cycle of O. hasei in the Pantanal.
Kong, Hyun G.; Kim, Byung K.; Song, Geun C.; Lee, Soohyun; Ryu, Choong-Min
Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. Infestation from phloem-sucking insects such as whitefly and aphid on plant leaves was previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1–V3 region) by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation, and the fluorescent Pseudomonas spp. recruited to the rhizosphere were confirmed to exhibit insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly infested plant rhizosphere. Our results indicate that whitefly infestation leads to the recruitment of specific groups of rhizosphere bacteria by the plant, which confer beneficial traits to the host plant. This
Cull, Benjamin; Vaux, Alexander G C; Ottowell, Lisa J; Gillingham, Emma L; Medlock, Jolyon M
Tick infestations on small mammals were studied from April to November, 2010, in deciduous woodland in southern England in order to determine whether co-infestations with tick stages occurred on small mammals, a key requirement for endemic transmission of tick-borne encephalitis virus (TBEV). A total of 217 small mammals was trapped over 1,760 trap nights. Yellow-necked mice (Apodemus flavicollis) made up the majority (52.5%) of animals, followed by wood mice (A. sylvaticus) 35.5% and bank voles (Myodes glareolus) 12%. A total of 970 ticks was collected from 169 infested animals; 96% of ticks were Ixodes ricinus and 3% I. trianguliceps. Over 98% of ticks were larval stages. Mean infestation intensities of I. ricinus were significantly higher on A. flavicollis (6.53 ± 0.67) than on A. sylvaticus (4.96 ± 0.92) and M. glareolus (3.25 ± 0.53). Infestations with I. ricinus were significantly higher in August than in any other month. Co-infestations with I. ricinus nymphs and larvae were observed on six (3.6%) infested individuals, and fifteen small mammals (8.9%) supported I. ricinus - I. trianguliceps co-infestations. This work contributes further to our understanding of European small mammal hosts that maintain tick populations and their associated pathogens, and indicates that co-infestation of larvae and nymph ticks does occur in lowland UK. The possible implications for transmission of tick-borne encephalitis virus between UK ticks and small mammals are discussed. © 2017 The Society for Vector Ecology.
Schloesser, Don W.; Nalepa, Thomas F.; Mackie, Gerald L.
In 1989, zebra mussels received national attention in North America when they reached densities exceeding 750,000/m2 in a water withdrawal facility along the shore of western Lake Erie of the Laurentian Great Lakes. Although water withdrawal problems caused by zebra mussels have been of immediate concern, ecological impacts attributed to mussels are likely to be the more important long-term issue for surface waters in North America. To date, the epizoic colonization (i.e., infestation) of unionid bivalve mollusks by zebra mussels has caused the most direct and severe ecological impact. Infestation of and resulting impacts caused by zebra mussels on unionids in the Great Lakes began in 1988. By 1990, mortality of unionids was occurring at some locations; by 1991, extant populations of unionids in western Lake Erie were nearly extirpated; by 1992, unionid populations in the southern half of Lake St. Clair were extirpated; by 1993, unionids in widely separated geographic areas of the Great Lakes and the Mississippi River showed high mortality due to mussel infestation. All infested unionid species in the Great Lakes (23) have become infested and exhibited mortality within two to four years after heavy infestation began. Data indicate that mean zebra mussel densities >5,000–6,000/m2 and infestation intensities >100-200/unionid in the presence of heavy zebra mussel recruitment results in near total mortality of unionids. At present, all unionid species in rivers, streams, and akes that sympatrically occur with zebra mussels have been infested and, in many locations, negatively impacted by zebra mussels. We do not know the potential consequences of infestation on the 297 unionid species found in North America, but believe zebra mussels pose an immediate threat to the abundance and diversity of unionids.
Altschuler, Deborah Z.; And Others
This booklet was intended to teach parents about head lice, which are small, wingless, crawling insects that feed on human blood. The booklet briefly discusses: (1) physical characteristics of lice; (2) ways of becoming infested with head lice, such as sharing combs; (3) nits, which are the eggs of lice; (4) the difference between nits and hair…
Shreve, Scott M; Johnson, Kevin P
The scaly-winged bark louse, Echmepteryx hageni, exhibits a unique pattern of co-existence of apparently differnt reproductive modes. Unisexuality is widespread in eastern North America, while sexual populations are restricted to isolated rock out-croppings in southern Illinois and eastern Kentucky. Three of the four nuclear loci examined show greater genetic diversity in the unisexual form compared to the sexual form of E. hageni, in accordance with the pattern previously shown in mitochondrial genetic data. Neutrality tests of the nuclear loci indicate a consistent signal of demographic expansion in asexual populations, but not in sexual populations. There was evidence of inbreeding in the isolated sexual populations at three of the nuclear loci, and one locus had signs of gene specific balancing selection. However, there is no significant genetic differentiation between bisexual and unisexual populations, possibly due to the greater effective population size of nuclear loci relative to mitochondrial loci. The mitochondrial differentiation of E. hageni populations in the northwestern part of their range (Minnesota and Wisconsin) was also not reflected in the nuclear data. We present three hypotheses that may explain the disparity in observed nuclear and mitochondrial genetic diversity between the reproductive forms of E. hageni.
Lee, Si Hyeock; Kang, Jae Soon; Min, Jee Sun; Yoon, Kyong Sup; Strycharz, Joseph P.; Johnson, Reed; Mittapalli, Omprakash; Margam, Venu M.; Sun, Weilin; Li, Hong-Mei; Xie, Jun; Wu, Jing; Kirkness, Ewen F.; Berenbaum, May R.; Pittendrigh, Barry R.; Clark, J. Marshall
The human body louse, Pediculus humanus humanus, has one of the smallest insect genomes, containing ~10,775 annotated genes (Kirkness et al. 2010). Annotation of detoxification [cytochrome P450 monooxygenase (P450), glutathione-S-transferase (GST), esterase (Est), and ATP-binding cassette transporter (ABC transporter)] genes revealed that they are dramatically reduced in P. h. humanus compared to other insects except for Apis mellifera. There are 37 P450, 13 GST and 17 Est genes present in P. h. humanus, approximately half of that found in Drosophila melanogaster and Anopheles gambiae. The number of putatively functional ABC transporter genes in P. h. humanus and A. mellifera are the same (36) but both have fewer than An. gambiae (44) or D. melanogaster (65). The reduction of detoxification genes in P. h. humanus may be due to their simple life history, where they do not encounter a wide variety of xenobiotics. Neuronal component genes are highly conserved across different insect species as expected due to their critical function. Although reduced in number, P. h. humanus still retains at least a minimum repertoire of genes known to confer metabolic or toxicokinetic resistance to xenobiotics (e.g., Cyp3 clade P450s, Delta GSTs, B clade Ests and B/C subfamily ABC transporters), suggestive of its high potential for resistance development. PMID:20561088
Liu, Yan; Wu, Bin; Weinstock, George; Walker, David H; Yu, Xue-Jie
Louse borne typhus (also called epidemic typhus) was one of man's major scourges, and epidemics of the disease can be reignited when social, economic, or political systems are disrupted. The fear of a bioterrorist attack using the etiologic agent of typhus, Rickettsia prowazekii, was a reality. An attenuated typhus vaccine, R. prowazekii Madrid E strain, was observed to revert to virulence as demonstrated by isolation of the virulent revertant Evir strain from animals which were inoculated with Madrid E strain. The mechanism of the mutation in R. prowazekii that affects the virulence of the vaccine was not known. We sequenced the genome of the virulent revertant Evir strain and compared its genome sequence with the genome sequences of its parental strain, Madrid E. We found that only a single nucleotide in the entire genome was different between the vaccine strain Madrid E and its virulent revertant strain Evir. The mutation is a single nucleotide insertion in the methyltransferase gene (also known as PR028) in the vaccine strain that inactivated the gene. We also confirmed that the vaccine strain E did not cause fever in guinea pigs and the virulent revertant strain Evir caused fever in guinea pigs. We concluded that a single nucleotide insertion in the methyltransferase gene of R. prowazekii attenuated the R. prowazekii vaccine strain E. This suggested that an irreversible insertion or deletion mutation in the methyl transferase gene of R. prowazekii is required for Madrid E to be considered a safe vaccine.
Nguyen-Hieu, Tung; Aboudharam, Gérard; Signoli, Michel; Rigeade, Catherine; Drancourt, Michel; Raoult, Didier
Background The new field of paleomicrobiology allows past outbreaks to be identified by testing dental pulp of human remains with PCR. Methods We identified a mass grave in Douai, France dating from the early XVIIIth century. This city was besieged during the European war of Spanish succession. We tested dental pulp from 1192 teeth (including 40 from Douai) by quantitative PCR (qPCR) for R. prowazekii and B. quintana. We also used ultra-sensitive suicide PCR to detect R. prowazekii and genotyped positive samples. Results and Discussion In the Douai remains, we identified one case of B. quintana infection (by qPCR) and R. prowazekii (by suicide PCR) in 6/21 individuals (29%). The R. prowazekii was genotype B, a genotype previously found in a Spanish isolate obtained in the first part of the XXth century. Conclusion Louse-borne outbreaks were raging during the XVIIIth century; our results support the hypothesis that typhus was imported into Europe by Spanish soldiers from America. PMID:21060879
Bush, Sarah E; Weckstein, Jason D; Gustafsson, Daniel R; Allen, Julie; DiBlasi, Emily; Shreve, Scott M; Boldt, Rachel; Skeen, Heather R; Johnson, Kevin P
Songbirds host one of the largest, and most poorly understood, groups of lice: the Brueelia-complex. The Brueelia-complex contains nearly one-tenth of all known louse species (Phthiraptera), and the genus Brueelia has over 300 species. To date, revisions have been confounded by extreme morphological variation, convergent evolution, and periodic movement of lice between unrelated hosts. Here we use Bayesian inference based on mitochondrial (COI) and nuclear (EF-1α) gene fragments to analyze the phylogenetic relationships among 333 individuals within the Brueelia-complex. We show that the genus Brueelia, as it is currently recognized, is paraphyletic. Many well-supported and morphologically unified clades within our phylogenetic reconstruction of Brueelia were previously described as genera. These genera should be recognized, and the erection of several new genera should be explored. We show that four distinct ecomorphs have evolved repeatedly within the Brueelia-complex, mirroring the evolutionary history of feather-lice across the entire order. We show that lice in the Brueelia-complex, with some notable exceptions, are extremely host specific and that the host family associations and geographic distributions of these lice are significantly correlated with our understanding of their phylogenetic history. Several ecological phenomena, including phoresis, may be responsible for the macroevolutionary patterns in this diverse group. Copyright © 2015 Elsevier Inc. All rights reserved.
Rukke, Bjørn Arne; Birkemoe, Tone; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben
Introduction Head lice infestations cause distress in many families. A well-founded strategy to reduce head lice prevalence must shorten the infectious period of individual hosts. To develop such a strategy, information about the actions taken (inspection, treatment and informing others about own infestations), level of knowledge and costs is needed. The present study is the first to consider all these elements combined. Materials and Methods A questionnaire was answered by 6203 households from five geographically separated municipalities in Norway. Results 94% of the households treated members with pediculicides when head lice were discovered. Nearly half of the households checked biannually or not at all. Previous occurrence of head lice and multiple children in a household improved both checking frequency and method. More than 90% of the households informed close contacts about their own pediculosis. Direct costs of pediculosis were low (less than €6.25 yearly) for 70% of the households, but the ability to pay for pediculicides decreased with the number of head lice infestations experienced. One in three households kept children from school because of pediculosis. Other widespread misconceptions, such as that excessive cleaning is necessary to fight head lice, may also add unnecessary burden to households. School affiliation had a significant effect on checking frequency and method, knowledge and willingness to inform others about own pediculosis. Conclusions Increased checking frequencies appear to be the most important element to reduce head lice prevalence in Norway and should be a primary focus of future strategies. National campaigns directed through schools to individual households, might be an important tool to achieve this goal. In addition to improving actions taken, such campaigns should also provide accurate information to reduce costs and enhance the level of knowledge about head lice in households. PMID:22393437
... won't stop crying complains of head and neck pain (younger or nonverbal children may be more fussy) ... vision pupils of unequal size weakness or paralysis neck pain or stiffness seizure If your child is unconscious: ...
Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)
... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...
Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)
... Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth Head Neck & Nervous System Heart Infections Learning Disabilities Obesity Orthopedic Prevention Sexually Transmitted Skin Tobacco ...
... object that's stuck in the wound. previous continue Concussions Concussions — the temporary loss of normal brain function due ... also a type of internal head injury. Repeated concussions can permanently damage the brain. In many cases, ...
Bouvresse, Sophie; Socolovshi, Cristina; Berdjane, Zohra; Durand, Rémy; Izri, Arezki; Raoult, Didier; Chosidow, Olivier; Brouqui, Philippe
The human body louse is the only known vector of Bartonella quintana. However, the presence of this bacterium has recently been detected in the head lice of homeless individuals and Nepalese slum children. Previous studies have reported the isolation of Acinetobacter baumannii from the body lice of homeless individuals. An epidemiological survey including 74 schools was conducted between 2008 and 2009 in Paris. After a first visual examination, the hair of children with suspected pediculosis was combed with a fine-tooth comb to collect live adult head lice. Molecular studies were performed on randomly selected DNA samples to detect B. quintana and A. baumannii by specific quantitative real-time PCR. Among a collection of 288 DNA samples, B. quintana was not detected, but A. baumannii was detected in 95 DNA samples (33%). Further study is needed to determine the significance of the finding of A. baumannii in head lice.
Sidoti, E; Bonura, F; Paolini, G; Tringali, G
High rates of pediculosis are found in every part of the world. The age-range most affected is between 3 and 12 years. No-nit policies are ineffective in preventing infestations. On the other hand, misdiagnosis and overuse of pediculicides, increase resistance to treatment. Lack of information leads people to consider this kind of infestation to be associated to low social classes and immigrants. This research has been implemented to find out about the information level on pediculosis on a sample of students (722) and teachers (408) of some primary schools in northern and southern Italy, and to highlight the role of personal aspects such as age, gender, cultural level, geographical position which may influence this topic and, eventually, allow the use of the correct knowledge in developing appropriate procedures within the school district. Data was obtained through a questionnaire containing 21 multiple choice questions for the teachers and 14 for the students. Standard descriptive statistics were computed. chi2 tests were applied to highlight statistical association among observed variables; test for the difference of two proportions were applied to confirm significant differences among the observed proportions. The level of information for students seems to be, approximately, the same both for northern and southern Italy. There was a slight prevalence of correct answers from southern teachers, probably because the phenomenon of pediculosis has a positive trend of growth in the south. The number of correct answers was, for all, on average about 60.0%; a negative result in itself considering the simplicity of the questions. Knowledge about the biology of the louse was virtually absent. The area of prevention showed lack of information and need for improvement. Most of the teachers believe that there are specific products that can prevent infestation by louse. Most of the teachers have information which does not come from scientific sources. Students receive some
Honda, M; Namikawa, K; Hirata, H; Neo, S; Maruo, T; Lynch, J; Chida, A; Morita, T
In June 2009, 27 guinea pigs kept at an animal petting facility at a zoo in Kanagawa Prefecture, Japan, were observed to scratch intensely, weaken, and develop lesions. Three sarcoptiform mites were found in skin scrapings taken from affected areas of 2 guinea pigs, and they were identified as Trixacarus caviae by morphological examination. This result confirmed the presence of T. caviae in Japan. For treatment, doses of 13.6-18.75 mg/head of selamectin were administered in a topical preparation applied to a single spot on the skin on the back of the neck, and no side effects were observed. In April 2010, a second outbreak of mange occurred at the zoo, and, following investigation, 2 mite eggs were observed. It was, therefore, thought probable that the mites had survived during the winter within nonclinical carriers. Accordingly, doses of 5.0-7.5 mg/head of selamectin were applied on days 0 and 28, after which clinical symptoms disappeared and general condition improved. This dose of selamectin was thus shown to be a suitable and economical treatment for guinea pigs infested with the mites. Because the mite is not always easily observed in infested guinea pigs and the potential for human infestation exists, clinicians should not hesitate to treat when the clinical presentation suggests infestation, particularly in a setting such as an animal petting facility, where large numbers of children and adults have direct contact with the animals.
Araújo, F R; Silva, M P; Lopes, A A; Ribeiro, O C; Pires, P P; Carvalho, C M; Balbuena, C B; Villas, A A; Ramos, J K
An investigation was conducted into a severe flea infestation on dairy calves. Inspection of the dairy revealed a high infestation of Ctenocephalides felis felis on four calves and thousands of fleas in the stable where cows and calves were brought in for milking. A 3-month-old female calf was highly infested with fleas. The animal showed an evident lethargy, weight loss, as well as pale mucous membranes and dehydration. Hematological analysis revealed anemia, with 10% packed cell volume and a 1.72 x 10(6) microl(-1) erythrocyte count. Blood transfusions were performed and the flea infestation was controlled with 1% fipronil pour-on (1 ml/10 kg). The farmer was advised to treat the other calves with fipronil, remove the manure from the stable and spread 1% propoxur powder (100 g/m2) onto the floor of the stable.
Mwale, Kamukwamba; Siziya, Seter
Background: Intestinal infestations are of considerable public health importance in Zambia and elsewhere in Africa. Children aged less than 5 years are at the highest risk of infection. Interventions for prevention and control of these infestations require identification of their determinants. This study investigates the determinants of intestinal infestations in children below 5 years of age admitted to a children’s hospital and assesses the most prevalent of the helminthes. Methods: This was a hospital based cross-sectional study conducted at Arthur Davison Children’s Hospital, Ndola, Zambia. Socio-demographic data of study participants and possible determinants for occurrence of intestinal infestations were collected using structured questionnaires. Stool samples were collected and examined for presence of parasites using direct techniques. The Pearson’s Chi-square and Fisher’s exact tests were used to establish associations. Results: Present study had 148 participants out of the expected 165, making a respondent rate of 89.7%. Over half of the participants were male (50.6%), and 68.9% were above the age of 2 years. Prevalence of intestinal infestations was 19.6%, and the most prevalent parasite was Ascaris lumbricoides. Factors independently associated with worm infestation were father’s employment (AOR = 0.41; 95 % CI [0.19, 0.90]) and history of prior worm infestation (AOR = 6.54; 95 % CI [3.28, 13.03]). Conclusion: Intestinal infestations particularly Ascaris lumbricoides were more prevalent in this study. There should be policy towards countrywide deworming programs and enhanced hygiene. PMID:27622006
Leelavathi, Muthupalaniappen; Norhayati, Moktar; Lee, Yin Yin
Cat flea bite in humans results in extremely pruritic skin lesions. It has been reported to occur among those living in domiciliary accommodation. However, nosocomial infestation with cat flea has not been reported. We hereby report a case of nosocomial infestation of cat flea in a hospital facility. Identification of the parasite, its appropriate eradication, and adequate medical management of the patients resulted in a satisfactory outcome.
Norhayati, Moktar; Lee, Yin Yin
Cat flea bite in humans results in extremely pruritic skin lesions. It has been reported to occur among those living in domiciliary accommodation. However, nosocomial infestation with cat flea has not been reported. We hereby report a case of nosocomial infestation of cat flea in a hospital facility. Identification of the parasite, its appropriate eradication, and adequate medical management of the patients resulted in a satisfactory outcome. PMID:22451739
Ortega-Marín, Lydia; Márquez-Serrano, Margarita; Lara-López, Luz M; Moncada, Ligia I; Idrovo, Alvaro J
The prevalence of pediculosis is high among elementary and secondary school children, which favors the belief that infestation occurs more often in schools than in homes. This study explored the role of households' social networks in the transmission of head lice. Seventeen school children and their social networks (n = 22) from Acatlipa (Morelos, Mexico) participated in a prospective observational study during school vacation. The hair of all the school children was washed with shampoo containing permethrin at the beginning of the study and the incidence of pediculosis (O) was evaluated at the beginning of the school term (follow-up at 1.5 months). The sets included in the qualitative comparative analysis were sex (S), length of hair (H), baseline diagnostic of pediculosis (I) and degree (D) and infestation index (N) obtained through the analysis of social networks. The prevalence of pediculosis was the same at the beginning and the end of follow-up (17.6%). The degree of the school children's networks ranged between 2 and 14. There were 8 configurations, the most frequent being F*i*d*n*h. The most parsimonious configuration associated with the incidence of pediculosis was F*I*d*H (female, previous infestation, low degree and long hair), with a coverage of 0.344 and a consistency of 0.941. Indicators of social networks made it possible to identify the role of households' social networks in the transmission of lice. Individual actions such as the use of shampoo containing insecticides are temporary and, therefore, structural actions should be favored.
Infestation patterns of digenetic trematodes in Corophium volutator (Pallas, 1766) were studied in a shallow-water area of the southern Baltic Sea. The amphipod C. volutator is the most common second intermediate host of microphallid trematodes, in particular Maritrema subdolum, in this area. Seasonal and interannual alterations in infestation among the amphipod population are described. The general trend of infestation followed a relatively invariable seasonal pattern. Lowest prevalences were generally observed in spring and early summer, when juvenile amphipods predominated. Increasing prevalences and relative infestation intensities were recorded over the summer, with the highest values in late summer and autumn. These observations are mainly explained by the population dynamics of C. volutator and the infection dynamics of the first intermediate hosts, mudsnails of the genus Hydrobia. Exceptionally high infestation rates in summer 1997 may have been triggered by the earlier appearance of high cercaria densities in the field compared to 1996. The coincidence of the infection dynamics of the first intermediate host with the population dynamics of C. volutator was apparently important. Parasite infestation, in turn, obviously induced mortality of the crustacean host, but conclusive evidence could not be provided based on the analysis of the parasite dispersion patterns in C. volutator.
RUKKE, BJØRN ARNE; BIRKEMOE, TONE; SOLENG, ARNULF; LINDSTEDT, HEIDI HEGGEN; OTTESEN, PREBEN
SUMMARY Head lice prevalence varies greatly between and within countries, and more knowledge is needed to approach causes of this variation. In the present study, we investigated head lice prevalence among elementary school students and their households in relation to individual and household characteristics as well as spatial variables. The investigation included households from 5 geographically separated municipalities. Present infestations among household members as well as previous infestations in the household were reported in a questionnaire. In elementary school students prevalence was low (1·63%), but more than one-third of the households (36·43%) had previously experienced pediculosis. Prevalence was higher in elementary school students than in other household members, and highest in third-grade children. Prevalence was also influenced by the school attended, which suggested that interactions between children in the same school are important for head lice transmission. Previous occurrence of head lice in homes also increased the risk of present infestation. Prevalence of previous infestations was higher in households with more children and in more densely populated municipalities, indicating that the density of hosts or groups of hosts influences transmission rates. These results demonstrate that information of hosts’ spatial distribution as well as household and individual characteristics is needed to better understand head lice population dynamics. PMID:21767439
Rukke, Bjørn Arne; Birkemoe, Tone; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben
Head lice prevalence varies greatly between and within countries, and more knowledge is needed to approach causes of this variation. In the present study, we investigated head lice prevalence among elementary school students and their households in relation to individual and household characteristics as well as spatial variables. The investigation included households from 5 geographically separated municipalities. Present infestations among household members as well as previous infestations in the household were reported in a questionnaire. In elementary school students prevalence was low (1·63%), but more than one-third of the households (36·43%) had previously experienced pediculosis. Prevalence was higher in elementary school students than in other household members, and highest in third-grade children. Prevalence was also influenced by the school attended, which suggested that interactions between children in the same school are important for head lice transmission. Previous occurrence of head lice in homes also increased the risk of present infestation. Prevalence of previous infestations was higher in households with more children and in more densely populated municipalities, indicating that the density of hosts or groups of hosts influences transmission rates. These results demonstrate that information of hosts' spatial distribution as well as household and individual characteristics is needed to better understand head lice population dynamics.
Marufu, Munyaradzi C; Dzama, Kennedy; Chimonyo, Michael
The blue tick, Rhipicephalus microplus, threatens cattle production in most tropical and subtropical areas of the world. Delayed skin hypersensitivity reactions are thought to cause Nguni cattle to be more resistant to R. microplus than Bonsmara cattle yet the cellular mechanisms responsible for these differences have not been classified. Tick counts and inflammatory cell infiltrates in skin biopsies from feeding sites of adult R. microplus ticks were determined in 9-month-old Nguni and Bonsmara heifers to determine the cellular mechanisms responsible for tick immunity. Nguni heifers (1.7 ± 0.03) had lower (P < 0.05) tick counts than the Bonsmaras (2.0 ± 0.03). Parasitized sites in Nguni heifers had higher counts of basophils, mast and mononuclear cells than those in the Bonsmara heifers. Conversely, parasitized sites in Nguni heifers had lower neutrophil and eosinophil counts than those in the Bonsmara heifers. Tick count was negatively correlated with basophil and mast cell counts and positively correlated with eosinophil counts in both breeds. In the Bonsmara breed, tick count was positively correlated with mononuclear cell counts. Cellular responses to adult R. microplus infestations were different and correlated with differences in tick resistance in Nguni and Bonsmara cattle breeds. It is essential to further characterise the molecular composition of the inflammatory infiltrate elicited by adult R. microplus infestation to fully comprehend immunity to ticks in cattle.
Strycharz, Joseph P; Yoon, Kyong Sup; Clark, J Marshall
This study examines the effectiveness of a new ivermectin formulation for the topical treatment of the human head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae). Permethrin-resistant lice originally obtained from south Florida and maintained on an in vitro rearing system were 100% susceptible to ivermectin formulations by using a semiclinical hair tuft bioassay. The formulation was 100% effective at killing lice using 1, 0.5, and 0.25% ivermectin concentrations after 10-min exposures. As judged by the lethal time (LT)50 and LT95 values, 0.5% formulated ivermectin was 3.8 and 3.2 times faster at killing lice, respectively, than 0.5% nonformulated ivermectin, indicating that the formulation may facilitate the penetration of ivermectin into the louse. The hair tuft-based bioassay in conjunction with the in vitro rearing system provides a standardized method to assess the comparative efficacy of pediculicide formulations in a reproducible format that mimics the exposure scenario that occurs on the human scalp.
El-Basheir, Zeinab M; Fouad, Mahmoud A H
Twelve different representative areas in Sharkia Governorate were surveyed for head lice, Pediculus humanus capitis. The pre-valence was investigated among 120 houses containing 2,448 individual, with different age, sex and socioeconomic status. Examination was done by naked eye aided with hand-lens. A total of 137 individuals were infested. Infestation rates were higher in the rural areas with low socioeconomic levels, concrete houses with over-crowded family members. Children had significantly higher infestation rates than adults. Males had lower infestation rates than females. However, the hair length and permanent hair washing were the factors accounted for both age and sex difference in prevalence of pediculosis. Head lice infestations were found all over the year, but increased in summer and spring. One hundred infested patients (90 females and 10 males) with different aged and hair length were treated with tour mixed cream from plants Lawsonia alba L. (Henna). Trigonella faemum-gracanum (Fenugreek), Hibiscus cannabinus (Hibiscus) and Artemisia cina (Wormseed). The head lice completely disappeared within a week among those patients treated by henna mixed with aqueous extract of sheah (100%) or mixed with helba (75%) or with karkada (50%).
Drali, Rezak; Benkouiten, Samir; Badiaga, Sékéné; Bitam, Idir
Louse-borne diseases are prevalent in the homeless, and body louse eradication has thus far been unsuccessful in this population. We aim to develop a rapid and robust genotyping method usable in large field-based clinical studies to monitor permethrin resistance in the human body louse Pediculus humanus corporis. We assessed a melting curve analysis genotyping method based on real-time PCR using hybridization probes to detect the M815I-T917I-L920F knockdown resistance (kdr) mutation in the paraorthologous voltage-sensitive sodium channel (VSSC) α subunit gene, which is associated with permethrin resistance. The 908-bp DNA fragment of the VSSC gene, encoding the α subunit of the sodium channel and encompassing the three mutation sites, was PCR sequenced from 65 lice collected from a homeless population. We noted a high prevalence of the 3 indicated mutations in the body lice collected from homeless people (100% for the M815I and L920F mutations and 56.73% for the T917I mutation). These results were confirmed by melting curve analysis genotyping, which had a calculated sensitivity of 100% for the M815I and T917I mutations and of 98% for the L920F mutation. The specificity was 100% for M815I and L920F and 96% for T917I. Melting curve analysis genotyping is a fast, sensitive, and specific tool that is fully compatible with the analysis of a large number of samples in epidemiological surveys, allowing the simultaneous genotyping of 96 samples in just over an hour (75 min). Thus, it is perfectly suited for the epidemiological monitoring of permethrin resistance in human body lice in large-scale clinical studies. PMID:22573588
Light, Jessica E; Toups, Melissa A; Reed, David L
Human head lice (Anoplura: Pediculidae: Pediculus) are pandemic, parasitizing countless school children worldwide due to the evolution of insecticide resistance, and human body (clothing) lice are responsible for the deaths of millions as a result of vectoring several deadly bacterial pathogens. Despite the obvious impact these lice have had on their human hosts, it is unclear whether head and body lice represent two morphological forms of a single species or two distinct species. To assess the taxonomic status of head and body lice, we provide a synthesis of publicly available molecular data in GenBank, and we compare phylogenetic and population genetic methods using the most diverse geographic and molecular sampling presently available. Our analyses find reticulated networks, gene flow, and a lack of reciprocal monophyly, all of which indicate that head and body lice do not represent genetically distinct evolutionary units. Based on these findings, as well as inconsistencies of morphological, behavioral, and ecological variability between head and body lice, we contend that no known species concept would recognize these louse morphotypes as separate species. We recommend recognizing head and body lice as morphotypes of a single species, Pediculus humanus, until compelling new data and analyses (preferably analyses of fast evolving nuclear markers in a coalescent framework) indicate otherwise.
Yimer, Mulat; Abera, Bayeh; Mulu, Wondemagegn; Bezabih, Belay; Mohammed, Jemal
Louse- borne relapsing fever (LBRF) is a vector borne acute febrile illness caused by Borrelia recurrentis and the disease is more prevalent in the high risk groups like prisoners, yekoloremaries and street children. However, prevalence and risk factors of LBRF in these populations about the disease are not known. Therefore, the aim of this study was to determine the prevalence and risk factors of LBRF in high risk populations. A cross- sectional survey on prevalence and risk factors of LBRF in high risk populations in Bahir Dar city was conducted in December, 2012. For the study, blood was taken from the tip of the left ring finger of the participants by laboratory technicians and thick blood film was prepared from each participant and stained with 3% Giemsa for 30 min. The slides were examined and the result was reported as positive or negative using light microscopy and finally, data was also collected using a pre- tested questionnaire by face to face interviews. Of the 407 study participants, 383 (94.1%) were males with the mean age of 31 years and 243 (59.7%) had no formal education. The prevalence of LBRF was 2.5% and the positivity rate of LBRF was highest in yekolotemaries (6.1%) followed by street children (4.9%). However, prisoners had nil and statistically significance association was observed between high risk populations and LBRF prevalence (p < 0.001). Those study participants who lived in mud houses had the highest positivity rate (2.2%), followed by those in wood houses (0.3%). However, those who lived in brick houses had nil. Study participants who had low levels of knowledge had the highest prevalence rate of LBRF. The overall prevalence of LBRF was 2.5% and the rate of positivity was highest in yekolotemaries, followed by street children. Therefore, health education should be given for these high risk populations.
Jakob, E; Barker, D E; Garver, K A
To better understand the role of vector transmission of aquatic viruses, we established an in vivo virus-parasite challenge specifically to address (1) whether Lepeophtheirus salmonis can acquire infectious haematopoietic necrosis virus (IHNV) after water bath exposure or via parasitizing infected Atlantic salmon Salmo salar and if so, define the duration of this association and (2) whether L. salmonis can transmit IHNV to naive Atlantic salmon and whether this transmission requires attachment to the host. Salmon lice which were water bath-exposed to 1 x 10(5) plaque-forming units (pfu) ml(-1) of IHNV for 1 h acquired the virus (2.1 x 10(4) pfu g(-1)) and remained IHNV-positive for 24 h post exposure. After parasitizing IHNV-infected hosts (viral titer in fish mucus 3.3 x 10(4) pfu ml(-1)) salmon lice acquired IHNV (3.4 x 10(3) pfu g(-1)) and remained virus-positive for 12 h. IHNV-positive salmon lice generated through water bath exposure or after parasitizing infected Atlantic salmon successfully transmitted IHNV, resulting in 76.5 and 86.6% of the exposed Atlantic salmon testing positive for IHNV, respectively. In a second experiment, only salmon lice that became IHNV-positive through water bath exposure transmitted IHNV to 20% of the naive fish, and no virus was transmitted when IHNV-infected salmon lice were cohabitated but restrained from attaching to naive fish. Under laboratory conditions, adult L. salmonis can acquire IHNV and transmit it to naive Atlantic salmon through parasitism. However, the ephemeral association of IHNV with L. salmonis indicates that the salmon louse act as a mechanical rather than a biological vector or reservoir.
Background Louse- borne relapsing fever is an acute febrile illness caused by Borrelia recurrentis and is transmitted by body lice, Pediculus humanus corporis. The disease has occurred as epidemic in different parts of the country.Therefore, the aim of this retrospective study was conducted to assess the LBRF profile for the last four years. Methods A retrospective study was conducted on patients with LBRF admitted from 2009–2012 at Felegehiwot referral hospital. The diagnosis was based on both clinical and laboratory methods. Patients with strong clinical suspicion of LBRF and positive for Borrelia species in their blood was diagnosed as LBRF cases. Data was collected from all patients with LBRF- like symptoms in their registration book. Data was checked for completeness, coded and analysed using SPSS version 16. P < 0.05 was considered significant for comparison. Results Of the 4559 patients admitted with LBRF- like symptoms, 4178 (91.6%) were males and 381 (8.4%) were females. Most of the patients (74.2%) were within age groups 11–20 years. The majority of patients (94.4%) were from urban residence. The overall prevalence of LBRF was 225 (4.9%) and the highest prevalence 171 (5.1%) was observed in age groups of 11–20 years. The association between seasonal variation and prevalence of LBRF showed that more patients with positive for Borrelia species were recorded in dry 27 (9.7%) than wet 198 (4.6%) seasons (P < 0.001). Finally, a trend in prevalence of LBRF for the last four years showed that the highest numbers of cases were documented in 2010. Conclusion The overall prevalence of LBRF was high and the highest prevalence was observed in young age groups. Moreover, most of the patients with LBRF were from urban dwellers. Therefore, health education should be delivered towards LBRF prevention in the city. PMID:24742342
Zammarchi, Lorenzo; Antonelli, Alberto; Bartolini, Laura; Pecile, Patrizia; Trotta, Michele; Rogasi, Pier Giorgio; Santini, Maria Grazia; Dilaghi, Beatrice; Grifoni, Stefano; Rossolini, Gian Maria; Bartoloni, Alessandro
Borrelia recurrentis, transmitted by Pediculus humanus humanus, is the etiological agent of louse-borne relapsing fever (LBRF). Currently the main focus of endemicity of LBRF is localized in East African countries. From July 2015 to October 2015, 36 cases of LBRF have been diagnosed in Europe in immigrants from the Horn of Africa. Here we report a case of LBRF with meningitis diagnosed in Florence, Italy, in an immigrant arrived from Somalia. In October 2015, a 19-year-old Somali male presented to the emergency department of the Azienda Ospedaliero Universitaria Careggi, Florence, Italy, with a 3-day history of high fever. The patient had disembarked in Sicily 10 days before admission after a long migration trip from his country of origin. On clinical examination, neck stiffness was found. Main laboratory findings were thrombocytopenia, increased procalcitonin, and increased polymorphonucleates in the cerebrospinal fluid. Suspecting a possible meningitis, the patient was treated with ceftriaxone, pending results of laboratory testing for malaria, and developed severe hypotension that was treated with fluid resuscitation and hydrocortisone. Hemoscopic testing revealed the presence of spirochetes and no malaria parasites. The patient rapidly improved with doxycycline for 7 days and ceftriaxone for 11 days, then was lost to follow-up. Total DNA from blood was extracted, and amplification and sequencing with universal 16S rDNA primers D88 and E94 revealed a 100% identity with B. recurrentis A1. LBRF is a rare but emerging infectious disease among vulnerable displaced immigrants from the Horn of Africa. Since immigrants from endemic areas can carry the vector with them, the infection should be suspected even in subjects with compatible clinical features living in the same place where new arrival immigrants are hosted. Healthcare providers should be aware of this condition to implement adequate diagnostic, therapeutic, and public health measures.
Paperna, I.; Diamant, A.; Overstreet, R. M.
Hyperinfection by the gill-infesting monogenean Allobivagina sp. (Microcotylea) caused mass mortalities in juveniles of Siganus luridus cultured in seawater earthen ponds and holding tanks in Eilat (Gulf of Aqaba, Red Sea). Other species of Siganus and adults of S. luridus cultured in the same systems acquired a low intensity of infestation. Most hyperinfected fish were emaciated and anaemic with hematocrit values below 10 %. Skin and mouth infestations by the monogenean Benedenia monticelli (Capsaloidea) caused mass mortalities in grey mullets (Mugilidae). These mortalities occurred in large individuals in wild populations of Liza carinata from lagoonal habitats in the Gulf of Suez and in most species of grey mullets cultured in Eilat. The intensity of infestation correlated positively with severity of infestation, and the common sites of infestation corresponded with areas of severe pathological alterations. Spontaneous recovery followed the climax of an epizootic, both for infested S. luridus and infested grey mullets. Decline in infestation coincided with remission of the pathological signs.
Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)
The author, a middle school art teacher, describes a sculpture project lesson involving Cone Heads (sculptures made from cardboard cones). Discussion of caricatures with exaggerated facial features and interesting profiles helped students understand that the more expressive the face, the better. This project took approximately four to five…
Figure 6.1 shows how rapidly the areal density of hard disk drives (HDD) has been increasing over the past 20 years . Several critical innovations were necessary to bring about such rapid progress in the field of magnetic recording . One of the most significant innovations from the viewpoint of material improvement was the electrodeposition of permalloy (Ni80Fe20), which was introduced by IBM in 1979 as the core material of a thin-film inductive head to increase the magnetic recording density . After the introduction of the magneto-resistive (MR) element as the read head and the electrodeposited permalloy as the write head by IBM in 1991 , the rate of increase in the recording density of HDDs jumped from 30% per year to 60% per year. Recently, a giant magneto-resistive (GMR) element has been used for the read element instead of the MR element. The rate of increase in the recording density jumped to over 100% per year in 1999, which is an incredible rate of increase. Since 2002, however, the rate of increase has decreased to 30%; thus, new innovations are required to maintain the rate of increase. In 2004, the practical use of perpendicular magnetic recording instead of longitudinal magnetic recording was announced . This system is a critical innovation for developing high-performance HDD systems with high-recording density. The design of the magnetic recording head was changed because of the change of the recording system.
Horwood, Martin A; Westlake, Terry; Kathuria, Amrit
A trial was conducted to determine the efficacy of termiticidal dusts (arsenic trioxide, triflumuron, and Metarhizium anisopliae), a timber fumigant (dazomet) and liquid termiticides (bifenthrin, chlorfenapyr, chlorpyrifos, fipronil, and imidacloprid) for controlling subterranean termites (Isoptera: Rhinotermitidae) infesting in-service power poles in New South Wales, Australia. Dusts were applied to parts of the pole where termites were present. Fumigant was inserted into holes drilled into the base of the pole. Liquid termiticides were mixed with soil around the base of the pole and injected into internal voids if present. Poles were inspected for up to 5 yr, and the time taken for reinfestation to occur was recorded. Before the start of the trial, the major Australian pole owners were surveyed to obtain an estimate of the annual national cost of termite infestation to the power supply industry. The annual costs of termite treatment and replacing damaged poles were estimated at AU$2 million and AU$13 million, respectively. Infestation rates were lower for all treatments compared with controls within the first 12 mo of the study. Dazomet, arsenic trioxide, fipronil, and chlorpyrifos were the most efficacious treatments. Efficacy was positively related to the amount of termiticide applied and negatively related to the infestation severity but was unaffected by geographical location. Survival curves were calculated of the time elapsed before the recurrence of termite infestations (survival absence of reinfestation). Survival was highest for poles treated with liquid termiticides.
Otaigbe, B E; Eneh, A U; Oruamabo, B
Intestinal helminthiasis is a major cause of morbidity and mortality in infants and children particularly in the tropics and subtropics. This report highlights the possibility of hookworm infestation in infancy. A case report of hookworm infestation in a three-month old infant who was managed in the University of Port Harcourt Teaching Hospital, Port Harcourt in May 2001 for failure to thrive and recurrent severe anaemia. The patient was admitted in the children's emergency ward with passage of dark watery stools, fever, excessive crying and severe anemia and was transfused twice. Stool microscopy revealed numerous ova of hookworm and she was treated with albendazole. Three days after administration of anti-helminthic, stools became formed with normal colour and temperature was normal. She gained weight before discharge home. Hookworm infestation should be suspected as a cause of severe anaemia in infants in communities with a high risk of infestation such as fishing port communities. To the best of my knowledge, symptomatic hookworm infestation in the first year of life has not been previously documented in Nigeria.
Minciullo, Paola Lucia; Cascio, Antonio; Isola, Stefania; Gangemi, Sebastiano
The tapeworm Taenia (T.) solium can be responsible for two different conditions: taeniasis and cysticercosis. Helminth infections in human host cause an immune response associated with elevated levels of IgE, tissue eosinophilia and mastocytosis, and with the presence of CD4+ T cells that preferentially produce IL-4, IL-5, and IL-13. Individuals exposed to helminth infections may have allergic inflammatory responses to parasites and parasite antigens. PubMed search of human cases of allergic reactions occurring during T. solium infestation was performed combining the terms (allergy, urticaria, angioedema, asthma, anaphylaxis) with T. solium. A study was considered eligible for inclusion in the review if it reported data on patients with T. solium infestation who had signs or symptoms of allergy. In literature we found six articles reporting the association between an allergic reaction and T. solium infestation: two cases of urticaria, two cases of relapsing angioedema, one case of asthma and two cases of anaphylaxis. Despite the large diffusion of T. solium infestation, we found only a few cases of concomitant allergic reaction and the presence of Taenia in the host. The association between T. solium infestation and allergic manifestations has never been clearly demonstrated, and in absence of a well-documented causality the hypotheses are merely speculative. Therefore, the association between Taenia infection and allergy needs to be thoroughly studied to better clarify if this association may really exist and which is the pathogenetic mechanism supported.
Kaiser, K. E.; McGlynn, B.; Emanuel, R.
Vegetation pattern and landscape structure intersect to exert strong control over ecohydrological dynamics at the watershed scale. The hydrologic implications of vegetation disturbance (e.g. fire, disease etc.) depend on the spatial pattern and form of environmental change. Here we investigate this intersection at Tenderfoot Creek Experimental Forest (TCEF), Montana with a focus on the mountain pine beetle (Dendroctonus ponderosae) epidemic currently affecting the Rocky Mountains. We calibrated QuickBird remote sensing imagery with a leaf-level spectral library of local vegetation. We used this spectral library to determine optimal vegetation indices for differentiating stages of beetle infestation within the 37 km2 TCEF watershed. These indices formed the basis of a three-component mixing model to quantify the extent and magnitude of beetle infestation across the TCEF watershed. We compared disturbance patterns to spatially distributed topography and vegetation variables derived from a LiDAR-based digital elevation model (DEM) of TCEF. We determined that certain landscape characteristics (low vegetation density, south facing slopes, steep slopes, locations with small contributing areas, and locations with lower values of the topographic wetness index (TWI)) were significantly more likely to exhibit the effects of beetle infestation. Our efforts to monitor vegetation mortality across space and time provide a context for assessing landscape susceptibility to initial mountain pine beetle infestation via feedbacks between biodiversity and hydrological patterns and further research into understanding how outbreak (i.e. landscape scale infestation) patterns may affect watershed ecohydrology via altered water and biogeochemical cycles.
Zakaria, Ossama M.; Zakaria, Hazem M.; Daoud, Mohamed Yasser; Al Wadaani, Hamed; Al Buali, Waleed; Al-Mohammed, Hamdan; Al Mulhim, Abdulrahman S.; Zaki, Wafaa
Objective The relationship between parasites and pediatric appendicitis is a highly debatable issue. This study aims to investigate the role of parasitic infestation in the etiology of acute pediatric appendicitis. Methods A retrospective study including 1600 pediatric and adolescent patients who had undergone surgical therapy for a diagnosis of acute appendicitis over a period of ten years from Jan 2001 to Dec 2010. Demographic data were retrieved including the patient's age, sex, clinical data, clinical presentations, laboratory investigations, operative data and pathological findings to identify the presence and type of parasites. Patients were divided into two groups according to the presence or absence of parasites in the appendix lumen. In group I (n: 88), parasitic infestation was observed, whereas in group II (n: 1502), no parasitic infestation was present. Results Parasites were present in 5.5% (88 patients), and of those 88 parasitic infestations, 45 (51.1%) were Enterobaisis, 8 (9.1%) were Schistosomiasis, 23 (26.1%) were Ascariasis, 7 (8%) Trichuriasis, and 5 (5.7%) were Teania Saginata. The percentage of patients with suppurative, gangrenous or perforated appendicitis was similar in both groups with no statistical significance, irrespective of the presence or absence of parasitic infestation. Conclusion The low prevalence of parasites among the appendectomy specimens did not support the notion that parasites were a major cause of appendicitis in pediatric patients. PMID:23599875
Leonardi, M S; Crespo, E A; Vales, D G; Feijoo, M; Raga, J A; Aznar, F J
Among Anoplura, the family Echinophthiriidae includes species that infest pinnipeds and otters. Previous evidence obtained from pinnipeds infested by echinophthiriids, specifically from seals, indicates that flippers are the preferred infestation sites, while lice from fur seals select areas in the pelage. We studied habitat selection of Antarctophthirus microchir on South American sea lion pups (Otaria flavescens Shaw, 1800) from Patagonia, Argentina, during the austral summer of 2009. We found a clear pattern of habitat selection: eggs are laid on the dorsal surface; nymphs 1 hatch there and then migrate to the belly, where they develop into adults and copulate; and then ovigerous females return to the dorsal surface. On the one hand, nymphs 1 are characterised by their low locomotory ability; therefore, the fact that they migrate as soon as they hatch suggests a clear pressure leading to microhabitat restriction. On the other hand, the described pattern of microhabitat selection seems to respond to the physiological requirements of each stage, which vary according to the physiological process considered, e.g. oviposition, morphogenesis, hatching and development. Accordingly, it appears that A. microchir would prefer the host's ventral area for development and copulation and the dorsal area for oviposition. However, the causes of this pattern are not clear, and many factors could be involved. Considering that sea lion pups periodically soak at high tides, and that prolonged immersion and very high humidity are known to be lethal for lice eggs, selecting the dorsal area would be advantageous for oviposition because it dries much faster. Furthermore, because humidity should be retained for longer periods on the ventral surface of the pup, wetter conditions on the sea lion would prevent desiccation of the nymphs in the very arid environment where O. flavescens breeds.
Kamiabi, F; Nakhaei, F Hosain
This descriptive, analytical study was carried out in 2003 to determine the prevalence of pediculosis capitis and some risk factors among primary-school pupils in Kerman. We selected 1200 pupils (53% girls) from 50 primary schools by multistage, systematic random sampling. Their hair was examined for head louse infestation: 45 (3.8%) were infected with lice, 43 (95.5%) girls and 2 (4.5%) boys. The highest rate of infestation was in 9-year-olds. There was a significant relationship between head louse infestation and sex (P < 0.0001), age (P < 0.05), parents' education (P < 0.0001), father's job (P < 0.01), family size (P < 0.01), length of hair (P < 0.0001) and having separate bathing facilities in the house (P < 0.0001).
Tagka, Anna; Lambrou, George I; Braoudaki, Maria; Panagiotopoulos, Takis; Papanikolaou, Eleni; Laggas, Dimitris
Pediculosis in humans and especially in children is a very common dermatological disorder caused by the ectoparasite Pediculus humanus capitis De Geer. We investigated the socioeconomic factors affecting the prevalence of pediculosis in the Greek urban area of Athens during 2004-2006. The target population consisted of children from kindergartens. In total, 434 children from single- or two-parent families were investigated with respect to socioeconomic factors such as education, income and family composition, and the prevalence of pediculosis. The overall pediculosis rate was 5.30%. Head louse infestations were significantly higher in female children and in two-parent families. Lice infestations peaked in low- and medium-income families. Head louse infestation rates were influenced by income, parents' education, and nationality. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Lescot, Magali; Audic, Stéphane; Robert, Catherine; Nguyen, Thi Tien; Blanc, Guillaume; Cutler, Sally J.; Wincker, Patrick; Couloux, Arnaud; Claverie, Jean-Michel; Raoult, Didier; Drancourt, Michel
In an effort to understand how a tick-borne pathogen adapts to the body louse, we sequenced and compared the genomes of the recurrent fever agents Borrelia recurrentis and B. duttonii. The 1,242,163–1,574,910-bp fragmented genomes of B. recurrentis and B. duttonii contain a unique 23-kb linear plasmid. This linear plasmid exhibits a large polyT track within the promoter region of an intact variable large protein gene and a telomere resolvase that is unique to Borrelia. The genome content is characterized by several repeat families, including antigenic lipoproteins. B. recurrentis exhibited a 20.4% genome size reduction and appeared to be a strain of B. duttonii, with a decaying genome, possibly due to the accumulation of genomic errors induced by the loss of recA and mutS. Accompanying this were increases in the number of impaired genes and a reduction in coding capacity, including surface-exposed lipoproteins and putative virulence factors. Analysis of the reconstructed ancestral sequence compared to B. duttonii and B. recurrentis was consistent with the accelerated evolution observed in B. recurrentis. Vector specialization of louse-borne pathogens responsible for major epidemics was associated with rapid genome reduction. The correlation between gene loss and increased virulence of B. recurrentis parallels that of Rickettsia prowazekii, with both species being genomic subsets of less-virulent strains. PMID:18787695
Mackenzie, Melville D.
This paper deals with some aspects of the control of louse-borne typhus fever. The epidemic form is associated with famine and overcrowding. In producing an epidemic in a hitherto endemic area malnutrition is of greater importance than over-crowding; another factor which brings this about is widespread movement of civil or military population thus bringing non-immunes into a district where typhus is endemic. Endemic typhus usually occurs in the early months of the year, whilst the epidemic form may appear at any time. Conditions under which epidemic typhus occurs favour the outbreak of other diseases so that an uncomplicated case is rarely seen. Louse-borne typhus fever lasts from twelve to sixteen days. The incubation period is usually twelve to fourteen days, though it may be from five to twenty-one days. The onset is sudden, but is often preceded by malaise and a rise of temperature. Two common initial symptoms are acute frontal or occipital headache and bronchitis. The first sign may be mental confusion or delirium. Acute delirium is usually present after the first week. PMID:19992447
Eisenhower, Christine; Farrington, Elizabeth Anne
Head lice infestations occur commonly each year in children of all socioeconomic statuses. However, head lice have become more of a nuisance as resistance to first-line agents, such as permethrin 1% and pyrethrins, has increased. Newer topical products provide unique mechanisms of action without current signs of resistance. As with older agents, proper application of products must be emphasized to ensure that treatment is effective. In addition, nonpharmacologic measures should be taken to avoid reinfestation in the patient and to prevent the spread of lice to close personal contacts.
Raza, Syed Nusrat; Shabbir, Syed Muhammad Asad
To assess the common presentations of leech infestation in leech endemic areas of Pakistan and to establish its association with unsafe water drinking habits of the individual. A cohort study. CMH, Kohat, between 1st February 1997 and 30th April 2002. Fourteen patients with leech infestation who reported to ENT department of CMH, Kohat, during the above period were selected for study. A specific comparison of their water drinking habits was made with a control group of 42 normal individuals who had come from the same leech endemic area as the first group and belonged to the same socioeconomic class. Twelve cases (83.4%) in the first group had unsafe water drinking habit i.e. they drank water directly from marshes without seeing its contents substituting cupped palm of hand for a drinking cup. This was in contrast to the control group where only 6 individuals (14%) gave a history of unsafe water drinking habits. Nose was the most common ENT site of leech infestation (71%) with epistaxis being the most prominent symptom. Other sites included hypopharynx (14%), nasopharynx (7 %) and oropharynx (7 %). All the 14 cases with leech infestation were males, 26.09 years being the mean age. The association between patient s unsafe water drinking habits and leech infestation in ENT region was statistically proved with odds ratio being 36. Epistaxis or any other related symptom must be taken with suspicion in leech endemic area. This condition is closely related to unsafe water drinking habits, therefore, the incidence of this infestation can be significantly reduced by educating the individuals to adopt safe water drinking habits.
Sönmez, Özlem Uysal; Yalçın, Zeliha Gülter; Karakeçe, Engin; Çiftci, İhsan Hakkı; Erdem, Teoman
Tumor-associated immune system cells secrete protease and cytokines that can inhibit the immune response. In particular, T-cell effector functions could be inhibited, potentially causing an increase in parasitic infestations. Demodex species are common inhabitants of normal hair follicles. Humans are the specific host for two species Demodex folliculorum and D. brevis. The aim of this study was to investigate the incidence and infestation of D. folliculorum and D. brevis in patients with cancer. In the present study, 101 patients with cancer were selected from among patients who were diagnosed and treated for cancer. The cancer patients were divided into four groups according to cancer type. Slides were examined for parasites using light microscopy at magnifications of ×40 and ×100. Infestation was defined as having at least five living parasites/cm(2) of skin. The ages of the patients with cancer ranged between 38 and 82 years, with a mean of 65.5±10.1 years. It was determined that 77 of the 101 (76.2%) cancer patients were positive for Demodex species. Infestation was positive in 18 (47.4%) of the 38 cases in the breast cancer group, 7 (29.2%) of the 24 cases in the lung cancer group, 5 (18.5%) of the 27 cases in the gastrointestinal system cancer group, and 2 (16.7%) of the 12 cases in the urogenital system cancer group. Results showed that the rate of Demodex species infestation was higher in patients with breast cancer. Thus, cancer - and particularly breast cancer - is a risk factor for Demodex species infestation.
Raju, Kalyani; Verappa, Seema; Venkataramappa, Srinivas Murthy
Although prevalence of Enterobius vermicularis (EV) infestation in Intestines ranges from 35% to 70%, its prevalence in female genital tract is not known despite several incidental findings. Acute inflammatory cells in the background of cervical Pap smear indicate infestation and should not be neglected as contamination. A 40-year-woman presented with white vaginal discharge persistent for past 1 year. Local examination showed hypertrophied cervix with eversion of both lips and hard consistency of the anterior lip of cervix. A clinical diagnosis of cervical carcinoma was made. However, cervical Pap smear indicated EV eggs in an inflammatory background, treatment to which resulted in completely recovery. PMID:26283859
Raju, Kalyani; Verappa, Seema; Venkataramappa, Srinivas Murthy
Although prevalence of Enterobius vermicularis (EV) infestation in Intestines ranges from 35% to 70%, its prevalence in female genital tract is not known despite several incidental findings. Acute inflammatory cells in the background of cervical Pap smear indicate infestation and should not be neglected as contamination. A 40-year-woman presented with white vaginal discharge persistent for past 1 year. Local examination showed hypertrophied cervix with eversion of both lips and hard consistency of the anterior lip of cervix. A clinical diagnosis of cervical carcinoma was made. However, cervical Pap smear indicated EV eggs in an inflammatory background, treatment to which resulted in completely recovery.
Jacobs, Bryan; Brown, David L
Dermatobia hominis, the botfly, is indigenous to Central and South America. Its usual host is a mammal, often a horse or cow. Cutaneous furuncular myiasis, human infestation by the botfly, has rarely been reported. Symptoms of infestation include a locally painful, firm furuncular lesion, often with a centrally located pore. Due to their infrequent occurrence, these lesions are often misdiagnosed as cellulitis, leishmaniasis, furunculosis, staphylococcal boil, insect bite or sebaceous cyst - conditions with similar presentations. The present case reiterates the need to think of 'zebras' when hearing 'hoof beats' that may have originated in a different land.
Jacobs, Bryan; Brown, David L
Dermatobia hominis, the botfly, is indigenous to Central and South America. Its usual host is a mammal, often a horse or cow. Cutaneous furuncular myiasis, human infestation by the botfly, has rarely been reported. Symptoms of infestation include a locally painful, firm furuncular lesion, often with a centrally located pore. Due to their infrequent occurrence, these lesions are often misdiagnosed as cellulitis, leishmaniasis, furunculosis, staphylococcal boil, insect bite or sebaceous cyst – conditions with similar presentations. The present case reiterates the need to think of ‘zebras’ when hearing ‘hoof beats’ that may have originated in a different land. PMID:19554228
Ullio-Gamboa, Gabriela; Palma, Santiago; Benoit, Jean Pierre; Allemandi, Daniel; Picollo, María Inés; Toloza, Ariel Ceferino
The use of pyrethroids to control the human head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), has suffered considerable loss of efficacy due to the evolution of resistance. Thus, the development of efficiently insecticide delivery systems is imperative for the control of head lice. We studied the insecticidal activity of ivermectin-loaded lipid nanocapsules (IVM-LNC) against permethrin-resistant head lice from Argentina. The LNC, prepared by a phase inversion procedure, were characterized in terms of size, surface potential, and physical stability. These nanoparticles were nearly spherical with mean diameters of 55 nm and narrow size distribution (PI ≤ 0.2). The KT50 mortality values of head lice after exposure to two IVM-LNC formulations (0.11 and 0.28%) were significantly smaller (5 and 3 h, respectively) compared to those exposed only to LNC control group (8 h). This investigation showed the effectiveness in the encapsulation of ivermectin (IVM) into stable LNC dispersion with a potential clinical activity against head lice.
González Audino, P; Barrios, S; Vassena, C; Mougabure Cueto, G; Zerba, E; Picollo, M I
We studied the profile of permethrin resistance in populations of head lice infesting children 6-12 yr old in schools and their homes in and around Buenos Aires, Argentina. Five permethrin-resistant populations with different levels of resistance were collected: Hogar Loyola (HL), Republica de Turquia (RT), Hogar Mitre (HM), Guardia de Honor (GH), and Ricardo Guiraldes (RG). One susceptible population, Bandera Argentina (BA), also was collected. Their level of resistance was evaluated, and results showed resistance ratios of 13 for HL, 16 for RT, 22 for HM, 61 for GH, and 69 for RG. To elucidate the possible involvement of the cytochrome P450 monooxygenase system in conferring permethrin resistance, ethoxycoumarin-O-deethylase (ECOD) activity was measured in abdomens of individual third instars and adults by using a fluorometric assay. The ECOD activity was lower in the susceptible BA population (4.7 ng per louse) than in the resistant ones (13.7 ng per louse for RG, 12.3 ng per louse for GH, 8.6 ng per louse for RT, and 8.2 ng per louse for HL). ECOD activity was significantly correlated with the level of resistance in the field populations (r = 0.97, P = 0.0009), suggesting a role for cytochrome monooxygenase P450 system in permethrin resistance by head louse, Pediculus humanus capitis De Geer.
Klompmaker, Adiël A; Artal, Pedro; van Bakel, Barry W M; Fraaije, René H B; Jagt, John W M
Parasites are common in modern ecosystems and are also known from the fossil record. One of the best preserved and easily recognisable examples of parasitism in the fossil record concerns isopod-induced swellings in the branchial chamber of marine decapod crustaceans. However, very limited quantitative data on the variability of infestation percentages at the species, genus, and family levels are available. Here we provide this type of data for a mid-Cretaceous (upper Lower Cretaceous, upper Albian) reef setting at Koskobilo, northern Spain, on the basis of 874 specimens of anomurans and brachyurans. Thirty-seven specimens (4.2%), arranged in ten species, are infested. Anomurans are more heavily infested than brachyurans, variability can be high within genera, and a relationship may exist between the number of specimens and infestation percentage per taxon, possibly suggesting host-specificity. We have also investigated quantitative patterns of infestation through geological time based on 88 infested species (25 anomurans, 55 brachyurans, seven lobsters, and one shrimp), to show that the highest number of infested species can be found in the Late Jurassic, also when corrected for the unequal duration of epochs. The same Late Jurassic peak is observed for the percentage of infested decapod species per epoch. This acme is caused entirely by infested anomurans and brachyurans. Biases (taphonomic and otherwise) and causes of variability with regard to the Koskobilo assemblage and infestation patterns through time are discussed. Finally, a new ichnogenus and -species, Kanthyloma crusta, are erected to accommodate such swellings or embedment structures (bioclaustrations).
Burkhart, Craig G; Burkhart, Craig N
Head lice infestation is a common and growing problem, primarily affecting school-aged children. There are growing numbers of treatment failures due to the emergence of treatment-resistant lice to the popular over-the-counter products that have been used for the past several decades. Resistance has also decreased the efficacy of lindane, a prescription pediculicide that has been commonly used for several generations. Malathion, recently reintroduced in the US as a prescription pediculicide, has been associated with some treatment resistance depending upon its formulation. Other insecticidal treatments, such as ivermectin, will have to be developed further, given the limited options presently available for the treatment of head lice. Given the number of anecdotal and market-driven reported studies on head lice, assessment of topical lice therapies requires standardised in vitro testing. Based on concerns about safety and decreasing efficacy due to resistance, a reassessment of the general topic of pediculicides for head lice is warranted.
Koch, W; Ritter, W
The deformations of bees occurring in connection with varroatosis was examined both in case of natural and artificial infestation. Under both conditions, the number of bees showing wing deformations increased with the degree of mite infestation. Shortened abdomina, however, only appeared in the case of natural infestation. Inadequate brood care in colonies severely infested by Varroa mites is supposed to be responsible. Wing deformations could be produced by experimental haemolymph extraction.
Light, Jessica E; Allen, Julie M; Long, Lauren M; Carter, Tamar E; Barrow, Lisa; Suren, Ganbold; Raoult, Didier; Reed, David L
Human head lice (Pediculus humanus capitis) are subdivided into 3 deeply divergent mitochondrial clades (Clades A, B, and C), each having unique geographical distributions. Determining the evolutionary history and geographic distribution of these mitochondrial clades can elucidate the evolutionary history of the lice as well as their human hosts. Previous data suggest that lice belonging to mitochondrial Clade B may have originated in North America or Asia; however, geographic sampling and sample sizes have been limited. With newly collected lice, we calculate the relative frequency, geographic distribution, and genetic diversity of louse mitochondrial clades to determine the geographic origin of lice belonging to Clade B. In agreement with previous studies, genetic diversity data support a North American origin of Clade B lice. It is likely that lice belonging to this mitochondrial clade recently migrated to other geographic localities, e.g., Europe and Australia, and, if not already present, may disperse further to occupy all geographic regions.
Bowerman, J G; Gomez, M P; Austin, R D; Wold, D E
The efficacy and safety of permethrin 1% creme rinse and lindane shampoo were compared for the treatment of head lice (Pediculus humanus var. capitis). A total of 1040 patients in the Nezahualcoyotl community of Mexico City representing 296 family groups were enrolled and randomized to treatment, with one patient in each family designated as the index patient. Among index patients 98% treated with permethrin and 76% treated with lindane were louse-free 2 weeks after treatment (P less than 0.001). Comparable results were found with nonindex patients as well. Mild dermal reactions, such as pruritus or erythema, occurred in 1.2% of permethrin-treated patients and 2.6% of lindane-treated patients. There were no reports of central nervous system adverse effects or conjunctivitis.
Bressa, María José; Papeschi, Alba Graciela; Toloza, Ariel Ceferino
The genus Pediculus L. that parasitize humans comprise two subspecies: the head lice Pediculus humanus capitis De Geer and the body lice Pediculus humanus humanus De Geer. Despite the 200 yr of the first description of these two species, there is still a long debate about their taxonomic status. Some authors proposed that these organisms are separate species, conspecifics, or grouped in clades. The sequencing of both forms indicated that the difference between them is one gene absent in the head louse. However, their chromosomal number remains to be determined. In this study, we described the male and female karyotypes, and male meiosis of head and body lice, and examined the chromatin structure by means of C-banding. In P. h. humanus and P. h. capitis, the diploid chromosome complement was 2 n = 12 in both sexes. In oogonial prometaphase and metaphase and spermatogonial metaphase, it is evident that chromosomes lack of a primary constriction. No identifiable sex chromosomes or B chromosomes were observed in head and body lice. Neither chiasmata nor chromatin connections between homologous chromosomes were detected in male meiosis. The meiotic behaviour of the chromosomes showed that they are holokinetic. C-banding revealed the absence of constitutive heterochromatin. Our results provide relevant information to be used in mapping studies of genes associated with sex determination and environmental sensing and response. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: email@example.com.
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Cattle; exposure to tick infestation... (INCLUDING POULTRY) AND ANIMAL PRODUCTS TEXAS (SPLENETIC) FEVER IN CATTLE § 72.12 Cattle; exposure to tick infestation after treatment or inspection prohibited. The cattle shall not be exposed to tick infestation...
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cattle; exposure to tick infestation... (INCLUDING POULTRY) AND ANIMAL PRODUCTS TEXAS (SPLENETIC) FEVER IN CATTLE § 72.12 Cattle; exposure to tick infestation after treatment or inspection prohibited. The cattle shall not be exposed to tick infestation...
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Cattle; exposure to tick infestation... (INCLUDING POULTRY) AND ANIMAL PRODUCTS BOVINE BABESIOSIS § 72.12 Cattle; exposure to tick infestation after treatment or inspection prohibited. The cattle shall not be exposed to tick infestation after treatment and...
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Cattle; exposure to tick infestation... (INCLUDING POULTRY) AND ANIMAL PRODUCTS TEXAS (SPLENETIC) FEVER IN CATTLE § 72.12 Cattle; exposure to tick infestation after treatment or inspection prohibited. The cattle shall not be exposed to tick infestation...
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Cattle; exposure to tick infestation... (INCLUDING POULTRY) AND ANIMAL PRODUCTS TEXAS (SPLENETIC) FEVER IN CATTLE § 72.12 Cattle; exposure to tick infestation after treatment or inspection prohibited. The cattle shall not be exposed to tick infestation...
... Inspection Service 7 CFR Part 301 Gypsy Moth Generally Infested Areas; Additions in Wisconsin AGENCY: Animal... are amending the gypsy moth regulations by adding areas in Wisconsin to the list of generally infested areas based on the detection of infestations of gypsy moth in those areas. As a result of this action...
The prevalence of Tropilaelaps mercedesae and Varroa destructor in concurrently infested A. mellifera colonies in Thailand was monitored. We also assessed the reproductive ability of T. mercedesae and V. destructor in naturally infested brood and in brood cells deliberately infested with both mite g...
The prevalence of Tropilaelaps mercedesae and Varroa destructor in concurrently infested A. mellifera colonies in Thailand was monitored. We also assessed the fecundity of T. mercedesae and V. destructor in naturally infested brood and in brood cells deliberately infested with both mite genera. Resu...
The goal of this research was to detect and predict degree of triticale seed infestation with rice weevils using near-infrared (NIR) spectroscopy. Groups of seeds at 11 different levels (degrees) of infestation were tested by combining mixtures of infested and uninfested seeds at different ratios. S...
Insect infestation of seeds of the triticale hybrid, Triticosecale, causes extraordinary storage losses as a consequence of vulnerability of triticale seed to insect infestation and its soft coat. Rice weevil, Sitophilus oryzae (L.), is a common insect that causes infestation in Florida, which was t...
Gene D. Amman; Gerhard F. Fedde
Infestations of the balsam woolly aphid, Adelges piceae (Ratz.), on European silver fir trees in a plantation were observed over a 7-year period. Infestations were usually light, but occasionally increased to heavy. Heavy infestations declined within 1 or 2 years without killing the trees or causing them apparent damage.
The fast-spreading-zebra mussel has significant potential to foul intakes and other water systems at North American hydro projects. Chemical controls can be effective in reducing infestations, but most have environmental and other drawbacks. Several non-chemical methods promise to help project operators reduce problems associated with the mussels.
Remote sensing technology has long been used for detecting insect infestations on agricultural crops. With recent advances in remote sensing sensors and other spatial information technologies such as Global Position Systems (GPS) and Geographic Information Systems (GIS), remote sensing is finding mo...
Zapardiel, Ignacio; Peiretti, Michele; Godoy-Tundidor, Sonia
The most common etiology of postpartum hemorrhage is uterine atony, although hematologic disorders may be present. A 36-year-old nulliparous woman underwent puerperal hysterectomy caused by uncontrolled postpartum hemorrhage. One day after discharge, she vomited in the emergency room a 24-cm long Ascaris lumbricoides. Infestation during gestation may cause hematologic disorders that could complicate pregnancy outcome.
David A. Gansner; Owen W. Herrick; Garland N. Mason; Kurt W. Gottschalk
Forest managers on new frontiers of infestation are searching for better ways to cope with the gypsy moth (Lymantria dispar). Presented herea are information and guidelines for remedial action to minimize future losses. Methods for assessing potential stand defoliation (susceptibility) and mortality (vulnerability), monitoring insect populations, and...
To detect popcorn kernels infested by the internal feeding stored-product insect pest Sitophilus zeamais, maize weevil, a laboratory roller mill was modified so that the electrical conductivity of the grain is measured while the kernels are milled between the rolls. When a kernel with a S. zeamais l...
C.J. Peterson; P.D. Gerard; T.L. Wagner
Fire is an important part of forest ecosystems, as is the insect fauna. Changes in wood brought aboutby fire may alter the ability of termites to use the wood, interrupting the decay cycle of woody debris.The ability of termites to find, infest, and feed upon wood after it had been charred was evaluated in
The challenges that land owners and resource managers face when trying to attempt applications and practices when attempting to rehabilitate rangelands infested with cheatgrass (Bromus tectorum) are over-whelming. Simply purchasing seed and spreading it throughout the rangelands is doomed for failu...
The relationship between the removal of mite-infested brood and mite drop was compared using Russian (RHB, n = 9) and Italian (IHB, n = 9) honey bee colonies. A cloake board was used to isolate test brood frame on the top hive body and the metal sheet served as a varroa trap. Inoculum mites were col...
Giorda, Federica; Guardone, Lisa; Mancini, Marialetizia; Accorsi, Annalisa; Macchioni, Fabio; Mignone, Walter
CBed bugs (Cimex lectularius) have been a common problem for humans for at least 3,500 years and in Europe their presence was endemic until the end of World War II, when infestations began to decrease. However, since the beginning of the 21st century new cases of infestations have been reported in developed countries. Many theories have been put forward to explain this change of direction, but none has been scientifically proven. The aim of this study is to provide some reports of bed bug infestations in Northern Italy (Liguria, Piedmont and Aosta valley regions) and a brief summary about their identification, clinical significance, bioecology and control. From 2008 to date, 17 bed bug infestations were identified in Northwest Italy. Knowledge about the presence and distribution of bed bugs in Italy is scanty, prior to this work only 2 studies reported the comeback of these arthropods in the Italian territory; further investigations would be necessary to better understand the current situation.
Padmaja, P G; Shwetha, B L; Swetha, G; Patil, J V
This research investigated the role of oxidative enzymes in the defense response of sorghum, Sorghum bicolor (L.) Moench (Poales: Poaceae), to the sorghum shoot fly, Atherigona soccata Rondani (Diptera: Muscidae). Changes in polyphenol oxidase and peroxidase activity and total protein content were observed in resistant and susceptible sorghum genotypes in response to A. soccata feeding. Resistant plants exhibited higher levels of peroxidase and polyphenol oxidase activities and total protein content compared with susceptible plants. Peroxidase and polyphenol oxidase activities and total protein content in the infested resistant and susceptible genotypes were higher when compared with their control plants, respectively. These findings suggest that resistant genotypes may be able to tolerate shoot fly feeding by increasing their peroxidase and polyphenol oxidase activities. Among the enzymes examined, differences in isozyme profiles for peroxidase and polyphenol oxidase were detected between control and infested IS 18551, M35-1, 296B, SSV 84, and DJ 6514 plants. Differences in protein profiles were observed between A. soccata infested and their respective uninfested controls of all the genotypes. In conclusion, this study revealed that these defense enzymes and proteins might attribute to the resistance mechanisms in sorghum plants against A. soccata infestation.
The European pear sawfly, Hoplocampa brevis (Klug), is a relatively new pest in the Mid-Atlantic fruit production region. A plot containing twelve Pyrus communis pear cultivars and one breeder’s selection in a randomized block design was surveyed for fruit damage. Infestation frequency ranged from...
J. Y. Zhu; Gary C. Myers
This study evaluated the quality of kraft pulp from bud-worm-infested jack pine. The logs were classified as merchantable live, suspect, or merchantable dead. Raw materials were evaluated through visual inspection, analysis of the chemical composition, SilviScan measurement of the density, and measurement of the tracheid length. Unbleached pulps were then refined using...
Leafy spurge is an invasive Eurasian weed on pastures and rangeland in North America where it reduces grass forage production. Our objective was to determine the effects of multispecies grazing combined with Aphthona 'ea beetles on leafy spurge-infested rangeland. On two western North Dakota sites d...
Despite the economic importance of eriophyoid mites as agricultural pests, especially of cereal crops, knowledge of the eriophyoid fauna in Turkey remains incomplete. This paper presents the results of a 3-year study on grass-infesting eriophyoid mites in Turkey. The aim of this study was to collect...
... Body lice are tiny insects (scientific name is Pediculus humanus corporis ) that are spread through close contact ... disease Images Body louse Lice, body with stool (Pediculus humanus) Body louse, female and larvae Head louse ...
Silva, Guilherme Araujo Collares da; Lins, Luciana Araujo; Irala, Márcio Josué Costa; Cárcamo, Marcial Corrêa; Ribeiro, Paulo Bretanha
The Siphonaptera are parasitic insects of endothermic animals and Ctenocephalides felis and Pulex irritans are important parasites of dogs. This study evaluated the effect of hair coat length and time of year on the population size of C. felis and P. irritans in naturally infested dogs. Fleas were collected from 14 dogs on a monthly basis for a year (February 2015 to January 2016) at a rural property in Bagé, Rio Grande do Sul, Brazil. The dogs were divided into two groups based on hair coat length: short coat (coat length < 5.0 cm, n= 7) and long coat (coat length > 5.0 cm, n= 7). In total, 2057 fleas were collected, 1541 of which were C. felis (74.91%) and 516 were P. irritans (25.08%). The number of C. felis and P. irritans individuals was significantly affected by hair coat length and time of year. The variation in flea numbers over the study months was higher in long-coated than in short-coated dogs for the two flea species and flea numbers increased with increasing mean monthly temperatures. The results provide a better understanding of behavioral aspects of flea communities in dogs and may help develop control strategies targeting these parasites.
Meyer-Kayser, Elisabeth; Hoffmann, Lothar; Silaghi, Cornelia; Pfister, Kurt; Mahling, Monia; Passos, Lygia M F
This study aimed to provide up-to-date information on the dynamics of tick infestations on foxes in Thuringia, as the most recent information available was published in 1997. Fox carcasses that had been sent to the Thuringian State Authority for Food Safety and Consumer Protection (Thüringer Landesamt für Lebensmittelsicherheit und Verbraucherschutz - TLLV), between January 1st and December 31st, 2009, were examined for the presence of ticks. All ticks collected were stored at -20 °C before being identified and classified according to their developmental stage and sex. Out of a total of 1286 foxes examined, 989 (76.9%) were infested with ticks. A total of 13,227 ticks were collected from the foxes. The stage most frequently found was the larva (48.1%), followed by the adult (34.1%), and the nymphal stage (17.8%). Regarding the adult stage, Ixodes ricinus was the most frequent tick species detected (82.2%), followed by I. canisuga (10.8%) and I. hexagonus (6.7%). Dermacentor reticulatus ticks were very rare (0.3%). With regard to nymphs, I. canisuga and I. hexagonus were the most frequent tick species found, and this was also assumed for the larval stage. The results indicate the occurrence of tick infestations in foxes throughout the year, mainly by I. ricinus, I. canisuga, and I. hexagonus, with seasonal variations. Foxes were infested by I. ricinus ticks significantly more frequently from April to September. This applied to all tick developmental stages, but especially to adults. In contrast to I. ricinus, the infestation of foxes with I. canisuga and I. hexagonus was significantly higher from January to March and from October to December, especially with the immature developmental stages. Copyright © 2012 Elsevier GmbH. All rights reserved.
Semmler, Margit; Abdel-Ghaffar, Fathy; Al-Quraishy, Saleh; Al-Rasheid, Khaled A S; Mehlhorn, Heinz
It is difficult to stop lice propagation just by treating infested heads, since reinfections are possible just a few hours after a successful elimination of all lice from a child's head by application of an active anti-louse product. Therefore, several products have been developed that claim to have a louse repellent activity; however, definite proofs are scarce. The present study involving two louse repellents (Linicin® Preventive Spray, Picksan® NoLice) and three substances (at 10% dilution) known for their general repellency activity shows that there are much more difficulties to repel lice when compared to other insects or even ticks. Thus, it must be feared that several repellents on the market might have used a problematical test system and thus might not be as effective as they claim.
Andreotti, Renato; Cunha, Rodrigo Casquero; Soares, Mariana Aparecida; Guerrero, Felix D; Leite, Fábio P Leivas; de León, Adalberto A Pérez
The cattle tick, Rhipicephalus microplus, is regarded as the most economically important ectoparasite of livestock globally. Control is achieved primarily through the use of acaricides. This approach is hampered by the development of resistance to commercial acaricides among cattle tick populations. Vaccination against R. microplus infestation is another technology that can be integrated for effective cattle tick control. Proteins belonging to the Kunitz-BPTI family are abundant in cattle tick salivary glands, midgut, and ovaries. These organs are attractive targets for the development of a novel cattle tick vaccine. Efficacy assessment against cattle tick infestation in bovines using a vaccine containing the recombinant form of a member of the Kunitz family from R. microplus produced in a yeast expression system is reported for the first time here. The yeast Pichia pastoris was bioengineered to produce the recombinant version of a trypsin inhibitor that is expressed in cattle tick larvae (rRmLTI). Immunization with rRmLTI afforded 32% efficacy against R. microplus. The estimated molecular weight of rRmLTI was 46 kDa. Structural homology to the native form of the larval trypsin inhibitor was documented by recognition of rRmLTI in Western-blots using polyclonal antibodies from mice immunized with cattle tick larval extract or rRmLTI. Bioinformatics analysis of the partial nucleotide and deduced amino acid sequences indicated that the rRmLTI closely resembles BmTI-6, which is a three-headed Kunitz protein present in cattle tick ovary and fat tissue. Published by Elsevier Ltd.
Vargas-Ocampo, F; Alvarado-Aleman, F J
An 11-year-old girl presented from Villa Azueta, Veracruz, a poor and small town on the Tesechoacan riverside. The Tesechoacan riverside is a tropical area in the south-east of Mexico, between 18 degrees, 04',32" latitude and 95 degrees, 42',23" longitude. Her family consisted of both parents and 12 brothers, all apparently healthy and living in a humble hut, with poor nutrition and hygiene. The main sign was a tumor on her neck that had developed during the previous 6 months. On clinical examination, the patient's temperature was normal and her weight was 27.5 kg. Below the right angle of the jaw a firm-to-hard tumor was noted measuring 5 x 3 cm, it was tender and lobulated (Fig. 1) with a central purulent fistula containing small worms with morphology of Lagochilascans minor (Fig. 2). Iron-deficiency anemia was found with no increase of blood eosinophils and a while blood count of 9000/mm3 with 72% of neutrophils. Roentgenograms of the head and chest were both normal. A stool was negative for parasites; glutamic oxalade and glutamic pyruvate transaminases were normal. Histopathologic examination revealed parakeratosis and mild acanthosis with exocytosis of eosinophils. The superficial dermis showed an inflammatory reaction, mainly composed of eosinophils, plasma cells, and histiocytes, and in the deep dermis an abscess containing different sections of the parasite was seen surrounded by a thin fibrous capsule (Fig. 3). There was no clinical improvement after medical treatment with two courses of thiabendazole (50 mg/kg orally, two 5-day pulses) and praziquantel (400 mg orally for 3 days). Therefore, the growth was extirpated under general anesthesia; however, the clinical condition of the patient did not improve. Eggs, larvae, and adult worms continued to be present in the pus after surgical excision. Finally, the patient asked for a discharge and did not return to the institute.
Aaen, S M; Hamre, L A; Horsberg, T E
Egg strings and nauplii of the salmon louse Lepeophtheirus salmonis were exposed to a variety of medicinal compounds at 50 mg L(-1) for 30 min in two experiment series. This medicine concentration was selected as a starting point for a screening series. Hatching of egg strings and development to copepodid larvae were monitored in one experiment, and the survival and development of nauplii were monitored in the other. Two compounds, emamectin benzoate and cypermethrin, inhibited hatching effectively. Several compounds affected nauplii, either directly or through inhibiting development to the infective stage. A total of 50 mg L(-1) of azamethiphos, cypermethrin, emamectin benzoate and propoxur was lethal to >70% of the larvae. Diflubenzuron, fenoxycarb, pymetrozine, pyriprole and tebufenozide diminished the ability of nauplii developing to copepodids. © 2016 John Wiley & Sons Ltd.
Kawabata, Ryuzou; Uefune, Masayoshi; Miike, Tohru; Okabe, Hirotaka; Takabayashi, Junji; Takagi, Masami; Kai, Shoichi
We studied spontaneous photon emission from kidney bean leaves infested with spider mites. Strong photon radiation was observed from the leaf veins where spider mites were crowding. Photon emission intensity increased with the decreases in chlorophyll content and photosynthesis yield; these decreases represented the degree of damage caused by the pest. When both infested and un-infested leaves were put on the same wet cotton, photon emission from the un-infested leaf increased, too. Photon emission from the un-infested leaf might be induced by an aqueous elicitor released from the infested leaf. Such an elicitor activates the plant defense response. Therefore, it is suggested that photon emission from an infested leaf conveys information on the direct injury (physical stresses) and physiological (biochemical) actions associated with the defensive response.
Harris, Marvin K; Hunt, Kenneth L; Cognato, Anthony I
Larvae found infesting fruit from a Carpathian walnut, Juglans regia L., tree in Missouri were confirmed by DNA analysis to be those of pecan weevil, Curculio caryae (Horn) (Coleoptera: Curculionidae). The infested walnut tree occurs in the midst of pecan weevil-infested pecans, Carya illinoinensis (Wang.) K. Koch; the larval haplotypes were found to be identical to pecan weevil larvae from the region, indicating that the walnut infestation arose by association with infested pecan. This is the first confirmed DNA analysis showing pecan weevil attacks J. regia and the second report that J. regia may be at risk of infestation by pecan weevil. Further study indicates this infestation on walnut is established and ongoing. The pecan weevil is a key pest of pecan and seems capable of inflicting similar damage to walnut if spread to commercial areas that produce J. regia.
Errard, Audrey; Ulrichs, Christian; Kühne, Stefan; Mewis, Inga; Drungowski, Mario; Schreiner, Monika; Baldermann, Susanne
Tomato is susceptible to pest infestations by both spider mites and aphids. The effects of each individual pest on plants are known, whereas multiple-pest infestations have received little interest. We studied the effects of single- versus multiple-pest infestation by Tetranychus urticae and Myzus persicae on tomato biochemistry (Solanum lycopersicum) by combining a metabolomic approach and analyses of carotenoids using UHPLC-ToF-MS and volatiles using GC-MS. Plants responded differently to aphids and mites after 3 weeks of infestation, and a multiple infestation induced a specific metabolite composition in plants. In addition, we showed that volatiles emissions differed between the adaxial and abaxial leaf epidermes and identified compounds emitted particularly in response to a multiple infestation (cyclohexadecane, dodecane, aromadendrene, and β-elemene). Finally, the carotenoid concentrations in leaves and stems were more affected by multiple than single infestations. Our study highlights and discusses the interplay of biotic stressors within the terpenoid metabolism.
Michalzik, B.; Levia, D. F., Jr.; Bischoff, S.; Näthe, K.
Mass outbreaks of herbivore insects are known to perturb the functional properties of forests. However, it is less clear how endemic to moderate aboveground herbivory affects the vertical flow of nutrients from tree canopies to the soil. Here, we report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). In a potted sapling experiment, we followed the vertical dynamics of nutrients via throughfall (TF), stemflow (SF) and litter leachates (LL) collected over ten weeks underneath infested and uninfested control trees. Aphid infestation amplifies the fluxes of K+, Mn2+ and particulate nitrogen (0.45μm < PN < 500 μm) in TF solution by 42% for K+, 59% for Mn2+ and 13% for PN relative to the control. In contrast, fluxes of NH4-N and SO4-S diminished during peaking aphid abundance by 26 and 16%, respectively. Differences in canopy-derived dissolved nitrogen and carbon compounds, sulfur (S), Ca2+, Mg2+, Na+ were < 10%. The effect of aphid abundance on nutrient dynamics was most notable in TF and SF and diminished in LL.Aphid infestation greatly altered the SF fluxes of DOC, K+, Mn2+, DON and sulfur-species, which were significantly concentrated at the tree base by "funneling" the rainfall through the canopy biomass to the trunk. Normalized to one square meter, water and nutrient fluxes were amplified by a factor of up to 200 compared to TF.Imaging of leaf surfaces by scanning electron microscopy exhibited notable differences of the surface morphology and microbiology of control, lightly infested, and heavily infested leaves. This observation might point to an aphid-mediated alteration of the phyllosphere ecology triggering the microbial uptake of NH4-N and SO4-S and its transformation to particulate N by magnified biomass growth of the phyllosphere microflora, consequently changing the chemical partitioning and temporal availability of nitrogen.
Kim, Dong-Hee; Son, Hyun-Mi; Lee, Sang Hwa; Park, Mi Kyung; Kang, Shin Ae; Park, Sang Kyun; Choi, Jun-Ho; Park, Jung Ha; Yu, Hak-Sun
To determine whether pinworm infections and head lice infestations spread among children in orphanages, 117 children from 4 orphanages in Busan-si and Ulsan-si, Korea, were examined for enterobiasis and head lice infestation between January and February 2014. The overall rate of Enterobius vermicularis egg positivity was 0.85%, whereas none of the children had head lice infestations. The rate of pinworm infection was much lower among the orphanage children compared to the rates observed in previous studies among kindergarten and primary school students. Moreover, the risk factors for enterobiasis were less frequent among these subjects than previously reported. The personal hygiene and health of the orphanage children were supervised by a regular, employed nurse through a health education program. In conclusion, pinworm infection was efficiently controlled among the children in orphanages, and this might be related to good personal hygiene practices in Korea. PMID:26323851
Kim, Dong-Hee; Son, Hyun-Mi; Lee, Sang Hwa; Park, Mi Kyung; Kang, Shin Ae; Park, Sang Kyun; Choi, Jun-Ho; Park, Jung Ha; Yu, Hak-Sun
To determine whether pinworm infections and head lice infestations spread among children in orphanages, 117 children from 4 orphanages in Busan-si and Ulsan-si, Korea, were examined for enterobiasis and head lice infestation between January and February 2014. The overall rate of Enterobius vermicularis egg positivity was 0.85%, whereas none of the children had head lice infestations. The rate of pinworm infection was much lower among the orphanage children compared to the rates observed in previous studies among kindergarten and primary school students. Moreover, the risk factors for enterobiasis were less frequent among these subjects than previously reported. The personal hygiene and health of the orphanage children were supervised by a regular, employed nurse through a health education program. In conclusion, pinworm infection was efficiently controlled among the children in orphanages, and this might be related to good personal hygiene practices in Korea.
Tinoco-Orta, Gissel Dalila; Cáceres-Martínez, Jorge
Burrowing worms that belong to Polydora spp. infest marine mollusks cultured worldwide, causing problems for production and marketing. The clam Chione fluctifraga is semi-cultured in Bahía Falsa, Baja California, NW Mexico, and some clams harbor burrowing worms. The present study was carried out to determine the identity of the worm species infesting the clam, the infesting process by cohabitation of infested and non-infested clams in aquaria with a variety of substrates (fine sand, gross sand, plastic bag used for clam culture, and aquarium without substrate) and turbulence conditions, and the occurrence of architomy phenomena in connection with infestation of the clam. The burrowing worm was considered as a nova species due to its singular limbate neurosetae and notosetae in the setiger 5, hooks in the setiger 6, eyes not present, and general pigmentation, among other characteristics. Infestation was similar in all substrates and turbulence conditions, but it was more abundant on clams previously infested than on those free of worms, showing a preferential settlement of worm infesting stages on pre-infested clams. Regeneration was observed in all segments of the worm: anterior (metastomium), medium, and posterior (prostomium); the complete regeneration time occurred in 40 days. This is the first record of architomy in a species of Polydora and this phenomenon could account for the increase of infestation intensity in pre-infested clams at the end of the study period. Infestation of clams by settling polichaete in the conditions studied, and the architomy process in this worm species, shows its great infesting capacity.
Saenz, Virna L; Booth, Warren; Schal, Coby; Vargo, Edward L
Bed bugs (Cimex lectularius L.) are a resurgent pest worldwide and infestations within the United States are increasing at a rapid rate. Because of the physical and psychological discomfort inflicted by their blood feeding habits, and allergies and secondary infections associated with bites, bed bugs are recognized as a significant public health problem. Although bed bug infestations are spreading and becoming more prevalent, we have a poor understanding of their dispersal patterns and sources of infestation. To help fill this gap, we conducted a genetic study of 21 bed bug infestations from the eastern United States, nearly all of which came from single rooms within residences. We genotyped samples comprised of 8-10 individuals per infestation at nine polymorphic microsatellite loci. Despite high genetic diversity across all infestations, with 5-17 alleles per locus (mean = 10.3 alleles per locus), we found low genetic diversity (1-4 alleles per locus) within all but one of the infestations. These results suggest that nearly all the studied infestations were started by a small propagule possibly consisting of a singly mated female and/or her progeny, or a female mated with multiple males that were highly related to her. All infestations were strongly genetically differentiated from each other (mean pairwise F(ST) between populations = 0.68) and we did not find strong evidence of a geographic pattern of genetic structure, indicating infestations located in closer proximity to each other were nearly as genetically differentiated as those located hundreds of kilometers away. The high level of genetic diversity across infestations from the eastern United States together with the lack of geographically organized structure is consistent with multiple introductions into the United States from foreign sources.
Head circumference is a measurement of the circumference of the child's head at its largest area (above the eyebrows and ears and around the back of the head). During routine check-ups, the distance is measured ...
Dewan, P; Miller, J; Musters, C; Taylor, R E; Bewley, A P
Delusional infestation (DI) is a psychiatric disorder characterized by a fixed, false belief that the patient is infested with extracorporeal agents. It is known by several names, including the more commonly used term 'delusional parasitosis'. The psychiatric disease is responsible for the cutaneous pathology. About 90% of patients with DI seek help from dermatologists, and most reject psychiatric referral. Thus, effective management requires incorporation of psychiatric principles. We report three cases of DI with inanimate materials, and examine 'Morgellons' disease. We believe that patients with unusual presentations of DI are likely to be seen more commonly in the future. These patients appear to be a subgroup of DI, and may be even more difficult to treat than other patients with DI.
Shah, Reena; Taylor, Ruth E; Bewley, Anthony
Delusional infestation (DI) is an uncommon psychiatric disorder in which patients present with the false and fixed belief (i.e. a delusion) that their skin and/or their environment is infested despite objective evidence to the contrary. Within psychodermatology specialist clinics there is a high rate of DI referrals. What is not known is the level of psychiatric and psychological co-morbidities associated with DI and whether psychiatric or psychological assessment would be warranted. One-hundred and thirty-eight adult patients with DI attending an outpatient psychodermatology clinic were given 3 standardised questionnaires. The results showed that 81% had a poor quality of life; 52% with anxiety, 41.6% with depression and 49% with appearance-related concerns. This study indicates high levels of psychiatric and psychological disorders in DI which require assessment and appropriate intervention.
Christopher Peterson; P. D. Gerard; Terence Wagner
Fire is an important part of forest ecosystems, as is the insect fauna. Changes in wood brought about by fire may alter the ability of termites to use the wood, interrupting the decay cycle of woody debris. The ability of termites to find, infest, and feed upon wood after it had been charred was evaluated inÂ the laboratory and field. Eastern subterranean termites,...
facilities. It was decided that sites where zebra mussel infestations would be most apparent were components of (1) navigation locks (walls, miter gates, fill... components likely to be negatively affected by zebra mussels. In addition, attendees prepared a preliminary list of strategies to deal with zebra mussel...struc- tural components , and suitable control strategies. The matrix was developed prior to the meeting by WES personnel and was based on an approach
Tafese, Adane; Jibat, Tariku; Aklilu, Nigatu; Zewdu, Hanna; Kumsa, Bersissa
A cross-sectional study was conducted to determine the prevalence and species composition of lice infesting horses in three agroecological zones in seven different districts in central Oromia from November 2011 to April 2012. For this purpose, a total of 420 horses were thoroughly examined for presence of lice. Collected lice were identified to species level under a microscope. The study showed an overall prevalence of 28.8 % (121/420) lice infestation on horses. We identified two spp. of lice on horses namely, Bovicola (Werneckiella) equi and Haematopinus asini with an overall prevalence of 22.9 % (96/420) and 5.9 % (25/420), respectively. The overall prevalence of lice infestation on horses in districts was 48.3, 43.3, 33.3, 23.3, 21.7, 18.3 and 13.3 %, in Debre Brehan, Shashemene, Hawassa, Akaki, Adama, Modjo and Bishoftu, respectively. B. equi was encountered as the predominant species on horses in all districts. Higher overall prevalence of lice infestation was recorded in highland agroecology than mid and lowland agroecological zones. Similarly, our study revealed significantly higher overall prevalence of lice on saddle horses than on cart horses. In view of the findings of the present study two species of lice are responsible for health and welfare problems of horses in all the districts. Detailed epidemiological studies on the significance, prevalence and role of lice as vectors of zoonotic pathogens in different agroecological zones, breeds and management systems warrant urgent attention. Animal owners and veterinarians should consider lice control in horses as part of the ectoparasite control in other species of animals.
Saravanakumar, A; Balasubramanian, T; Raja, K; Trilles, Jean-Paul
In this study, a massive infestation of the sea snake Enhydrina schistosa by the cymothoid isopod Nerocila serra, commonly parasitizing fishes, is reported for the first time from India. This isopod was found attached on the different parts of the body of the snake. According to the month, the parasitic prevalence ranged from 30.8 to 55.3%, increasing during the monsson period. It was higher in female than in male snakes.
Honig, P J
Readily available information as to the management of arthropod bites, stings, and infestations is important to have but often difficult to find. This article brings such information together in one reference for use by the practicing pediatrician, dermatologist, and family practitioner. Preventive measures are stressed and therapy is outlined for each entity; the rationale for many of the interventions is discussed. It is not the intent of this paper to cover each subject comprehensively.
Visser, M; Rehbein, S; Wiedemann, C
The species of flea infesting pets and hedgehogs in Germany were investigated through a survey of small animal practitioners throughout the country who were asked to collect specimens at their veterinary practices. A total of 625 veterinarians/veterinary practices responded and provided 2445 intact anti identifiable flea specimens. These fleas originated from 294 dogs (795 fleas), 334 cats (1152 fleas), 76 hedgehogs (481 fleas), five domestic rabbits (10 fleas), one golden hamster (four fleas) and one ferret (three fleas). Dogs were found to be infested with Archaeopsylla erinacei, Chaetopsylla globiceps, Ctenocephalides canis, Ctenocephalides felis, Hystrichopsylla talpae, Nosopsyllus fasciatus, Paraceras melis and Pulex irritans. From cats, Archaeopsylla erinacei, Ceratophyllus gallinae, Ceratophyllus garei, Ctenocephalides felis, Ctenophthalmus assimilis, Hystrichopsylla talpae, Monopsyllus sciurorum, Nosopsyllus fasciatus, Spilopsyllus cuniculi and Typhloceras poppei were collected. In both dogs and cats the most prevalent species were Ctenocephalides felis (78.9% and 91.6%, respectively) and Archaeopsylla erinacei (21.1% and 12.6%, respectively) followed by Ctenocephalides canis in dogs (5.8%) and Hystrichopsylla talpae in cats (1.2%). The fleas isolated from rabbits were Ctenocephalides felis, Hystrichopsylla talpae and Spilopsyllus cuniculi. Nosopsyllus fasciatus and Ctenocephalides felis were recovered from the golden hamster and the ferret, respectively. The hedgehogs were found to be infested with Archaeopsylla erinacei, Ceratophyllus gallinae and Ctenocephalides felis.
Peng, Zhiwei; Liu, Shijie; Hou, Zhijun; Xing, Mingwei
The Siberian tiger is endangered and is listed by the International Union for the Conservation of Nature; the captive environment is utilized to maintain Siberian tiger numbers. Little information regarding the prevalence of parasites in Siberian tigers is available. A total of 277 fecal samples of Siberian tigers were analyzed in this study. The microscopic analysis indicated the presence of ascarid eggs of Toxascaris leonina and Toxocara cati. The ascarid infection rate was 67.5% in Siberian tigers. The internal transcribed spacer-1 (ITS-1) phylogenetic analysis indicated that T. leonina belonged to Toxascaris and that Toxo. cati belonged to Toxocara. The infestation rate and intensity of T. leonina were higher than those of Toxo. cati. One-way analysis of variance showed that the presence of T. leonina was significantly associated with age (P<0.05). Temperature changes also influenced T. leonina and Toxo. cati infestation, and a rise in temperature caused an increase in the number of T. leonina and Toxo. cati eggs. This study provides a better understanding of ascarid infestation among the captive Siberian tigers and is helpful for the prevention of the spread of infectious parasitic diseases among other tigers in the zoo. Copyright © 2016 Elsevier B.V. All rights reserved.
Scheiman, D.M.; Bollinger, E.K.; Johnson, D.H.
Grassland bird populations are declining. Invasive plant species may be contributing to these declines by altering habitat quality. However, the effects of invasive plants on grassland birds are largely unknown. Leafy spurge (Euphorbia esula) is an exotic, invasive weed in the northern Great Plains. We examined the effects of leafy spurge infestation on densities of breeding birds, nest-site selection, and nest success in grasslands on the Sheyenne National Grassland (SNG), North Dakota, USA, 1999-2000. We categorized spurge-infested grasslands into 3 groups (low, medium, high), based on the area covered by spurge patches. We surveyed 75 100-m-radius circular points (25 in each group), and searched for nests in 6 16-ha plots (2 in each group). Grasshopper sparrow (Ammodramus savannarum) and savannah sparrow (Passerculus sandwichensis) densities were lower on high-spurge points than on low- and medium-spurge points. Bobolink (Dolichonyx oryzivorus) and western meadowlark (Sturnella neglecta) densities were not significantly different among spurge cover groups. Spurge cover did not appear to be an important factor in nest-site selection. However, western meadowlark nest success was positively associated with spurge cover. Vegetation structure is an important indicator of habitat quality and resource availability for grassland birds. Changes in vegetation structure caused by introduced plant species, such as spurge, can alter resource availability and hence affect bird community composition. Managers of spurge-infested grasslands should continue current spurge control measures to help prevent further declines in grassland habitat quality and grassland bird populations.
Kmieć, K; Kot, I; Golan, K; Górska-Drabik, E; Łagowska, B; Rubinowska, K; Michałek, W
The harmfulness of mealybugs resulting from sucking plant sap, secreting honeydew, and transmitting plant viruses can give them the status of serious pests. This study documents the influence of Pseudococcus maritimus (Ehrhorn) and Pseudococcus longispinus (Targioni Tozzetti) infestation on alterations in selected physiological parameters of Phalaenopsis x hybridum 'Innocence'. The condition of the cytoplasmic membranes was expressed as the value of thiobarbituric acid reactive substances. We have determined changes in the activities of catalase and guaiacol peroxidase and measured the following chlorophyll fluorescence parameters: maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield (Y), photochemical quenching (qP), and nonphotochemical quenching (qN). The strongest physiological response of orchids was recorded in the initial period of mealybugs infestation. Prolonged insect feeding suppressed lipid peroxidation, peroxidase and catalase activity, as well as photosynthesis photochemistry. The pattern of changes was dependent on mealybug species. This indicated the complexity of the processes responsible for plant tolerance. Data generated in this study have provided a better understanding of the impact of two mealybug species infestation on Phalaenopsis and should be useful in developing pest management strategies.
Akkapulu, N; Abdullazade, S
Enterobius vermicularis might be seen in specimens of patients who underwent surgery due to acute appendicitis. There is still debate as to E. vermicularis infestation causes acute appendicitis. The primary aim of this study is to determine the incidence of E. vermicularis infestation, and the secondary aim is to determine the possible role of E. vermicularis in pathogenesis of appendicitis as well as the adequacy of demographic data and laboratory values in predicting infestation preoperatively. A retrospective investigation was conducted with all patients who underwent appendectomy due to acute appendicitis in a secondary care center. Patients with E. vermicularis were compared with 24 controls that underwent appendectomy during the same time period. Demographic data, preoperative white blood cell (WBC) count, eosinophil counts, and histopathological findings for both groups were analyzed and compared. Enterobius vermicularis was detected in the appendectomy materials in 9 of 1446 patients (0.62 %). Histopathologically, only one of nine patients had acute appendicitis while the others were diagnosed with lymphoid hyperplasia. There were no statistically significant differences between the groups except WBC count. However, the WBC count was significantly (p < 0.05) lower in the group which was detected E. vermicularis. Enterobius vermicularis is rarely associated with the histopathological findings of acute appendicitis. Also eosinophil count and elevation of white blood counts are inadequate for predicting preoperative E. vermicularis.
Marcellino, Wani L; Julla, Ibrahim I; Salih, Diaeldin A; El Hussein, Abdel R M
Ticks infesting cattle represent a serious problem for improvement of cattle productivity in South Sudan. There has been limited information on ticks and tick-borne diseases in southern Sudan. This study was initiated to update the current distribution of ticks infesting cattle in the Central Equatoria region of South Sudan. The surveys for the present study were conducted at various cattle camps in Juba, Mangalla and Terekeka between December 2004 and June 2005. A total of 2322 ticks were collected from the bodies of 88 randomly selected cattle. Ticks were preserved in 70% ethanol for later identification. Seven ixodid tick species were found to infest cattle in Juba whilst six species were recorded in Mangalla and only four species in Terekeka. Amblyomma variegatum was the most common and widely distributed species found on cattle across all the study locations. Amblyomma lepidum was not found during this study. Based on these findings, it would be advisable to preempt the situation and institute containment procedures before possible East Coast fever outbreaks occur.
Anderegg, William R L; Callaway, Elizabeth S
Drought impacts on forests, including widespread die-off, are likely to increase with future climate change, although the physiological responses of trees to lethal drought are poorly understood. In particular, in situ examinations of carbon starvation and its interactions with and effects on infestation and hydraulic vulnerability are largely lacking. In this study, we conducted a controlled, in situ, repeated defoliation experiment to induce carbon stress in isolated trembling aspen (Populus tremuloides) ramets. We monitored leaf morphology, leaves per branch, and multitissue carbohydrate concentrations during canopy defoliation. We examined the subsequent effects of defoliation and defoliation-induced carbon stress on vulnerability to insect/fungus infestation and hydraulic vulnerability the following year. Defoliated ramets flushed multiple canopies, which coincided with moderate drawdown of nonstructural carbohydrate reserves. Infestation frequency greatly increased and hydraulic conductivity decreased 1 year after defoliation. Despite incomplete carbohydrate drawdown from defoliation and relatively rapid carbohydrate recovery, suggesting considerable carbohydrate reserves in aspen, defoliation-induced carbon stress held significant consequences for vulnerability to mortality agents and hydraulic performance. Our results indicate that multiyear consequences of drought via feedbacks are likely important for understanding forests' responses to drought and climate change over the coming decades.
Background The genus Haematopinus contains 21 species of blood-sucking lice, parasitizing both even-toed ungulates (pigs, cattle, buffalo, antelopes, camels and deer) and odd-toed ungulates (horses, donkeys and zebras). The mitochondrial genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, Haematopinus apri, have been sequenced recently; both lice have fragmented mitochondrial genomes with 37 genes on nine minichromosomes. To understand whether the composition of mitochondrial minichromosomes and the gene content and gene arrangement of each minichromosome are stable within the genus, we sequenced the mitochondrial genome of the horse louse, Haematopinus asini. Methods We used a PCR-based strategy to amplify four mitochondrial minichromosomes in near full-length, and then amplify the entire coding regions of all of the nine mitochondrial minichromosomes of the horse louse. These amplicons were sequenced with an Illumina Hiseq platform. Results We identified all of the 37 mitochondrial genes typical of bilateral animals in the horse louse, Haematopinus asini; these genes are on nine circular minichromosomes. Each minichromosome is 3.5–5.0 kb in size and consists of a coding region and a non-coding region except R-nad4L-rrnS-C minichromosome, which contains two coding regions and two non-coding regions. Six of the nine minichromosomes of the horse louse have their counterparts in the pig lice with the same gene content and gene arrangement. However, the gene content and arrangement of the other three minichromosomes of the horse louse, including R-nad4L-rrnS-C, are different from that of the other three minichromosomes of the pig lice. Conclusions Comparison between the horse louse and the pig lice revealed variation in the composition of mitochondrial minichromosomes within the genus Haematopinus, which can be accounted for by gene translocation events between minichromosomes. The current study indicates that inter
Song, Simon D; Barker, Stephen C; Shao, Renfu
The genus Haematopinus contains 21 species of blood-sucking lice, parasitizing both even-toed ungulates (pigs, cattle, buffalo, antelopes, camels and deer) and odd-toed ungulates (horses, donkeys and zebras). The mitochondrial genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, Haematopinus apri, have been sequenced recently; both lice have fragmented mitochondrial genomes with 37 genes on nine minichromosomes. To understand whether the composition of mitochondrial minichromosomes and the gene content and gene arrangement of each minichromosome are stable within the genus, we sequenced the mitochondrial genome of the horse louse, Haematopinus asini. We used a PCR-based strategy to amplify four mitochondrial minichromosomes in near full-length, and then amplify the entire coding regions of all of the nine mitochondrial minichromosomes of the horse louse. These amplicons were sequenced with an Illumina Hiseq platform. We identified all of the 37 mitochondrial genes typical of bilateral animals in the horse louse, Haematopinus asini; these genes are on nine circular minichromosomes. Each minichromosome is 3.5-5.0 kb in size and consists of a coding region and a non-coding region except R-nad4L-rrnS-C minichromosome, which contains two coding regions and two non-coding regions. Six of the nine minichromosomes of the horse louse have their counterparts in the pig lice with the same gene content and gene arrangement. However, the gene content and arrangement of the other three minichromosomes of the horse louse, including R-nad4L-rrnS-C, are different from that of the other three minichromosomes of the pig lice. Comparison between the horse louse and the pig lice revealed variation in the composition of mitochondrial minichromosomes within the genus Haematopinus, which can be accounted for by gene translocation events between minichromosomes. The current study indicates that inter-minichromosome recombination plays a major role in generating the
Ralph, Nancy; Jones, Heidi E; Thorpe, Lorna E
Bed bug infestations have risen precipitously in urban areas. Little is known about risk factors for infestations or health outcomes resulting from these infestations. In the 2009 Community Health Survey, which is a representative population-based survey, 9,934 noninstitutionalized adults in New York City reported on bed bug infestations requiring an exterminator in the past year. The authors estimated infestation prevalence and explored predictors of infestation and associations between infestations and health outcomes using logistic regression. Seven percent of adults in New York City reported bed bug infestations. Significant individual and household risk factors were younger age, increased household poverty, and having three or more adults in the household. Environmental risk factors included living in high poverty neighborhoods and in buildings with more housing units, suggesting apartment-to-apartment transmission. Bed bug infestations were not associated with stress-related outcomes of alcohol consumption or recent depression, and, unlike cockroach infestation, were not associated with recent asthma episodes caused by allergens or contaminants.
Previte, D.; Olds, B. P.; Yoon, K.; Sun, W.; Muir, W.; Paige, K. N.; Lee, S. H.; Clark, J.; Koehler, J. E.; Pittendrigh, B. R.
Human head and body lice are obligatory hematophagous ectoparasites that belong to a single species, Pediculus humanus. Only body lice, however, are vectors of the infectious Gram-negative bacterium Bartonella quintana. Because of their near identical genomes, yet differential vector competence, head and body lice provide a unique model system to study the gain or loss of vector competence. Using our in vitro louse-rearing system, we infected head and body lice with blood containing B. quintana in order to detect both differences in the proliferation of B. quintana and transcriptional differences of immune-related genes in the lice. B. quintana proliferated rapidly in body lice at 6 days postinfection, but plateaued in head lice at 4 days postinfection. RNAseq and quantitative real-time PCR validation analyses determined gene expression differences. Eight immunoresponse genes were observed to be significantly different with many associated with the Toll pathway: Fibrinogen-like protein, Spaetzle, Defensin 1, Serpin, Scavenger receptor A and Apolipoporhrin 2. Our findings support the hypothesis that body lice, unlike head lice, fight infection from B. quintana only at the later stages of its proliferation. PMID:24404961
Previte, D; Olds, B P; Yoon, K; Sun, W; Muir, W; Paige, K N; Lee, S H; Clark, J; Koehler, J E; Pittendrigh, B R
Human head and body lice are obligatory hematophagous ectoparasites that belong to a single species, Pediculus humanus. Only body lice, however, are vectors of the infectious Gram-negative bacterium Bartonella quintana. Because of their near identical genomes, yet differential vector competence, head and body lice provide a unique model system to study the gain or loss of vector competence. Using our in vitro louse-rearing system, we infected head and body lice with blood containing B. quintana in order to detect both differences in the proliferation of B. quintana and transcriptional differences of immune-related genes in the lice. B. quintana proliferated rapidly in body lice at 6 days post-infection, but plateaued in head lice at 4 days post-infection. RNAseq and quantitative real-time PCR validation analyses determined gene expression differences. Eight immunoresponse genes were observed to be significantly different with many associated with the Toll pathway: Fibrinogen-like protein, Spaetzle, Defensin 1, Serpin, Scavenger receptor A and Apolipoporhrin 2. Our findings support the hypothesis that body lice, unlike head lice, fight infection from B. quintana only at the later stages of its proliferation.
Kirkendall, D T; Jordan, S E; Garrett, W E
In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the
Currie, Marian J; Reynolds, Graham J; Glasgow, Nicholas J; Bowden, Francis J
Head lice are a common, costly public health problem worldwide. We aimed to determine the feasibility of an ivermectin intervention program. Consenting students in two schools were screened for head lice. Infested students and siblings at one school were offered a head lice fact sheet and two doses of oral ivermectin, 7 days apart. Parents of infested students in the other school were given the same fact sheet and asked to treat the child and siblings using their preferred topical treatment. Seven hundred two of 754 (93.1%) students enrolled in the two schools were screened; 40 (5.3%; 95% CI 3.7-6.9) had head lice; 31 (9.4%; 95% CI 6.1-12.2) in the intervention school and nine (2.5%; 95% CI 1.1-3.8) in the control school. Subsequently 93.6% of children in the intervention school were treated with oral ivermectin. No adverse events were reported. At 6 months the reduction in the head lice infestation rates for the intervention and control schools were 87% and 56%, respectively. This pilot study suggests that school wide screening for head lice and the administration of oral ivermectin is feasible and acceptable. A randomized controlled trial at 20 schools is planned. © 2010 Wiley Periodicals, Inc.
Klompmaker, Adiël A.; Artal, Pedro; van Bakel, Barry W. M.; Fraaije, René H. B.; Jagt, John W. M.
Parasites are common in modern ecosystems and are also known from the fossil record. One of the best preserved and easily recognisable examples of parasitism in the fossil record concerns isopod-induced swellings in the branchial chamber of marine decapod crustaceans. However, very limited quantitative data on the variability of infestation percentages at the species, genus, and family levels are available. Here we provide this type of data for a mid-Cretaceous (upper Lower Cretaceous, upper Albian) reef setting at Koskobilo, northern Spain, on the basis of 874 specimens of anomurans and brachyurans. Thirty-seven specimens (4.2%), arranged in ten species, are infested. Anomurans are more heavily infested than brachyurans, variability can be high within genera, and a relationship may exist between the number of specimens and infestation percentage per taxon, possibly suggesting host-specificity. We have also investigated quantitative patterns of infestation through geological time based on 88 infested species (25 anomurans, 55 brachyurans, seven lobsters, and one shrimp), to show that the highest number of infested species can be found in the Late Jurassic, also when corrected for the unequal duration of epochs. The same Late Jurassic peak is observed for the percentage of infested decapod species per epoch. This acme is caused entirely by infested anomurans and brachyurans. Biases (taphonomic and otherwise) and causes of variability with regard to the Koskobilo assemblage and infestation patterns through time are discussed. Finally, a new ichnogenus and -species, Kanthyloma crusta, are erected to accommodate such swellings or embedment structures (bioclaustrations). PMID:24667587
Sangaré, Abdoul Karim; Doumbo, Ogobara K; Raoult, Didier
Of the three lice (head, body, and pubic louse) that infest humans, the body louse is the species involved in epidemics of louse-borne typhus, trench fever, and relapsing fever, but all the three cause pediculosis. Their infestations occur today in many countries despite great efforts to maintain high standards of public health. In this review, literature searches were performed through PubMed, Medline, Google Scholar, and EBSCOhost, with key search words of "Pediculus humanus", "lice infestation", "pediculosis", and "treatment"; and controlled clinical trials were viewed with great interest. Removing lice by hand or with a lice comb, heating infested clothing, and shaving the scalp were some of the oldest methods of controlling human lice. Despite the introduction of other resources including cresol, naphthalene, sulfur, mercury, vinegar, petroleum, and insecticides, the numbers of lice infestation cases and resistance have increased. To date, viable alternative treatments to replace insecticides have been developed experimentally in vitro. Today, the development of new treatment strategies such as symbiotic treatment and synergistic treatment (antibiotics + ivermectin) in vitro has proved effective and is promising. Here, we present an overview on managing and treating human lice and highlight new strategies to more effectively fight pediculosis and prevent resistance.
Zipple, Anthony M; Batscha, Catherine L; Flaherty, Peggy; Reynolds, Jared L
Bedbug infestation has become a major problem in the United States. Infestations can be frightening and expensive and appear to be more prevalent in urban settings and low-income housing such as homeless shelters, public housing, and single-room occupancy apartments. This exposes consumers and staff of psychiatric rehabilitation agencies to higher risk of infestation. This brief report outlines practical suggestions for managing bedbug infestation in such agencies. Drawing on resources readily available on the Internet and the experience of Thresholds, a large provider of psychiatric rehabilitation services based in Chicago, this report describes strategies for responding to infestation. Providers need to assume that bedbug infestation is a significant risk and prepare accordingly. Assertive, persistent, and calm response is recommended.
Bawin, Thomas; De Backer, Lara; Dujeu, David; Legrand, Pauline; Caparros Megido, Rudy; Francis, Frédéric; Verheggen, François J.
The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a devastating pest that develops principally on solanaceous plants throughout South and Central America and Europe. In this study, we tested the influence of three levels of T. absoluta infestations on the attraction and oviposition preference of adult T. absoluta. Three infestation levels (i.e., non-infested plants, plants infested with 10 T. absoluta larvae, and plants infested with 20 T. absoluta larvae) were presented by pairs in a flying tunnel to groups of T. absoluta adults. We found no differences in terms of adult attraction for either level of infestations. However, female oviposition choice is influenced by larvae density on tomato plants. We discuss the underlying mechanisms and propose recommendations for further research. PMID:26462946
Barnes, Emily R; Murray, Billie S
I t could happen to anyone. A family is vacationing, and after checking into a hotel the kids and their mother go to bed. A short while later, the husband approaches the bed where his wife is sleeping; he notices something moving on the white sheet near her head. It's an insect. He catches it, places it on a tissue, and logs onto his computer to try to identify it. Soon he realizes it's a bedbug, wakes his wife and children, and calls the front desk. The hotel's pest manager comes up and confirms it: there's a bedbug infestation in the room, and the hotel moves the family to another part of the building.
Villa, José D; Danka, Robert G
Worker honey bees from genetic strains selected for being resistant (R) or susceptible (S) to tracheal mites typically show large differences in infestation in field colonies and in bioassays that involve controlled exposure to infested bees. We used bioassays exposing newly emerged individuals to infested workers to compare the propensity for tracheal mites to infest queens, drones and workers from R and S colonies. In tests with queens, newly emerged R and S queens were either simultaneously confined in infested colonies (n = 95 and 87 respectively), or individually caged with groups of 5-20 infested workers (n = 119 and 115 respectively). Mite prevalence (percentage of individuals infested) and abundance (foundress mites per individual) after 4-6 days did not differ between R and S queens. In another test, five newly emerged drones and workers from both an R and an S colony, and a queen of one of the two strains, were caged in each of 38 cages with 20 g of workers infested at 60-96% prevalence. Infestations of the R queens (n = 17) and S queens (n = 19) did not differ significantly, but R workers had half the mite abundance of S workers, while R drones received about a third more migrating mites than S drones. In tests to evaluate possible mechanisms, removal of one mesothoracic leg from R and S workers resulted in 2- to 10-fold increase in mite abundance on the treated side, but excising legs did not affect infestation of the corresponding tracheae in drones. This suggests that differences in infestation between R and S workers, but not drones, are largely determined by their ability to remove mites through autogrooming. If autogrooming is the primary mechanism of colony resistance to tracheal mites, selection for resistance to tracheal mites using infestation of hemizygous drones may be inefficient.
Li, Yehua; Weldegergis, Berhane T; Chamontri, Surachet; Dicke, Marcel; Gols, Rieta
Attraction of parasitoids to plant volatiles induced by multiple herbivory depends on the specific combinations of attacking herbivore species, especially when their feeding modes activate different defense signalling pathways as has been reported for phloem feeding aphids and tissue feeding caterpillars. We studied the effects of pre-infestation with non-host aphids (Brevicoryne brassicae) for two different time periods on the ability of two parasitoid species to discriminate between volatiles emitted by plants infested by host caterpillars alone and those emitted by plants infested with host caterpillars plus aphids. Using plants originating from three chemically distinct wild cabbage (Brassica oleracea) populations, Diadegma semiclausum switched preference for dually infested plants to preference for plants infested with Plutella xylostella hosts alone when the duration of pre-aphid infestation doubled from 7 to 14 days. Microplitis mediator, a parasitoid of Mamestra brassicae caterpillars, preferred dually-infested plants irrespective of aphid-infestation duration. Separation of the volatile blends emitted by plants infested with hosts plus aphids or with hosts only was poor, based on multivariate statistics. However, emission rates of individual compounds were often reduced in plants infested with aphids plus hosts compared to those emitted by plants infested with hosts alone. This effect depended on host caterpillar species and plant population and was little affected by aphid infestation duration. Thus, the interactive effect of aphids and hosts on plant volatile production and parasitoid attraction can be dynamic and parasitoid specific. The characteristics of the multi-component volatile blends that determine parasitoid attraction are too complex to be deduced from simple correlative statistical analyses.
Pilger, Daniel; Heukelbach, Jorg; Khakban, Adak; Oliveira, Fabiola Araujo; Fengler, Gernot; Feldmeier, Hermann
To generate evidence on the effectiveness of household-wide treatment for preventing the transmission of pediculosis capitis (head lice) in resource-poor communities. We studied 132 children without head lice who lived in a slum in north-eastern Brazil. We randomized the households of the study participants into an intervention and a control group and prospectively calculated the incidence of infestation with head lice among the children in each group. In the intervention group, all of the children's family members who lived in the household were treated with ivermectin; in the control group, no family member was treated. We used the chi(2) test with continuity correction or Fisher's exact test to compare proportions. We performed survival analysis using Kaplan-Meier estimates with log rank testing and the Mann-Whitney U test to analyse the length of lice-free periods among sentinel children, and we used Cox regression to analyse survival data on a multivariate level. We also carried out a subgroup analysis based on gender. Children in the intervention group remained free from infestation with head lice significantly longer than children in the control group. The median infestation-free period in the intervention group was 24 days (interquartile range, IQR: 11-45), as compared to 14 days (IQR: 11-25) in the control group (P = 0.01). Household-wide treatment with ivermectin proved significantly more effective among boys than among girls (P = 0.005). After treatment with ivermectin, the estimated number of annual episodes of head lice infestation was reduced from 19 to 14 in girls and from 15 to 5 in boys. Female sex and extreme poverty were independent risk factors associated with a shortened disease-free period. In an impoverished community, girls and the poorest of the poor are the population groups that are most vulnerable for head lice infestation. To decrease the number of head lice episodes per unit of time, control measures should include the treatment of all
Pilger, Daniel; Heukelbach, Jorg; Khakban, Adak; Oliveira, Fabiola Araujo; Fengler, Gernot
Abstract Objective To generate evidence on the effectiveness of household-wide treatment for preventing the transmission of pediculosis capitis (head lice) in resource-poor communities. Methods We studied 132 children without head lice who lived in a slum in north-eastern Brazil. We randomized the households of the study participants into an intervention and a control group and prospectively calculated the incidence of infestation with head lice among the children in each group. In the intervention group, all of the children’s family members who lived in the household were treated with ivermectin; in the control group, no family member was treated. We used the χ² test with continuity correction or Fisher’s exact test to compare proportions. We performed survival analysis using Kaplan–Meier estimates with log rank testing and the Mann–Whitney U test to analyse the length of lice-free periods among sentinel children, and we used Cox regression to analyse survival data on a multivariate level. We also carried out a subgroup analysis based on gender. Findings Children in the intervention group remained free from infestation with head lice significantly longer than children in the control group. The median infestation-free period in the intervention group was 24 days (interquartile range, IQR: 11–45), as compared to 14 days (IQR: 11–25) in the control group (P = 0.01). Household-wide treatment with ivermectin proved significantly more effective among boys than among girls (P = 0.005). After treatment with ivermectin, the estimated number of annual episodes of head lice infestation was reduced from 19 to 14 in girls and from 15 to 5 in boys. Female sex and extreme poverty were independent risk factors associated with a shortened disease-free period. Conclusion In an impoverished community, girls and the poorest of the poor are the population groups that are most vulnerable for head lice infestation. To decrease the number of head lice episodes per unit of
Duscher, Georg G; Feiler, Andrea; Leschnik, Michael; Joachim, Anja
Effective control of tick infestation and pathogen transmission requires profound knowledge of tick biology in view of their vector function. The particular time of the year when the different tick species start to quest and the favoured sites on the canine host are of major interest. The efficacy of acaricides/repellents to control ticks in the field requires observation. To address these issues, 90 dogs, grouped in "untreated", "acaricide/repellent" (permethrin) and "acaricide only" (fipronil) animals and subjected to tick infestation under natural conditions in Burgenland (Eastern Austria), were examined. The number and species of ticks occurring during and outside the protection time was evaluated during a period of 11 months and the biting location on the dogs' skin was recorded. Of the 700 ticks collected, the most common species in that particular walking area was Ixodes ricinus, followed by Dermacentor reticulatus and Haemaphysalis concinna. Regarding the on-host activity, D. reticulatus displayed more infestations in early spring and late autumn, whereas I. ricinus occurred almost one month later in spring and one month earlier in autumn. H. concinna followed a monophasic pattern of activity with a peak in summer. The preferred feeding sites of the ticks on the dogs were on the head, neck, shoulder and chest. This distribution over the dog's body was not influenced by the use of the drugs, although on the whole fewer ticks (22.5% of all ticks) were found during the protection time. Interestingly, differences occurred with the use of drugs compared to non-protected dogs with regard to the infestation over the year. Acaricide-treated dogs displayed a higher prevalence in April, May and September, whereas dogs of the acaricide/repellent group showed a higher infestation in March, July, October and November. The different tick species display different on-dog activity peaks over the year, during which particular canine diseases can be expected and predicted
Nielsen, K F; Gravesen, S; Nielsen, P A; Andersen, B; Thrane, U; Frisvad, J C
In this study, the ability to produce mycotoxins during growth on artificially infested building materials was investigated for Penicillium chrysogenum, Pen. polonicum, Pen. brevicompactum, Chaetomium spp., Aspergillus ustus, Asp. niger, Ulocladium spp., Alternaria spp., and Paecilomyces spp., all isolated from water-damaged building materials. Spores from the different isolates of the above mentioned species were inoculated on gypsum board with and without wallpaper and on chipboard with and without wallpaper. Fungal material was scraped off the materials, extracted, and analyzed using high performance liquid chromatography-diode array detection and thin layer chromatography. All six isolates of C. globosum produced the toxic chaetoglobosins A and C, at levels of up to 50 and 7 microg/cm2 respectively. The quantities of secondary metabolites produced by Penicillia were generally low, and no toxin production was detected from any of the five isolates of Pen. chrysogenum. Both isolates of Pen. polonicum produced 3-methoxy-viridicatin, verrucosidin, and verrucofortine. Two of five isolates of Pen. brevicompactum produced mycophenolic acid. From five out of six isolates of Alternaria spp., altenariol and alternariol monomethyl ether were detected. From Ulocladium spp., Paecilomyces spp., and Asp. ustus no known mycotoxins were detected, although the latter two are known mycotoxin producers. Asp. niger produced several naphtho-gamma-pyrones and tetra-cyclic compounds. All investigated species, especially Asp. ustus and Asp. niger produced many unknown secondary metabolites on the building materials. Analyses of wallpaper and glass-fibre wallpaper naturally infested with Asp. versicolor revealed sterigmatocystin and 5-methoxysterigmatocystin. Analyses of naturally infested wallpaper showed that C. globosum produced the chaetoglobosins A and C, and Pen. chrysogenum produced the antibiotic meleagrin.
Weerakoon, Kanchana; Li, Suiquing; Shu, Hungjen J.; Chin, Bryan A.
The financial losses and destruction of crops due to insect infestation in the United States are estimated by the USDA to exceed 20 billion dollars annually. Much of these losses could be avoided by having a sensor that could effectively identify the early stages of insect infestation. However, traditional detection methods are time consuming, require trained personnel, and are not sufficient for early detection. Several previous research studies showed that emitting organic volatile compounds is a defensive mechanism activated by some plant species after being attacked by herbivores and parasites. Corn, cotton, pine, Brussels sprouts when attacked by Beet army worm, spider mites, bark beetles and caterpillars respectively, emits different blends of plant volatiles including γ-terpinene, α-pinene, p-cymene, farnesene, limonene and cis-hexenyl acetate, with a concentration of about 50 ppm. Therefore, monitoring for these volatile compounds may enable on-site early detection of insect infestations. In this study, a chemical resistor sensor to detect plant volatiles was designed and fabricated. The sensor platform consists of micro electronically fabricated interdigitated electrodes. On to this platform, a poly3-hexylthiophene (P3HT) thin film was deposited, using a spin coater at 8000 rpm for 30 seconds. The sensor was tested and found to be sensitive to a variety of plant volatiles, including γ-terpinene, α-pinene, p-cymene, farnesene, limonene and cis-hexenyl acetate at room temperature. These vapors interacted with the P3HT film causing an increase in the resistance of the sensor by more than one order of magnitude
Raszeja-Kotelba, Barbara; Jenerowicz, Dorota; Izdebska, Joanna N; Bowszyc-Dmochowska, Monika; Tomczak, Małgorzata; Dembińska, Magdalena
The importance of demodicids (Demodex folliculorum and D. brevis) infestation and their effect on skin lesions has been described based on literature data and our own clinical and parasitological investigations. Hair follicle mites have been detected in 45% of patients with rosacea, 27% of patients with perioral dermatitis, 28% of patients suffering from seborrhoeic dermatitis and in 3 out of 7 patients with chronic blepharitis. Clinical picture of demodecosis included erythemato-papulous and pustulous (rosacea-like) skin lesions together with erythemato-desquamative changes of the face.
Dantas-Torres, Filipe; Oliveira-Filho, Edmilson F; Soares, Fábio Angelo M; Souza, Bruno O F; Valença, Raul Baltazar P; Sá, Fabrício B
Ticks infesting amphibians and reptiles in the State of Pernambuco are reviewed, based on the current literature and new collections recently carried out by the authors. To date, three tick species have been found on amphibians and reptiles in Pernambuco. Amblyomma fuscum appears to be exclusively associated with Boa constrictor, its type host. Amblyomma rotundatum has a relatively low host-specificity, being found on toads, snakes, and iguana. Amblyomma dissimile has been found on a lizard and also small mammals (i.e., rodents and marsupials). New tick-host associations and locality records are given.
Erskine, Sally E; Schelenz, Silke; Philpott, Carl M
We present a case of long-standing unilateral cacosmia in a healthy 67-year-old man due to maxillary fungal infestation. Treatment with septoplasty had been attempted 10 years prior but no further investigation or management undertaken and symptoms continued. Subsequent MRI scan revealed significant opacification of the left maxillary sinus. This was readily amenable to treatment by balloon sinuplasty. This yielded viscous grey mucus which grew Scedosporium apiospermum. The case highlights the need for careful investigation of olfactory symptoms, including blood tests to exclude systemic causes, endoscopy and imaging where indicated. PMID:23563684
Nduka, Jude Chiedu; Mcnair, Rory
A retired man in his 60s was referred to the on call orthopaedic team by his general practitioner following several attempts to extricate a human botfly larva from his forearm. While on holiday in Belize with his daughter 8 weeks previously they both were bitten by some insects. She developed an infestation which was treated locally. Once back in the UK, he subsequently reported of localised itching and discomfort. A botfly larva was successfully removed in the emergency department following local anaesthetic infiltration. 2014 BMJ Publishing Group Ltd.