Body lice and head lice (Anoplura: Pediculidae) have the smallest genomes of any hemimetabolous insect reported to date.

PubMed

Johnston, J Spencer; Yoon, Kyong Sup; Strycharz, Joseph P; Pittendrigh, Barry R; Clark, J Marshall

2007-11-01

The human body louse, Pediculus humanus humanus L. (Anoplura: Pediculidae), is a vector of several diseases, including louse-borne epidemic typhus, relapsing fever, and trench fever, whereas the head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), is more a pest of social concern. Sequencing of the body louse genome has recently been proposed and undertaken by National Human Genome Research Institute. One of the first steps in understanding an organism's genome is to determine its genome size. Here, using flow cytometry determinations, we present evidence that body louse genome size is 104.7 +/- 1.4 Mb for females and 108.3 +/- 1.1 Mb for males. Our results suggest that head lice also have a small genome size, of similar size to the body louse. Thus, Pediculus lice have one of the smallest genome sizes known in insects, suggesting it may be a suitable choice as a minimal hemimetabolous genome.

Pediculosis capitis: new insights into epidemiology, diagnosis and treatment.

PubMed

Feldmeier, H

2012-09-01

Pediculosis capitis is a ubiquitous parasitic skin disease caused by Pediculus humanus capitis. Head lice are highly specialised parasites which can propagate only on human scalp and hair. Transmission occurs by direct head-to-head contact. Head lice are vectors of important bacterial pathogens. Pediculosis capitis usually occurs in small epidemics in play groups, kindergartens and schools. Population-based studies in European countries show highly diverging prevalences, ranging from 1% to 20%. The diagnosis of head lice infestation is made through the visual inspection of hair and scalp or dry/wet combing. The optimal method for the diagnosis of active head lice infestation is dry/wet combing. Topical application of a pediculicide is the most common treatment. Compounds with a neurotoxic mode of action are widely used but are becoming less effective due to resistant parasite populations. Besides, their use is restricted by safety concerns. Dimeticones, silicone oils with a low surface tension and the propensity to perfectly coat surfaces, have a purely physical mode of action. This group of compounds is highly effective and safe, and there is no risk that head lice become resistant. The control of epidemics requires active contact tracing and synchronised treatment with an effective and safe pediculicide.

An incurable itch: head lice.

PubMed

Smith, Christine H; Goldman, Ran D

2012-08-01

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.

Cytogenetic Features of Human Head and Body Lice (Phthiraptera: Pediculidae).

PubMed

Bressa, María José; Papeschi, Alba Graciela; Toloza, Ariel Ceferino

2015-09-01

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: journals.permissions@oup.com.

Treatment of pediculosis capitis infested children with 1% permethrin shampoo in Turkey.

PubMed

Yazar, Suleyman; Sahin, Izzet

2005-10-01

Pediculosis capitis (head lice) is an infestation that affects many children. Although, there are a number of different treatment modalities, at the present study, we investigated the efficacy of permethrin in the treatment of pediculosis capitis in children. This study was carried out in 3 village primary schools in the Kayseri region involving 185 of 712 school children infested with Pediculus humanus capitis during a survey conducted in March 2001. It was found that 173 (97.29%) of the 178 students who applied the prescribed medications were cured, indicating that interestingly 1% permethrin shampoo (Kwellada) is an effective and safe treatment choice for pediculosis capitis.

The mitochondrial genome of the chimpanzee louse, Pediculus schaeffi: insights into the process of mitochondrial genome fragmentation in the blood-sucking lice of great apes.

PubMed

Herd, Kate E; Barker, Stephen C; Shao, Renfu

2015-09-03

Blood-sucking lice in the genera Pediculus and Pthirus are obligate ectoparasites of great apes. Unlike most bilateral animals, which have 37 mitochondrial (mt) genes on a single circular chromosome, the sucking lice of humans have extensively fragmented mt genomes. The head louse, Pediculus capitis, and the body louse, Pe. humanus, have their 37 mt genes on 20 minichromosomes. The pubic louse, Pthirus pubis, has its 34 mt genes known on 14 minichromosomes. To understand the process of mt genome fragmentation in the sucking lice of great apes, we sequenced the mt genome of the chimpanzee louse, Pe. schaeffi, and compared it with the three human lice. We identified all of the 37 mt genes typical of bilateral animals in the chimpanzee louse; these genes are on 18 types of minichromosomes. Seventeen of the 18 minichromosomes of the chimpanzee louse have the same gene content and gene arrangement as their counterparts in the human head louse and the human body louse. However, five genes, cob, trnS 1 , trnN, trnE and trnM, which are on three minichromosomes in the human head louse and the human body louse, are together on one minichromosome in the chimpanzee louse. Using the human pubic louse, Pt. pubis, as an outgroup for comparison, we infer that a single minichromosome has fragmented into three in the lineage leading to the human head louse and the human body louse since this lineage diverged from the chimpanzee louse ~6 million years ago. Our results provide insights into the process of mt genome fragmentation in the sucking lice in a relatively fine evolutionary scale.

In vitro pediculicidal activity of herbal shampoo base on Thai local plants against head louse (Pediculus humanus capitis De Geer).

PubMed

Rassami, Watcharawit; Soonwera, Mayura

2013-04-01

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.

[The Distribution of Pediculus humanus capitis Among Primary School Pupils of the Turkish Chamber of Commerce and Stock Exchange Organisation in Van].

PubMed

Karaaslan, Selver; Yılmaz, Hasan

2015-03-01

This study was performed in order to study the prevalence of Pediculus humanus capitis (P. h. capitis). The study was carried out on pupils between 5-15 years old in a school and kindergarden belonging to the Turkish Chamber of Commerce and Stock Exchange Organization in Van City between November-December 2007. The hair of 863 pupils (especially the neck and the back of head areas), 385 girls and 478 boys, were examined for eggs, nymphs and adults of P. h. capitis. A questionnaire was given to the pupils, which was collected the following day. Lice and their eggs/nits, which were removed from the head of children were transferred to a bottle containing 5% glycerin in 70% ethyl alcohol. Later they were sent to the Parasitology Laboratory of the Health Research and Training Hospital of Yüzüncü Yıl University. Eggs/nits were found in 164 (42.6%) of the girls and in 34 (7.1%) of the boys (overall 198 (22.9%) infested pupils). The prevalence of P. h. capitis was high, especially in girls. The infestation rates observed and the evaluation of the questionnaire showed that there is a statistically significant relationships between pediculosis capitis and sex, level of family income, education level of the mother, number of baths taken per weekly, number of family members living in the same home, room number per capita, and hair length (p<0.001). However, there was no significant relationship between pediculosis capitis and cleaning materials used to wash the head (p>0.05).

Contact and fumigant toxicity of hexane flower bud extract of Syzygium aromaticum and its compounds against Pediculus humanus capitis (Phthiraptera: Pediculidae).

PubMed

Bagavan, Asokan; Rahuman, Abdul Abdul; Kamaraj, Chinnaperumal; Elango, Gandhi; Zahir, Abdul Abduz; Jayaseelan, Chidambaram; Santhoshkumar, Thirunavukkarasu; Marimuthu, Sampath

2011-11-01

The head lice, Pediculus humanus capitis De Geer is an obligate ectoparasite of humans that causes pediculosis capitis, a nuisance for millions of people worldwide, with high prevalence in children. P. humanus capitis has been treated by methods that include the physical remotion of lice, various domestic treatments, and conventional insecticides. None of these methods render complete protection, and there is clear evidence for the evolution of resistance and cross-resistance to conventional insecticides. Non-toxic alternative options are hence needed for head lice treatment and/or prevention, and natural products from plants are good candidates for safer control agents that may provide good anti-lice activity. The plant extracts are good and safe alternatives due to their low toxicity to mammals and easy biodegradability. The present study carried out the pediculocidal activity using the hexane flower bud extract of Syzygium aromaticum (Myrtaceae) against P. humanus capitis examined by direct contact and fumigant toxicity (closed- and open-container methods) bioassay. The chemical composition of S. aromaticum flower bud hexane extract was analyzed by gas chromatography-mass spectrometry. The major chemical constituent (58.79%) of flower bud hexane extract S. aromaticum was identified as chavibetol (5-allyl-2-methoxyphenol) by comparison of mass spectral data and retention times. The hexane extract of S. aromaticum was subjected to gas chromatography analysis, and totally 47 compounds were detected, of which chavibetol was predominantly present. The other major constituents present in the hexane extract were eugenol acetate (phenol,2-methoxy-4-(2-propenyl)-,acetate (15.09%), caryophyllene-(I1) (2,6,10,10-tetramethyl bicyclo [7.2.0] undeca-1,6-diene (13.75%), caryophyllene oxide (3.04%), 2,6,6,9-tetramethyl-1,4,8-cycloundecatriene (1.67%), and copaene (1.33%). The filter paper contact bioassay study showed pronounced pediculicidal activity in the flower bud hexane

[Understanding mitochondrial genome fragmentation in parasitic lice (Insecta: Phthiraptera)].

PubMed

Dong, Wen-Ge; Guo, Xian-Guo; Jin, Dao-Chao; Xue, Shi-Peng; Qin, Feng; Simon, Song; Stephen, C Barker; Renfu, Shao

2013-07-01

Lice are obligate ectoparasites of mammals and birds. Extensive fragmentation of mitochondrial genomes has been found in some louse species in the families Pediculidae, Pthiridae, Philopteridae and Trichodectidae. For example, the mt genomes of human body louse (Pediculus humanus), head louse (Pediculus capitis), and public louse (Pthirus pubis) have 20, 20 and 14 mini-chromosomes, respectively. These mini-chromosomes might be the results of deletion and recombination of mt genes. The factors and mechanisms of mitochondrial genome fragmentation are currently unknown. The fragmentation might be the results of evolutionary selection or random genetic drift or it is probably related to the lack of mtSSB (mitochondrial single-strand DNA binding protein). Understanding the fragmentation of mitochondrial genomes is of significance for understanding the origin and evolution of mitochondria. This paper reviews the recent advances in the studies of mito-chondrial genome fragmentation in lice, including the phenomena of mitochondrial genome fragmentation, characteristics of fragmented mitochondrial genomes, and some factors and mechanisms possibly leading to the mitochondrial genome fragmentation of lice. Perspectives for future studies on fragmented mt genomes are also discussed.

Genotyping of human lice suggests multiple emergencies of body lice from local head louse populations.

PubMed

Li, Wenjun; Ortiz, Gabriel; Fournier, Pierre-Edouard; Gimenez, Gregory; Reed, David L; Pittendrigh, Barry; Raoult, Didier

2010-03-23

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

Genotyping of Human Lice Suggests Multiple Emergences of Body Lice from Local Head Louse Populations

PubMed Central

Li, Wenjun; Ortiz, Gabriel; Fournier, Pierre-Edouard; Gimenez, Gregory; Reed, David L.; Pittendrigh, Barry; Raoult, Didier

2010-01-01

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

Molecular Survey of Head and Body Lice, Pediculus humanus, in France.

PubMed

Candy, Kerdalidec; Amanzougaghene, Nadia; Izri, Arezki; Brun, Sophie; Durand, Rémy; Louni, Meriem; Raoult, Didier; Fenollar, Florence; Mediannikov, Oleg

2018-05-01

Human lice, Pediculus humanus, are obligate blood-sucking parasites. Phylogenetically, they belong to several mitochondrial clades exhibiting some geographic differences. Currently, the body louse is the only recognized disease vector, with the head louse being proposed as an additional vector. In this article, we study the genetic diversity of head and body lice collected from Bobigny, a town located close to Paris (France), and look for louse-borne pathogens. By amplifying and sequencing the cytb gene, we confirmed the presence of clades A and B in France. Besides, by amplifying and sequencing both cytb and cox1 gene, we reported, for the first time, the presence of clade E, which has thus far only been found in lice from West Africa. DNA from Bartonella quintana was detected in 16.7% of body lice from homeless individuals, but in none of the head lice collected from 47 families. Acinetobacter DNA was detected in 11.5% of head lice belonging to all three clades and 29.1% of body lice. Six species of Acinetobacter were identified, including two potential new ones. Acinetobacter baumannii was the most prevalent, followed by Candidatus Acinetobacter Bobigny-1, Acinetobacter calcoaceticus, Acinetobacter nosocomialis, Acinetobacter junii, and Candidatus Acinetobacter Bobigny-2. Body lice were found to be infected only with A. baumannii. These findings show for the first time, the presence of clade E head lice in France. This study is also the first to report the presence of DNAs of several species of Acinetobacter in human head lice in France.

Lethal effects of treatment with a special dimeticone formula on head lice and house crickets (Orthoptera, Ensifera: Acheta domestica and Anoplura, phthiraptera: Pediculus humanus). Insights into physical mechanisms.

PubMed

Richling, Ira; Böckeler, Wolfgang

2008-01-01

The present study provides the first convincing explanation of the mode of action of the medical device NYDA, a special dimeticone (CAS 9006-65-9) formula containing 92% of two dimeticones with different viscosities specifically designed for the physical treatment of head lice infestations (pediculosis capitis) by suffocation. Both, lice (Pediculus humanus) and house crickets (Acheta domestica) treated with this anti-head lice product are knocked out to the status "of no major vital signs" within less than 1 min that in consequence is accompanied irreversibly with the death of the respective insects. Scanning electron microscopical investigations have revealed that the cuticle is coated by a thin closed layer of the dimeticone formula that also enters the stigmata. In vivo observations and dissections of Acheta domestica have shown that application of the medical device to the thoracic stigmata invariably leads to rapid death; this is strongly correlated with the influx of the special dimeticone formula into the head trachea, whereby the solution effectively blocks the oxygen supply of the central nervous system. Dissections after application of the stained product show that it also enters the finest tracheal branches. Analogous in vivo observations in Pediculus humanus have confirmed the correlation between the disappearance of major vital signs and the displacement of air by the dimeticone formula in the tracheal system of the head. For both insect species, statistical data are provided for the chronological sequence of the filling of the tracheal system in relation to the respective vitality conditions of the Insects. On average, the special dimeticone formula reaches the insect's head tracheae within 0.5 min in house crickets and in less than 1 min in lice with a complete filling of the entire head tracheal system of lice within 3.5 min. In addition, a timed sequence of images illustrates this process for lice. The experiments clearly reveal the exclusive and

Safety, Efficacy, and Physicochemical Characterization of Tinospora crispa Ointment: A Community-Based Formulation against Pediculus humanus capitis

PubMed Central

Torre, Gerwin Louis Tapan Dela; Ponsaran, Kerstin Mariae Gonzales; de Guzman, Angelica Louise Dela Peña; Manalo, Richelle Ann Mallapre; Arollado, Erna Custodio

2017-01-01

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of 6.92±0.09. It has spreadability value of 15.04±0.98 g·cm/sec and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control Kwell®, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I. PMID:28877572

Molecular Markers of Pesticide Resistance and Pathogens in Human Head Lice (Phthiraptera: Pediculidae) From Rural Georgia, USA.

PubMed

Eremeeva, Marina E; Capps, Danielle; Winful, Emmanuel B; Warang, Shamta S; Braswell, Sarah E; Tokarevich, Nikolay K; Bonilla, Denise L; Durden, Lance A

2017-07-01

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: journals.permissions@oup.com.

In Vitro Screening of Anti-lice Activity of Pongamia pinnata Leaves

PubMed Central

Radhamani, Suraj; Gopinath, Rejitha; Kalusalingam, Anandarajagopal; Vimala, Anita Gnana Kumari Anbumani; Husain, Hj Azman

2009-01-01

Growing patterns of pediculocidal drug resistance towards head louse laid the foundation for research in exploring novel anti-lice agents from medicinal plants. In the present study, various extracts of Pongamia pinnata leaves were tested against the head louse Pediculus humanus capitis. A filter paper diffusion method was conducted for determining the potential pediculocidal and ovicidal activity of chloroform, petroleum ether, methanol, and water extracts of P. pinnata leaves. The findings revealed that petroleum ether extracts possess excellent anti-lice activity with values ranging between 50.3% and 100% where as chloroform and methanol extracts showed moderate pediculocidal effects. The chloroform and methanol extracts were also successful in inhibiting nymph emergence and the petroleum ether extract was the most effective with a complete inhibition of emergence. Water extract was devoid of both pediculocidal and ovicidal activities. All the results were well comparable with benzoyl benzoate (25% w/v). These results showed the prospect of using P. pinnata leave extracts against P. humanus capitis in difficult situations of emergence of resistance to synthetic anti-lice agents. PMID:19967085

Comparison of the humoral and cellular immune responses between body and head lice following bacterial challenge.

PubMed

Kim, Ju Hyeon; Min, Jee Sun; Kang, Jae Soon; Kwon, Deok Ho; Yoon, Kyong Sup; Strycharz, Joseph; Koh, Young Ho; Pittendrigh, Barry Robert; Clark, J Marshall; Lee, Si Hyeock

2011-05-01

The differences in the immune response between body lice, Pediculus humanus humanus, and head lice, Pediculus humanus capitis, were investigated initially by measuring the proliferation rates of two model bacteria, a Gram-positive Staphylococcus aureus and a Gram-negative Escherichia coli, following challenge by injection. Body lice showed a significantly reduced immune response compared to head lice particularly to E. coli at the early stage of the immune challenge. Annotation of the body louse genome identified substantially fewer immune-related genes compared with other insects. Nevertheless, all required genetic components of the major immune pathways, except for the immune deficiency (Imd) pathway, are still retained in the body louse genome. Transcriptional profiling of representative genes involved in the humoral immune response, following bacterial challenge, revealed that both body and head lice, regardless of their developmental stages, exhibited an increased immune response to S. aureus but little to E. coli. Head lice, however, exhibited a significantly higher phagocytotic activity against E. coli than body lice, whereas the phagocytosis against S. aureus differed only slightly between body and head lice. These findings suggest that the greater immune response in head lice against E. coli is largely due to enhanced phagocytosis and not due to differences in the humoral immune response. The reduced phagocytotic activity in body lice could be responsible, in part, for their increased vector competence. Copyright © 2011 Elsevier Ltd. All rights reserved.

Of lice and math: using models to understand and control populations of head lice.

PubMed

Laguna, María Fabiana; Laguna, Mara Fabiana; Risau-Gusman, Sebastián

2011-01-01

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.

Efficacy and safety of spinosad and permethrin creme rinses for pediculosis capitis (head lice).

PubMed

Stough, Dow; Shellabarger, Susan; Quiring, John; Gabrielsen, Alvin A

2009-09-01

Studies compared spinosad creme rinse and permethrin lice treatment under "actual-use" conditions for pediculosis capitis (head lice). Two phase-3, multicenter, randomized, evaluator/investigator-blinded studies compared 0.9% spinosad without nit-combing to 1% permethrin with combing (according to product instructions) in 1038 males and females aged > or =6 months. Spinosad-with-combing groups were included for descriptive, noninferential purposes only. Within 391 households, youngest members having > or =3 live lice were designated primary participants. All household members with lice received the same treatment. Participants administered product 1 to 2 times during the 21-day home-use period on the basis of complete lice eradication after a single use or the presence of lice requiring a second treatment. Scalp evaluations were performed at baseline, day 7, and day 14 (and day 21 for participants treated twice). The primary end point was the proportion of lice-free primary participants 14 days after last treatment. A total of 84.6% (study 1) and 86.7% (study 2) of spinosad-treated participants were lice free versus 44.9% and 42.9% permethrin-treated participants (P < .001). Most spinosad-treated participants required 1 application, whereas most permethrin-treated participants required 2 applications. Few adverse events were reported, but those occurring were mild to moderate, including eye irritation (permethrin), ocular hyperemia, and application-site erythema/irritation (both medications). No laboratory measure changed significantly. Spinosad, which did not require nit combing, was significantly more effective than permethrin in 2 studies reflecting actual-use conditions, and most spinosad-treated participants required only 1 application. Spinosad is a more convenient and effective treatment for pediculosis capitis.

Do drowning and anoxia kill head lice?

PubMed

Candy, Kerdalidec; Brun, Sophie; Nicolas, Patrick; Durand, Rémy; Charrel, Remi N; Izri, Arezki

2018-01-01

Chemical, physical, and mechanical methods are used to control human lice. Attempts have been made to eradicate head lice Pediculus humanus capitis by hot air, soaking in various fluids or asphyxiation using occlusive treatments. In this study, we assessed the maximum time that head lice can survive anoxia (oxygen deprivation) and their ability to survive prolonged water immersion. We also observed the ingress of fluids across louse tracheae and spiracle characteristics contrasting with those described in the literature. We showed that 100% of lice can withstand 8 h of anoxia and 12.2% survived 14 h of anoxia; survival was 48.9% in the untreated control group at 14 h. However, all lice had died following 16 h of anoxia. In contrast, the survival rate of water-immersed lice was significantly higher when compared with non-immersed lice after 6 h (100% vs. 76.6%, p = 0.0037), and 24 h (50.9% vs. 15.9%, p = 0.0003). Although water-immersed lice did not close their spiracles, water did not penetrate into the respiratory system. In contrast, immersion in colored dimeticone/cyclomethicone or colored ethanol resulted in penetration through the spiracles and spreading to the entire respiratory system within 30 min, leading to death in 100% of the lice. © K. Candy et al., published by EDP Sciences, 2018.

Efficacy of the LouseBuster, a new medical device for treating head lice (Anoplura:Pediculidae).

PubMed

Bush, Sarah E; Rock, Alex N; Jones, Sherri L; Malenke, Jael R; Clayton, Dale H

2011-01-01

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.

Of Lice and Math: Using Models to Understand and Control Populations of Head Lice

PubMed Central

Laguna, Mara Fabiana; Risau-Gusman, Sebastián

2011-01-01

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

The mode of action of dimeticone 4% lotion against head lice, Pediculus capitis

PubMed Central

Burgess, Ian F

2009-01-01

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

A ghost covered in lice: a case of severe blood loss with long-standing heavy pediculosis capitis infestation.

PubMed

Hau, Veronica; Muhi-Iddin, Nadia

2014-12-19

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.

Ivermectin lipid-based nanocarriers as novel formulations against head lice.

PubMed

Ullio-Gamboa, Gabriela; Palma, Santiago; Benoit, Jean Pierre; Allemandi, Daniel; Picollo, María Inés; Toloza, Ariel Ceferino

2017-08-01

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 KT 50 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.

Comparative efficacy of commercial combs in removing head lice (Pediculus humanus capitis) (Phthiraptera: Pediculidae).

PubMed

Gallardo, Anabella; Toloza, Ariel; Vassena, Claudia; Picollo, María Inés; Mougabure-Cueto, Gastón

2013-03-01

The use of a fine comb for removing lice from the head of the human host is a relevant tool both in the diagnosis of infestations and as part of an integrated control strategy of head lice. The effectiveness of a fine comb depends, in part, on the design and material they are built. The aim of this study was to compare in vivo the efficacy of metal and plastic combs that are currently used in the removal of head lice and eggs worldwide. The space between comb teeth and the length was 0.23 and 13 mm in KSL® plastic, 0.3 and 10.7 mm in NOPUCID® plastic, 0.15 and 31 mm in KSL® metal and 0.09 and 37 mm in ASSY® metal. The assays were performed comparing the combs in pairs: (a) KSL® vs. NOPUCID® plastic combs, (b) KSL® vs. ASSY® metal combs and (c) KSL® plastic comb vs. ASSY® metal comb. The most effective plastic comb was KSL®, removing a higher number of individuals of all stages. The most effective metal comb was ASSY®, removing more insects of all stages (except adults). The comparative test between KSL® plastic and ASSY® metal showed that ASSY® was the most effective in removing head lice and their eggs.

Identification and characterization of an esterase involved in malathion resistance in the head louse Pediculus humanus capitis.

PubMed

Kwon, Deok Ho; Kim, Ju Hyeon; Kim, Young Ho; Yoon, Kyong Sup; Clark, J Marshall; Lee, Si Hyeock

2014-06-01

Enhanced malathion carboxylesterase (MCE) activity was previously reported to be involved in malathion resistance in the head louse Pediculus humanus capitis (Gao et al., 2006 [8]). To identify MCE, the transcriptional profiles of all five esterases that had been annotated to be catalytically active were determined and compared between the malathion-resistant (BR-HL) and malathion-susceptible (KR-HL) strains of head lice. An esterase gene, designated HLCbE3, exhibited approximately 5.4-fold higher transcription levels, whereas remaining four esterases did not exhibit a significant increase in their transcription in BR-HL, indicating that HLCbE3 may be the putative MCE. Comparison of the entire cDNA sequences of HLCbE3 revealed no sequence differences between the BR-HL and KR-HL strains and suggested that no single nucleotide polymorphism is associated with enhanced MCE activity. Two copies of the HLCbE3 gene were observed in BR-HL, implying that the over-transcription of HLCbE3 is due to the combination of a gene duplication and up-regulated transcription. Knockdown of HLCbE3 expression by RNA interference in the BR-HL strain led to increases in malathion susceptibility, confirming the identity of HLCbE3 as a MCE responsible for malathion resistance in the head louse. Phylogenetic analysis suggested that HLCbE3 is a typical dietary esterase and belongs to a clade containing various MCEs involved in malathion resistance. Copyright © 2014 Elsevier Inc. All rights reserved.

Heteroplasmy in the Mitochondrial Genomes of Human Lice and Ticks Revealed by High Throughput Sequencing

PubMed Central

Xiong, Haoyu; Barker, Stephen C.; Burger, Thomas D.; Raoult, Didier; Shao, Renfu

2013-01-01

The typical mitochondrial (mt) genomes of bilateral animals consist of 37 genes on a single circular chromosome. The mt genomes of the human body louse, Pediculus humanus, and the human head louse, Pediculus capitis, however, are extensively fragmented and contain 20 minichromosomes, with one to three genes on each minichromosome. Heteroplasmy, i.e. nucleotide polymorphisms in the mt genome within individuals, has been shown to be significantly higher in the mt cox1 gene of human lice than in humans and other animals that have the typical mt genomes. To understand whether the extent of heteroplasmy in human lice is associated with mt genome fragmentation, we sequenced the entire coding regions of all of the mt minichromosomes of six human body lice and six human head lice from Ethiopia, China and France with an Illumina HiSeq platform. For comparison, we also sequenced the entire coding regions of the mt genomes of seven species of ticks, which have the typical mitochondrial genome organization of bilateral animals. We found that the level of heteroplasmy varies significantly both among the human lice and among the ticks. The human lice from Ethiopia have significantly higher level of heteroplasmy than those from China and France (Pt<0.05). The tick, Amblyomma cajennense, has significantly higher level of heteroplasmy than other ticks (Pt<0.05). Our results indicate that heteroplasmy level can be substantially variable within a species and among closely related species, and does not appear to be determined by single factors such as genome fragmentation. PMID:24058467

Heteroplasmy in the mitochondrial genomes of human lice and ticks revealed by high throughput sequencing.

PubMed

Xiong, Haoyu; Barker, Stephen C; Burger, Thomas D; Raoult, Didier; Shao, Renfu

2013-01-01

The typical mitochondrial (mt) genomes of bilateral animals consist of 37 genes on a single circular chromosome. The mt genomes of the human body louse, Pediculus humanus, and the human head louse, Pediculus capitis, however, are extensively fragmented and contain 20 minichromosomes, with one to three genes on each minichromosome. Heteroplasmy, i.e. nucleotide polymorphisms in the mt genome within individuals, has been shown to be significantly higher in the mt cox1 gene of human lice than in humans and other animals that have the typical mt genomes. To understand whether the extent of heteroplasmy in human lice is associated with mt genome fragmentation, we sequenced the entire coding regions of all of the mt minichromosomes of six human body lice and six human head lice from Ethiopia, China and France with an Illumina HiSeq platform. For comparison, we also sequenced the entire coding regions of the mt genomes of seven species of ticks, which have the typical mitochondrial genome organization of bilateral animals. We found that the level of heteroplasmy varies significantly both among the human lice and among the ticks. The human lice from Ethiopia have significantly higher level of heteroplasmy than those from China and France (Pt<0.05). The tick, Amblyomma cajennense, has significantly higher level of heteroplasmy than other ticks (Pt<0.05). Our results indicate that heteroplasmy level can be substantially variable within a species and among closely related species, and does not appear to be determined by single factors such as genome fragmentation.

The unusual reproductive system of head and body lice (Pediculus humanus)

PubMed Central

ANDREWES, S.; CLARK, J. M.; ROSS, L.

2017-01-01

Abstract Insect reproduction is extremely variable, but the implications of alternative genetic systems are often overlooked in studies on the evolution of insecticide resistance. Both ecotypes of Pediculus humanus (Phthiraptera: Pediculidae), the human head and body lice, are human ectoparasites, the control of which is challenged by the recent spread of resistance alleles. The present study conclusively establishes for the first time that both head and body lice reproduce through paternal genome elimination (PGE), an unusual genetic system in which males transmit only their maternally derived chromosomes. Here, we investigate inheritance patterns of parental genomes using a genotyping approach across families of both ecotypes and show that heterozygous males exclusively or preferentially pass on one allele only, whereas females transmit both in a Mendelian fashion. We do however observe occasional transmission of paternal chromosomes through males, representing the first known case of PGE in which whole‐genome meiotic drive is incomplete. Finally, we discuss the potential implications of this finding for the evolution of resistance and invite the development of new theoretical models of how this knowledge might contribute to increasing the success of pediculicide‐based management schemes. PMID:29266297

In vitro efficacy of synthetic skin repellent IR3535 on head lice (Pediculus capitis).

PubMed

Rupes, Vaclav; Vlckova, Jana; Kollarova, Helena; Horakova, Dagmar; Mazanek, Libor; Kensa, Michal

2013-10-01

In in vitro tests, skin repellent IR3535, applied in the form of the Diffusil H Prevental product in an aerosol bomb (active compound 20%), killed 100% of head lice (females and males) and nymphs 2 and 3, when directly sprayed at a dose of 0.94 mg of the active compound per square centimeter. Crawling lice exposed for 1 min on the filter paper impregnated by the same concentration showed no effort to suck blood 30 min after exposition. Twenty hours later, their mortality rate was 11 %. After the lice had been exposed for approximately 1 min (until they actively left the area) on 5 cm round areas of skin of test persons treated with the repellent at a mean total dose of 23.3 mg of active compound, they showed no effort to suck blood on the clean skin of other test person either immediately after exposure or 30 min later. Their mortality after 20 h ranged from 59 to 16%, depending on the time elapsed from skin treatment (10 min to 27 h).

A preliminary pilot survey on head lice, pediculosis in Sharkia Governorate and treatment of lice with natural plant extracts.

PubMed

El-Basheir, Zeinab M; Fouad, Mahmoud A H

2002-12-01

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%).

Acute poisoning in a child following topical treatment of head lice (pediculosis capitis) with an organophosphate pesticide.

PubMed

Hamad, Muddathir H; Adeel, Ahmed Awad; Alhaboob, Ali Abdu N; Ashri, Ahmed M; Salih, Mustafa A

2016-01-01

This is a case report of acute organophosphate poisoning in a child treated with topical application of Diazinon-60 (WHO Class II toxicity) for head lice (pediculosis capitis). The patient presented with neurological symptoms and signs. After emergency respiratory and circulatory resuscitation the patient underwent dermal decontamination and was treated with atropine, high flow oxygen and pralidoxime. Scanning electron micrographs of scalp hair specimens revealed both viable and empty head lice nits (lice eggs that attach to the hair shaft). The patient was hospitalized for seven days and discharged after full recovery. The case highlights the importance of raising the awareness of health workers and the community about the danger of misusing pesticides for the treatment of head lice.

'Royal' pediculosis in Renaissance Italy: lice in the mummy of the King of Naples Ferdinand II of Aragon (1467-1496).

PubMed

Fornaciari, Gino; Giuffra, Valentina; Marinozzi, Silvia; Picchi, Malayka Samantha; Masetti, Massimo

2009-07-01

Pediculosis seems to have afflicted humans since the most ancient times and lice have been found in several ancient human remains. Examination of the head hair and pubic hair of the artificial mummy of Ferdinand II of Aragon (1467-1496), King of Naples, revealed a double infestation with two different species of lice, Pediculus capitis, the head louse, and Pthirus pubis, the pubic louse. The hair samples were also positive for the presence of mercury, probably applied as an anti-pediculosis therapy. This is the first time that these parasites have been found in the hair of a king, demonstrating that even members of the wealthy classes in the Renaissance were subject to louse infestation.

The unusual reproductive system of head and body lice (Pediculus humanus).

PubMed

DE LA Filia, A G; Andrewes, S; Clark, J M; Ross, L

2018-06-01

Insect reproduction is extremely variable, but the implications of alternative genetic systems are often overlooked in studies on the evolution of insecticide resistance. Both ecotypes of Pediculus humanus (Phthiraptera: Pediculidae), the human head and body lice, are human ectoparasites, the control of which is challenged by the recent spread of resistance alleles. The present study conclusively establishes for the first time that both head and body lice reproduce through paternal genome elimination (PGE), an unusual genetic system in which males transmit only their maternally derived chromosomes. Here, we investigate inheritance patterns of parental genomes using a genotyping approach across families of both ecotypes and show that heterozygous males exclusively or preferentially pass on one allele only, whereas females transmit both in a Mendelian fashion. We do however observe occasional transmission of paternal chromosomes through males, representing the first known case of PGE in which whole-genome meiotic drive is incomplete. Finally, we discuss the potential implications of this finding for the evolution of resistance and invite the development of new theoretical models of how this knowledge might contribute to increasing the success of pediculicide-based management schemes. © 2017 The Authors. Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society.

Head lice

MedlinePlus

Pediculosis capitis - head lice ... Head lice infect hair on the head. Tiny eggs on the hair look like flakes of dandruff . However, ... flaking off the scalp, they stay in place. Head lice can live up to 30 days on a ...

Hemocytes from Pediculus humanus humanus are hosts for human bacterial pathogens

PubMed Central

Coulaud, Pierre-Julien; Lepolard, Catherine; Bechah, Yassina; Berenger, Jean-Michel; Raoult, Didier; Ghigo, Eric

2015-01-01

Pediculus humanus humanus is an human ectoparasite which represents a serious public health threat because it is vector for pathogenic bacteria. It is important to understand and identify where bacteria reside in human body lice to define new strategies to counterstroke the capacity of vectorization of the bacterial pathogens by body lice. It is known that phagocytes from vertebrates can be hosts or reservoirs for several microbes. Therefore, we wondered if Pediculus humanus humanus phagocytes could hide pathogens. In this study, we characterized the phagocytes from Pediculus humanus humanus and evaluated their contribution as hosts for human pathogens such as Rickettsia prowazekii, Bartonella Quintana, and Acinetobacter baumannii. PMID:25688336

Sequencing of a new target genome: the Pediculus humanus humanus (Phthiraptera: Pediculidae) genome project.

PubMed

Pittendrigh, B R; Clark, J M; Johnston, J S; Lee, S H; Romero-Severson, J; Dasch, G A

2006-11-01

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.

Resistance and the control of lice on humans and production animals.

PubMed

Levot, G

2000-03-01

Phthiraptera (lice) are specialised insects adapted to parasitise many warm-blooded vertebrates, including domestic animals and humans. Often, attempts by the host to alleviate the irritation created by lice, causes derangement of the hair/fur coat. Unless treated, this derangement may cause economic losses due to hide damage and/or downgrading of wool/hair/fur. In 1981, application of aqueous insecticide solutions (dipping) for the control of sheep body lice (Bovicola ovis) was largely superseded by off-shears pyrethroid "pour-on" treatments. By 1985, several field failures with these products were found to be due to low-level (20x) insecticide resistance. In 1990, high-level (640x) resistance was diagnosed in a New South Wales population. However, despite 30+years use, organophosphate-based products are still usually effective. Until recently, cattle lice caused little concern. Treatments were applied mainly for aesthetic reasons when cattle were to be presented for sale, and also to prevent damage to fences by rubbing cattle. However, the introduction of quality-management programmes have raised awareness of the economic losses due to hide damage associated with lice infestations. Emerging industries such as emu and alpaca farming have raised the pest status of other louse species, and necessitated insecticidal intervention. In humans, attempts to control head lice, Pediculus humanus capitis, infestations have repeatedly failed around the world.

Detection of bacterial pathogens including potential new species in human head lice from Mali.

PubMed

Amanzougaghene, Nadia; Fenollar, Florence; Sangaré, Abdoul Karim; Sissoko, Mahamadou S; Doumbo, Ogobara K; Raoult, Didier; Mediannikov, Oleg

2017-01-01

In poor African countries, where no medical and biological facilities are available, the identification of potential emerging pathogens of concern at an early stage is challenging. Head lice, Pediculus humanus capitis, have a short life, feed only on human blood and do not transmit pathogens to their progeny. They are, therefore, a perfect tool for the xenodiagnosis of current or recent human infection. This study assessed the occurrence of bacterial pathogens from head lice collected in two rural villages from Mali, where a high frequency of head lice infestation had previously been reported, using molecular methods. Results show that all 600 head lice, collected from 117 individuals, belonged to clade E, specific to West Africa. Bartonella quintana, the causative agent of trench fever, was identified in three of the 600 (0.5%) head lice studied. Our study also shows, for the first time, the presence of the DNA of two pathogenic bacteria, namely Coxiella burnetii (5.1%) and Rickettsia aeschlimannii (0.6%), detected in human head lice, as well as the DNA of potential new species from the Anaplasma and Ehrlichia genera of unknown pathogenicity. The finding of several Malian head lice infected with B. quintana, C. burnetii, R. aeschlimannii, Anaplasma and Ehrlichia is alarming and highlights the need for active survey programs to define the public health consequences of the detection of these emerging bacterial pathogens in human head lice.

DNA detection rates of host mtDNA in bloodmeals of human body lice (Pediculus humanus L., 1758).

PubMed

Davey, J S; Casey, C S; Burgess, I F; Cable, J

2007-09-01

Using polymerase chain reaction, we investigated the extent to which digestion affects the potential to amplify 12S mitochondrial DNA sequences from bloodmeals of individual human body lice (Pediculus humanus L.) (Phthiraptera, Pediculidae) up to 72 h after feeding on a surrogate rabbit host (Oryctolagus cuniculus L.) (Lagomorpha, Leporidae). Two rabbit-specific primer pairs were developed to produce amplicons of 199 bp and 283 bp, the smaller of which was found to have a significantly slower decay rate. Median detection periods (T50) for the amplicons were 20 h and 12 h, with maximum detection periods of 24 h and 12 h, respectively, suggesting an inversely proportional linear relationship between amplicon size and digestion time. The data provide an indication of timeframes essential for the design of forensic sampling protocols and a basis for investigating the feeding frequency of human lice.

Second-generation sequencing of entire mitochondrial coding-regions (∼15.4 kb) holds promise for study of the phylogeny and taxonomy of human body lice and head lice.

PubMed

Xiong, H; Campelo, D; Pollack, R J; Raoult, D; Shao, R; Alem, M; Ali, J; Bilcha, K; Barker, S C

2014-08-01

The Illumina Hiseq platform was used to sequence the entire mitochondrial coding-regions of 20 body lice, Pediculus humanus Linnaeus, and head lice, P. capitis De Geer (Phthiraptera: Pediculidae), from eight towns and cities in five countries: Ethiopia, France, China, Australia and the U.S.A. These data (∼310 kb) were used to see how much more informative entire mitochondrial coding-region sequences were than partial mitochondrial coding-region sequences, and thus to guide the design of future studies of the phylogeny, origin, evolution and taxonomy of body lice and head lice. Phylogenies were compared from entire coding-region sequences (∼15.4 kb), entire cox1 (∼1.5 kb), partial cox1 (∼700 bp) and partial cytb (∼600 bp) sequences. On the one hand, phylogenies from entire mitochondrial coding-region sequences (∼15.4 kb) were much more informative than phylogenies from entire cox1 sequences (∼1.5 kb) and partial gene sequences (∼600 to ∼700 bp). For example, 19 branches had > 95% bootstrap support in our maximum likelihood tree from the entire mitochondrial coding-regions (∼15.4 kb) whereas the tree from 700 bp cox1 had only two branches with bootstrap support > 95%. Yet, by contrast, partial cytb (∼600 bp) and partial cox1 (∼486 bp) sequences were sufficient to genotype lice to Clade A, B or C. The sequences of the mitochondrial genomes of the P. humanus, P. capitis and P. schaeffi Fahrenholz studied are in NCBI GenBank under the accession numbers KC660761-800, KC685631-6330, KC241882-97, EU219988-95, HM241895-8 and JX080388-407. © 2014 The Royal Entomological Society.

Head Lice Surveillance on a Deregulated OTC-Sales Market: A Study Using Web Query Data

PubMed Central

Lindh, Johan; Magnusson, Måns; Grünewald, Maria; Hulth, Anette

2012-01-01

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

Head lice surveillance on a deregulated OTC-sales market: a study using web query data.

PubMed

Lindh, Johan; Magnusson, Måns; Grünewald, Maria; Hulth, Anette

2012-01-01

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.

Severe head lice infestation in an Andean mummy of Arica, Chile.

PubMed

Arriaza, Bernardo; Orellana, Nancy C; Barbosa, Helene S; Menna-Barreto, Rubem F S; Araújo, Adauto; Standen, Vivien

2012-04-01

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.

Pair of lice lost or parasites regained: the evolutionary history of anthropoid primate lice

PubMed Central

Reed, David L; Light, Jessica E; Allen, Julie M; Kirchman, Jeremy J

2007-01-01

Background The parasitic sucking lice of primates are known to have undergone at least 25 million years of coevolution with their hosts. For example, chimpanzee lice and human head/body lice last shared a common ancestor roughly six million years ago, a divergence that is contemporaneous with their hosts. In an assemblage where lice are often highly host specific, humans host two different genera of lice, one that is shared with chimpanzees and another that is shared with gorillas. In this study, we reconstruct the evolutionary history of primate lice and infer the historical events that explain the current distribution of these lice on their primate hosts. Results Phylogenetic and cophylogenetic analyses suggest that the louse genera Pediculus and Pthirus are each monophyletic, and are sister taxa to one another. The age of the most recent common ancestor of the two Pediculus species studied matches the age predicted by host divergence (ca. 6 million years), whereas the age of the ancestor of Pthirus does not. The two species of Pthirus (Pthirus gorillae and Pthirus pubis) last shared a common ancestor ca. 3–4 million years ago, which is considerably younger than the divergence between their hosts (gorillas and humans, respectively), of approximately 7 million years ago. Conclusion Reconciliation analysis determines that there are two alternative explanations that account for the current distribution of anthropoid primate lice. The more parsimonious of the two solutions suggests that a Pthirus species switched from gorillas to humans. This analysis assumes that the divergence between Pediculus and Pthirus was contemporaneous with the split (i.e., a node of cospeciation) between gorillas and the lineage leading to chimpanzees and humans. Divergence date estimates, however, show that the nodes in the host and parasite trees are not contemporaneous. Rather, the shared coevolutionary history of the anthropoid primates and their lice contains a mixture of

Detection of bacterial pathogens including potential new species in human head lice from Mali

PubMed Central

Amanzougaghene, Nadia; Fenollar, Florence; Sangaré, Abdoul Karim; Sissoko, Mahamadou S.; Doumbo, Ogobara K.; Raoult, Didier

2017-01-01

In poor African countries, where no medical and biological facilities are available, the identification of potential emerging pathogens of concern at an early stage is challenging. Head lice, Pediculus humanus capitis, have a short life, feed only on human blood and do not transmit pathogens to their progeny. They are, therefore, a perfect tool for the xenodiagnosis of current or recent human infection. This study assessed the occurrence of bacterial pathogens from head lice collected in two rural villages from Mali, where a high frequency of head lice infestation had previously been reported, using molecular methods. Results show that all 600 head lice, collected from 117 individuals, belonged to clade E, specific to West Africa. Bartonella quintana, the causative agent of trench fever, was identified in three of the 600 (0.5%) head lice studied. Our study also shows, for the first time, the presence of the DNA of two pathogenic bacteria, namely Coxiella burnetii (5.1%) and Rickettsia aeschlimannii (0.6%), detected in human head lice, as well as the DNA of potential new species from the Anaplasma and Ehrlichia genera of unknown pathogenicity. The finding of several Malian head lice infected with B. quintana, C. burnetii, R. aeschlimannii, Anaplasma and Ehrlichia is alarming and highlights the need for active survey programs to define the public health consequences of the detection of these emerging bacterial pathogens in human head lice. PMID:28931077

Determination, mechanism and monitoring of knockdown resistance in permethrin-resistant human head lice, Pediculus humanus capitis

PubMed Central

Clark, J. Marshall

2009-01-01

Permethrin resistance has been reported worldwide and clinical failures to commercial pediculicides containing permethrin have likewise occurred. Permethrin resistance in head lice populations from the U.S. is widespread but is not yet uniform and the level of resistance is relatively low (~4–8 fold). Permethrin-resistant lice are cross-resistant to pyrethrins, PBO-synergized pyrethrins and to DDT. Nix®, when applied to human hair tufts following manufacture’s instructions, did not provide 100% control when assessed by the hair tuft bioassay in conjunction with the in vitro rearing system. Resistance to permethrin is due to knockdown resistance (kdr), which is the result of three point mutations within the α-subunit gene of the voltage-gated sodium channel that causes amino acid substitutions, leading to nerve insensitivity. A three-tiered resistance monitoring system has been established based on molecular resistance detection techniques. Quantitative sequencing (QS) has been developed to predict the kdr allele frequency in head lice at a population level. The speed, simplicity and accuracy of QS made it an ideal candidate for a routine primary resistance monitoring tool to screen a large number of louse populations as an alternative to conventional bioassay. As a secondary monitoring method, real-time PASA (rtPASA) has been devised for a more precise determination of low resistance allele frequencies. To obtain more detailed information on resistance allele zygosity, as well as allele frequency, serial invasive signal amplification reaction (SISAR) has been developed as an individual genotyping method. Our approach of using three tiers of molecular resistance detection should facilitate large-scale routine resistance monitoring of permethrin resistance in head lice using field-collected samples. PMID:20161186

Chemical composition and efficacy of some selected plant oils against Pediculus humanus capitis in vitro.

PubMed

Yones, Doaa A; Bakir, Hanaa Y; Bayoumi, Soad A L

2016-08-01

Natural compounds have been suggested as alternative sources for pediculosis capitis control. We aimed to investigate the chemical composition and evaluate the pediculicidal activity of spearmint, clove, cassia, thyme, eucalyptus, and anise essential oils in addition to sesame oil against human head lice in vitro. A filter paper contact bioassay method was used by applying 0.25 and 0.5 mg/cm(2) of each tested oil to filter paper in Petri dishes with 15 females head lice and another with ten nits. The lice mortalities were reported every 5 min for 180 min. The percentage of inhibition of hatch (PIH) was used to calculate ovicidal activity by daily microscopic inspections 5 days after the hatching of controls. Comparison with the widely used pediculicide (malathion) was performed. The most effective essential oil was spearmint followed by cassia and clove with KT50 values of 4.06, 7.62, and 12.12 at 0.5 mg/cm(2) and 8.84, 11.38, and 19.73 at 0.25 mg/cm(2), respectively. Thyme, eucalyptus, and anise were also effective adulticides with KT50 values of 18.61, 32.65, and 37.34 at 0.5 mg/cm(2) and 29.92, 43.16, and 45.37 at 0.25 mg/cm(2), respectively. Essential oils were also successful in inhibiting nymph emergence. Spearmint oil was the most effective, with a complete inhibition of emergence at 0.5 mg/cm(2). Sesame fixed oil did not show any adulticidal or ovicidal activity against head lice in vitro. The observed insecticidal activity was comparable to malathion. The results herein described the effectiveness of these essential oils as potential pediculicides for head lice control. Incorporation of essential oils in pediculicide formulations needs proper formulation and clinical trials.

Ex vivo effectiveness of French over-the-counter products against head lice (Pediculus humanus capitis De Geer, 1778).

PubMed

Combescot-Lang, Catherine; Vander Stichele, Robert H; Toubate, Berthine; Veirron, Emilie; Mumcuoglu, Kosta Y

2015-05-01

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.

Head Lice of Pygmies Reveal the Presence of Relapsing Fever Borreliae in the Republic of Congo.

PubMed

Amanzougaghene, Nadia; Akiana, Jean; Mongo Ndombe, Géor; Davoust, Bernard; Nsana, Nardiouf Sjelin; Parra, Henri-Joseph; Fenollar, Florence; Raoult, Didier; Mediannikov, Oleg

2016-12-01

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.

Comparing the Efficacy of Commercially Available Insecticide and Dimeticone based Solutions on Head Lice, Pediculus capitis: in vitro Trials.

PubMed

Balcıoğlu, I Cüneyt; Karakuş, Mehmet; Arserim, Suha K; Limoncu, M Emin; Töz, Seray; Baştemur, Serkan; Öncel, Koray; Özbel, Yusuf

2015-12-01

Head lice infestation is a public health and social problem for almost all countries worldwide. For its treatment, insecticide and dimeticone-based solutions are currently available in the markets in many countries. We aimed to compare the efficacy of commercially available anti-head lice shampoos containing insecticide and physically effective products with different percentages of dimeticone using an in vitro technique. Head lice specimens were collected from primary school children using special plastic and metal combs. Anti-head lice products were commercially purchased and used directly. The specimens were placed one by one in 5-cm Petri dishes containing a slightly wet filter paper and were kept in a plastic cage at 28±2°C and 50%±20% relative humidity. A standardized protocol was used for testing all the products, and mortality data were obtained after 24 h. Two control tests were performed with each batch of trials. For each product and control, 10-20 head lice specimens were used, and the results were statistically analyzed. Our study demonstrated that among all the tested products, two products containing mineral oils [5.5% dimeticone & silicone (patented product) and dimeticone (no percentage mentioned in the prospectus) & cyclopentasiloxane] were found to be more effective for killing head lice in vitro. Physically effective products can be repetitively used because they are non-toxic and resistance to them is not expected. To control the infestation at a public level, the use of these products needs to be encouraged with respect to their cost price.

Head Lice of Pygmies Reveal the Presence of Relapsing Fever Borreliae in the Republic of Congo

PubMed Central

Amanzougaghene, Nadia; Akiana, Jean; Mongo Ndombe, Géor; Davoust, Bernard; Nsana, Nardiouf Sjelin; Parra, Henri-Joseph; Fenollar, Florence; Raoult, Didier; Mediannikov, Oleg

2016-01-01

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

Activity of tea tree oil and nerolidol alone or in combination against Pediculus capitis (head lice) and its eggs.

PubMed

Di Campli, Emanuela; Di Bartolomeo, Soraya; Delli Pizzi, Patricia; Di Giulio, Mara; Grande, Rossella; Nostro, Antonia; Cellini, Luigina

2012-11-01

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.

A systematic literature review of pediculosis due to head lice in the Pacific Island Countries and Territories: what country specific research on head lice is needed?

PubMed Central

2014-01-01

Background Lack of guidelines on control of pediculosis in the Solomon Islands led to a search for relevant evidence on head lice in the Pacific Island Countries and Territories (PICTs). The aim of this search was to systematically evaluate evidence in the peer reviewed literature on pediculosis due to head lice (Pediculus humanus var capitis) in the 22 PICTs from the perspective of its value in informing national guidelines and control strategies. Methods PubMed, Web of Science, CINAHL and Scopus were searched using the terms (pediculosis OR head lice) AND each of the 22 PICTs individually. PRISMA methodology was used. Exclusion criteria were: i) not on topic; ii) publications on pediculosis not relevant to the country of the particular search; iii) in grey literature. Results Of 24 publications identified, only 5 were included. Four related to treatment and one to epidemiology. None contained information relevant to informing national guidelines. Conclusions Current local evidence on head lice in the PICTs is minimal and totally inadequate to guide any recommendations for treatment or control. We recommend that local research is required to generate evidence on: i) epidemiology; ii) knowledge, attitudes and practices of health care providers and community members; iii) efficacy of local commercially available pharmaceutical treatments and local customary treatments; iv) acceptability, accessibility and affordability of available treatment strategies; and iv) appropriate control strategies for families, groups and institutions. We also recommend that operational research be done by local researchers based in the PICTs, supported by experienced head lice researchers, using a two way research capacity building model. PMID:24962507

A systematic literature review of pediculosis due to head lice in the Pacific Island Countries and Territories: what country specific research on head lice is needed?

PubMed

Speare, Rick; Harrington, Humpress; Canyon, Deon; Massey, Peter D

2014-06-24

Lack of guidelines on control of pediculosis in the Solomon Islands led to a search for relevant evidence on head lice in the Pacific Island Countries and Territories (PICTs). The aim of this search was to systematically evaluate evidence in the peer reviewed literature on pediculosis due to head lice (Pediculus humanus var capitis) in the 22 PICTs from the perspective of its value in informing national guidelines and control strategies. PubMed, Web of Science, CINAHL and Scopus were searched using the terms (pediculosis OR head lice) AND each of the 22 PICTs individually. PRISMA methodology was used. Exclusion criteria were: i) not on topic; ii) publications on pediculosis not relevant to the country of the particular search; iii) in grey literature. Of 24 publications identified, only 5 were included. Four related to treatment and one to epidemiology. None contained information relevant to informing national guidelines. Current local evidence on head lice in the PICTs is minimal and totally inadequate to guide any recommendations for treatment or control. We recommend that local research is required to generate evidence on: i) epidemiology; ii) knowledge, attitudes and practices of health care providers and community members; iii) efficacy of local commercially available pharmaceutical treatments and local customary treatments; iv) acceptability, accessibility and affordability of available treatment strategies; and iv) appropriate control strategies for families, groups and institutions. We also recommend that operational research be done by local researchers based in the PICTs, supported by experienced head lice researchers, using a two way research capacity building model.

Prevalence of head lice in two socio-economically different schools in the center of Izmir City, Turkey.

PubMed

Karakuş, Mehmet; Arıcı, Aylin; Töz, Seray Özensoy; Özbel, Yusuf

2014-01-01

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.

Treatment of human head lice infestations in a single application with a new galenic lotion.

PubMed

Militão de Sousa, F; Vasconcelos, A W; de Nadon, J; Duhot, P-Y

2010-10-01

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.

Comparative efficacy of new commercial pediculicides against adults and eggs of Pediculus humanus capitis (head lice).

PubMed

Gallardo, Anabella; Mougabure-Cueto, Gastón; Vassena, Claudia; Picollo, María Inés; Toloza, Ariel Ceferino

2012-05-01

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.

White piedra and pediculosis capitis in the same patient.

PubMed

Marques, Silvio Alencar; Richini-Pereira, Virgínia Bodelão; Camargo, Rosângela Maria Pires de

2012-01-01

White piedra is a superficial mycosis caused by the genus Trichosporon. It is characterized by nodules on the hair shaft. Pediculosis capitis is caused by Pediculus humanus var. capitis of the suborder Anoplura. Whereas pediculosis is a common infestation, clinical reports of white piedra are rare. Molecular biology procedures identified T. inkin as the agent of white piedra in this case report. The authors present associations between the two diseases in the same patient in order to highlight their clinical differences.

What's in a name: the taxonomic status of human head and body lice.

PubMed

Light, Jessica E; Toups, Melissa A; Reed, David L

2008-06-01

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.

Pediculosis and the pediatrician.

PubMed

Rasmussen, J E

1984-07-01

Head lice commonly evoke feelings of disgust, revulsion, anger, and shame among parents and patients. There should, however, be no great cause for such alarm if a physician suspects pediculosis capitis. The recent introduction of several new pediculicidal drugs now allows a choice among four distinct therapeutic agents, which should substantially improve control of isolated cases and epidemics. Physicians must be aware that consumer groups are pressing public health authorities and drug manufacturers to establish proper treatment standards and safety warnings for the use of these agents. In addition, some controversy surrounds the use of lindane in children. This paper reviews the epidemiology and clinical appearance of pediculosis capitis in children, with emphasis on these recent developments. Pubic lice (Phthirus pubis) and body lice (Pediculus humanus corporis), both of which are much less common pediatric infestations, are mentioned only briefly.

Clinical Practice Update: Pediculosis Capitis.

PubMed

Bohl, Brittany; Evetts, Jessica; McClain, Kymberli; Rosenauer, Amanda; Stellitano, Emily

2015-01-01

A review of the current evidence on primary treatment modalities of head lice demonstrates increasing resistance to current regimens. New and alternative therapies are now available. A treatment algorithm was created to address safety and efficacy of treatments, as well as to guide clinicians through navigation of the regimens. Through an online journal search, 59 articles were selected for the review. Literature searches were performed through PubMed, Medline, Ebsco Host, and CINAHL, with key search words of "Pediculosis capitis" and "head lice" in the title, abstract, and index. Meta-analyses and controlled clinical trials were viewed with greater weight if they had a large sample size, were statistically significant, and did not allude to bias. When resistant infestations are well-documented in a locality, changes to the treatment regimen are indicated, and alternative treatments should be considered. Recent studies and U.S. Food and Drug Administration (FDA) approvals have changed the available treatment options for Pediculosis capitis, including benzyl alcohol, topical ivermectin, spinosad, and the LouseBuster. Further, environmental management and prevention measures should be taken to avoid reinfestation and to prevent the spread of head lice. Continued study is recommended to establish long-term safety of new and alternative agents.

Wet combing for the eradication of head lice.

PubMed

2013-03-01

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.

Evolution of extensively fragmented mitochondrial genomes in the lice of humans.

PubMed

Shao, Renfu; Zhu, Xing-Quan; Barker, Stephen C; Herd, Kate

2012-01-01

Bilateral animals are featured by an extremely compact mitochondrial (mt) genome with 37 genes on a single circular chromosome. The human body louse, Pediculus humanus, however, has its mt genes on 20 minichromosomes. We sequenced the mt genomes of two other human lice: the head louse, P. capitis, and the pubic louse, Pthirus pubis. Comparison among the three human lice revealed the presence of fragmented mt genomes in their most recent common ancestor, which lived ∼7 Ma. The head louse has exactly the same set of mt minichromosomes as the body louse, indicating that the number of minichromosomes, and the gene content and gene arrangement in each minichromosome have remained unchanged since the body louse evolved from the head louse ∼107,000 years ago. The pubic louse has the same pattern of one protein-coding or rRNA gene per minichromosome (except one minichromosome with two protein-coding genes, atp6 and atp8) as the head louse and the body louse. This pattern is apparently ancestral to all human lice and has been stable for at least 7 Myr. Most tRNA genes of the pubic louse, however, are on different minichromosomes when compared with their counterparts in the head louse and the body louse. It is evident that rearrangement of four tRNA genes (for leucine, arginine and glycine) was due to gene-identity switch by point mutation at the third anticodon position or by homologous recombination, whereas rearrangement of other tRNA genes was by gene translocation between minichromosomes, likely caused by minichromosome split via gene degeneration and deletion.

Detection of bacterial pathogens in clade E head lice collected from Niger's refugees in Algeria.

PubMed

Louni, Meriem; Amanzougaghene, Nadia; Mana, Nassima; Fenollar, Florence; Raoult, Didier; Bitam, Idir; Mediannikov, Oleg

2018-06-15

Head lice, Pediculus humanus capitis, are obligate blood-sucking parasites. Phylogenetically, they occur in five divergent mitochondrial clades (A, D, B, C and E), each having a particular geographical distribution. Recent studies have revealed that head lice, as is the case of body lice, can act as a vector for louse-borne diseases. Here, we aimed to study the genetic diversity of head lice collected from Niger's refugees (migrant population) arriving in Algeria, northern Africa, and to look for louse-borne pathogens. Comparative head lice samples collected from indigenous population of schoolchildren (non-immigrant) were also analyzed to frame the study. In this study, 37 head lice samples were collected from 31 Nigerien refugees, as well as 45 head lice from 27 schoolchildren. The collection was established in three localities of eastern Algiers, north Algeria. Quantitative real-time PCR screening of pathogens bacteria and the genetic characterisation of the head lice satut were performed. Through amplification and sequencing of the cytb gene, results showed that all head lice of Nigerien refugees 37/82 (45.12%) belonged to clade E with the presence of four new haplotypes, while, of the 45 head lice of schoolchildren, 34/82 lice (41.46%) belonged to clade A and 11/82 (13.41%) belonged to clade B. Our study is the first to report the existence of clade E haplogroup in Nigerien head lice. DNA of Coxiella burnetii was detected in 3/37 (8.10%) of the head lice collected from 3 of the 31 (9.67%) migrant population. We also revealed the presence of Acinetobacter DNA in 20/37 (54.05%) of head lice collected from 25/31 (80.64%) of the Nigerien refugees, and in 25/45 (55.55%) head lice collected from 15/27 (55.55%) schoolchildren. All positive Nigerien-head lice for Acinetobacter spp. were identified as A. baumannii, while positive schoolchildren-head lice were identified as A. johnsonii 15/25 (60%), A. variabilis 8/25 (32%) and A. baumannii 2/25 (8%). Based on these

Pediculosis capitis: an update.

PubMed

Madke, Bhushan; Khopkar, Uday

2012-01-01

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.

Efficacy of herbal shampoo base on native plant against head lice (Pediculus humanus capitis De Geer, Pediculidae: Phthiraptera) in vitro and in vivo in Thailand.

PubMed

Soonwera, Mayura

2014-09-01

Head lice infestation (or pediculosis) is an important public health problem in Thailand, especially in children between the ages 5 and 11 years. Head lice resistance is increasing, chemical pediculicides have lost their efficacy, and, therefore, alternative pediculicides such as herbal shampoos have been proposed to treat head lice infestation. Thus, the present study investigated the efficacy of three herbal shampoos based on native plants in Thailand (Acorus calamus Linn., Phyllanthus emblica Linn., and Zanthoxylum limonella Alston) against head lice and compared them with carbaryl shampoo (Hafif shampoo, 0.6% w/v carbaryl), malathion shampoo (A-Lice shampoo, 1.0% w/v malathion), and commercial shampoos (Babi Mild Natural' N Mild and Johnson's baby shampoo) in order to assess their in vitro and in vivo efficacy. For in vitro study, doses of 0.12 and 0.25 ml/cm(2) of each herbal shampoo were applied to filter paper, then 10 head lice were place on the filter paper. The mortalities of head lice were recorded at 5, 15, 30, and 60 min. The results revealed that all herbal shampoo were more effective on pediculicidal activity than chemical and commercial shampoos with 100% mortality at 15 min; LT₅₀ values ranged from 0.25 to 1.90 min. Meanwhile, chemical shampoos caused 20-80% mortality, and LT₅₀ values ranged from 6.50 to 85.43 min. On the other side, commercial shampoos showed 4.0% mortality. The most effective pediculicide was Z. limonella shampoo, followed by A. calamus shampoo, P. emblica shampoo, carbaryl shampoo, malathion shampoo, and commercial shampoo, respectively. In vivo results showed that all herbal shampoos were also more effective for head lice treatment than chemical and commercial shampoos with 94.67-97.68% of cure rate after the first treatment; the second treatment, 7 days later, revealed that the cure rate was 100%. Meanwhile, chemical shampoo showed 71.67-93.0% of cure rate and, unfortunately, commercial shampoos were nontoxic to

Pediculicidal effect of herbal shampoo against Pediculus humanus capitis in vitro.

PubMed

Watcharawit, R; Soonwera, M

2013-06-01

Human head lice infestation is an important public health problem in Thailand. Lice resistance is increasing, chemical pediculicides have lost their efficacy and thus alternative products such as herbal shampoos have been proposed to treat lice infestation. The present study investigated the efficacy of twenty nine herbal shampoos based on zinbiberaceae plants, piperaceae plants and native plants against human head lice and compared them with malathion shampoo (A-lices shampoo®: 1% w/v malathion) and commercial shampoo (BabiMild Natural'N Mild®) in order to assess their in vitro efficacy. All herbal shampoo were more effective than commercial shampoo with 100% mortality at 60 seconds and LT50 values ranged from 11.30 to 31.97 seconds, meanwhile, commercial shampoo caused 14.0-15.0% mortality and LT50 values ranged from 83.96 to 87.43 seconds. The nine herbal shampoos from Zingiber cassumunar, Piper betle, Piper ribesioides, Averrhoa bilimbi, Clitoria ternatea, Plectranthus amboincus, Myristica fragrans, Tacca chantrieri and Zanthoxylum limonella were more effective pediculicide than malathion shampoo with 100% mortality at 30 seconds and LT50 values ranged from 11.30-13.58 seconds, on the other hand malathion shampoo showed LT50 values ranging from 12.39 to 13.67 seconds. LT50 values indicated the order of pediculicidal activity in the herbal shampoos as Z. cassumunar shampoo > P. betle shampoo > Za. limonella shampoo > Av. bilimbi shampoo > P. ribesioides shampoo > My. fragrans shampoo > T. chantrieri shampoo > Pl. amboincus shampoo. Our data showed that eight of the twenty nine herbal shampoos in this study were of high potential pediculicide to human head lice treatments for Thai children.

Lice.

PubMed

Do-Pham, Giao; Monsel, Gentiane; Chosidow, Olivier

2014-09-01

Pediculosis (capitis, corporis, and pubis) share well-known features: worldwide prevalence (involving millions of people annually); parasites inducing skin lesions directly, and indirectly as a result of itching and hypersensitivity to parasites; and treatment based on good entomological knowledge of the parasite and practical considerations (ie, most available treatments do not act on eggs and should be repeated, depending on the life cycle of the parasites). Infestations are spread most commonly by close contacts. Social stigma and persistent misconceptions complicate the implementation of appropriate management strategies. Head and pubic lice infestations are diagnosed by the visualization of insects or viable nits (eggs). Primary treatments are topical pediculicides (permethrin or malathion), used twice, but emergence of resistance against pediculicides has created the need of alternative treatments including topical or oral ivermectin. Pubic lice are treated the same as head lice, but this finding should prompt evaluation for other sexually transmitted diseases. Body lice infestation should be suspected when symptoms of generalized itching occur in persons who do not change or wash their clothing or bedding regularly; lice may be found in the seams of their clothing.Topically administered permethrin may help to eradicate body lice, but personal hygiene measures are essential for successful treatment. Environmental treatment is also necessary for the eradication of the infestation. Health care personnel who come into contact with this population need to be well informed of the facts in order to disseminate accurate information for diagnosis and management.

Parental attitudes towards head lice infestation in Greece.

PubMed

Doulgeraki, Artemis; Valari, Manthoula

2011-06-01

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.

The origin and distribution of human lice in the world.

PubMed

Boutellis, Amina; Abi-Rached, Laurent; Raoult, Didier

2014-04-01

Two genera of lice parasitize humans: Pthirus and Pediculus. The latter is of significant public health importance and comprises two ecotypes: the body louse and the head louse. These ecotypes are morphologically and genetically notably similar; the body louse is responsible for three infectious diseases: Louse-borne epidemic typhus, relapsing fever, and trench fever. Mitochondrial DNA studies have shown that there are three obviously divergent clades of head lice (A, B and C), and only one clade of body lice is shared with head lice (clade A). Each clade has a unique geographic distribution. Lice have been parasitizing humans for millions of years and likely dispersed throughout the World with the human migrations out of Africa, so they can be good markers for studying human evolution. Here, we present an overview of the origin of human lice and their role in vector pathogenic bacteria that caused epidemics, and we review the association between lice clades and human migrations. Copyright © 2014 Elsevier B.V. All rights reserved.

Management and Treatment of Human Lice

PubMed Central

Sangaré, Abdoul Karim; Doumbo, Ogobara K.

2016-01-01

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. PMID:27529073

Management and Treatment of Human Lice.

PubMed

Sangaré, Abdoul Karim; Doumbo, Ogobara K; Raoult, Didier

2016-01-01

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.

First Detection of the Kdr Mutation T929I in Head Lice (Phthiraptera: Pediculidae) in Schoolchildren of the Metropolitan Area of Nuevo Leon and Yucatan, Mexico.

PubMed

Ponce-Garcia, Gustavo; Villanueva-Segura, Karina; Trujillo-Rodriguez, Gerardo; Rodriguez-Sanchez, Iram P; Lopez-Monroy, Beatriz; Flores, Adriana E

2017-07-01

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: journals.permissions@oup.com.

An incurable itch

PubMed Central

Smith, Christine H.; Goldman, Ran D.

2012-01-01

Abstract Question 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? Answer 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. PMID:22893334

THE EXPERIMENTAL INFECTION OF THE HUMAN BODY LOUSE, PEDICULUS HUMANUS CORPORIS, WITH MURINE AND EPIDEMIC LOUSE-BORNE TYPHUS STRAINS

PubMed Central

Snyder, J. C.; Wheeler, C. M.

1945-01-01

Experiments are described which demonstrate that human body lice (Pediculus humanus corporis), were infected experimentally with murine and epidemic louse-borne strains of typhus fever by feeding on suitably prepared rabbits. Details of the two methods of infection, the "bleb technique" and the "I.V. technique," are presented. It is concluded that the experimental infection of human lice with typhus can be accomplished very easily and rapidly with these methods. The possible applications of the method are discussed. PMID:19871482

Treatment of pediculosis capitis: a critical appraisal of the current literature.

PubMed

Feldmeier, Hermann

2014-10-01

Pediculosis capitis is the most common ectoparasitic disease in children in industrialized countries and extremely common in resource-poor communities of the developing world. The extensive use of pediculicides with a neurotoxic mode of action has led to the development and spread of resistant head lice populations all over the world. This triggered the development of compounds with other modes of action. The current literature on treatment approaches of head lice infestation was searched, and published randomized controlled trials were critically analyzed. The following compounds/family of compounds were identified: spinosad, a novel compound with a new neurotoxic mode of action, isopropyl myristate, 1,2-octanediol, ivermectin, plant-based products, and dimeticones. The efficacy and safety of these compounds are reviewed and recommendations for the treatment of pediculosis capitis in individuals as well as the interruption of ongoing epidemics are provided.

Geographical distribution of pyrethroid resistance allele frequency in head lice (Phthiraptera: Pediculidae) from Argentina.

PubMed

Toloza, Ariel Ceferino; Ascunce, Marina S; Reed, David; Picollo, María Inés

2014-01-01

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.

Efficacy of a grapefruit extract on head lice: a clinical trial.

PubMed

Abdel-Ghaffar, Fathy; Semmler, Margit; Al-Rasheid, Khaled; Klimpel, Sven; Mehlhorn, Heinz

2010-01-01

Twenty children aging 2-9 years old--four boys with short hair and 16 girls with long hair--were included in a clinical test on the efficacy of a product against head lice (Pediculus humanus capitis). Their hair were exposed to Licatack, which is a recently developed new anti-louse medicinal product containing extracts of grapefruits besides high quality shampoo components. Prior to this field trial, the product Licatack was tested dermatologically to be skin safe receiving the grade "very good". The children's mothers combed the kids prior to the start of the test in order to confirm that they were all lice-infested. The obtained lice were used for in vitro tests. All children were heavily infested. After combing and preservation of the living lice, the hair was wet with tap water. Then, 50 ml of the Licatack shampoo was placed onto the top of each child's head. Then, the mothers distributed the rather fluid product all over the hair thoroughly from their base at the skin until the free end. During this process, a type of massage, the product became foamy and it was easily recognized where the product covered the hair, thus, avoiding untreated spots. The hair of half of the treated children were washed with tap water after 10 min of exposition; while in the other half of the children, the exposition period was prolonged to 20 min before washing. When combing the kids with a metal louse comb after the washing, the lice were found immobile and they did not recover during the following observation period of 4 h. Only two lice from the group with an exposition time of only 10 min showed some slight leg movements after they had been combed off, but they died within the next 2 h. Thus, this new anti-louse medicinal product has a very quick and efficient activity besides its advantages of being non-inflammable, skin safe, and nice smelling. None of the kids claimed any burning at the skin or other side effects, although the skin showed, prior to treatment, lots of scars

Evidence that clade A and clade B head lice live in sympatry and recombine in Algeria.

PubMed

Boutellis, A; Bitam, I; Fekir, K; Mana, N; Raoult, D

2015-03-01

Pediculus humanus L. (Psocodea: Pediculidae) can be characterized into three deeply divergent lineages (clades) based on mitochondrial DNA. Clade A consists of both head lice and clothing lice and is distributed worldwide. Clade B consists of head lice only and is mainly found in North and Central America, and in western Europe and Australia. Clade C, which consists only of head lice, is found in Ethiopia, Nepal and Senegal. Twenty-six head lice collected from pupils at different elementary schools in two localities in Algiers (Algeria) were analysed using molecular methods for genotyping lice (cytochrome b and the multi-spacer typing (MST) method. For the first time, we found clade B head lice in Africa living in sympatry with clade A head lice. The phylogenetic analysis of the concatenated sequences of these populations of head lice showed that clade A and clade B head lice had recombined, suggesting that interbreeding occurs when lice live in sympatry. © 2014 The Royal Entomological Society.

Solanum trilobatum extract-mediated synthesis of titanium dioxide nanoparticles to control Pediculus humanus capitis, Hyalomma anatolicum anatolicum and Anopheles subpictus.

PubMed

Rajakumar, Govindasamy; Rahuman, Abdul Abdul; Jayaseelan, Chidambaram; Santhoshkumar, Thirunavukkarasu; Marimuthu, Sampath; Kamaraj, Chinnaperumal; Bagavan, Asokan; Zahir, Abdul Abduz; Kirthi, Arivarasan Vishnu; Elango, Gandhi; Arora, Pooja; Karthikeyan, Rajan; Manikandan, Sivan; Jose, Sujin

2014-02-01

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in paints, printing ink, rubber, paper, cosmetics, sunscreens, car materials, cleaning air products, industrial photocatalytic processes, and decomposing organic matters in wastewater due to their unique physical, chemical, and biological properties. The present study was conducted to assess the antiparasitic efficacies of synthesized TiO2 NPs utilizing leaf aqueous extract of Solanum trilobatum against the adult head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae); larvae of cattle tick Hyalomma anatolicum (a.) anatolicum Koch (Acari: Ixodidae), and fourth instar larvae of malaria vector Anopheles subpictus Grassi (Diptera: Culicidae). The green synthesized TiO2 NPs were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy analysis (EDX), and Atomic force microscopy (AFM). XRD analysis of synthesized TiO2 NPs revealed that the particles were in the form of nanocrystals as evidenced by the major peaks at 2θ values of 27.52°, 36.21°, and 54.43° identified as 110, 101, and 211 reflections, respectively. FTIR spectra exhibited a prominent peak at 3,466 cm(-1) and showed OH stretching due to the alcoholic group, and the OH group may act as a capping agent. SEM images displayed NPs that were spherical, oval in shape, individual, and some in aggregates with an average size of 70 nm. Characterization of the synthesized TiO2 NPs using AFM offered a three-dimensional visualization and uneven surface morphology. The pediculocidal and acaricidal activities of synthesized TiO2 NPs showed the percent mortality of 31, 42, 63, 82, 100; 36, 44, 67, 89, and 100 at 2, 4, 6, 8, and 10 mg/L, respectively, against P. h. capitis and H. a. anatolicum. The average larval percent mortality of synthesized TiO2 NPs was 38, 47, 66, 79, and 100 at 1, 2, 3, 4, and 5 mg/L, respectively, against A. subpictus

Body lice of homeless people reveal the presence of several emerging bacterial pathogens in northern Algeria.

PubMed

Louni, Meriem; Mana, Nassima; Bitam, Idir; Dahmani, Mustapha; Parola, Philippe; Fenollar, Florence; Raoult, Didier; Mediannikov, Oleg

2018-04-01

Human lice, Pediculus humanus, are obligate blood-sucking parasites. Body lice, Pediculus h. humanus, occur in two divergent mitochondrial clades (A and D) each exhibiting a particular geographic distribution. Currently, the body louse is recognized as the only vector for louse-borne diseases. In this study, we aimed to study the genetic diversity of body lice collected from homeless populations in three localities of northern Algeria, and to investigate louse-borne pathogens in these lice. In this study, 524 body lice specimens were collected from 44 homeless people in three localities: Algiers, Tizi Ouzou and Boumerdès located in northern Algeria. Duplex clade specific real-time PCRs (qPCR) and Cytochrome b (cytb) mitochondrial DNA (mtDNA) analysis were performed in order to identify the mitochondrial clade. Screening of louse-borne pathogens bacteria was based on targeting specific genes for each pathogen using qPCR supplemented by sequencing. All body lice belong to clade A. Through amplification and sequencing of the cytb gene we confirmed the presence of three haplotypes: A5, A9 and A63, which is novel. The molecular investigation of the 524 body lice samples revealed the presence of four human pathogens: Bartonella quintana (13.35%), Coxiella burnetii (10.52%), Anaplasma phagocytophilum (0.76%) and Acinetobacter species (A. baumannii, A. johnsonii, A. berezeniae, A. nosocomialis and A. variabilis, in total 46.94%). To the best of our knowledge, our study is the first to show the genetic diversity and presence of several emerging pathogenic bacteria in homeless' body lice from Algeria. We also report for the first time, the presence of several species of Acinetobacter in human body lice. Our results highlight the fact that body lice may be suspected as being a much broader vector of several pathogenic agents than previously thought. Nevertheless, other studies are needed to encourage epidemiological investigations and surveys of louse-associated infections.

Body lice of homeless people reveal the presence of several emerging bacterial pathogens in northern Algeria

PubMed Central

Louni, Meriem; Mana, Nassima; Bitam, Idir; Dahmani, Mustapha; Parola, Philippe; Fenollar, Florence; Raoult, Didier

2018-01-01

Background Human lice, Pediculus humanus, are obligate blood-sucking parasites. Body lice, Pediculus h. humanus, occur in two divergent mitochondrial clades (A and D) each exhibiting a particular geographic distribution. Currently, the body louse is recognized as the only vector for louse-borne diseases. In this study, we aimed to study the genetic diversity of body lice collected from homeless populations in three localities of northern Algeria, and to investigate louse-borne pathogens in these lice. Methodology/Principal findings In this study, 524 body lice specimens were collected from 44 homeless people in three localities: Algiers, Tizi Ouzou and Boumerdès located in northern Algeria. Duplex clade specific real-time PCRs (qPCR) and Cytochrome b (cytb) mitochondrial DNA (mtDNA) analysis were performed in order to identify the mitochondrial clade. Screening of louse-borne pathogens bacteria was based on targeting specific genes for each pathogen using qPCR supplemented by sequencing. All body lice belong to clade A. Through amplification and sequencing of the cytb gene we confirmed the presence of three haplotypes: A5, A9 and A63, which is novel. The molecular investigation of the 524 body lice samples revealed the presence of four human pathogens: Bartonella quintana (13.35%), Coxiella burnetii (10.52%), Anaplasma phagocytophilum (0.76%) and Acinetobacter species (A. baumannii, A. johnsonii, A. berezeniae, A. nosocomialis and A. variabilis, in total 46.94%). Conclusions/Significance To the best of our knowledge, our study is the first to show the genetic diversity and presence of several emerging pathogenic bacteria in homeless’ body lice from Algeria. We also report for the first time, the presence of several species of Acinetobacter in human body lice. Our results highlight the fact that body lice may be suspected as being a much broader vector of several pathogenic agents than previously thought. Nevertheless, other studies are needed to encourage

An unusual autopsy case of lethal hypothermia exacerbated by body lice-induced severe anemia.

PubMed

Nara, Akina; Nagai, Hisashi; Yamaguchi, Rutsuko; Makino, Yohsuke; Chiba, Fumiko; Yoshida, Ken-ichi; Yajima, Daisuke; Iwase, Hirotaro

2016-05-01

Pediculus humanus humanus (known as body lice) are commonly found in the folds of clothes, and can cause skin disorders when they feed on human blood, resulting in an itching sensation. Body lice are known as vectors of infectious diseases, including typhus, recurrent fever, and trench fever. An infestation with blood-sucking body lice induces severe cutaneous pruritus, and this skin disorder is known as "vagabond's disease." A body lice infestation is sometimes complicated with iron deficiency anemia. In the present case, a man in his late 70s died of lethal hypothermia in the outdoors during the winter season. The case history and autopsy findings revealed that the cause of the lethal hypothermia was iron deficiency anemia, which was associated with a prolonged infestation of blood-sucking body lice. Also, he had vagabond's disease because the skin on his body was abnormal and highly pigmented. This is an unusual autopsy case since the body lice contributed to the cause of the death.

Human pediculosis: a critical health problem and what about nursing policy?

PubMed

El-Bahnasawy, Mamdouh M; Abdel, Fadil Eman Ebrahim; Morsy, Tosson A

2012-12-01

Lice infestation on the human body (also known as pediculosis) is very common. Cases number in the hundreds of millions worldwide. Three distinct presentations of lice infection exist and each is caused by a unique parasite. Head lice (Pediculus humanus capitis) is by far and away the most common infestation and favors no particular socioeconomic group. A genetically close "cousin," Pediculus humanus corporis, is responsible for body lice and is more commonly associated with poverty, overcrowding, and poor hygiene. Pubic lice (crabs) are caused by Pthirus pubis and is transmitted by intimate and/or sexual contact. No doubt, human lice infestation is an increasing problem worldwide, Apart from being an irritating and a shaming human ecto-parasite, they transmit serious infectious diseases; epidemic or classical typhus, epidemic relapsing fever as well as Trench fever. Eradication of lice infestation prevents transmission of infectious diseases. People who live and work in close proximity to louse-infested individuals may secondarily acquire lice even if they regularly wash their clothes and have good hygiene. Thus, all louse-infested persons and workers in close contact with such persons should periodically inspected and use long-acting safe insecticides. Human lice can be treated with agents such as DDT, malathion, and lindane, but reports of resistance to one or more of them have recently appeared. Pyrethroid permethrin when applied as a dust or spray to clothing or bedding is highly effective against lice and is the delousing agent of choice. Fabric treated with permethrin retains toxicity to lice even after 20 washings, thereby offering significant long-term passive protection against epidemic typhus. Itching may continue even after all lice are destroyed. This happens because of a lingering allergic reactionto their bites. Over-the-counter cortisone (corticosteroid) creams or calamine lotion may help.

Pediculosis capitis among primary-school children in Mafraq Governorate, Jordan.

PubMed

AlBashtawy, M; Hasna, F

2012-01-01

Pediculosis capitis (head lice infestation) is a worldwide public health concern affecting mostly primary-school children. In a cross-sectional study in 2009/2010, the prevalence of pediculosis capitis and some risk factors for infestation were investigated among 1550 randomly selected primary-school children in Mafraq governorate, Jordan. The prevalence of pediculosis capitis was 26.6%. There were significant differences in the prevalence between girls (34.7%) and boys (19.6%), rural (31.2%) and urban (23.5%) residents, and history of infestation in the previous year (57.4%) versus no history (11.5%), as well as between children of different ages, family size and income (P<0.001). Longer hair length, lack of bathing facilities, low frequency of hair-washing and bathing, and sharing of articles (e.g. combs, scarves) were significantly associated with infestation (P<0.001). The prevalence of infestation was higher than reported in previous studies in Jordan (< 14%). Programmes are needed to increase awareness of pediculosis capitis and the importance of good personal hygiene.

Mitochondrial genome deletions and minicircles are common in lice (Insecta: Phthiraptera)

PubMed Central

2011-01-01

Background The gene composition, gene order and structure of the mitochondrial genome are remarkably stable across bilaterian animals. Lice (Insecta: Phthiraptera) are a major exception to this genomic stability in that the canonical single chromosome with 37 genes found in almost all other bilaterians has been lost in multiple lineages in favour of multiple, minicircular chromosomes with less than 37 genes on each chromosome. Results Minicircular mt genomes are found in six of the ten louse species examined to date and three types of minicircles were identified: heteroplasmic minicircles which coexist with full sized mt genomes (type 1); multigene chromosomes with short, simple control regions, we infer that the genome consists of several such chromosomes (type 2); and multiple, single to three gene chromosomes with large, complex control regions (type 3). Mapping minicircle types onto a phylogenetic tree of lice fails to show a pattern of their occurrence consistent with an evolutionary series of minicircle types. Analysis of the nuclear-encoded, mitochondrially-targetted genes inferred from the body louse, Pediculus, suggests that the loss of mitochondrial single-stranded binding protein (mtSSB) may be responsible for the presence of minicircles in at least species with the most derived type 3 minicircles (Pediculus, Damalinia). Conclusions Minicircular mt genomes are common in lice and appear to have arisen multiple times within the group. Life history adaptive explanations which attribute minicircular mt genomes in lice to the adoption of blood-feeding in the Anoplura are not supported by this expanded data set as minicircles are found in multiple non-blood feeding louse groups but are not found in the blood-feeding genus Heterodoxus. In contrast, a mechanist explanation based on the loss of mtSSB suggests that minicircles may be selectively favoured due to the incapacity of the mt replisome to synthesize long replicative products without mtSSB and thus the

Mitochondrial genome deletions and minicircles are common in lice (Insecta: Phthiraptera).

PubMed

Cameron, Stephen L; Yoshizawa, Kazunori; Mizukoshi, Atsushi; Whiting, Michael F; Johnson, Kevin P

2011-08-04

The gene composition, gene order and structure of the mitochondrial genome are remarkably stable across bilaterian animals. Lice (Insecta: Phthiraptera) are a major exception to this genomic stability in that the canonical single chromosome with 37 genes found in almost all other bilaterians has been lost in multiple lineages in favour of multiple, minicircular chromosomes with less than 37 genes on each chromosome. Minicircular mt genomes are found in six of the ten louse species examined to date and three types of minicircles were identified: heteroplasmic minicircles which coexist with full sized mt genomes (type 1); multigene chromosomes with short, simple control regions, we infer that the genome consists of several such chromosomes (type 2); and multiple, single to three gene chromosomes with large, complex control regions (type 3). Mapping minicircle types onto a phylogenetic tree of lice fails to show a pattern of their occurrence consistent with an evolutionary series of minicircle types. Analysis of the nuclear-encoded, mitochondrially-targetted genes inferred from the body louse, Pediculus, suggests that the loss of mitochondrial single-stranded binding protein (mtSSB) may be responsible for the presence of minicircles in at least species with the most derived type 3 minicircles (Pediculus, Damalinia). Minicircular mt genomes are common in lice and appear to have arisen multiple times within the group. Life history adaptive explanations which attribute minicircular mt genomes in lice to the adoption of blood-feeding in the Anoplura are not supported by this expanded data set as minicircles are found in multiple non-blood feeding louse groups but are not found in the blood-feeding genus Heterodoxus. In contrast, a mechanist explanation based on the loss of mtSSB suggests that minicircles may be selectively favoured due to the incapacity of the mt replisome to synthesize long replicative products without mtSSB and thus the loss of this gene lead to the

Influence of the formulations in removing eggs of Pediculus humanus capitis (Phthiraptera: Pediculidae).

PubMed

Ortega-Insaurralde, Isabel; Toloza, Ariel Ceferino; Picollo, María Inés; Vassena, Claudia

2014-09-01

Head lice lay eggs in human head hairs in order to reproduce. There is a difficulty associated to the process of detaching these eggs: they are tightly gripped to the hair by a secretion produced by female head lice. The physical removal of eggs has become an important part of treatment of louse infestations. The finding of new products to loosen the eggs is necessary to avoid mistaken diagnosis or reinfestations. This work aimed to compare different kinds of pediculicide formulations in order to find if their presentations represented differences in the egg remover effect. We also wanted to present a new device to test the efficacy of the egg remover formulations. Products with creamy presentations (Bio infant lice and egg remover and hair conditioner) and one containing dimethicone (Nyda) showed the lower mean forces compared with the control (lower mean forces represented best removal activity). Whereas, the Biferdil egg remover (gel) and Nopucid Tribit (hydroalcoholic lotion) had no egg removal effect, presenting the highest mean forces (177.82 and 189.99 mN, respectively) compared with the control. Additionally, we proposed a removal index (RI) to compare the efficacy of different products on the egg removal activity (RI > 0, good performance). The higher index values were for Bio infant lice and egg remover (0.72) and Biferdil hair conditioner (0.58). The lowest index values were for Biferdil egg remover (-0.26) and Nopucid Tribit (-0.35).The formulation of over the counter pediculicides in the egg remover effect was discussed.

Assessment of topical versus oral ivermectin as a treatment for head lice.

PubMed

Ahmad, Hesham M; Abdel-Azim, Eman S; Abdel-Aziz, Rasha T

2014-01-01

Many medications are available for treatment of pediculosis capitis including ivermectin. Our aim is to compare the efficacy and safety of topical versus oral ivermectin in treatment of pediculosis capitis. Sixty-two patients with proved head lice infestation were included and divided into group I (31 patients; received single topical application of 1% ivermectin) and group II (31 patients; received single dose of oral ivermectin). Treatment was repeated after 1 week for nonresponders. At 1 week after treatment, the eradication rates and improvement of pruritus were significantly higher among patients who received topical than oral ivermectin. When a second treatment, topical or oral, was given to nonresponders, the cure rates of infestation and pruritus was 100% and 97% among patients treated with topical and oral ivermectin, respectively with no significant difference between the two groups. This study suggests that both topical and oral ivermectin demonstrate high efficacy and tolerability in treatment of pediculosis capitis. However, a single treatment with topical ivermectin provides significantly higher cure of infestation and faster relief of pruritus than oral ivermectin. In addition, whether topical or oral ivermectin is used to treat head lice, a second dose is required in some cases to ensure complete eradication. © 2014 Wiley Periodicals, Inc.

Evidence That Head and Body Lice on Homeless Persons Have the Same Genotype

PubMed Central

Veracx, Aurélie; Rivet, Romain; McCoy, Karen D.; Brouqui, Philippe; Raoult, Didier

2012-01-01

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

Evidence that head and body lice on homeless persons have the same genotype.

PubMed

Veracx, Aurélie; Rivet, Romain; McCoy, Karen D; Brouqui, Philippe; Raoult, Didier

2012-01-01

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.

[Lice and lice-borne diseases in humans].

PubMed

Houhamdi, L; Parola, P; Raoult, D

2005-01-01

Among the three lice which parasite the human being, the human body louse, Pediculus humanus humanus, is a vector of infectious diseases. It lives and multiplies in clothes and human infestation is associated with cold weather and a lack of hygiene. Three pathogenic bacteria are transmitted by the body louse: 1) Rickettsia prowazekii, the agent of epidemic typhus of which the most recent outbreak (and the largest since World War II) was observed during the civil war in Burundi; 2) Borrelia recurrentis, the agent of relapsing fever, historically responsible of massive outbreaks in Eurasia and Africa, which prevails currently in Ethiopia and neighboring countries; 3) Bartonella quintana, the agent of trench fever, bacillary angiomatosis, chronic bacteremia, endocarditis, and lymphadenopathy. Body louse infestation, associated with a decline in social and hygienic conditions provoked by civil unrest and economic instability, is reemergent worldwide. Recently, a forth human pathogen, Acinetobacter baumannii, has been associated to the body louse.

Oral ivermectin for the treatment of head lice infestation.

PubMed

Sanchezruiz, Wendy L; Nuzum, Donald S; Kouzi, Samir A

2018-05-22

Published literature describing the use of oral ivermectin for the treatment of head lice infestation is reviewed. In the United States and globally, head lice infestation, or pediculosis capitis, remains a public health issue with both social and medical implications. Treatment with oral or topical medications is typically required for head lice eradication. Resistance to traditional topical therapies for head lice infestation is increasing, creating a need for consideration of additional treatment options. A growing body of data describing the potential role of oral ivermectin for the treatment or prevention of head lice infestation is available. A literature search identified 5 clinical trials that evaluated safety and/or effectiveness outcomes of oral ivermectin use as an alternative to malathion, other topical prescription medications, and traditional, nonprescription remedies; those studies were conducted in various parts of the world (e.g., Australia, Brazil, Mexico, Egypt) and likely involved varying types and degrees of lice resistance. Clinical research findings to date, while not consistently robust, suggest that oral ivermectin is comparable or superior in effectiveness to other topical treatment options for head lice infestation while being well tolerated and favorably perceived by patients and caretakers. Oral ivermectin is an option for the treatment of head lice infestation, especially in individuals who have experienced a treatment failure. Published evidence from clinical trials indicates that oral ivermectin is as effective as currently available topical treatments. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Topical ivermectin 0.5% lotion for treatment of head lice.

PubMed

Deeks, Louise S; Naunton, Mark; Currie, Marian J; Bowden, Francis J

2013-09-01

To investigate the pharmacology, pharmacokinetics, efficacy, adverse effects, and place in therapy of a single application of topical ivermectin 0.5% lotion for head lice treatment. Literature was obtained by searching MEDLINE, PubMed, CINAHL, and Scopus (January 1980 to January 2013). Abstracts were searched for the terms ivermectin AND (head lice or pediculus or pediculosis), topical ivermectin, ivermectin lotion, ivermectin AND (pharmacology OR pharmacokinetics). The New Drug Application filed with the Food and Drug Administration and the product data sheets for ivermectin were obtained. All English-language articles retrieved from the search were evaluated for relevance to the objective. The recommended first-line head lice treatments in the United States are permethrin 1% or pyrethrins, with malathion 0.5% lotion used as a second-line treatment. Significantly more of the 289 head lice-infested participants using topical ivermectin 0.5% lotion were lice-free at day 15 when compared with vehicle control (73.8% vs 17.6%; P < .001) in 2 studies. Although this rate is lower than other third-line treatments (eg, spinosad 0.9% or benzyl alcohol 5%), topical ivermectin 0.5% lotion is well tolerated (pruritus, the most common adverse event, 0.9%) and requires only a single application. Topical ivermectin 0.5% lotion kills head lice by increasing chloride in muscle cells, causing hyperpolarization and paralysis. Only 1 application is required; when the treated eggs hatch, the lice are not viable because they cannot feed as a result of pharyngeal muscle paralysis. Minimal systemic absorption occurs following topical application. Studies have demonstrated that topical ivermectin 0.5% is a safe and efficacious treatment for head lice. Although it has no documented resistance, there is limited clinical experience, it requires a prescription, and it is expensive. Therefore it should be reserved as a third-line treatment for head lice in the United States.

Differential gene expression in laboratory strains of human head and body lice when challenged with Bartonella quintana, a pathogenic bacterium

PubMed Central

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.

2014-01-01

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

Differential gene expression in laboratory strains of human head and body lice when challenged with Bartonella quintana, a pathogenic bacterium.

PubMed

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

2014-04-01

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. © 2014 The Royal Entomological Society.

Effects of blood type and blood handling on feeding success, longevity and egg production in the body louse, Pediculus humanus humanus.

PubMed

Mumcuoglu, K Y; Danilevich, M; Zelig, O; Grinbaum, H; Friger, M; Meinking, T L

2011-03-01

The effects of feeding different types of human blood to human body lice, Pediculus humanus humanus L. (Phthiraptera: Pediculidae), on feeding success, longevity and numbers of eggs laid were investigated using an artificial blood-feeding system in the laboratory. No significant differences were found between lice fed on different human blood types for any of the parameters tested. However, when lice were fed on human blood of one blood type followed immediately by a different blood type, they took significantly smaller bloodmeals, their longevity was reduced and they laid fewer eggs per female than control lice that had been fed twice on the same human blood type. When lice were fed human blood that had been stored for 1-26 weeks, the quantity of blood taken, the proportion of lice that became fully engorged and lice longevity diminished gradually as the storage time of the blood increased, but there was no effect of storage time on the mean number of eggs laid per female. However, lice would not feed on 26-week-old blood. The type of anticoagulant used had a significant effect on the proportion fed, longevity and number of eggs laid per female. Generally, EDTA (ethylenediaminetetraacetic acid)-treated blood reduced longevity and the number of eggs laid per female to a greater degree than heparinized or citrated blood. Lice fed on rabbit blood took significantly larger amounts of blood, lived longer and laid a higher mean number of eggs per female than lice fed on human blood. © 2010 The Authors. Medical and Veterinary Entomology © 2010 The Royal Entomological Society.

The single mitochondrial chromosome typical of animals has evolved into 18 minichromosomes in the human body louse, Pediculus humanus.

PubMed

Shao, Renfu; Kirkness, Ewen F; Barker, Stephen C

2009-05-01

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.

Transmission ratio distortion in the human body louse, Pediculus humanus (Insecta: Phthiraptera).

PubMed

McMeniman, C J; Barker, S C

2006-01-01

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.

Variable microsatellite loci for population genetic analysis of Old World monkey lice (Pedicinus sp.).

PubMed

Scholl, Katlyn; Allen, Julie M; Leendertz, Fabian H; Chapman, Colin A; Reed, David L

2012-10-01

Parasitic lice have been valuable informants of their host's evolutionary history because they complete their entire life cycle on the host and move between hosts primarily through direct host-to-host contact. Therefore, lice are confined to their hosts both in ecological and evolutionary time. Lice on great apes have been studied to examine details of their host's evolutionary history; however, species of Pedicinus, which parasitize the Old World monkeys, are less well known. We sampled lice from 2 groups of red colobus (Procolobus spp.) in Kibale National Park in Uganda and from red colobus and black and white colobus (Procolobus polycomos) in Taï National Park in Côte d'Ivoire. We used next-generation sequencing data analysis and the human body louse (Pediculus humanus humanus) genome to search for microsatellites for population genetic studies of Pedicinus lice. The 96 primer sets for microsatellite loci designed from the human body louse genome failed to amplify microsatellites in Pedicinus sp., perhaps due to the fast rate of evolution in parasitic lice. Of 63 microsatellites identified by next-generation sequencing data analysis of Pedicinus sp., 12 were variable among populations and 9 were variable within a single population. Our results suggest that these loci will be useful across the genus Pedicinus. We found that the lice in Uganda are not structured according to their hosts' social group; rather, 2 non-interbreeding populations of lice were found on both groups of red colobus. Because direct host-to-host contact is usually required for lice to move among hosts, these lice could be useful for identification and study of behavioral interactions between primate species.

The single mitochondrial chromosome typical of animals has evolved into 18 minichromosomes in the human body louse, Pediculus humanus

PubMed Central

Shao, Renfu; Kirkness, Ewen F.; Barker, Stephen C.

2009-01-01

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

Experimentally infected human body lice (pediculus humanus humanus) as vectors of Rickettsia rickettsii and Rickettsia conorii in a rabbit model.

PubMed

Houhamdi, Linda; Raoult, Didier

2006-04-01

The human body louse, the natural vector of Rickettsia prowazekii, is able to experimentally transmit the normally flea-borne rickettsia R. typhi, suggesting that the relationships between the body louse and rickettsiae are not specific. We used our experimental infection model to test the ability of body lice to transmit two prevalent tick-borne rickettsiae. Each of two rabbits was made bacteremic by injecting intravenously 2 x 10(6) plaque-forming units of either R. rickettsii or R. conorii. Four hundred body lice were infected by feeding on the bacteremic rabbit and were compared with 400 uninfected lice. Each louse group was fed once a day on a separate seronegative rabbit. The survival of infected lice was not different from that of uninfected controls. Lice remained infected for their lifespan, excreted R. rickettsii and R. conorii in their feces, but did not transmit the infection to their progeny. The nurse rabbit of uninfected lice remained asymptomatic and seronegative. Those rabbits used to feed infected lice developed bacteremia and seroconverted. Although the body louse is not a known vector of spotted fevers, it was able in our study to acquire, maintain, and transmit both R. rickettsii and R. conorii.

Impact of family ownerships, individual hygiene, and residential environments on the prevalence of pediculosis capitis among schoolchildren in urban and rural areas of northwest of Iran.

PubMed

Dehghanzadeh, Reza; Asghari-Jafarabadi, Mohammad; Salimian, Shahin; Asl Hashemi, Ahmad; Khayatzadeh, Simin

2015-11-01

In the appraisal of head lice outbreak, in addition to socioeconomic factors and availability of health care services, environmental conditions of the households must be taken into account. However, interviewing with children or mailing questionnaires to families may not reflect the actualities. Therefore, in this study, all the inclusive factors which may be associated with head lice outbreak were thoroughly and closely investigated. The data were collected by examining students at schools and surveying patients' households. A questionnaire concerning children's personal hygienic practices, family features, and environmental conditions of the households was filled out during the close assessment of the residential area. The overall prevalence of head lice was obtained as 5.9%, and the difference was not significant within the urban (5.1%) and rural (6.1%) communities. Overall, the number of infested students was more frequent in girls (6.6%) than boys (2.8%), but the difference was not significant. The highest infestation rate was obtained in the examined students whose fathers were unemployed, farmer, and herdsman. Family income showed greater correlation with the prevalence of pediculosis capitis. A high frequency of pediculosis capitis was identified among the students who were sharing individual items with siblings. Assessment of households showed that room flooring material and keeping animals at home were highly correlated with head lice prevalence. Households should be informed that infestations happen, irrespective of socioeconomic status. However, the physical and environmental conditions of living areas and households play an important role in head lice prevention.

Genetic analysis of lice supports direct contact between modern and archaic humans.

PubMed

Reed, David L; Smith, Vincent S; Hammond, Shaless L; Rogers, Alan R; Clayton, Dale H

2004-11-01

Parasites can be used as unique markers to investigate host evolutionary history, independent of host data. Here we show that modern human head lice, Pediculus humanus, are composed of two ancient lineages, whose origin predates modern Homo sapiens by an order of magnitude (ca. 1.18 million years). One of the two louse lineages has a worldwide distribution and appears to have undergone a population bottleneck ca. 100,000 years ago along with its modern H. sapiens host. Phylogenetic and population genetic data suggest that the other lineage, found only in the New World, has remained isolated from the worldwide lineage for the last 1.18 million years. The ancient divergence between these two lice is contemporaneous with splits among early species of Homo, and cospeciation analyses suggest that the two louse lineages codiverged with a now extinct species of Homo and the lineage leading to modern H. sapiens. If these lice indeed codiverged with their hosts ca. 1.18 million years ago, then a recent host switch from an archaic species of Homo to modern H. sapiens is required to explain the occurrence of both lineages on modern H. sapiens. Such a host switch would require direct physical contact between modern and archaic forms of Homo.

Genetic Analysis of Lice Supports Direct Contact between Modern and Archaic Humans

PubMed Central

Smith, Vincent S; Hammond, Shaless L; Rogers, Alan R; Clayton, Dale H

2004-01-01

Parasites can be used as unique markers to investigate host evolutionary history, independent of host data. Here we show that modern human head lice, Pediculus humanus, are composed of two ancient lineages, whose origin predates modern Homo sapiens by an order of magnitude (ca. 1.18 million years). One of the two louse lineages has a worldwide distribution and appears to have undergone a population bottleneck ca. 100,000 years ago along with its modern H. sapiens host. Phylogenetic and population genetic data suggest that the other lineage, found only in the New World, has remained isolated from the worldwide lineage for the last 1.18 million years. The ancient divergence between these two lice is contemporaneous with splits among early species of Homo, and cospeciation analyses suggest that the two louse lineages codiverged with a now extinct species of Homo and the lineage leading to modern H. sapiens. If these lice indeed codiverged with their hosts ca. 1.18 million years ago, then a recent host switch from an archaic species of Homo to modern H. sapiens is required to explain the occurrence of both lineages on modern H. sapiens. Such a host switch would require direct physical contact between modern and archaic forms of Homo. PMID:15502871

Evaluation of an intervention program for head lice infestation in school children.

PubMed

Sarov, B; Neumann, L; Herman, Y; Naggan, L

1988-03-01

In order to investigate the point prevalence rate of pediculosis capitis (human head lice) among children in the southern region of Israel, 1431 elementary school children (6 to 15 years old), representing rural and urban environments, were examined and characterized by sociodemographic variables. An intervention program was initiated immediately after the first examination, which included "health education" for children and parents and free medicated shampoo (with pediculocides) provided for each child detected as "positive." The intervention program was evaluated by a second examination performed on the same population after an interval of 1 month. Fifty-five percent of the children (793 of 1431) were found to be infested with one of the markers of head lice, with the highest rate in kibbutz children (80%) and the lowest rate (37%) among children who live in an urban neighborhood of high socioeconomic status. Analysis of various characteristics (related to the children screened in this study) revealed that crowding was the main factor contributing to the variation in the rates of infestation. Evaluation of the intervention program revealed a significant success in reducing head lice infestation that was not influenced by variation in socioeconomic status or place of residence.

A New Clade of African Body and Head Lice Infected by Bartonella quintana and Yersinia pestis-Democratic Republic of the Congo.

PubMed

Drali, Rezak; Shako, Jean-Christophe; Davoust, Bernard; Diatta, Georges; Raoult, Didier

2015-11-01

The human body louse is known as a vector for the transmission of three serious diseases-specifically, epidemic typhus, trench fever, and relapsing fever caused by Rickettsia prowazekii, Bartonella quintana, and Borrelia recurrentis, respectively-that have killed millions of people. It is also suspected in the transmission of a fourth pathogen, Yersinia pestis, which is the etiologic agent of plague. To date, human lice belonging to the genus Pediculus have been classified into three mitochondrial clades: A, B, and C. Here, we describe a fourth mitochondrial clade, Clade D, comprising head and body lice. Clade D may be a vector of B. quintana and Y. pestis, which is prevalent in a highly plague-endemic area near the Rethy Health District, Orientale Province, Democratic Republic of the Congo. © The American Society of Tropical Medicine and Hygiene.

Odorant receptor-based discovery of natural repellents of human lice.

PubMed

Pelletier, Julien; Xu, Pingxi; Yoon, Kyong S; Clark, John M; Leal, Walter S

2015-11-01

The body louse, Pediculus humanus humanus, is an obligate blood-feeding ectoparasite and an important insect vector that mediates the transmission of diseases to humans. The analysis of the body louse genome revealed a drastic reduction of the chemosensory gene repertoires when compared to other insects, suggesting specific olfactory adaptations to host specialization and permanent parasitic lifestyle. Here, we present for the first time functional evidence for the role of odorant receptors (ORs) in this insect, with the objective to gain insight into the chemical ecology of this vector. We identified seven putative full-length ORs, in addition to the odorant receptor co-receptor (Orco), and expressed four of them in the Xenopus laevis oocytes system. When screened with a panel of ecologically-relevant odorants, PhumOR2 responded to a narrow set of compounds. At the behavior level, both head and body lice were repelled by the physiologically-active chemicals. This study presents the first evidence of the OR pathway being functional in lice and identifies PhumOR2 as a sensitive receptor of natural repellents that could be used to develop novel efficient molecules to control these insects. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Pubic lice

MedlinePlus

... humans. Other types of lice include: Body lice Head lice You are at greater risk for pubic lice ... Images Crab louse, female Pubic louse-male Crab lice Head louse and pubic louse References Diaz JH. Lice ( ...

Body lice

MedlinePlus

... other people. Two other types of lice are: Head lice Pubic lice Causes Body lice live in the ... the armpits. You should also be checked for head and pubic lice if you have body lice. Treatment To get ...

Tinea capitis in adults.

PubMed

Auchus, Isabella C; Ward, Kimberley M; Brodell, Robert T; Brents, Melissa J; Jackson, Jeremy D

2016-03-16

Tinea capitis is caused by dermatophyte fungi that utilize keratin as a nutrient source.  Scalp erythema, scaling, andcrusting are typical signs of this disease.  Although most commonly seen in prepubescent children, tinea capitis can occur in adults. Endothrix tinea capitis owing to Trichophyton tonsurans commonly produces generalized scaling and localized perifollicular inflammation reminiscent of lichen planopilaris. Ectothrix tinea capitis owing to Microsporum sp. produces well- demarcated erythematous plaques suggestive of psoriasis. H&E stained biopsy specimens, KOH preparations or fungal cultures will confirm the diagnosis. Because of a low index of suspicion for tinea capitis in adults with scaling and alopecia, diagnosis and appropriate treatment are often delayed. Resistance to treatment for seborrheic dermatitis or psoriasis should prompt a KOH, fungal culture orbiopsy to confirm the diagnosis of tinea capitis and initiate systemic antifungal agents.

Pediculosis capitis: prevalence and its associated factors in primary school children living in rural and urban areas in Kayseri, Turkey.

PubMed

Gulgun, Mustafa; Balci, Elçin; Karaoğlu, Abdülbaki; Babacan, Oğuzhan; Türker, Türker

2013-06-01

The aim of this study was to investigate the prevalence and risk factors of pediculosis capitis in schoolchildren living in rural and urban areas in Kayseri, a city located in central Anatolia in Turkey. This cross-sectional school-based study was performed in 24 randomly selected public schools. A total of 8,122 schoolchildren aged 5-16 years, from kindergarten to eighth grade, were examined for the presence of pediculosis capitis. A child was defined as being infested by the presence of live or dead lice or eggs/nits. The results were analyzed using the chi-squared test and logistic regression analysis. The overall prevalence of head lice infestation was 13.1%. Pediculosis was more frequent in girls (25.2%) than in boys (0.86%) (p < 0.001). The prevalence was lower in children aged 5-8 years than in those aged 9-11 or 12-16 years (p < 0.001). In multiple regression analyses, the variables demonstrating statistically significant association with pediculosis were: being a girl (OR = 40.93; 95% Cl = 29.06-57.66), being 9-11 years old (OR = 1.54; 95% Cl = 1.25-1.89), residing with > or = 3 siblings (OR = 1.98; 95% Cl = 1.57-2.50), having a mother with no education (OR = 1.73; 95% CI = 1.29-2.33), having a father with no education (OR = 1.45; 95% Cl = 1.08-1.94), living in a rural area (OR = 2.34; 95% Cl = 2.02-2.71) and living in a one-room house (OR = 2.39; 95% CI = 1.41-4.08). Pediculosis capitis remains a health problem in schoolchildren in Kayseri, Turkey. In addition to improvement in socioeconomic status, collaborative and participation efforts among physicians, nurses, teachers, and parents are necessary to maintain effective epidemiological surveillance and provide treatment.

Arrestant Effect of Human Scalp Components on Head Louse (Phthiraptera: Pediculidae) Behavior.

PubMed

Ortega-Insaurralde, Isabel; Ceferino Toloza, Ariel; Gonzalez-Audino, Paola; Inés Picollo, María

2017-03-01

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: journals.permissions@oup.com.

Body Lice

MedlinePlus

What are body lice? Body lice (also called clothes lice) are tiny insects which live and lay nits (lice eggs) on clothing. They are parasites, ... usually only move to the skin to feed. Body lice are one of the three types of ...

The sex ratio distortion in the human head louse is conserved over time

PubMed Central

Perotti, M Alejandra; Catalá, Silvia S; Ormeño, Analía del V; Żelazowska, Monika; Biliński, Szczepan M; Braig, Henk R

2004-01-01

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

Survey assessment on pediatricians’ attitudes on head lice management

PubMed Central

2013-01-01

Background Pediculosis capitis is a worldwide health problem. One of the most important factor in effective head lice eradication is to ensure that infestation is adequately recognized and treated. Our survey investigated the knowledge and practice among primary care Italian pediatricians regarding to the prevention and treatment of head lice. Methods The questionnaire was distributed to all the pediatricians registered at the Annual Congress of Practice in Pediatrics held in Florence, Italy, November 11–12, 2011. It includes 10 questions in a multiple choice format, and one answer for each question was provided. The questionnaire was conceived by pediatricians at the Infectious Disease Unit of the Department of Science for the Health of Woman and Child, University of Florence. Questions were designed according to the guidelines by the Italian Pediatric Society (SIP), and international guidelines, such as the Centers for Disease Control and Prevention (CDC), and the American Academy of Pediatrics (AAP). Results Overall, 364/600 pediatricians (60.7% of physicians registered to the Congress) returned the questionnaire. The majority of them (232/364; 63,7%) believe that parents consult their primary care pediatrician only after the failure of other “remedies”. Mostly, they prescribe Malathion (116/364, 31,8%) as first line treatment. Two-hundred-fourty-three (66.7%) of participants consider creams, foams and gels the most effective formulations. Two-hundred-sixty-two of pediatricians interviewed (72.0%) suggest to repeat the treatment after one week, 37/364 (10.2%) after two weeks. The majority of the pediatricians interviewed reported that recurrences occur in less than 30% of cases (279/364; 76,6%). In their own opinion, most of recurrences are the consequence of a reinfestation in the community (259/264; 77%). Three-hundred-thirty-four (91.7%) of them have never prescribed oral therapy for the treatment of head lice. Finally, 289/364 (79.4%) pediatricians

Survey assessment on pediatricians' attitudes on head lice management.

PubMed

Fancelli, Claudia; Prato, Manuela; Montagnani, Carlotta; Pierattelli, Monica; Becherucci, Paolo; Chiappini, Elena; de Martino, Maurizio; Galli, Luisa

2013-10-03

Pediculosis capitis is a worldwide health problem. One of the most important factor in effective head lice eradication is to ensure that infestation is adequately recognized and treated. Our survey investigated the knowledge and practice among primary care Italian pediatricians regarding to the prevention and treatment of head lice. The questionnaire was distributed to all the pediatricians registered at the Annual Congress of Practice in Pediatrics held in Florence, Italy, November 11-12, 2011. It includes 10 questions in a multiple choice format, and one answer for each question was provided. The questionnaire was conceived by pediatricians at the Infectious Disease Unit of the Department of Science for the Health of Woman and Child, University of Florence. Questions were designed according to the guidelines by the Italian Pediatric Society (SIP), and international guidelines, such as the Centers for Disease Control and Prevention (CDC), and the American Academy of Pediatrics (AAP). Overall, 364/600 pediatricians (60.7% of physicians registered to the Congress) returned the questionnaire. The majority of them (232/364; 63,7%) believe that parents consult their primary care pediatrician only after the failure of other "remedies". Mostly, they prescribe Malathion (116/364, 31,8%) as first line treatment. Two-hundred-fourty-three (66.7%) of participants consider creams, foams and gels the most effective formulations. Two-hundred-sixty-two of pediatricians interviewed (72.0%) suggest to repeat the treatment after one week, 37/364 (10.2%) after two weeks. The majority of the pediatricians interviewed reported that recurrences occur in less than 30% of cases (279/364; 76,6%). In their own opinion, most of recurrences are the consequence of a reinfestation in the community (259/264; 77%). Three-hundred-thirty-four (91.7%) of them have never prescribed oral therapy for the treatment of head lice. Finally, 289/364 (79.4%) pediatricians believe that no product is effective

Head Lice

MedlinePlus

What are head lice? Head lice are tiny insects that live on people's heads. Adult lice are about the size of sesame seeds. The eggs, called ... often at the neckline and behind the ears. Head lice are parasites, and they need to feed on ...

Household-wide ivermectin treatment for head lice in an impoverished community: randomized observer-blinded controlled trial

PubMed Central

Pilger, Daniel; Heukelbach, Jorg; Khakban, Adak; Oliveira, Fabiola Araujo; Fengler, Gernot

2010-01-01

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

Household-wide ivermectin treatment for head lice in an impoverished community: randomized observer-blinded controlled trial.

PubMed

Pilger, Daniel; Heukelbach, Jorg; Khakban, Adak; Oliveira, Fabiola Araujo; Fengler, Gernot; Feldmeier, Hermann

2010-02-01

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

Pediculosis capitis among Primary School Children and Related Risk Factors in Urmia, the Main City of West Azarbaijan, Iran.

PubMed

Tappeh, K Hazrati; Chavshin, Ar; Hajipirloo, H Mohammadzadeh; Khashaveh, S; Hanifian, H; Bozorgomid, A; Mohammadi, M; Gharabag, D Jabbari; Azizi, H

2012-01-01

Pediculosis capitis is cosmopolitan health problem. In addition to its physical problems, its psychological effects especially on pupils are more important. This study was conducted to determine the Pediculosis capitis among primary school pupils and also find out the role of probable related risk factors in Urmia city, Iran 2010. 35 primary schools of Urmia City according to the defined clusters randomly have been selected during 2010. 2040 pupils (866 boys and 1174 girls) were included and examined individually and privately by experts. Presence of adult or immature lice or having nits less than 1 cm from the hair basis were defined as positive. Data about demographic features and factors which their effect should be determined were recorded in standard questionnaire. Data were analyzed by SPSS software with proper statistical test. Infestation was determined around 4%. Girls show significantly greater infestation. The availability of suitable warm water for bathing and hair length (separately in girls and boys) are significantly related to infestation load as well as infestation among different age groups. There was no significant relation between parent's education and job and infestation as well as bathing repetition per week and the kind of energy source which they have. Also there is no significant correlation between educational grades and head lice infestation. The head louse pediculosis is a health problem and remains a health threatening for school children.Effective risk factors should be determined carefully and regionally. Proper training plays a great role in order to prevent and control the problem.

Examining the prevalence rate of Pediculus capitis infestation according to sex and social factors in primary school children

PubMed Central

Doroodgar, Abbas; Sadr, Fakhraddin; Doroodgar, Masoud; Doroodgar, Moein; Sayyah, Mansour

2014-01-01

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.

Acaricidal, pediculicidal and larvicidal activity of synthesized ZnO nanoparticles using Momordica charantia leaf extract against blood feeding parasites.

PubMed

Gandhi, P Rajiv; Jayaseelan, C; Mary, R Regina; Mathivanan, D; Suseem, S R

2017-10-01

The aim of the present study was to evaluate the acaricidal, pediculicidal and larvicidal effect of synthesized zinc oxide nanoparticles (ZnO NPs) using Momordica charantia leaf extract against the larvae of Rhipicephalus (Boophilus) microplus, adult of Pediculus humanus capitis, and the larvae of Anopheles stephensi, Culex quinquefasciatus. The ZnO NPs were characterized by using UV, XRD, FTIR and SEM-EDX. The SEM image confirms that the synthesized nanoparticles were spherical in shape with a size of 21.32 nm. The results of GC-MS analysis indicates the presence of the major compound of Nonacosane (C 29 H 60 ) in the M. charantia leaf extract. Cattle tick, head lice and mosquito larvae were exposed to a varying concentrations of the synthesized ZnO NPs and M. charantia leaf extract for 24 h. Compared to the leaf aqueous extract, biosynthesized ZnO NPs showed higher toxicity against R. microplus, P. humanus capitis, An. stephensi, and Cx. Quinquefasciatus with the LC 50 values of 6.87, 14.38, 5.42, and 4.87 mg/L, respectively. The findings revealed that synthesized ZnO NPs possess excellent anti-parasitic activity. These results suggest that the green synthesized ZnO NPs has the potential to be used as an ideal ecofriendly approach for the control of R. microplus, P. humanus capitis and the mosquito larvae of An. Stephensi and Cx. quinquefasciatus. Copyright © 2017 Elsevier Inc. All rights reserved.

The clinical trials supporting benzyl alcohol lotion 5% (Ulesfia): a safe and effective topical treatment for head lice (pediculosis humanus capitis).

PubMed

Meinking, Terri L; Villar, Maria E; Vicaria, Maureen; Eyerdam, Debbie H; Paquet, Diane; Mertz-Rivera, Kamara; Rivera, Hector F; Hiriart, Javier; Reyna, Susan

2010-01-01

Benzyl alcohol lotion 5% (BAL 5%) is a non-neurotoxic topical head lice treatment that is safe and effective in children as young as 6 months of age. The safety and efficacy of this pediculicide has been studied in 695 (confirm number) subjects in all phases of clinical development. Scanning electron micrographs (SEM) demonstrated that the active agent appears to stun the breathing spiracles open, enabling the vehicle to penetrate the respiratory mechanism (spiracles), therefore asphyxiating the lice. Initial phase II trials compared this novel product to RID using identical volumes of treatment (4 oz/application) and yielding, almost, identical efficacy. This outcome pointed to the significant importance of completely saturating the hair with the product in order to achieve maximum treatment success. A second phase II trial, which allowed the use of sufficient product to saturate the hair, resulted in 100% efficacy after both 10 and 30 minute treatments. A third phase II trial verified an effective dose. Phase III trials compared BAL 5% to vehicle placebo for two 10-minute applications. It proved to be safe and effective (p < 0.001) for treatment of head lice and is the first FDA-approved non-neurotoxic lice treatment, now available in the United States as Ulesfia lotion.

Head lice.

PubMed

Devore, Cynthia D; Schutze, Gordon E

2015-05-01

Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2010 clinical report on head lice was published by the American Academy of Pediatrics, newer medications have been approved for the treatment of head lice. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting. Copyright © 2015 by the American Academy of Pediatrics.

Head Lice among Governmental Primary School Students in Southern Jordan: Prevalence and Risk Factors.

PubMed

Khamaiseh, Abdullah Mousa

2018-01-01

Head lice, a common social and health problem among all age groups, is especially widespread among school-aged children. This study aimed to assess the prevalence of pediculosis capitis among governmental primary school students in Southern Jordan and its related risk factors. A sample of 500 primary schools students aged 6-12 from two male and two female public primary schools in four educational directorates were selected randomly in this cross-sectional study. Data were collected using a modified questionnaire that was completed by the students with the help of their parents. Students were then asked to return the questionnaire a day ahead of the examination date with a signed consent from the parents. SPSS software was used with Chi-square testing to study the significant relationship between lice infestation prevalence and the independent variables. Statistical significance was set at P < 0.05. The overall prevalence of lice infestation was 20.4% and was significantly higher among girls than boys. The prevalence rate was higher among rural residents, those living in shared rooms, families with a monthly income of <200 Jordanian Dinar, illiterate father and mother, those living in families with more than five members, houses with fewer than three rooms, students with longer hair, those with a history of infestation in the previous year, and students who share home articles with other family members. Female gender, low socioeconomic status, a history of contact, inadequate hygiene practices, and sharing articles were the major risk factors.

Ovicidal Response of NYDA Formulations on the Human Head Louse (Anoplura: Pediculidae) Using a Hair Tuft Bioassay

PubMed Central

STRYCHARZ, JOSEPH P.; LAO, ALICE R.; ALVES, ANNA-MARIA; CLARK, J. MARSHALL

2012-01-01

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. PMID:22493852

Tinea capitis: diagnostic criteria and treatment options.

PubMed

Meadows-Oliver, Mikki

2009-01-01

Tinea capitis is a fungal infection involving the hair shaft of the scalp. It is commonly referred to as ringworm and occurs primarily in children. Treatment with a systemic anti-fungal rather than topical treatment is required. Currently, two medications, griseofulvin (Grifulvin) and terbinafine (Lamisil Granules), are FDA-approved to treat tinea capitis. Treatment with griseofulvin is usually 6 to 8 weeks, while treatment with terbinafine requires 6 weeks. There are other medications currently not FDA-approved to treat tinea capitis that have similar cure rates and shorter durations of treatment for tinea capitis, and as a result, are being used off-label. This article reviews the research-based literature related to the treatment of tinea capitis with various pharmacologic agents.

Tinea capitis: diagnostic criteria and treatment options.

PubMed

Meadows-Oliver, Mikki

2009-01-01

Tinea capitis is a fungal infection involving the hair shaft of the scalp. It is commonly referred to as ringworm and occurs primarily in children. Treatment with a systemic anti-fingal rather than topical treatment is required. Currently, two medications, griseofulvin (Grifulvin) and terbinafine (Lamisil Granules), are FDA-approved to treat tinea capitis. Treatment with griseofulvin is usually 6 to 8 weeks, while treatment with terbinafine requires 6 weeks. There are other medications currently not FDA-approved to treat tinea capitis that have similar cure rates and shorter durations of treatment for tinea capitis, and as a result, are being used off-label. The research-based literature related to the treatment of tinea capitis with various pharmacologic agents is reviewed.

Tinea capitis in Lahore, Pakistan.

PubMed

Hussain, I; Aman, S; Haroon, T S; Jahangir, M; Nagi, A H

1994-04-01

The causative fungi of tinea capitis vary with geography and time. This study was planned to identify the etiologic agents and determine clinicoetiologic correlations of tinea capitis in Lahore, Pakistan. From clinically suspected cases of tinea capitis, skin scrapings and hair samples were taken and subjected to microscopy and culture. Of 180 evaluable patients, 95% were children below 12 years of age with equal sex incidence. Noninflammatory lesions were seen in 62.2% of cases. Trichophyton violaceum was the most common etiologic agent responsible for 69.4% of infection, followed by T. tonsurans (16.7%), T. verrucosum (10%), Microsporum audouinii (2.2%), and T. mentagrophytes (1.7%). T. violaceum is the predominant pathogen causing tinea capitis in children and adults in this part of the world and gives rise to a varied clinical picture. Our findings agree with data from other parts of Pakistan and many countries abroad.

A highly efficacious pediculicide based on dimeticone: Randomized observer blinded comparative trial

PubMed Central

Heukelbach, Jorg; Pilger, Daniel; Oliveira, Fabíola A; Khakban, Adak; Ariza, Liana; Feldmeier, Hermann

2008-01-01

Background Infestation with the human head louse (Pediculus humanus capitis) occurs worldwide. Existing treatment options are limited, and reports of resistance to commonly used pediculicides have been increasing. In this trial we assessed the efficacy of a product containing a high (92%) concentration of the silicone oil dimeticone (identical in composition to NYDA®), as compared to a 1% permethrin lotion. Methods Randomized, controlled, observer blinded clinical trial. Participants were recruited from a poor urban neighbourhood in Brazil where pediculosis capitis was highly prevalent. To minimize reinfestation during the trial, participants (145 children aged 5–15 years with head lice infestations) were transferred to a holiday resort outside the endemic area for a period of 9 days. Two applications of dimeticone or 1% permethrin were done, seven days apart. Outcome measures were defined as cure (absence of vital head lice) after first application and before and after second applications, degree of itching, cosmetic acceptability, and clinical pathology. Results Overall cure rates were: day 2 – dimeticone 94.5% (95% CI: 86.6% – 98.5%) and permethrin 66.7% (95% CI: 54.6% – 77.3%; p < 0.0001); day 7 – dimeticone 64.4% (95% CI: 53.3% – 75.3%) and permethrin 59.7% (95% CI: 47.5% – 71.1%; p = 0.5); day 9 – dimeticone 97.2% (95% CI: 90.3% – 99.7%) and permethrin 67.6% (95% CI: 55.4%-78.2%); p < 0.0001). Itching was reduced similarly in both groups. Cosmetic acceptability was significantly better in the dimeticone group as compared to the permethrin group (p = 0.01). Two mild product-related incidents occurred in the dimeticone group. Conclusion The dimeticone product is a safe and highly efficacious pediculicide. Due to its physical mode of action (interruption of the lice's oxygen supply of the central nervous system), development of resistance is unlikely. Trial registration Current Controlled Trials ISRCTN15117709. PMID:18783606

Effect of a health education program on reduction of pediculosis in school girls at Amphoe Muang, Khon Kaen Province, Thailand.

PubMed

Yingklang, Manachai; Sengthong, Chatchawan; Haonon, Ornuma; Dangtakot, Rungtiwa; Pinlaor, Porntip; Sota, Chulaporn; Pinlaor, Somchai

2018-01-01

Pediculosis caused by head lice (Pediculus humanus capitis) infestation is still an important health problem in schoolchildren, especially girls, worldwide, including in Thailand. Although pediculicidal agents effectively kill head lice, the re-infestation rate is still high. Thus, prevention is an important strategy for any sustainable control program. We aimed to develop and evaluate the efficacy of a health education program for increasing knowledge, changing attitudes and promoting preventive practices to reduce prevalence of pediculosis among school girls in Amphoe Muang, Khon Kaen, northeastern Thailand. Six schools were selected using multistage simple randomization and were allocated into intervention or control groups. A total of 267 girls was enrolled from these schools. A "knowledge, attitude and practice" (KAP) questionnaire, consent forms and health education materials were constructed and tested by experts and in one pilot school before the main investigation. Baseline prevalence of adult lice and nits was determined. The health education package was given only to the intervention group. The KAP questionnaire was re-evaluated at two months after intervention. At baseline, the prevalence and intensity of head lice infestation, and the KAP scores did not differ significantly between the two groups. After re-evaluation at two months, the KAP score was significantly greater in the intervention group. A significant decrease of the infestation rate from 59% to 44% was observed in the intervention group, whereas infestation increased in the control group (from 56% to 65%). The incidence of new cases in the intervention group (6.14%) was lower than in the control group (12.62%). These findings indicated that the newly-established health education package is an effective tool for increasing KAP and reducing head lice infestation in school girls. Efforts to combat pediculosis in schoolchildren elsewhere may consider including this, or a similar, health

A clinico-etiologic correlation in tinea capitis.

PubMed

Jahangir, M; Hussain, I; Khurshid, K; Haroon, T S

1999-04-01

Tinea capitis is a dermatophytosis with diverse clinical manifestations. The causative fungi of tinea capitis vary with geography and time. This study aimed to identify the etiologic agents and to determine the clinico-etiologic correlation of tinea capitis in Lahore, Pakistan. From clinically suspected cases of tinea capitis, skin scrapings and hair samples were taken and subjected to microscopy and culture. Of 100 evaluable patients, 95% were children below 12 years of age with almost equal sex incidence. Noninflammatory and inflammatory lesions were seen in 56.4% and 43.6%, respectively. Trichophyton violaceum was the most common etiologic agent, responsible for 82% of infection, followed by T. tonsurans (8%), T. verrucosum (5%), and T. mentagrophytes (5%). T. violaceum is the predominant pathogen causing tinea capitis in this part of the world, and gives rise to a varied clinical picture.

Head Lice among Governmental Primary School Students in Southern Jordan: Prevalence and Risk Factors

PubMed Central

Khamaiseh, Abdullah Mousa

2018-01-01

Background: Head lice, a common social and health problem among all age groups, is especially widespread among school-aged children. Aims: This study aimed to assess the prevalence of pediculosis capitis among governmental primary school students in Southern Jordan and its related risk factors. Settings and Design: A sample of 500 primary schools students aged 6–12 from two male and two female public primary schools in four educational directorates were selected randomly in this cross-sectional study. Materials and Methods: Data were collected using a modified questionnaire that was completed by the students with the help of their parents. Students were then asked to return the questionnaire a day ahead of the examination date with a signed consent from the parents. Statistical Analysis: SPSS software was used with Chi-square testing to study the significant relationship between lice infestation prevalence and the independent variables. Statistical significance was set at P < 0.05. Results and Conclusion: The overall prevalence of lice infestation was 20.4% and was significantly higher among girls than boys. The prevalence rate was higher among rural residents, those living in shared rooms, families with a monthly income of <200 Jordanian Dinar, illiterate father and mother, those living in families with more than five members, houses with fewer than three rooms, students with longer hair, those with a history of infestation in the previous year, and students who share home articles with other family members. Female gender, low socioeconomic status, a history of contact, inadequate hygiene practices, and sharing articles were the major risk factors. PMID:29563717

Tinea capitis in eastern Nepal.

PubMed

Jha, Bibeka Nand; Garg, Vijay Kumar; Agrawal, Sudha; Khanal, Basudha; Agarwalla, Arun

2006-02-01

Tinea capitis is an increasing public health concern throughout the world. The clinical types and etiological agents vary from time to time and place to place. This study was undertaken to identify the etiological agents and to determine the clinico-etiological correlation of tinea capitis in eastern Nepal. Sixty-nine clinically diagnosed cases of tinea capitis were enrolled in this study. Hair roots and skin scrapings were collected from each patient and subjected to microscopy and culture for identification of fungal hyphae and spores. Tinea capitis accounted for 4.6% of all dermatophyte infections: 68.1% occurred in patients below the age of 11 years with a male to female ratio of 1 : 1.9. "Gray patch" was the most common clinical type (52.2%), followed by "black dot" (17.4%), seborrhoeic dermatitis (13%), alopecia areata (11.6%) and pustular (4.3%). Direct microscopy of hair was positive in 62.3% of patients. Culture positivity was found in 56.7% of patients. Common isolated organisms were Trichophyton violaceum (48.71%), T. mentagrophytes (15.38%), T. tonsurans (12.82%), Microsporum canis (7.69%), T. rubrum and M. gypseum (5.12% each), and M. audouinii and M. nanum (2.56% each). Trichophyton violaceum was the most common pathogen of tinea capitis. The clinical manifestations were variable and "gray patch" was the most common clinical presentation in this part of the world.

Staphylococcus capitis isolated from prosthetic joint infections.

PubMed

Tevell, S; Hellmark, B; Nilsdotter-Augustinsson, Å; Söderquist, B

2017-01-01

Further knowledge about the clinical and microbiological characteristics of prosthetic joint infections (PJIs) caused by different coagulase-negative staphylococci (CoNS) may facilitate interpretation of microbiological findings and improve treatment algorithms. Staphylococcus capitis is a CoNS with documented potential for both human disease and nosocomial spread. As data on orthopaedic infections are scarce, our aim was to describe the clinical and microbiological characteristics of PJIs caused by S. capitis. This retrospective cohort study included three centres and 21 patients with significant growth of S. capitis during revision surgery for PJI between 2005 and 2014. Clinical data were extracted and further microbiological characterisation of the S. capitis isolates was performed. Multidrug-resistant (≥3 antibiotic groups) S. capitis was detected in 28.6 % of isolates, methicillin resistance in 38.1 % and fluoroquinolone resistance in 14.3 %; no isolates were rifampin-resistant. Heterogeneous glycopeptide-intermediate resistance was detected in 38.1 %. Biofilm-forming ability was common. All episodes were either early post-interventional or chronic, and there were no haematogenous infections. Ten patients experienced monomicrobial infections. Among patients available for evaluation, 86 % of chronic infections and 70 % of early post-interventional infections achieved clinical cure; 90 % of monomicrobial infections remained infection-free. Genetic fingerprinting with repetitive sequence-based polymerase chain reaction (rep-PCR; DiversiLab®) displayed clustering of isolates, suggesting that nosocomial spread might be present. Staphylococcus capitis has the potential to cause PJIs, with infection most likely being contracted during surgery or in the early postoperative period. As S. capitis might be an emerging nosocomial pathogen, surveillance of the prevalence of PJIs caused by S. capitis could be recommended.

[Pediculosis capita in childhood: epidemiological and socio-medical results from screening of school beginners].

PubMed

Jahnke, C; Bauer, E; Feldmeier, H

2008-11-01

Although pediculosis capitis is the most frequent parasitosis in childhood, reliable data on its epidemiology and morbidity are scarce. In Germany population-based data do not exist. During the routine medical examination of 5-6-year-old pre-school children in Braunschweig city (n=1 890) the children were also examined for the presence of head lice and head lice-associated pathology. Visual inspection of five predilection sites was used to diagnose head lice infestation. Knowledge of careers on head lice infestation and disease perception were analysed using a standardised questionnaire. Socio-demographic variables of the households to which the children belonged were correlated to current or historical head lice infestation. Head lice infestation was diagnosed in 14 out of the 1 890 children (0.7%). Considering the low sensitivity of visual inspection the true prevalence should be higher by a factor 3 to 4. In addition, 5.6% of the children examined had suffered from a head lice infestation in the previous 12 months. This results in an incidence of 598 cases per 10,000 children aged 5 to 6 years per year. Households with a low educational level of the parents and without a background of migration were significantly more often affected by pediculosis capitis during the previous 12 months. The analysis of the questionnaires showed a rather low level of knowledge about pediculosis capitis, a tendency towards polypragmatic therapeutic approaches and partially aberrant reactions such as hysteria. The knowledge about pediculosis capitis was significantly lower in parents with a low educational level. Our study provides for the first time reliable data on the prevalence, incidence and disease perception of head lice infestation as well as concerning the knowledge parents have about this parasitic skin disease.

Lice Aren't So Nice

MedlinePlus

... much scratching can lead to scalp infections. Lice Love Everyone Because lice are parasites, they will set ... lice are dirty doesn't know that lice love everyone and that includes the cleanest kid in ...

Evidence from mitochondrial DNA that head lice and body lice of humans (Phthiraptera: Pediculidae) are conspecific.

PubMed

Leo, N P; Campbell, N J H; Yang, X; Mumcuoglu, K; Barker, S C

2002-07-01

The specific status of the head and body lice of humans has been debated for more than 200 yr. To clarify the specific status of head and body lice, we sequenced 524 base pairs (bp) of the cytochrome oxidase I (COI) gene of 28 head and 28 body lice from nine countries. Ten haplotypes that differed by 1-5 bp at 11 nucleotide positions were identified. A phylogeny of these sequences indicates that these head and body lice are not from reciprocally monophyletic lineages. Indeed, head and body lice share three of the 10 haplotypes we found. F(ST) values and exact tests of haplotype frequencies showed significant differences between head and body lice. However, the same tests also showed significant differences among lice from different countries. Indeed, more of the variation in haplotype frequencies was explained by differences among lice from different countries than by differences between head and body lice. Our results indicate the following: (1) head and body lice do not represent reciprocally monophyletic lineages and are conspecific; (2) gene flow among populations of lice from different countries is limited; and (3) frequencies of COI haplotypes can be used to study maternal gene flow among populations of head and body lice and thus transmission of lice among their human hosts.

Alternative Splice in Alternative Lice

PubMed Central

Tovar-Corona, Jaime M.; Castillo-Morales, Atahualpa; Chen, Lu; Olds, Brett P.; Clark, John M.; Reynolds, Stuart E.; Pittendrigh, Barry R.; Feil, Edward J.; Urrutia, Araxi O.

2015-01-01

Genomic and transcriptomics analyses have revealed human head and body lice to be almost genetically identical; although con-specific, they nevertheless occupy distinct ecological niches and have differing feeding patterns. Most importantly, while head lice are not known to be vector competent, body lice can transmit three serious bacterial diseases; epidemictyphus, trench fever, and relapsing fever. In order to gain insights into the molecular bases for these differences, we analyzed alternative splicing (AS) using next-generation sequencing data for one strain of head lice and one strain of body lice. We identified a total of 3,598 AS events which were head or body lice specific. Exon skipping AS events were overrepresented among both head and body lice, whereas intron retention events were underrepresented in both. However, both the enrichment of exon skipping and the underrepresentation of intron retention are significantly stronger in body lice compared with head lice. Genes containing body louse-specific AS events were found to be significantly enriched for functions associated with development of the nervous system, salivary gland, trachea, and ovarian follicle cells, as well as regulation of transcription. In contrast, no functional categories were overrepresented among genes with head louse-specific AS events. Together, our results constitute the first evidence for transcript pool differences in head and body lice, providing insights into molecular adaptations that enabled human lice to adapt to clothing, and representing a powerful illustration of the pivotal role AS can play in functional adaptation. PMID:26169943

High diversity and rapid diversification in the head louse, Pediculus humanus (Pediculidae: Phthiraptera)

PubMed Central

Ashfaq, Muhammad; Prosser, Sean; Nasir, Saima; Masood, Mariyam; Ratnasingham, Sujeevan; Hebert, Paul D. N.

2015-01-01

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

Head Lice (For Parents)

MedlinePlus

... Videos for Educators Search English Español First Aid: Head Lice KidsHealth / For Parents / First Aid: Head Lice Print A head louse is a tiny, wingless ... Prevention! You can help protect your kids from head lice by teaching them to: avoid head-to-head ...

Head Lice to Dead Lice: Safe Solutions for Frantic Families. A New Treatment Program To Address Persistent Head Lice Infestations. [Videotape].

ERIC Educational Resources Information Center

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…

Alternative Splice in Alternative Lice.

PubMed

Tovar-Corona, Jaime M; Castillo-Morales, Atahualpa; Chen, Lu; Olds, Brett P; Clark, John M; Reynolds, Stuart E; Pittendrigh, Barry R; Feil, Edward J; Urrutia, Araxi O

2015-10-01

Genomic and transcriptomics analyses have revealed human head and body lice to be almost genetically identical; although con-specific, they nevertheless occupy distinct ecological niches and have differing feeding patterns. Most importantly, while head lice are not known to be vector competent, body lice can transmit three serious bacterial diseases; epidemictyphus, trench fever, and relapsing fever. In order to gain insights into the molecular bases for these differences, we analyzed alternative splicing (AS) using next-generation sequencing data for one strain of head lice and one strain of body lice. We identified a total of 3,598 AS events which were head or body lice specific. Exon skipping AS events were overrepresented among both head and body lice, whereas intron retention events were underrepresented in both. However, both the enrichment of exon skipping and the underrepresentation of intron retention are significantly stronger in body lice compared with head lice. Genes containing body louse-specific AS events were found to be significantly enriched for functions associated with development of the nervous system, salivary gland, trachea, and ovarian follicle cells, as well as regulation of transcription. In contrast, no functional categories were overrepresented among genes with head louse-specific AS events. Together, our results constitute the first evidence for transcript pool differences in head and body lice, providing insights into molecular adaptations that enabled human lice to adapt to clothing, and representing a powerful illustration of the pivotal role AS can play in functional adaptation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Eradication of Lice in Cattle

PubMed Central

Nafstad, O; Grønstøl, H

2001-01-01

The purpose of this field study was to develop and evaluate eradication as a strategy to control lice in cattle. Thirty-three herds of cattle were selected and observed during a period of two and a half years. Before eradication, biting lice (Damalinia bovis) were present in 94% of the herds and 27% of the animals. Sucking lice (Linognathus vituli) were present in 42% of the herds and 5% of the animals. These levels were very similar to those reported from other countries in Northern Europe. The eradication strategy was successful in 28 of 33 herds, but lice were still present in 5 herds 3 to 6 months after treatment. Biting lice were present in all these 5 herds, sucking lice were present in 3 herds. During the next 12 months, nine of the 28 herds were reinfected with lice. Six herds were reinfected with just biting lice, 2 herds with just sucking lice and one herd was reinfected with both. There was no significant difference between the 2 louse species regarding the risk of unsuccessful eradication or reinfection. The only significant risk factor for reinfection was either purchase of livestock or use of common pasture, combined with failure in pre-treatment of newly introduced animals. PMID:11455904

Human Lice in Paleoentomology and Paleomicrobiology.

PubMed

Drali, Rezak; Mumcuoglu, Kosta; Raoult, Didier

2016-08-01

Lice are a classic example of cospeciation. Human lice confirm this cospeciation with lice specialized in hominids which differ from those of gorillas and chimpanzees. Head lice and body lice seem to belong to closely related species with different ecotypes and a different geographical distribution which may reflect population movements. Paleo-entomology allows us in some cases to trace the migrations of archaic human populations. The analysis of lice found on mummies in Egypt and South America has clarified a certain number of these migrations, also the study of lice and the diseases they transmit has shed a new light on the epidemics of the past.

[Tinea capitis by Microsporum gypseum, an infrequent species].

PubMed

García-Agudo, Lidia; Espinosa-Ruiz, Jorge J

2018-04-01

Tinea capitis is considered the most frequent dermatophyte infection in children. The etiological agents vary from time to time and by geographical area, although they normally are zoophilic dermatophytes and in the last years also anthropophilic species. We report a clinical case of inflammatory tinea capitis in a 6-year-old child caused by Microsporum gypseum, a geophilic fungus pathogenic to humans and animals. The sources of human infection are soil, cats, dogs and small mammals. This species is less frequent as a cause of dermatophytosis in humans, described mainly in tinea corporis and rarely in tinea capitis. In the diagnosis of tinea capitis identifying the causative species is a determinant of the treatment. Sociedad Argentina de Pediatría.

Tinea capitis among children in the Columbus area, Ohio, USA.

PubMed

Coloe, Jacquelyn R; Diab, Mohammad; Moennich, Jessica; Diab, Diab; Pawaskar, Manjiri; Balkrishnan, Rajesh; Bechtel, Mark A

2010-03-01

Tinea capitis is a fungal infection of the hair follicles of the scalp. In the US, the most common organisms have traditionally been Trichophyton tonsurans, and occasionally Microsporum canis. This study was designed to examine patterns of organisms causing tinea capitis and determine factors associated with infection. A retrospective database analysis was conducted to locate records of patients with tinea capitis from May 2001 to May 2006 at Nationwide Children's Hospital in Columbus, OH. Descriptive statistics, frequency analysis, chi-squared test, and Student's t-test were performed to evaluate types of causative organisms and associated patient characteristics. One hundred and eighty-nine charts of patients with a positive scalp culture for tinea capitis were located. Trichophyton tonsurans (88.9%) was the foremost causative agent followed by Trichophyton violaceum (4.2%). Tinea capitis was more prevalent among African Americans and was more common in urban areas (P < 0.05). Children of African descent inhabiting urban settings were most vulnerable to tinea capitis. The most common organism isolated in this retrospective study was T. tonsurans. Trichophyton violaceum and Trichophyton soudanense were also isolated, which are not commonly reported causes of tinea capitis in the US.

Tinea Capitis in Children and Trichoscopic Criteria.

PubMed

Elghblawi, Ebtisam

2017-01-01

Tinea capitis is the most common pediatric superficial dermatophyte infection. The causative species vary, as for instance, Microsporum canis predominates in Europe, while Trichophyton tonsurans predominates in North America. Tinea capitis does not respond well to topical therapy alone, thus oral therapy is requisite. The drug of choice is griseofulvin; however in some countries, it is no longer available. Fungal culture should be requested in the persistent, scalp lesion and trichoscopy can put forward a speedy diagnosis by its characteristic findings. Scalp dermoscopy or "trichoscopy" represents a valuable, noninvasive technique for the evaluation of patients with hair loss due to tenia capitis. It is simple, quick, and easy to perform.

Distinguishing body lice from head lice by multiplex real-time PCR analysis of the Phum_PHUM540560 gene.

PubMed

Drali, Rezak; Boutellis, Amina; Raoult, Didier; Rolain, Jean Marc; Brouqui, Philippe

2013-01-01

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. 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. 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. We confirmed that the Phum_PHUM540560 gene is a useful genetic marker for the study of lice.

Tinea Capitis in Children and Trichoscopic Criteria

PubMed Central

Elghblawi, Ebtisam

2017-01-01

Tinea capitis is the most common pediatric superficial dermatophyte infection. The causative species vary, as for instance, Microsporum canis predominates in Europe, while Trichophyton tonsurans predominates in North America. Tinea capitis does not respond well to topical therapy alone, thus oral therapy is requisite. The drug of choice is griseofulvin; however in some countries, it is no longer available. Fungal culture should be requested in the persistent, scalp lesion and trichoscopy can put forward a speedy diagnosis by its characteristic findings. Scalp dermoscopy or “trichoscopy” represents a valuable, noninvasive technique for the evaluation of patients with hair loss due to tenia capitis. It is simple, quick, and easy to perform. PMID:28839385

[Human pediculosis, or how to treat lice infestations?].

PubMed

García Sanchón, Carlos

2004-05-01

The author reports on relevant aspects of pediculosis humanus, citing the lice species implicated, their location in the zones affected by lice infestations on human bodies and in their clothing; furthermore, he describes the most frequent lesions produced by lice, the adequate handling of lice infestations and their treatment. Lice are not a recent phenomenon; probably the lice which we encounter today acting as a parasite on humans is very similar to lice which infested humans centuries ago.

Lice induced immuno-oxidative wreckage of goats.

PubMed

Ajith, Y; Dimri, U; Singh, Shanker K; Gopalakrishnan, A; Devi, Gopinath; Verma, M R; Joshi, Vivek; Alam, Shahjahan

2017-08-15

The present study aimed to evaluate the immuno-oxidative patho-biology of lice infestation in goats. Sixty goats were divided into five groups; sucking lice (Linognathus africanus) infested (Group 1, n=12), chewing lice (Bovicola caprae) infested-mild (Group 2, n=12), chewing lice (B. caprae) infested-moderate (Group 3, n=12), chewing lice (B. caprae) infested-severe (Group 4, n=12) and healthy control (Group 5, n=12). To assess the pathological changes, markers of oxidative stress (lipid peroxidation-LPO, reduced glutathione-GSH, superoxide dismutase-SOD, Catalase-CAT and total antioxidant capacity-TAC), the markers of immune status (Tumour necrosis factor alpha- TNF-α, Interleukin-10- IL-10, Transforming growth factor beta 1- TGF-β1, ratios of TNF-α/IL-10 and TNF-α/TGF-β1) and hemato-biochemical status were evaluated. Significant anemia, hypoglycemia, hypoproteinemia and hypoalbuminemia were observed in caprine pediculosis irrespective of the type of lice infested. Remarkably increased oxidative stress was observed in chewing lice infested goats and no significant changes in oxidative stress markers were observed in sucking lice infested goats. TGF-β mediated suppression of Th1 and Th2 immune responses was observed in sucking lice infested goats; whereas, a Th2 cytokine dominant inflammatory response was observed in chewing lice infested goats. From the present study, it may be concluded that sucking lice infestation produces remarkable immunosuppression and chewing lice infestation produces significant oxidative stress and inflammatory responses in goats. Copyright © 2017 Elsevier B.V. All rights reserved.

Lice outbreak in buffaloes: evidence of Anaplasma marginale transmission by sucking lice Haematopinus tuberculatus.

PubMed

Da Silva, Aleksandro Schafer; Lopes, Leandro Sâmia; Diaz, Jorge Damian Stumpfs; Tonin, Alexandre Alberto; Stefani, Lenita Moura; Araújo, Denise Nunes

2013-06-01

Lice infestations are commonly seen in buffaloes, causing damage directly to the animal, i.e., itching, skin lesions, and anemia. In addition, these insects can also be vectors for infectious diseases. The present study describes an outbreak of lice in buffaloes as well as evidence for Haematopinus tuberculatus acting as a vector of anaplasmosis. Lice and blood were collected from 4 young buffaloes (2- to 4-mo-old) and a molecular analysis for the presence of Anaplasma marginale was conducted. DNA of A. marginale was detected in the blood of all 4 animals. Twelve lice were collected and separated in 4 groups, with 3 insects each, to comprise a pool of samples. After DNA extraction and molecular analysis, a positive PCR for A. marginale was found in all pooled samples. These results identify sucking lice as potential vectors of anaplasmosis. However, additional studies are necessary to fully evaluate the vector potential of H. tuberculatus for A. maginale transmission.

Head Lice.

PubMed

Meister, Laura; Ochsendorf, Falk

2016-11-11

Conflicting information about the proper treatment of head lice has given rise to uncertainty among patients and treating personnel. For example, the reported efficacy of permethrin fell from 97% in the 1990s to 30% in 2010. Review of the literature based on a selective search of PubMed. In Germany, outbreaks of head lice mainly occur among 5- to 13-year-olds returning to school after the summer vacation. Nymphs hatch from eggs after an average of 8 days and become sexually mature lice over the ensuing 9 days. The main route of transmission is direct head-to-head contact; transmission via inanimate objects is of no relevance. Symptoms arise 4-6 weeks after an initial infestation; many affected persons have no symptoms at all. Wet combing is the most sensitive method of establishing the diagnosis and monitoring treatment. Resistance to neurotoxic pediculocidal drugs is increasing around the world. Dimethicones are the treatment of choice, with 97% efficacy. Outbreaks must be managed with the synchronous treatment of all infested persons to break the chain of infestation. If the agent used is not ovicidal, the treatment must be repeated in 8-10 days and sometimes in a further 7 days as well. Outbreaks of head lice can be successfully terminated by synchronous treatment with ovicidal dimethicones.

Head Lice - Multiple Languages

MedlinePlus

... Are Here: Home → Multiple Languages → All Health Topics → Head Lice URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Head Lice - Multiple Languages To use the sharing features on ...

Using lice to identify cowbird hosts

USGS Publications Warehouse

Hahn, D.C.; Osenton, P.C.; Price, R.W.

1995-01-01

Avian lice may link fledgling Brown-headed Cowbirds to the host species that raised them. Lice, if host-specific and transferred to nestling cowbirds, could serve to identify the principal host species raising cowbirds in a local area. This approach of trapping cowbird fledglings in a feeding flock, then collecting and identifying the lice they carry is economical. The alternative requires a team of people to locate large numbers of parasitized host nests. We trapped 250 cowbird fledglings during June-August 1994 on Patuxent Research Center, and from them we collected 426 lice identified as representing 6 genera and 12 species. We. also collected and identified 347 lice from 30 known host species that were mist-netted on our Center. The lice found on cowbird fledglings in this population can be linked to Wood Thrush, Red-eyed Vireo, Common Yellowthroat, Rufous-sided Towhee, Red-winged Blackbird, Common Grackle, Song Sparrow, Field Sparrow, and Tree sparrow, based on this study and also on published reports.

Primates, Lice and Bacteria: Speciation and Genome Evolution in the Symbionts of Hominid Lice

PubMed Central

Allen, Julie M.; Nguyen, Nam-Phuong; Vachaspati, Pranjal; Quicksall, Zachary S.; Warnow, Tandy; Mugisha, Lawrence; Johnson, Kevin P.; Reed, David L.

2017-01-01

Abstract Insects with restricted diets rely on symbiotic bacteria to provide essential metabolites missing in their diet. The blood-sucking lice are obligate, host-specific parasites of mammals and are themselves host to symbiotic bacteria. In human lice, these bacterial symbionts supply the lice with B-vitamins. Here, we sequenced the genomes of symbiotic and heritable bacterial of human, chimpanzee, gorilla, and monkey lice and used phylogenomics to investigate their evolutionary relationships. We find that these symbionts have a phylogenetic history reflecting the louse phylogeny, a finding contrary to previous reports of symbiont replacement. Examination of the highly reduced symbiont genomes (0.53–0.57 Mb) reveals much of the genomes are dedicated to vitamin synthesis. This is unchanged in the smallest symbiont genome and one that appears to have been reorganized. Specifically, symbionts from human lice, chimpanzee lice, and gorilla lice carry a small plasmid that encodes synthesis of vitamin B5, a vitamin critical to the bacteria-louse symbiosis. This plasmid is absent in an old world monkey louse symbiont, where this pathway is on its primary chromosome. This suggests the unique genomic configuration brought about by the plasmid is not essential for symbiosis, but once obtained, it has persisted for up to 25 My. We also find evidence that human, chimpanzee, and gorilla louse endosymbionts have lost a pathway for synthesis of vitamin B1, whereas the monkey louse symbiont has retained this pathway. It is unclear whether these changes are adaptive, but they may point to evolutionary responses of louse symbionts to shifts in primate biology. PMID:28419279

Pubic lice: an endangered species?

PubMed

Dholakia, Shamik; Buckler, Jonathan; Jeans, John Paul; Pillai, Andrew; Eagles, Natasha; Dholakia, Shruti

2014-06-01

The incidence of pubic lice infestations is estimated to be between 1.3% and 4.6%, with an average incidence of 2% worldwide. It is also estimated that 70% to 80% of adults now remove pubic hair in part or entirety, using a variety of methods. It is hypothesized that the destruction of this pubic hair habitat may account for the falling incidence of pubic lice and may possibly lead to its eradication or atypical presentation. To report the changing incidence of pubic lice infestation from our unit over the last 10 years and assess its association, if any, with pubic hair removal of any kind. Assessment of medical records and questionnaires were used to identify the incidence of hair removal and pubic lice infestation over a 10-year period. Data were anonymized and analyzed to identify any correlation. A significant and strong correlation between the falling incidence of pubic lice infections and increase in pubic hair removal was observed, with a Pearson correlation r value of 0.9686 (95% confidence intervals, 0.88-0.992). The P value is less than 0.0001. The increased incidence of hair removal may lead to atypical patterns of pubic lice infestations or its complete eradication as the natural habitat of this parasite is destroyed.

Evidence for an African cluster of human head and body lice with variable colors and interbreeding of lice between continents.

PubMed

Veracx, Aurélie; Boutellis, Amina; Merhej, Vicky; Diatta, Georges; Raoult, Didier

2012-01-01

Human head lice and body lice have been classified based on phenotypic characteristics, including geographical source, ecotype (preferred egg laying site hair or clothes), shape and color. More recently, genotypic studies have been based on mitochondrial genes, nuclear genes and intergenic spacers. Mitochondrial genetic analysis reclassified lice into three genotypes (A, B and C). However, no previous study has attempted to correlate both genotypic and phenotypic data. Lice were collected in four African countries: Senegal, Burundi, Rwanda and Ethiopia and were photographed to compare their colors. The Multi-Spacer-Typing (MST) method was used to genotype lice belonging to the worldwide Clade A, allowing a comparison of phenotypic and genotypic data. No congruence between louse color and genotype has been identified. Phylogenetic analysis of the spacer PM2, performed including lice from other sources, showed the existence of an African cluster of human lice. However, the analysis of other spacers suggested that lice from different areas are interbreeding. We identified two geotypes of Clade A head and body lice including one that is specifically African, that can be either black or grey and can live on the head or in clothing. We also hypothesized that lice from different areas are interbreeding.

21 CFR 880.5960 - Lice removal kit.

Code of Federal Regulations, 2014 CFR

2014-04-01

... § 880.5960 Lice removal kit. (a) Identification. The lice removal kit is a comb or comb-like device intended to remove and/or kill lice and nits from head and body hair. It may or may not be battery operated... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lice removal kit. 880.5960 Section 880.5960 Food...

21 CFR 880.5960 - Lice removal kit.

Code of Federal Regulations, 2013 CFR

2013-04-01

... § 880.5960 Lice removal kit. (a) Identification. The lice removal kit is a comb or comb-like device intended to remove and/or kill lice and nits from head and body hair. It may or may not be battery operated... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Lice removal kit. 880.5960 Section 880.5960 Food...

21 CFR 880.5960 - Lice removal kit.

Code of Federal Regulations, 2012 CFR

2012-04-01

... § 880.5960 Lice removal kit. (a) Identification. The lice removal kit is a comb or comb-like device intended to remove and/or kill lice and nits from head and body hair. It may or may not be battery operated... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Lice removal kit. 880.5960 Section 880.5960 Food...

21 CFR 880.5960 - Lice removal kit.

Code of Federal Regulations, 2010 CFR

2010-04-01

... § 880.5960 Lice removal kit. (a) Identification. The lice removal kit is a comb or comb-like device intended to remove and/or kill lice and nits from head and body hair. It may or may not be battery operated... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lice removal kit. 880.5960 Section 880.5960 Food...

21 CFR 880.5960 - Lice removal kit.

Code of Federal Regulations, 2011 CFR

2011-04-01

... § 880.5960 Lice removal kit. (a) Identification. The lice removal kit is a comb or comb-like device intended to remove and/or kill lice and nits from head and body hair. It may or may not be battery operated... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Lice removal kit. 880.5960 Section 880.5960 Food...

[Scalp ringworm tinea capitis in Tunisian infants].

PubMed

Meziou, T J; Dammak, A; Zaz, T; Mseddi, M; Boudaya, S; Bouzid, L; Akrout, F; Maalej, S; Ayadi, A; Turki, H

2011-09-01

The aim of the study was to specify the epidemiological, clinical, and mycological particularities of tinea capitis in infants. We retrospectively collected data from the files of 245 infants presenting with tinea capitis, followed in the Hedi-Chaker hospital dermatology department and in two mycology laboratories of the Sfax hospital, between January 1995 and December 2006. We collected the epidemiological, clinical, and mycological data for each patient. We included 137 boys and 108 girls with trichophytic tinea in 62 % of cases and microsporic tinea in 34 % of cases. Trichophyton violaceum and Microsporum canis were identified by culture respectively in 51 and 37 % of cases. Tinea capitis is frequent observed in our region, Trichophyton violaceum and Microsporum canis are the most frequent mycological agents. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Black Dot Tinea Capitis in an Immunosuppressed Man

PubMed Central

Mendese, Gary W.; Loo, Daniel S.

2013-01-01

Tinea capitis is a common superficial fungal infection of the scalp primarily afflicting young children. In adults, this infection may have an atypical presentation that may lead to a delay in diagnosis. The authors present a case report of black dot tinea capitis in an immunosuppressed Asian man with psoriasis and provide a review of the literature. PMID:23710273

Multiple origins of parasitism in lice.

PubMed Central

Johnson, Kevin P.; Yoshizawa, Kazunori; Smith, Vincent S.

2004-01-01

A major fraction of the diversity of insects is parasitic, as herbivores, parasitoids or vertebrate ectopara sites. Understanding this diversity requires information on the origin of parasitism in various insect groups. Parasitic lice (Phthiraptera) are the only major group of insects in which all members are permanent parasites of birds or mammals. Lice are classified into a single order but are thought to be closely related to, or derived from, book lice and bark lice (Psocoptera). Here, we use sequences of the nuclear 18S rDNA gene to investigate the relationships among Phthiraptera and Psocoptera and to identify the origins of parasitism in this group (termed Psocodea). Maximum-likelihood (ML), Bayesian ML and parsimony analyses of these data indicate that lice are embedded within the psocopteran infraorder Nanopsocetae, making the order Psocoptera paraphyletic (i.e. does not contain all descendants of a single common ancestor). Furthermore, one family of Psocoptera, Liposcelididae, is identified as the sister taxon to the louse suborder Amblycera, making parasitic lice (Phthiraptera) a polyphyletic order (i.e. descended from two separate ancestors). We infer from these results that parasitism of vertebrates arose twice independently within Psocodea, once in the common ancestor of Amblycera and once in the common ancestor of all other parasitic lice. PMID:15315891

Tinea capitis: temporal shift in pathogens and epidemiology.

PubMed

Ziegler, Wiebke; Lempert, Sigrid; Goebeler, Matthias; Kolb-Mäurer, Annette

2016-08-01

Tinea capitis is the most common type of dermatomycosis in children. Its pathogen profile shows geographic variations as well as temporal shifts. Data from 150 patients with mycologically confirmed tinea capitis treated at the Department of Dermatology, University Hospital Würzburg, between 1990 and 2014 were analyzed with respect to gender, age, and pathogen spectrum. Two time periods, each 12.5 years long, were compared. Although tinea capitis was most frequently diagnosed in children between the ages of 0 and 5, the percentage of adults (16 %) was higher than previously reported. The zoophilic dermatophyte Microsporum canis was most frequently identified as the causative agent of tinea capitis. However, there was a rise in infections caused by the anthropophilic fungi Trichophyton tonsurans and Trichophyton rubrum, and also a trend towards a lower percentage of zoophilic versus anthropophilic pathogens. Over the course of time, we observed an increase in the diversity of the pathogen spectrum. Dermatophytes such as Trichophyton soudanense, the Trichophyton anamorph of Arthroderma benhamiae, Trichophyton schoenleinii, and Microsporum audouinii were isolated either for the first time or for the first time after a long hiatus. Although Microsporum canis infections still predominate, there has been an increase in anthropophilic pathogens. Given the unexpectedly high percentage of adults, tinea capitis should be included in the differential diagnostic considerations in all age groups. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Tinea capitis: Erregerspektrum und Epidemiologie im zeitlichen Wandel.

PubMed

Ziegler, Wiebke; Lempert, Sigrid; Goebeler, Matthias; Kolb-Mäurer, Annette

2016-08-01

Die Tinea capitis ist die häufigste Dermatomykose des Kindesalters. Das Erregerprofil zeigt unterschiedliche geographische Verteilungsmuster und variiert im Laufe der Zeit. Zwischen 1990-2014 an der Würzburger Universitätsklinik für Dermatologie erhobene Daten von 150 Patienten mit mykologisch gesicherter Tinea capitis wurden hinsichtlich Alter, Geschlecht und Erregerspektrum analysiert und über zwei Zeiträume von jeweils 12,5 Jahren miteinander verglichen. Obwohl eine Tinea capitis am häufigsten bei Kindern der Altersgruppe zwischen 0 und 5 Jahren diagnostiziert wurde, lag der Anteil betroffener Erwachsener mit 16 % höher als bislang berichtet. Der zoophile Dermatophyt Microsporum canis konnte am häufigsten als Erreger der Tinea capitis identifiziert werden, jedoch war ein Anstieg von Infektionen mit den anthropophilen Pilzen Trichophyton tonsurans und Trichophyton rubrum zu verzeichnen. Tendenziell sank der Anteil zoophiler im Verhältnis zu den anthropophilen Erregern. Im zeitlichen Verlauf zeigte sich eine zunehmende Heterogenität des Erregerspektrums: Dermatophyten wie Trichophyton soudanense und Trichophyton violaceum, Trichophyton anamorph von Arthroderma benhamiae sowie Trichophyton schoenleinii und Microsporum audouinii konnten erstmalig bzw. nach langer Zeit wieder erneut isoliert werden. Wenngleich Microsporum-canis-Infektionen noch dominieren, sind zunehmend anthropophile Erreger nachzuweisen. Angesichts des unerwartet hohen Anteils von Erwachsenen sollte eine Tinea capitis in allen Altersgruppen differenzialdiagnostisch in Betracht gezogen werden. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Pediculosis capitis is a growing neglected infestation due to migration in southeast Turkey.

PubMed

Eroglu, Fadime; Basaran, Ümit; Kürklü, Cennet Gizem; Yüceer, Mervenur; Yalcıntürk, Rabia Gül; Tanrıverdi, Mustafa; Daglı, Eda Icbay; Koltas, Ismail Soner

2016-06-01

Demographic, socio-economical, and environmental changes affecting prevalence of Pediculosis capitis. The aim of this study was to investigate the prevalence of P. capitis and external factors affecting the distribution of P. capitis. A total of 6004 primary-school students between 5 and 11 years were screened for P. capitis at 28 different primary-schools in Gaziantep, located in southeastern of Turkey, during different two education terms (First education term is in September 2013 to May 2014, second education term is in September 2014 and May 2015). The prevalence of P. capitis was found to be positive 1.5 % (90/6004) and 6.9 % (415/6004) in first education term and in second education term, respectively. In this study shown that the rate of P. capitis's prevalence was increased 5.4 % in Gaziantep. P. capitis is a neglected infestation and it has re-emerged in Gaziantep, located in the southeastern of Turkey. Health staff member must improve health education programs in primary-school students especially girl students.

Prevalence and causative fungal species of tinea capitis among schoolchildren in Gabon.

PubMed

Hogewoning, A A; Adegnika, A A; Bouwes Bavinck, J N; Yazdanbakhsh, M; Kremsner, P G; van der Raaij-Helmer, E M H; Staats, C C G; Willemze, R; Lavrijsen, A P M

2011-09-01

Tinea capitis is endemic among schoolchildren in tropical Africa. The objective was to determine the prevalence of symptomatic tinea capitis in schoolchildren in Gabon. A cross-sectional study was conducted with 454 children aged 4-17 years, attending a rural school and an urban school. The diagnosis of tinea capitis was based on clinically manifest infection, direct microscopic examination using 20% potassium hydroxide (KOH) solution and fungal culture. Based on clinical examination, 105 (23.1%) of 454 children had tinea capitis. Seventy-four (16.3%) children were positive by direct examination (KOH) and/or fungal culture. The prevalence of tinea capitis depended on the school studied and ranged from 20.4% in the urban school with a higher socioeconomic status to 26.3% in the rural school with a lower socioeconomic status. Similarly, the spectrum of causative species varied between the different schools. Taken the schools together, Trichophyton soudanense (29.4%) was the most prominent species, followed by Trichophyton tonsurans (27.9%) and Microsporum audouinii (25.0%). Clinically manifest tinea capitis is endemic among schoolchildren in the Lambaréné region in Gabon. The prevalence of tinea capitis and the causative species depended on the type of school that was investigated. © 2010 Blackwell Verlag GmbH.

Body Lice Prevention and Control

MedlinePlus

... and General Public. Contact Us Parasites Home Prevention & Control Recommend on Facebook Tweet Share Compartir Body lice ... that can be taken to help prevent and control the spread of body lice: Bathe regularly and ...

Identification of repellent odorants to the body louse, Pediculus humanus corporis, in clove essential oil.

PubMed

Iwamatsu, Takuma; Miyamoto, Daisuke; Mitsuno, Hidefumi; Yoshioka, Yoshiaki; Fujii, Takeshi; Sakurai, Takeshi; Ishikawa, Yukio; Kanzaki, Ryohei

2016-04-01

The control of body lice is an important issue for human health and welfare because lice act as vectors of disease such as typhus, relapsing fever, and trench fever. Body lice exhibit avoidance behavior to some essential oils, including clove essential oil. Therefore, odorants containing clove essential oil components may potentially be useful in the development of repellents to body lice. However, such odorants that induce avoidance behavior in body lice have not yet been identified from clove essential oil. Here, we established an analysis method to evaluate the avoidance behavior of body lice to specific odorants. The behavioral analysis of the body lice in response to clove essential oil and its constituents revealed that eugenol, a major component of clove essential oil, has strong repellent effect on body lice, whereas the other components failed to induce obvious avoidance behavior. A comparison of the repellent effects of eugenol with those of other structurally related odorants revealed possible moieties that are important for the avoidance effects to body lice. The repellent effect of eugenol to body lice was enhanced by combining it with the other major component of clove essential oil, β-caryophyllene. We conclude that a synthetic blend of eugenol and β-caryophyllene is the most effective repellent to body lice. This finding will be valuable as the potential use of eugenol as body lice repellent.

Biology and genetics of human head and body lice.

PubMed

Veracx, Aurélie; Raoult, Didier

2012-12-01

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

Use of lice to identify cowbird hosts

USGS Publications Warehouse

Hahn, D.C.; Price, R.D.; Osenton, P.C.

2000-01-01

The host specificity of avian lice (Phthiraptera) may be utilized by biologists to investigate the brood parasitism patterns of Brown-headed Cowbirds (Molothrus ater). As nestlings, brood parasites have a unique opportunity to encounter lice that are typically host specific. Lice are permanent hemimetabolic ectoparasites, a group found strictly on the body of the host, and they are transferred almost exclusively by bodily contact between hosts during care of young and at copulation. We investigated whether cowbird nestlings become infested with avian lice from their host parents and carry these lice away when they fledge, in effect bearing ectoparasite indicators of the species that raised them. The technique of examining the lice on cowbird fledglings to identify their foster parents would be much less costly than hiring a team of experts to determine parasitism patterns in the conventional way by finding hundreds of songbird nests. We examined 244 cowbird fledglings and found that they carried a rich fauna of lice representing 11 species and six genera, almost the entire spectrum of louse genera known to occur on passerines. We also examined 320 songbirds from 30 species, all known hosts of the Brown-headed Cowbird. As a group the host birds bore a diversity of louse species comparable to that on the fledgling cowbirds: 13 species of lice from seven genera. In contrast, most individual passerine host species yielded only 1 or 2 louse species, significantly fewer than the cowbird fledglings (p < 0.0001). Of 44 fledgling cowbirds carrying lice, 11 were linked to their probable avian foster parents via louse indicators, and these are the Wood Thrush and Red-winged Blackbird. Eighteen additional fledglings were linked to one of two possible foster parents. We concluded that cowbird fledglings do carry away host lice and this survey technique provides a partial assessment of local community parasitism patterns. The incomplete state of passerine louse taxonomy requires

Head lice: the feelings people have.

PubMed

Parison, Julie C; Speare, Richard; Canyon, Deon V

2013-02-01

Head lice are a source of amusement for outsiders and an embarrassing nuisance to those who have to deal with them. Our study collected the emotions experienced by people dealing with head lice. An area with extremely sparse literature, our purpose is to inform the development of more effective programs to control head lice. We asked "what were your feelings upon discovery of head lice?" as part of a study exploring the experience of those treating head lice. A short questionnaire was available via the authors' head lice information internet site. A total of 294 eligible responses were collected over several months and analyzed, supported by QSR N6. The predominantly female (90 · 9%) respondents were residents of Australia (56 · 1%), USA (20 · 4%), Canada (7 · 2%), or UK (4 · 4%), and working full-time (43·0%) or part-time (34 · 2%). Reactions and feelings fell into three categories: strong (n = 320; 79% of all stated emotions), mediocre (n = 56; 20%), and neutral (n = 29; 9 · 8%). There were no positive emotions. The significant negative reaction was expected. The range of feeling expressed demonstrates the stigma held for these ectoparasites within western market economies. This contrasts with conceptions of head lice in traditional societies. The negative social effects of this perception create more problematic issues than the infection itself; these include quarantine, overtreatment, and a potentially negative psychological impact. Head lice control strategies and programs that address these negative emotional reactions may prove more effective than current biomedical focus. © 2013 The International Society of Dermatology.

The evolution of host specificity in dove body lice.

PubMed

Johnson, Kevin P; Weckstein, Jason D; Bush, Sarah E; Clayton, Dale H

2011-11-01

Conventional wisdom suggests that parasites evolve increased host specialization over time. Host specificity, which describes the number of host species parasitized, is one aspect of host specialization. Recent studies of vertebrate parasites indicate that highly host-specific parasite lineages are not, in fact, evolutionary dead ends; host generalists can evolve from host specialists. Using phylogenetic reconstruction methods, we evaluate these patterns in the body lice (Insecta: Phthiraptera) of pigeons and doves, which are permanent ectoparasites that complete their entire life cycle on the body of the host. We find that species of body lice that parasitize more than one species of host (generalists) are invariably derived from lice parasitizing only one species of host (specialists). A previous study of the wing lice of pigeons and doves also found that generalists were derived from specialists, and that these changes were correlated with the presence of a potentially competing species of wing louse on the same host. For body lice we did not find such a correlation with competition. Instead, the evolution of host generalists in body lice was correlated with host ecology. When we compared body lice that parasitize terrestrial versus arboreal hosts, we found that the evolution of host generalists was associated with terrestrial hosts. In contrast, wing lice showed no correlation between the evolution of generalists and host ecology. The correlation in body lice suggests that dispersal between host species may occur via the ground. This, in turn, suggests that body lice may fall to the ground more often than wing lice. To test this hypothesis, we conducted an experiment to compare the rate at which body and wing lice are dislodged from the bodies of preening pigeons. Interestingly, our results showed that body lice are dislodged four times more often than wing lice. Therefore, species of terrestrial doves are far more likely to encounter body lice than wing lice

Tinea capitis: still an unsolved problem?

PubMed

Patel, Gopal A; Schwartz, Robert A

2011-05-01

Tinea capitis is a fungal infection specifically involving the scalp and hair. It is the most common dermatophyte infection in children under 12 years of age, with a predominance in those of sub-Saharan African descent. Common signs include hair loss, scaling, erythema and impetigo-like plaques. Adults may also be affected, but to a lesser degree. The causative species are from the Microsporum and Trichophyton genera. Limited treatment options and diverse modes of transmission complicate the clinician's ability to address this disease adequately. Although dermatophytes are ubiquitous in our environment and tinea capitis is common, therapeutic options can be utilised to reduce morbidity. © 2009 Blackwell Verlag GmbH.

Epidemiological profile of tinea capitis in São Paulo City.

PubMed

Veasey, John Verrinder; Miguel, Barbara Arruda Fraletti; Mayor, Silvia Assumpção Soutto; Zaitz, Clarisse; Muramatu, Laura Hitomi; Serrano, Juliane Agarinakamura

2017-01-01

Tinea capitis is the most common fungal infection in children. The identification of the etiologic agent helps clinicians make their therapeutic choice. Studies conducted in different countries show a changing pattern of the main etiological agents according to their regions. We performed a retrospective study in the tertiary public service in São Paulo, analyzing the isolated etiological agents in patients with tinea capitis from March 2013 to May 2015. Microsporum canis was the main agent (56.6%), followed by Trichophyton tonsurans (36.6%). Despite recent migratory movements in the city, we observed no change in the causative agent of tinea capitis.

Primary Grade Teachers' Knowledge and Perceptions of Head Lice.

ERIC Educational Resources Information Center

Kirchofer, Gregg M.; Price, James H.; Telljohann, Susan K.

2001-01-01

Surveyed primary school teachers regarding knowledge of head lice, self-efficacy in handling head lice, and preferred information sources. Teachers needed more knowledge about head lice. About half had high efficacy expectations regarding their ability to control the spread of lice. Most reported receiving information from school nurses. Knowledge…

Epidemiological profile of tinea capitis in São Paulo City*

PubMed Central

Veasey, John Verrinder; Miguel, Barbara Arruda Fraletti; Mayor, Silvia Assumpção Soutto; Zaitz, Clarisse; Muramatu, Laura Hitomi; Serrano, Juliane Agarinakamura

2017-01-01

Tinea capitis is the most common fungal infection in children. The identification of the etiologic agent helps clinicians make their therapeutic choice. Studies conducted in different countries show a changing pattern of the main etiological agents according to their regions. We performed a retrospective study in the tertiary public service in São Paulo, analyzing the isolated etiological agents in patients with tinea capitis from March 2013 to May 2015. Microsporum canis was the main agent (56.6%), followed by Trichophyton tonsurans (36.6%). Despite recent migratory movements in the city, we observed no change in the causative agent of tinea capitis. PMID:28538903

Antimicrobial Susceptibility of Tinea Capitis in Children from Egypt

PubMed Central

Doss, Reham William; El-Rifaie, Abdel-Aziz; Radi, Nagla; El-Sherif, Aya Yehia

2018-01-01

Background: Dermatophytic fungi of genera Trichophyton and Microsporum are the most important fungal species causing tinea capitis. Choice of treatment for tinea capitis is determined by the species of fungus. Aim: The aim of the study was to investigate the most prevalent fungal species causing tinea capitis in children from Egypt and the most useful antifungal agent for treatment. Patients and Methods: A total of 100 patients diagnosed clinically with tinea capitis were included in the study. Samples were collected and sent to the microbiology and immunology laboratory for sample processing and fungal identification by routine laboratory techniques. A study of antifungal susceptibility to chosen antifungal medications (fluconazole, ketoconazole, clotrimazole, miconazole, amphotericin, caspofungin, itraconazole, terbinafine, and griseofulvin) was done by minimum inhibitory concentration technique. Results: Our analysis revealed that Microsporum canis is the most commonly isolated strain. Amphotericin was the most effective antifungal agent followed by terbinafine. The most sensitive strain to fluconazole and griseofulvin is Microsporum gypseum, while Microsporum audouinii was mostly responsive to terbinafine. Conclusion: Identification and evaluation of the antifungal susceptibility of the pathogenic species in a certain geographic region is important to achieve a good clinical response. PMID:29692458

Antimicrobial Susceptibility of Tinea Capitis in Children from Egypt.

PubMed

Doss, Reham William; El-Rifaie, Abdel-Aziz; Radi, Nagla; El-Sherif, Aya Yehia

2018-01-01

Dermatophytic fungi of genera Trichophyton and Microsporum are the most important fungal species causing tinea capitis. Choice of treatment for tinea capitis is determined by the species of fungus. The aim of the study was to investigate the most prevalent fungal species causing tinea capitis in children from Egypt and the most useful antifungal agent for treatment. A total of 100 patients diagnosed clinically with tinea capitis were included in the study. Samples were collected and sent to the microbiology and immunology laboratory for sample processing and fungal identification by routine laboratory techniques. A study of antifungal susceptibility to chosen antifungal medications (fluconazole, ketoconazole, clotrimazole, miconazole, amphotericin, caspofungin, itraconazole, terbinafine, and griseofulvin) was done by minimum inhibitory concentration technique. Our analysis revealed that Microsporum canis is the most commonly isolated strain. Amphotericin was the most effective antifungal agent followed by terbinafine. The most sensitive strain to fluconazole and griseofulvin is Microsporum gypseum , while Microsporum audouinii was mostly responsive to terbinafine. Identification and evaluation of the antifungal susceptibility of the pathogenic species in a certain geographic region is important to achieve a good clinical response.

[Tinea capitis. Dermoscopic findings in 37 patients].

PubMed

Arrazola-Guerrero, Jisel; Isa-Isa, Rafael; Torres-Guerrero, Edoardo; Arenas, Roberto

2015-01-01

Tinea capitis is a common fungal infection in children. Diagnosis is confirmed by mycological study, including direct examination of the samples with potassium hydroxide/chlorazol black and culture. Previous studies have reported the presence of "comma hairs" and "corkscrew hairs", as well as short hairs and black dots. To describe the dermoscopic patterns in the trichoscopic examination in patients with tinea capitis. A descriptive, observational and cross-sectional study was conducted on 37 patients with tinea capitis, studied during May, 2012, at Dr. Manuel Gea González General Hospital in Mexico, and the Instituto Dermatológico y Cirugía de Piel Dr. Huberto Bogaert Díaz, in the Dominican Republic. Clinical, mycological and dermoscopic evaluations were performed. Of the 37 patients included, 28 were of mixed race from Dominican Republic and 9 mixed race cases from Mexico. Seventy six percent were male and 24% female, and 94% were children. The following dermoscopic patterns were confirmed: "comma hairs" (41%), "corkscrew hairs" (22%), short hairs (49%), and black dots (33%). The presence of scales (89%), peripilar casts (46%), alopecia (65%), pustules (8%), and meliceric crusts (16%), were also observed. Dermoscopy in tinea capitis showed the presence of "comma hairs", and "corkscrew hairs". Scales, peripilar casts and alopecia were also found. It would be desirable to establish this diagnostic tool, particularly when an optical microscope or a mycology reference laboratory are not available. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Changing in the Epidemiology of Tinea Capitis among School Children in Egypt.

PubMed

Bassyouni, Rasha H; El-Sherbiny, Naglaa A; Abd El Raheem, Talal A; Mohammed, Basma H

2017-02-01

Tinea capitis remains a prevalent health problem among school-aged children. To estimate the prevalence of tinea capitis among primary school students, in Fayoum, Egypt with identification of etiological agents in both public and private primary schools. A cross-sectional study was conducted in twelve primary schools. The students were selected from different grades with a total number of 12,128 students. Hair and scalp were clinically examined for any lesions that may suspect tinea capitis and mycological samples were collected for direct microscopy and culture. The prevalence of tinea capitis in the study group was 0.4% and higher in public than private schools (73.5% versus 26.5% respectively). Boys were more affected than girls with boy to girls' ratio 5:1. Intrafamily history of infection was present in 40.8% of tested group while 51% showed low social standard profile. Mycological culture revealed that Microsporum canis was the predominant isolated organism followed by M. audouinii (52% and 36% respectively). M. canis is replacing Trichophyton violaceum as an etiology for tinea capitis in Egypt with lower prevalence rate than reported previously.

Barriers to Treatment of Tinea Capitis in Children Living in the Jane Finch Community of Toronto.

PubMed

Zur, Rebecca L; Shapero, Jonathan; Shapero, Harvey

2015-01-01

Tinea capitis is a common fungal infection of the scalp. If left untreated, tinea capitis infection can cause severe inflammatory reactions and the development of kerion. Tinea capitis is effectively treated with oral antifungals, but at present these are not covered under government assistance programs. To assess the potential impact of a limited use code for antifungal therapy in the treatment of childhood tinea capitis. Fourteen family physicians practicing in the Jane Finch area were surveyed on their experience treating tinea capitis in this community. Seventy-one percent of surveyed family physicians felt that cost impedes the treatment of tinea capitis in their practice, and 100% felt that a limited use code would have a positive impact on their patients. A limited use code for oral antifungal treatments of tinea capitis may provide a simple, cost-effective solution to a major problem impacting children in the Jane Finch area. © The Author(s) 2015.

The Lice-Buster Book: What To Do When Your Child Comes Home with Head Lice!

ERIC Educational Resources Information Center

Copeland, Lennie

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,…

Detection of Bartonella quintana in African Body and Head Lice

PubMed Central

Sangaré, Abdoul Karim; Boutellis, Amina; Drali, Rezak; Socolovschi, Cristina; Barker, Stephen C.; Diatta, Georges; Rogier, Christophe; Olive, Marie-Marie; Doumbo, Ogobara K.; Raoult, Didier

2014-01-01

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

Compromising on School for Students with Head Lice

ERIC Educational Resources Information Center

Education Digest: Essential Readings Condensed for Quick Review, 2004

2004-01-01

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…

Changing in the Epidemiology of Tinea Capitis among School Children in Egypt

PubMed Central

El-Sherbiny, Naglaa A.; Abd El Raheem, Talal A.; Mohammed, Basma H.

2017-01-01

Background Tinea capitis remains a prevalent health problem among school-aged children. Objective To estimate the prevalence of tinea capitis among primary school students, in Fayoum, Egypt with identification of etiological agents in both public and private primary schools. Methods A cross-sectional study was conducted in twelve primary schools. The students were selected from different grades with a total number of 12,128 students. Hair and scalp were clinically examined for any lesions that may suspect tinea capitis and mycological samples were collected for direct microscopy and culture. Results The prevalence of tinea capitis in the study group was 0.4% and higher in public than private schools (73.5% versus 26.5% respectively). Boys were more affected than girls with boy to girls' ratio 5:1. Intrafamily history of infection was present in 40.8% of tested group while 51% showed low social standard profile. Mycological culture revealed that Microsporum canis was the predominant isolated organism followed by M. audouinii (52% and 36% respectively). Conclusion M. canis is replacing Trichophyton violaceum as an etiology for tinea capitis in Egypt with lower prevalence rate than reported previously. PMID:28223741

Different Trichoscopic Features of Tinea Capitis and Alopecia Areata in Pediatric Patients

PubMed Central

El-Taweel, Abd-Elaziz; El-Esawy, Fatma; Abdel-Salam, Osama

2014-01-01

Background. Diagnosis of patchy hair loss in pediatric patients is often a matter of considerable debate among dermatologists. Trichoscopy is a rapid and noninvasive tool to detect more details of patchy hair loss. Like clinical dermatology, trichoscopy works parallel to the skin surface and perpendicular to the histological plane; like the histopathology, it thus allows the viewing of structures not discovered by the naked eye. Objective. Aiming to compare the different trichoscopic features of tinea capitis and alopecia areata in pediatric patients. Patients and Methods. This study included 40 patients, 20 patients with tinea capitis and 20 patients with alopecia areata. They were exposed toclinical examination, laboratory investigations (10% KOH and fungal culture), and trichoscope examination. Results. Our obtained results reported that, in tinea capitis patients, comma shaped hairs, corkscrew hairs, and zigzag shaped hairs are the diagnostic trichoscopic features of tinea capitis. While in alopecia areata patients, the most trichoscopic specific features were yellow dots, exclamation mark, and short vellus hairs. Conclusion. Trichoscopy can be used as a noninvasive tool for rapid diagnosis of tinea capitis and alopecia areata in pediatric patients. PMID:25024698

Clinical study of Tinea capitis in Northern Karnataka: A three-year experience at a single institute.

PubMed

Pai, Varadraj V; Hanumanthayya, Keloji; Tophakhane, Raghavendra S; Nandihal, Namrata W; Kikkeri, Narayan Shetty Naveen

2013-01-01

Tinea capitis is a superficial fungal infection of the hair follicle of scalp. Most of the dermatophytosis do not have such age propensity as tinea capitis which almost invariably involves the paediatric age group. The exact incidence of tinea capitis is not known. This study is done in order to isolate the species variation in an area, to know the changing patterns of occurrence of different species and their association with clinical pattern All clinically diagnosed cases of tinea capitis which presented to our out patient department over a period of one year were included in the study. 70 cases of Tinea capitis were studied. Tinea capitis is a disease of prepubertal children with common in age group of 5- 15 years. The incidence varies from 0.5% to 10%. Most common presenting feature was alopecia.

[Lice, fleas and other beasts].

PubMed

Hufnagel, Markus; Berner, Reinhard

2007-07-01

Bedbugs, lice, fleas and mites are blood-sucking ectoparasites whose bites cause allergic skin reactions. Diagnosis of bites is based on the morphology of the skin eruptions and the pattern of involved skin areas. Confirmation of the diagnosis often requires detection of the causal parasite. The main reservoir for ectoparasites (e.g., bedbugs, fleas, lice and scabies mites) are humans, but animals are also known to harbor ectoparasites (e.g., certain fleas and mites). Fleas, body lice and certain mite larvae in the tropics can transmit infectious diseases, but bedbugs, headlice, pubic lice and scabies mites cannot. Therapy is primarily directed against itching and bacterial superinfections. Pediculosis and scabies are additionally treated with t0pical insecticides. In order to kill freshly hatched larvae, topical treatmentmust be repeated after one week. In the case of pediculosis, people who have come into contact with symptomatic individuals also need to be treated, whereas with scabies, all contact persons must undergo treatment in order toprevent further transmission. Topicalinsecticides, in combination with anti-itch treatment, is usually sufficientto immediately relieve the symptoms and promote permanent healing of the skin lesions.

Detection of Bartonella quintana in African body and head lice.

PubMed

Sangaré, Abdoul Karim; Boutellis, Amina; Drali, Rezak; Socolovschi, Cristina; Barker, Stephen C; Diatta, Georges; Rogier, Christophe; Olive, Marie-Marie; Doumbo, Ogobara K; Raoult, Didier

2014-08-01

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. © The American Society of Tropical Medicine and Hygiene.

Outbreak of Tinea capitis and corporis in a primary school in Antananarivo, Madagascar.

PubMed

Carod, Jean-François; Ratsitorahina, Mahery; Raherimandimby, Hasina; Hincky Vitrat, Virginie; Ravaolimalala Andrianaja, Vololomboahangy; Contet-Audonneau, Nelly

2011-10-13

Tinea capitis is common among schoolchildren in developing countries but underreported in Madagascar. We report the occurrence of an outbreak of gray patch tinea capitis due to Microsporum langeronii in a public primary school of Antananarivo, the capital city of Madagascar. Forty-two children were included, 27 (64%) of them presenting with tinea capitis and 32 (76%) with Tinea corporis. Patients were treated with griseofulvin 500 mg and Povidone-iodine 4% and followed up for four weeks. Twenty-five (93%) of the 27 children with tinea capitis presented a gray patch as the main clinical feature. All these cases were fluorescent under Wood's UV light and positive in cultures for M. langeronii. All 27 children reported a contact with infected classmates, and 19 (70%) reported to have infected brothers and sisters at home. After four weeks of treatment, all patients recovered. Appropriate treatment and improved hygienic practices reduced the occurrence of tinea in the studied school and no more cases of tinea capitis or corporis occurred after the outbreak.

Head lice. Dimeticone is the pediculicide of choice.

PubMed

2014-07-01

Infestation of the scalp by head lice, or pediculosis, is a common, unpleasant but harmless parasitosis. For patients with pediculosis, which topical treatment eradicates the parasites effectively while causing the least harm? We reviewed the available evidence using the standard Prescrire methodology. Lice can be eradicated by shaving the head or combing the hair several times a day for several weeks with a fine-toothed lice comb, although combing is only completely effective in about 50% of cases. Pyrethroids (permethrin, phenothrin and bioallethrin), often combined with piperonyl butoxide, are insecticides that are neurotoxic to lice. The lice eradication rates achieved in trials of these agents are highly variable, ranging from 13% to 75% depending on the country, probably due to the development of resistance. In five randomised trials, the organophosphorus insecticide malathion was more effective than permethrin or phenothrin, achieving eradication rates of 80% to 98%. Topical application of the insecticides ivermectin or spinosad was effective in 75% to 85% of patients in randomised trials. Insecticides have mainly local adverse effects: pruritus and irritation of the scalp. Cases of malathion poisoning have been reported following topical application or ingestion. The long-term toxicity of insecticides is unclear; it therefore appears preferable to minimise their use. Agents that kill lice through physical mechanisms have few known adverse effects. It seems unlikely that lice will develop resistance to them. Dimeticone, a silicone compound, is not absorbed through the skin and provokes very few adverse effects. It is one of the better evaluated agents: in three randomised trials, 70% to 97% of patients were lice-free after two weeks. Other agents with a physical action on lice have been evaluated, each in one randomised trial including a few dozen patients. One of these, 1,2-octanediol, applied in an alcoholic solution, seemed to eradicate lice effectively

An experimental model of human body louse infection with Rickettsia typhi.

PubMed

Houhamdi, Linda; Fournier, Pierre-Edouard; Fang, Rong; Raoult, Didier

2003-06-01

Murine (endemic) typhus caused by Rickettsia typhi, one of the most widely distributed arthropod-borne diseases, is transmitted to humans mainly by the oriental rat flea. The human body louse, Pediculus humanus corporis, has been suspected to have a role in the transmission of R. typhi to humans. To evaluate the potential role of Pediculus humanus corporis as a vector of murine typhus, we used R. typhi in an experimental model of human body louse infection previously used with R. prowazekii. A rabbit was made bacteremic by inoculating it with 2 x 10(6) plaque-forming units of R. typhi; it remained bacteremic for at least 59 hours. Two hundred body lice infected by feeding on the bacteremic rabbit were compared to 200 uninfected control lice. Each louse population was fed once a day on the abdomen of a seronegative rabbit. On day 8 post-infection, as a result of disruption of the gut cells and leakage of the blood meal into the hemolymph, four infected lice became bright red and died within four hours. The life span of infected lice was 20 days less than that of the controls. Infected lice did not transmit R. typhi to their progeny (eggs and larvae) as demonstrated by PCR amplification and cell culture. With an immunofluorescence assay, R. typhi was detected in feces from day 7 post-infection, and the organism remained viable in feces for up to 80 days as demonstrated by cell culture. From the 21st day post-infection, the rabbit used to feed the R. typhi-infected lice developed an immunoglobulin response with a titer of 1:50 increasing to 1:200 at the 42nd day post-infection. It showed no clinical signs of infection. The rabbit that was used to feed uninfected lice remained seronegative. Although body lice are not clearly identified vectors of R. typhi, it seems that under certain circumstances they could transmit R. typhi.

Clinical study of Tinea capitis in Northern Karnataka: A three-year experience at a single institute

PubMed Central

Pai, Varadraj V.; Hanumanthayya, Keloji; Tophakhane, Raghavendra S.; Nandihal, Namrata W.; Kikkeri, Narayan Shetty Naveen

2013-01-01

Background: Tinea capitis is a superficial fungal infection of the hair follicle of scalp. Most of the dermatophytosis do not have such age propensity as tinea capitis which almost invariably involves the paediatric age group. The exact incidence of tinea capitis is not known. This study is done in order to isolate the species variation in an area, to know the changing patterns of occurrence of different species and their association with clinical pattern Materials and Methods: All clinically diagnosed cases of tinea capitis which presented to our out patient department over a period of one year were included in the study. Results: 70 cases of Tinea capitis were studied. Discussion: Tinea capitis is a disease of prepubertal children with common in age group of 5- 15 years. The incidence varies from 0.5% to 10%. Most common presenting feature was alopecia. PMID:23439970

Prevalence of Tinea Capitis among School Children in Nok Community of Kaduna State, Nigeria

PubMed Central

Dogo, Josephine; Dung, Edward Christopher

2016-01-01

In recent years, the prevalence of tinea capitis, an infection of the scalp by dermatophytes, has increased in children worldwide. This cross-sectional study was carried out to determine the prevalence and risk factor of tinea capitis among school children in Nok community of Kaduna State, Nigeria. A total of 100 children were screened and 45% were diagnosed to have tinea capitis after fungal culture and microscopy. The prevalence of tinea capitis among girls was higher (51.4%) than that among boys (41.5%) but not significantly different (p = 0.402). The prevalence with respect to age was lower for the age group 5–10 years (42.6%) than that of 11–15 years (50%) but was not significantly different (p = 0.524). Trichophyton rubrum (28.8%) and Microsporum canis (22.7%) were the most prevalent dermatophytes isolated and the least were Trichophyton verrucosum (4.5%) and Trichophyton tonsurans (4.5%). There were 73.3% single infection while 26.7% had 2–4 dermatophytes of the genera Microsporum and Trichophyton. The predisposing factors with statistically significant association with tinea capitis were number of children in the family (p = 0.02) and sharing of the same bed (p = 0.002). This indicates the high tendencies of spread of tinea capitis through human-to-human mode of transmission and possible animal contact. Community health education on the cause, mode of transmission, prevention, and prompt treatment of tinea capitis is recommended. PMID:27471603

Prevalence of Tinea Capitis among School Children in Nok Community of Kaduna State, Nigeria.

PubMed

Dogo, Josephine; Afegbua, Seniyat Larai; Dung, Edward Christopher

2016-01-01

In recent years, the prevalence of tinea capitis, an infection of the scalp by dermatophytes, has increased in children worldwide. This cross-sectional study was carried out to determine the prevalence and risk factor of tinea capitis among school children in Nok community of Kaduna State, Nigeria. A total of 100 children were screened and 45% were diagnosed to have tinea capitis after fungal culture and microscopy. The prevalence of tinea capitis among girls was higher (51.4%) than that among boys (41.5%) but not significantly different (p = 0.402). The prevalence with respect to age was lower for the age group 5-10 years (42.6%) than that of 11-15 years (50%) but was not significantly different (p = 0.524). Trichophyton rubrum (28.8%) and Microsporum canis (22.7%) were the most prevalent dermatophytes isolated and the least were Trichophyton verrucosum (4.5%) and Trichophyton tonsurans (4.5%). There were 73.3% single infection while 26.7% had 2-4 dermatophytes of the genera Microsporum and Trichophyton. The predisposing factors with statistically significant association with tinea capitis were number of children in the family (p = 0.02) and sharing of the same bed (p = 0.002). This indicates the high tendencies of spread of tinea capitis through human-to-human mode of transmission and possible animal contact. Community health education on the cause, mode of transmission, prevention, and prompt treatment of tinea capitis is recommended.

Lice infesting horses in three agroecological zones in central Oromia.

PubMed

Tafese, Adane; Jibat, Tariku; Aklilu, Nigatu; Zewdu, Hanna; Kumsa, Bersissa

2014-12-01

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.

Experimental infection of human body lice with Acinetobacter baumannii.

PubMed

Houhamdi, Linda; Raoult, Didier

2006-04-01

The human body louse is currently recognized as a vector of Rickettsia prowazekii, Borrelia recurrentis, and Bartonella quintana. Previous studies have reported the isolation of Acinetobacter baumannii from the body lice of homeless patients. To study how the body louse acquires A. baumannii, we infected a rabbit by infusing 2 x 10(6) colony-forming units of the louse strain of A. baumannii. Two hundred body lice were infected by feeding on the bacteremic rabbit and compared with 200 uninfected lice and two groups of 200 lice feeding on rabbits infected either with another strain of A. baumannii or A. lwoffii. Each louse group received maintenance feedings once a day on another seronegative rabbit. Body lice that fed on rabbits infused with each Acinetobacter species demonstrated a generalized infection. The body lice did not transmit their infection to the nurse rabbit by bite while feeding or to their progeny (eggs and larvae). The lice excreted living Acinetobacter species within their feces. Only the louse strain of A. baumannii was pathogenic for the body louse. An increased mortality rate was observed between the second and third days post-infection; however, they remained infected for their lifespan.

Head Lice

MedlinePlus

... the-counter shampoos and lotions containing pyrethrin (one brand name: Rid) or permethrin (brand name: Nix) are commonly used to treat head ... hand or by using a special comb (one brand name: LiceMeister comb) to remove them. Comb through ...

Tinea capitis caused by Trichophyton rubrum mimicking favus.

PubMed

Boyd, Alan S

2016-12-01

Favus is an uncommon form of tinea capitis (TC) currently seen in geographic areas with poor sanitation and limited access to health care such as emerging nations. Several variants of this condition have been described including one exhibiting a plaque composed of parchmentlike material. The makeup of this plaque has not been described. Tinea capitis is rare in adults, particularly when the infectious agent is Trichophyton rubrum , and affected patients often exhibit comorbidities associated with diminished immune surveillance. This case report describes an elderly woman with TC due to T rubrum mimicking a rare form of favus.

Borrelia recurrentis in head lice, Ethiopia.

PubMed

Boutellis, Amina; Mediannikov, Oleg; Bilcha, Kassahun Desalegn; Ali, Jemal; Campelo, Dayana; Barker, Stephen C; Raoult, Didier

2013-05-01

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.

[Tinea capitis in elderly women: a report of 4 cases].

PubMed

Morell, L; Fuente, M J; Boada, A; Carrascosa, J M; Ferrándiz, C

2012-03-01

Tinea capitis is a condition usually found only in children. However, its epidemiological profile has changed in recent decades, with regard to age at onset and the causative microorganisms. We report the cases of 4 women over 65 years of age diagnosed with tinea capitis. One presented plaques of alopecia with desquamation and the other 3 developed crusted inflammatory lesions. Cultures were positive for Trichophyton tonsurans (2 patients), Trichophyton rubrum, and Trichophyton mentagrophytes. The relative rarity of tinea capitis in the elderly and the frequently atypical presentation in this age group can delay diagnosis, leading to irreversible sequelae and increasing the risk of contagion. Fungal culture should be included in the study of persistent, atypical dermatoses of the scalp, particularly in the elderly. Copyright © 2010 Elsevier España, S.L. and AEDV. All rights reserved.

Prophylactic ketoconazole shampoo for tinea capitis in a high-risk pediatric population.

PubMed

Bookstaver, P Brandon; Watson, Holly J; Winters, Shauna D; Carlson, Adrian L; Schulz, Richard M

2011-07-01

Although topical agents for the treatment of tinea capitis decrease viable fungal elements and reduce shedding, their use as a prophylactic agent has not been investigated. This study evaluated the effectiveness of a prophylactic ketoconazole shampoo (Nizoral 2%) protocol to reduce the number of clinically evident tinea capitis infections in a high-risk African American, urban population. We conducted a retrospective analysis of a ketoconazole prophylaxis protocol that was implemented at an urban pediatric clinic for medically fragile children. Patients at high risk for tinea capitis received twice-weekly ketoconazole shampoo. The primary outcome of the study was a reduction in the number of documented tinea capitis infections between the 12-month preprotocol and 12-month postprotocol periods. A secondary outcome included the evaluation of predisposing risk factors for acquiring tinea infections. Ninety-seven patients, with a mean age of 8.06 years, were included. Most patients (78%) were African American. There were a total of 13 tinea capitis infections during the 12-month preprotocol period. During the 12-month postprotocol period, 41 infections were documented: 37 (90.2%) in the prophylaxis group and 4 (9.8%) in the nonprophylaxis group. The average numbers of per-patient infections in the postprotocol period were 0.79 and 0.08 in the prophylaxis and nonprophylaxis groups, respectively. Initiation of prophylaxis did not reduce tinea capitis infections (p=NS). Previous history of infection and a high level of care were significant predictors of infections (p<0.05). Improved hygiene, adherence to prescribed treatment regimens, and prevention of recurrent environmental exposure to surviving fomites should be stressed in high-risk patients and supersede the need for an antifungal (ketoconazole shampoo) prophylaxis protocol.

Body Lice

MedlinePlus

... lice live in your clothing and bedding and travel to your skin several times a day to feed on blood. The most ... typically live in your clothes and bedding. They travel to your skin several times a day to feed on blood. The seams ...

Dermatophytid in tinea capitis: rarely reported common phenomenon with clinical implications.

PubMed

Cheng, Nancy; Rucker Wright, Dakara; Cohen, Bernard A

2011-08-01

Tinea capitis may be associated with a dermatophytid, which appears as a disseminated eczematous eruption. This phenomenon may occur before or after initiation of systemic antifungal drug therapy and is not an indication for stopping medication. We present here a series of cases that involve 5 children with tinea capitis who developed a dermatophytid before or during the course of their management. In each child, the eruption resolved despite continuation of oral antifungal therapy. Our experience suggests that dermatophytid secondary to tinea capitis is much more common than reported. Furthermore, parents and clinicians frequently mistake dermatophytid for drug allergy. Recognition of this phenomenon, distinction of dermatophytid from drug allergy, and continuation of systemic treatment is essential for clearing the infection and dermatophytid.

Evaluation of two methods for quantifying passeriform lice

PubMed Central

Koop, Jennifer A. H.; Clayton, Dale H.

2013-01-01

Two methods commonly used to quantify ectoparasites on live birds are visual examination and dust-ruffling. Visual examination provides an estimate of ectoparasite abundance based on an observer’s timed inspection of various body regions on a bird. Dust-ruffling involves application of insecticidal powder to feathers that are then ruffled to dislodge ectoparasites onto a collection surface where they can then be counted. Despite the common use of these methods in the field, the proportion of actual ectoparasites they account for has only been tested with Rock Pigeons (Columba livia), a relatively large-bodied species (238–302 g) with dense plumage. We tested the accuracy of the two methods using European Starlings (Sturnus vulgaris; ~75 g). We first quantified the number of lice (Brueelia nebulosa) on starlings using visual examination, followed immediately by dust-ruffling. Birds were then euthanized and the proportion of lice accounted for by each method was compared to the total number of lice on each bird as determined with a body-washing method. Visual examination and dust-ruffling each accounted for a relatively small proportion of total lice (14% and 16%, respectively), but both were still significant predictors of abundance. The number of lice observed by visual examination accounted for 68% of the variation in total abundance. Similarly, the number of lice recovered by dust-ruffling accounted for 72% of the variation in total abundance. Our results show that both methods can be used to reliably quantify the abundance of lice on European Starlings and other similar-sized passerines. PMID:24039328

In vitro comparison of four treatments which discourage infestation by head lice.

PubMed

Greive, Kerryn A; Barnes, Tanya M

2012-05-01

Products which discourage the transmission of head lice are appealing; however, few studies have tested this concept. This study aims to test the efficacy of four commercial products which claim to discourage infestation by head lice; MOOV Head Lice Defence Spray (MOOV), Wild Child Quit Nits Head Lice Defence Spray (Wild Child), 100% Natural Head Lice Beater (Lice Beater) or Lysout Natural Anti-Lice Spray (Lysout). An in vitro challenge test was used. Briefly, one half of a filter paper lining the base of a petri dish was treated with the test product. Lice were then introduced to the centre of the dish, which was covered and placed in the dark at 20°C for 30 min. The number of lice on the treated and untreated sides of the filter paper was then counted after 2, 4 and 8 h post-application. MOOV was significantly more effective at discouraging the transmission of lice than the water control (p < 0.01), while Wild Child and Lysout were not at all time points. Lice Beater was significantly worse than the water control after 2 h (p < 0.01), while there was no difference after 4 and 8 h. MOOV was found to perform significantly better than Wild Child (p < 0.05) and Lice Beater (p < 0.05) at all time points. It also performed significantly better than Lysout at 2 (p < 0.05) and 8 h (p < 0.05), but not 4 h. MOOV offers the best efficacy and consistency of performance of the four products tested to discourage the transmission of head lice.

Prevalence of Tinea capitis in school going children in Kolkata, West Bengal.

PubMed

Kundu, D; Mandal, L; Sen, G

2012-07-01

In recent years the incidence of Tinea capitis, infection of scalp by dermatophytes, has increased in United Kingdom and North America. The trend may be similar in India. The objective of this study is to find the prevalence of Tinea capitis in school going urban children in Kolkata, West Bengal state. The present study is a cross-sectional study conducted in a government higher primary school in Kolkata. Totally 505 students were screened and 52 were diagnosed to have Tinea capitis by clinical examination, giving a prevalence rate of 10% among school children. Prevalence rates among the age groups of 6-8, 9-11 and 12-14 years were almost the same, ranging from 9 to 11%. The prevalence rate was significantly high among the boys (14%). There was no significant difference in prevalence of infection among coconut oil users and castor oil users. Measures of general hygiene were similar among those who were infected with Tinea capitis and those who were not. The commonest clinical type of infection found was dull grey patches. Itching with hair loss was the major symptom and most of the infected children had cervical lymphadenopathy. The potassium hydroxide studies revealed endothrix spores in majority of samples. Tinea capitis in prevalent in school going urban children in Kolkata, West Bengal state and necessary measures must be undertaken to curtail this incidence.

Critical evaluation of five methods for quantifying chewing lice (Insecta: Phthiraptera).

PubMed

Clayton, D H; Drown, D M

2001-12-01

Five methods for estimating the abundance of chewing lice (Insecta: Phthiraptera) were tested. To evaluate the methods, feral pigeons (Columba livia) and 2 species of ischnoceran lice were used. The fraction of lice removed by each method was compared, and least squares linear regression was used to determine how well each method predicted total abundance. Total abundance was assessed in most cases using KOH dissolution. The 2 methods involving dead birds (body washing and post-mortem-ruffling) provided better results than 3 methods involving live birds (dust-ruffling, fumigation chambers, and visual examination). Body washing removed the largest fraction of lice (>82%) and was an extremely accurate predictor of total abundance (r2 = 0.99). Post-mortem-ruffling was also an accurate predictor of total abundance (r2 > or = 0.88), even though it removed a smaller proportion of lice (<70%) than body washing. Dust-ruffling and fumigation chambers removed even fewer lice, but were still reasonably accurate predictors of total abundance, except in the case of data sets restricted to birds with relatively few lice. Visual examination, the only method not requiring that lice be removed from the host, was an accurate predictor of louse abundance, except in the case of wing lice on lightly parasitized birds.

Clonal outbreak of Trichophyton tonsurans tinea capitis gladiatorum among wrestlers in Adana, Turkey.

PubMed

Ilkit, Macit; Ali Saracli, Mehmet; Kurdak, Hatice; Turac-Bicer, Aygul; Yuksel, Tuba; Karakas, Mehmet; Schuenemann, Eric; Abdel-Rahman, Susan M

2010-05-01

Tinea capitis gladiatorum and tinea corporis gladiatorum caused by the anthropophilic dermatophyte Trichophyton tonsurans are well-known clinical entities in individuals involved in combat sports, e.g., wrestlers and judo practitioners. We present an outbreak of Trichophyton tonsurans tinea capitis gladiatorum among wrestlers at a boarding school in Adana, Turkey. Fourteen of the 29 wrestlers examined (48.3%) harbored the pathogen, including eight asymptomatic scalp carriers, five with tinea capitis superficialis, and one asymptomatic trunk carrier. Dermatophytes were isolated from samples of the neck (1), nape (1), trunk (3) and inguinal area (2) in four of the five tinea capitis cases. A total of five inanimate objects, i.e., two wrestling mats, two pillowcases, and one sheet were also found to be positive for T. tonsurans. Mixed-marker strain typing examining 24 sequence variations in 12 gene loci confirmed that the outbreak was caused by a single strain of T. tonsurans.

[Tinea capitis: Main mycosis child. Epidemiological study on 10years].

PubMed

Kallel, A; Hdider, A; Fakhfakh, N; Belhadj, S; Belhadj-Salah, N; Bada, N; Chouchen, A; Ennigrou, S; Kallel, K

2017-09-01

Despite the changes in their epidemiology, and the improving level of hygiene of the population, tinea capitis is still considered a public health problem in our country, and is the most common type of dermatophytosis in our country. The aim of our study was to evaluate the epidemiological, clinical and mycological features of tinea capitis in children encountered in the Tunis region. A retrospective study concerned 1600 children aged 6 months to 15 years suspected to have tinea capitis was conducted in Parasitology-Mycology laboratory, Rabta hospital, over a 10-years period (2005-2014). Dermatophyte infections were confirmed using scalp scrapings examinated with direct microscopy using potash at 30% and/or culture on Sabouraud medium agar. Tinea capitis diagnosis was confirmed in 947 cases (59.18%). The sex ratio was 2.61 and the average age of 6.28 years with predominance in the age group of 4 to 8 years (52.27%). The most common clinical presentation was ringworm (87.65%). Ringworm large plaque was predominant (65.9%). Direct examination was positive in 884 cases (93.35%). Microsporic tinea was the most frequent (63.25%) followed by trichophytic tinea (29.78%). Positive cultures of dermatophytes were obtained in 912 cases (96.30%). The following dermatophyte species were isolated: Microsporum canis (67%), Trichophyton violaceum (31.68%), Trichophyton mentagrophytes (0.66%), Microsporum audouinii (0.22%), Trichophyton schoenleinii (0.22%) and Microsporum gypseum (0.22%). M. canis is currently the most frequently incriminated species in tinea capitis in Tunisia. This change is related to a change in behavior of our population, in fact the cat; main reservoir of M. canis cohabiting increasingly with Tunisian families. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Persistent Desquamation of the Scalp as a Manifestation of Tinea Capitis in Sub-Saharan Children.

PubMed

Betlloch-Mas, I; Albares-Tendero, M P; Soro-Martínez, M P; Pérez-Crespo, M

2015-10-01

Scalp hyperkeratosis of childhood is most often associated with atopic or seborrheic dermatitis. However, in black children can be associated with tinea capitis. We undertook a retrospective study in all Sub-Saharan children presenting with chronic scalp scaling between June 2010 and June 2013, to determine whether chronic desquamation of the scalp is a clinical manifestation of tinea capitis. The criterion used to diagnose tinea capitis was a positive mycolological culture. Of the 23 Sub-Saharan African children attended, 12 (43.4%) presented with chronic scalp flaking. Mycological culture was performed in 9 of the 12 cases. The culture was positive in 6 out of 9, so 26% of the Sub-Saharan African children attended were diagnosed with tinea capitis. In 52.1% of the cases with persistent scalp scaling the culture was positive. In conclusion, chronic scaling of the scalp may well be the sole form of presentation of tinea capitis in Sub-Saharan children.

Rectal fluconazole for tinea capitis

PubMed Central

Pernica, Jeffrey M; Dayneka, Natalie; Hui, Charles PS

2009-01-01

The present report describes a case of tinea capitis in a boy with autistic spectrum disorder and an aversion to oral medications. He refused weekly oral fluconazole and there was a poor response to daily rectal griseofulvin. He tolerated once-weekly rectal fluconazole (10 mg/kg) well and there was an excellent clinical outcome. PMID:21037831

Tinea capitis in adults in southern Spain. A 17-year epidemiological study.

PubMed

Lova-Navarro, Miguel; Gómez-Moyano, Elisabeth; Martínez Pilar, Leandro; Fernandez-Ballesteros, María Dolores; Godoy-Díaz, Daniel Jesus; Vera-Casaño, Angel; Crespo-Erchiga, Vicente

2016-01-01

Tinea capitis is an infection of the hair due to keratinophilic fungi, known as dermatophytes. Although the disease is common in children, several studies have also shown that it is far from unusual in adults, especially in post-menopausal women and immunocompromised persons. To determine the incidence of tinea capitis in adults in our area, as well as the predisposing factors (gender, immunity), and causative species. A retrospective study was conducted over a period of 17 years, from 1995 to 2011, collecting data on cases of tinea capitis diagnosed in our dermatology department. Information collected for all patients included age, gender, location of the lesions, results of direct examination and culture, immune status, cause of immunosuppression, and the prescribed treatment. Thirty-three cases (11.4%) out of 289 cases of tinea capitis occurred in adults. Most of these adults (72%) were immunocompetent, and the rest were immunocompromised for different reasons. Three of the patients were men and 30 women, with 70% of the latter being post-menopausal. Trichophyton species were isolated in 76% of these adult patients, with Trichophyton violaceum being the most common. Treatment with oral terbinafine was successful in all these cases. Microsporum species were responsible for the other cases, all treated successfully with oral griseofulvin. This series of tinea capitis in adults is one of the largest to date. It shows that tinea capitis is not uncommon among the immunocompetent adult population. In our geographical area, except for prepubescent patients, most cases affecting the adult population were caused by species of the genus Trichophyton. In these cases the treatment of choice was oral terbinafine, which considerably shortened the treatment time, and was associated with fewer side effects than the classical griseofulvin. Copyright © 2015 Asociación Española de Micología. Published by Elsevier Espana. All rights reserved.

Prophylactic Ketoconazole Shampoo for Tinea Capitis in a High-Risk Pediatric Population

PubMed Central

Bookstaver, P. Brandon; Watson, Holly J.; Winters, Shauna D.; Carlson, Adrian L.; Schulz, Richard M.

2011-01-01

OBJECTIVES Although topical agents for the treatment of tinea capitis decrease viable fungal elements and reduce shedding, their use as a prophylactic agent has not been investigated. This study evaluated the effectiveness of a prophylactic ketoconazole shampoo (Nizoral 2%) protocol to reduce the number of clinically evident tinea capitis infections in a high-risk African American, urban population. METHODS We conducted a retrospective analysis of a ketoconazole prophylaxis protocol that was implemented at an urban pediatric clinic for medically fragile children. Patients at high risk for tinea capitis received twice-weekly ketoconazole shampoo. The primary outcome of the study was a reduction in the number of documented tinea capitis infections between the 12-month preprotocol and 12-month postprotocol periods. A secondary outcome included the evaluation of predisposing risk factors for acquiring tinea infections. RESULTS Ninety-seven patients, with a mean age of 8.06 years, were included. Most patients (78%) were African American. There were a total of 13 tinea capitis infections during the 12-month preprotocol period. During the 12-month postprotocol period, 41 infections were documented: 37 (90.2%) in the prophylaxis group and 4 (9.8%) in the nonprophylaxis group. The average numbers of per-patient infections in the postprotocol period were 0.79 and 0.08 in the prophylaxis and nonprophylaxis groups, respectively. Initiation of prophylaxis did not reduce tinea capitis infections (p=NS). Previous history of infection and a high level of care were significant predictors of infections (p<0.05). CONCLUSIONS Improved hygiene, adherence to prescribed treatment regimens, and prevention of recurrent environmental exposure to surviving fomites should be stressed in high-risk patients and supersede the need for an antifungal (ketoconazole shampoo) prophylaxis protocol. PMID:22479162

A double-blind randomized placebo-controlled clinical trial of squalamine ointment for tinea capitis treatment.

PubMed

Coulibaly, Oumar; Thera, Mahamadou A; Koné, Abdoulaye K; Siaka, Goïta; Traoré, Pierre; Djimdé, Abdoulaye A; Brunel, Jean-Michel; Gaudart, Jean; Piarroux, Renaud; Doumbo, Ogobara K; Ranque, Stéphane

2015-04-01

Novel treatments against for tinea capitis are needed, and the natural aminosterol squalamine is a potential topical antidermatophyte drug candidate. This phase II randomized double-blind placebo-controlled clinical trial aimed at testing the efficacy and safety of a three-week squalamine ointment regimen for the treatment of tinea capitis. Males aged 6-15 years presenting with tinea capitis were treated with either topical squalamine ointment or placebo for 3 weeks. The primary endpoint was complete clinical cure. The secondary endpoints were the occurrence of local and/or systemic adverse events, mycological cure, and partial clinical response. Prospective follow-up of clinical adverse events was performed daily. Five patients were treated with 1% squalamine ointment and 15 with placebo. No complete cure was observed. No clinical or biological adverse event was recorded. A significantly (p = 0.03) better hair-growth score, indicating a partial clinical improvement of the tinea capitis lesion, was observed in the patients treated with squalamine compared to those treated with placebo. This three-week squalamine ointment regimen was well tolerated and showed an encouraging partial clinical activity for the treatment of tinea capitis. Further studies are needed to evaluate the efficacy of topical squalamine alone against tinea corporis or in combination with a systemic antidermatophyte drug against tinea capitis.

Fragmented mitochondrial genomes are present in both major clades of the blood-sucking lice (suborder Anoplura): evidence from two Hoplopleura rodent lice (family Hoplopleuridae).

PubMed

Dong, Wen-Ge; Song, Simon; Guo, Xian-Guo; Jin, Dao-Chao; Yang, Qianqian; Barker, Stephen C; Shao, Renfu

2014-09-02

The suborder Anoplura contains 540 species of blood-sucking lice that parasitize over 840 species of eutherian mammals. Fragmented mitochondrial (mt) genomes have been found in the lice of humans, pigs, horses and rats from four families: Pediculidae, Pthiridae, Haematopinidae and Polyplacidae. These lice, eight species in total, are from the same major clade of the Anoplura. The mt genomes of these lice consist of 9-20 minichromosomes; each minichromosome is 1.5-4 kb in size and has 1-8 genes. To understand mt genome fragmentation in the other major clade of the Anoplura, we sequenced the mt genomes of two species of rodent lice in the genus Hoplopleura (family Hoplopleuridae). We identified 28 mt genes on 10 minichromosomes in the mouse louse, Ho. akanezumi; each minichromosome is 1.7-2.7 kb long and has 1-6 genes. We identified 34 mt genes on 11 minichromosomes in the rat louse, Ho. kitti; each minichromosome is 1.8-2.8 kb long and has 1-5 genes. Ho. akanezumi also has a chimeric minichromosome with parts of two rRNA genes and a full-length tRNA gene for tyrosine. These two rodent lice share the same pattern for the distribution of all of the protein-coding and rRNA genes but differ in tRNA gene content and gene arrangement in four minichromosomes. Like the four genera of blood-sucking lice that have been investigated in previous studies, the Hoplopleura species have four minichromosomes that are only found in this genus. Our results indicate that fragmented mt genomes were present in the most recent common ancestor of the two major clades of the blood-sucking lice, which lived ~75 million years ago. Intra-genus variation in the pattern of mt genome fragmentation is common in the blood-sucking lice (suborder Anoplura) and genus-specific minichromosomes are potential synapomorphies. Future studies should expand into more species, genera and families of blood-sucking lice to explore further the phylogenetic utility of the novel features associated with fragmented

A hitchhiker's guide to parasite transmission: The phoretic behaviour of feather lice.

PubMed

Harbison, Christopher W; Jacobsen, Matthew V; Clayton, Dale H

2009-04-01

Transmission to new hosts is a fundamental challenge for parasites. Some species meet this challenge by hitchhiking on other, more mobile parasite species, a behaviour known as phoresis. For example, feather-feeding lice that parasitise birds disperse to new hosts by hitchhiking on parasitic louse flies, which fly between individual birds. Oddly, however, some species of feather lice do not engage in phoresis. For example, although Rock Pigeon (Columba livia) "wing" lice (Columbicola columbae) frequently move to new hosts phoretically on louse flies (Pseudolynchia canariensis), Rock Pigeon "body" lice (Campanulotes compar) do not. This difference in phoretic behaviour is puzzling because the two species of lice have very similar life cycles and are equally dependent on transmission to new hosts. We conducted a series of experiments designed to compare the orientation, locomotion and attachment capabilities of these two species of lice, in relation to louse flies. We show that wing lice use fly activity as a cue in orientation and locomotion, whereas body lice do not. We also show that wing lice are more capable of remaining attached to active flies that are walking, grooming or flying. The superior phoretic ability of wing lice may be related to morphological adaptations for life on wing feathers, compared to body feathers.

Epidemiology of Lice

ERIC Educational Resources Information Center

Juranek, Dennis D.

1977-01-01

Research into the epidemiology of lice indicates that infestation is uncommon in blacks, more common in females than males, significantly higher in low income groups, and transmission is by way of articles of clothing. (JD)

Prevalence of Tinea capitis in school going children in Kolkata, West Bengal

PubMed Central

Kundu, D.; Mandal, L.; Sen, G.

2012-01-01

Background: In recent years the incidence of Tinea capitis, infection of scalp by dermatophytes, has increased in United Kingdom and North America. The trend may be similar in India. The objective of this study is to find the prevalence of Tinea capitis in school going urban children in Kolkata, West Bengal state. Materials and Methods: The present study is a cross-sectional study conducted in a government higher primary school in Kolkata. Results: Totally 505 students were screened and 52 were diagnosed to have Tinea capitis by clinical examination, giving a prevalence rate of 10% among school children. Prevalence rates among the age groups of 6–8, 9–11 and 12–14 years were almost the same, ranging from 9 to 11%. The prevalence rate was significantly high among the boys (14%). There was no significant difference in prevalence of infection among coconut oil users and castor oil users. Measures of general hygiene were similar among those who were infected with Tinea capitis and those who were not. The commonest clinical type of infection found was dull grey patches. Itching with hair loss was the major symptom and most of the infected children had cervical lymphadenopathy. The potassium hydroxide studies revealed endothrix spores in majority of samples. Conclusion: Tinea capitis in prevalent in school going urban children in Kolkata, West Bengal state and necessary measures must be undertaken to curtail this incidence. PMID:23225977

Understanding sources of sea lice for salmon farms in Chile.

PubMed

Kristoffersen, A B; Rees, E E; Stryhn, H; Ibarra, R; Campisto, J-L; Revie, C W; St-Hilaire, S

2013-08-01

The decline of fisheries over recent decades and a growing human population has coincided with an increase in aquaculture production. As farmed fish densities increase, so have their rates of infectious diseases, as predicted by the theory of density-dependent disease transmission. One of the pathogen that has increased with the growth of salmon farming is sea lice. Effective management of this pathogen requires an understanding of the spatial scale of transmission. We used a two-part multi-scale model to account for the zero-inflated data observed in weekly sea lice abundance levels on rainbow trout and Atlantic salmon farms in Chile, and to assess internal (farm) and external (regional) sources of sea lice infection. We observed that the level of juvenile sea lice was higher on farms that were closer to processing plants with fish holding facilities. Further, evidence for sea lice exposure from the surrounding area was supported by a strong positive correlation between the level of juvenile sea lice on a farm and the number of gravid females on neighboring farms within 30 km two weeks prior. The relationship between external sources of sea lice from neighboring farms and juvenile sea lice on a farm was one of the strongest detected in our multivariable model. Our findings suggest that the management of sea lice should be coordinated between farms and should include all farms and processing plants with holding facilities within a relatively large geographic area. Understanding the contribution of pathogens on a farm from different sources is an important step in developing effective control strategies. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Inventory of lice of mammals and farmyard chicken in North-eastern Algeria.

PubMed

Meguini, Mohamed Nadir; Righi, Souad; Zeroual, Fayçal; Saidani, Khelaf; Benakhla, Ahmed

2018-03-01

Lice are permanent ectoparasites, extremely specific to their hosts. Their great importance in veterinary medicine remain significant, they can cause their direct pathogenic actions like irritability, dermatitis, anemia, decreased weight gain, and milk production. The purpose of this work was to made the first time an inventory of mammalian lice in North-eastern Algeria. Our survey of lice infestation was conducted on several animal species from five provinces of North-eastern Algeria. A total of 57 cattle, 83 sheep, 77 goats, 111 wild boars, and 63 farmyard chickens were examined. The collection of lice was carried out much more in mammals and chickens during the winter period. Lice were collected either manually or using brushing and kept in flasks containing 70% ethanol. The identification of lice was achieved in the laboratory using a binocular loupe. Concerning cattle, 63% and 27% of those examined subjects from Souk-Ahras and Guelma study areas, respectively, were carriers of lice. Damalinia bovis was the louse most frequently found on cattle in these two regions. Three other species were identified in Souk-Ahras: Haematopinus eurysternus (25%), Linognathus vituli (10%), and Solenopotes capillatus (5%). Regarding sheep, 39% and 24% of examined animals in Souk-Ahras and Guelma, were carrying lice. Damalinia ovis was the most frequently encountered lice on sheep in both regions. Linognathus ovillus also was identified in Souk-Ahras, representing 0.3% of the collected lice. Concerning goats, 53% and 30% of examined animals in Souk-Ahras and Guelma, were parasitized of lice. Two species of lice were found: Damalinia caprae and Linognathus africanus . For farmyard chickens, 69% and 100% of the farmyard chicken in Souk-Ahras and Mila were parasitized by lice, respectively. Menopon gallinae was the most frequently encountered louse in farmyard chicken in both regions. Eight other species were identified in Mila and four other species only in Souk-Ahras. Finally, 25

Inventory of lice of mammals and farmyard chicken in North-eastern Algeria

PubMed Central

Meguini, Mohamed Nadir; Righi, Souad; Zeroual, Fayçal; Saidani, Khelaf; Benakhla, Ahmed

2018-01-01

Background and Aim: Lice are permanent ectoparasites, extremely specific to their hosts. Their great importance in veterinary medicine remain significant, they can cause their direct pathogenic actions like irritability, dermatitis, anemia, decreased weight gain, and milk production. The purpose of this work was to made the first time an inventory of mammalian lice in North-eastern Algeria. Materials and Methods: Our survey of lice infestation was conducted on several animal species from five provinces of North-eastern Algeria. A total of 57 cattle, 83 sheep, 77 goats, 111 wild boars, and 63 farmyard chickens were examined. The collection of lice was carried out much more in mammals and chickens during the winter period. Lice were collected either manually or using brushing and kept in flasks containing 70% ethanol. The identification of lice was achieved in the laboratory using a binocular loupe. Results: Concerning cattle, 63% and 27% of those examined subjects from Souk-Ahras and Guelma study areas, respectively, were carriers of lice. Damalinia bovis was the louse most frequently found on cattle in these two regions. Three other species were identified in Souk-Ahras: Haematopinus eurysternus (25%), Linognathus vituli (10%), and Solenopotes capillatus (5%). Regarding sheep, 39% and 24% of examined animals in Souk-Ahras and Guelma, were carrying lice. Damalinia ovis was the most frequently encountered lice on sheep in both regions. Linognathus ovillus also was identified in Souk-Ahras, representing 0.3% of the collected lice. Concerning goats, 53% and 30% of examined animals in Souk-Ahras and Guelma, were parasitized of lice. Two species of lice were found: Damalinia caprae and Linognathus africanus. For farmyard chickens, 69% and 100% of the farmyard chicken in Souk-Ahras and Mila were parasitized by lice, respectively. Menopon gallinae was the most frequently encountered louse in farmyard chicken in both regions. Eight other species were identified in Mila and

Tinea capitis in schoolchildren in a rural area in southern Ethiopia.

PubMed

Leiva-Salinas, Maria; Marin-Cabanas, Irene; Betlloch, Isabel; Tesfasmariam, Abraham; Reyes, Francisco; Belinchon, Isabel; Ramos, José Manuel

2015-07-01

Skin diseases, especially tinea capitis, represent some of the most frequent causes of morbidity in developing countries. The aim of this study was to examine the prevalences of fungal infections in schoolchildren in a primary school located in a rural area in southern Ethiopia and to perform an analysis of the risk factors associated with tinea capitis. This school-based, prospective cross-sectional study was conducted in October 2012 in Gambo School, Kore, West Arsi, Oromya Region, Ethiopia. Detailed interviews and dermatological examinations were performed. No laboratory examinations were conducted. A total of 647 students were interviewed and examined. The mean age of these children was 10 years (range: 4-14 years). Of the children examined, 236 had some type of dermatophytosis (prevalence: 36.5%, 95% confidence interval [CI] 32.8-40.3), which represented the most frequent type of skin problem. The prevalence of dermatophytoses was more common in males than in females (42.2% and 30.5%, respectively; P = 0.002), and among pupils aged 5-7 years (46.9%; P < 0.001). A total of 159 (prevalence: 24.6%, 95% CI 21.3-28.1) children had tinea capitis, 56 (8.7%) had tinea pedis, 50 (7.7%) had tinea corporis, and six (0.9%) had tinea unguium. In multivariate analysis, the risk factors for tinea capitis were: age (odds ratio [OR] 0.75, 95% CI 0.69-0.84; P < 0.001), and male gender (OR 2.56, 95% CI 1.69-13.39; P = 0.002). Fungal dermatoses, especially tinea capitis, are common in primary schoolchildren in rural areas of southern Ethiopia, especially in young boys. © 2014 The International Society of Dermatology.

Genetic recombination events between sympatric Clade A and Clade C lice in Africa.

PubMed

Veracx, Aurélie; Boutellis, Amina; Raoult, Didier

2013-09-01

Human head and body lice have been classified into three phylogenetic clades (Clades A, B, and C) based on mitochondrial DNA. Based on nuclear markers (the 18S rRNA gene and the PM2 spacer), two genotypes of Clade A head and body lice, including one that is specifically African (Clade A2), have been described. In this study, we sequenced the PM2 spacer of Clade C head lice from Ethiopia and compared these sequences with sequences from previous works. Trees were drawn, and an analysis of genetic diversity based on the cytochrome b gene and the PM2 spacer was performed for African and non-African lice. In the tree drawn based on the PM2 spacer, the African and non-African lice formed separate clusters. However, Clade C lice from Ethiopia were placed within the African Clade A subcluster (Clade A2). This result suggests that recombination events have occurred between Clade A2 lice and Clade C lice, reflecting the sympatric nature of African lice. Finally, the PM2 spacer and cytochrome b gene sequences of human lice revealed a higher level of genetic diversity in Africa than in other regions.

Use of temperature and water immersion to control the human body louse (Anoplura: Pediculidae).

PubMed

Mumcuoglu, K Y; Friger, M; Cohen, R

2006-07-01

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%).

Risk Factors for Human Lice and Bartonellosis among the Homeless, San Francisco, California, USA

PubMed Central

Cole-Porse, Charsey; Kjemtrup, Anne; Osikowicz, Lynn; Kosoy, Michael

2014-01-01

Homeless persons in San Francisco, California, USA, have been shown to have head and body lice infestations and Bartonella quintana infections. We surveyed a self-selected population of homeless persons in San Francisco to assess infestations of head and body lice, risks of having body lice, and presence of B. quintana in lice. A total of 203 persons who reported itching were surveyed during 2008–2010 and 2012: 60 (30%) had body lice, 10 (4.9%) had head lice, and 6 (3.0%) had both. B. quintana was detected in 10 (15.9%) of 63 body lice pools and in 6 (37.5%) of 16 head lice pools. Variables significantly associated (p<0.05) with having body lice in this homeless population included male sex, African–American ethnicity, and sleeping outdoors. Our study findings suggest that specific segments of the homeless population would benefit from information on preventing body lice infestations and louseborne diseases. PMID:25280380

Risk factors for human lice and bartonellosis among the homeless, San Francisco, California, USA.

PubMed

Bonilla, Denise L; Cole-Porse, Charsey; Kjemtrup, Anne; Osikowicz, Lynn; Kosoy, Michael

2014-10-01

Homeless persons in San Francisco, California, USA,have been shown to have head and body lice infestations and Bartonella quintana infections. We surveyed a self selected population of homeless persons in San Francisco to assess infestations of head and body lice, risks of having body lice, and presence of B. quintana in lice. A total of 203 persons who reported itching were surveyed during 2008-2010 and 2012: 60 (30%) had body lice, 10 (4.9%)had head lice, and 6 (3.0%) had both. B. quintana was detected in 10 (15.9%) of 63 body lice pools and in 6 (37.5%)of 16 head lice pools. Variables significantly associated(p<0.05) with having body lice in this homeless population included male sex, African-American ethnicity, and sleeping outdoors. Our study findings suggest that specific segments of the homeless population would benefit from information on preventing body lice infestations and louse borne diseases.

Evolutionary history of mammalian sucking lice (Phthiraptera: Anoplura)

PubMed Central

2010-01-01

Background Sucking lice (Phthiraptera: Anoplura) are obligate, permanent ectoparasites of eutherian mammals, parasitizing members of 12 of the 29 recognized mammalian orders and approximately 20% of all mammalian species. These host specific, blood-sucking insects are morphologically adapted for life on mammals: they are wingless, dorso-ventrally flattened, possess tibio-tarsal claws for clinging to host hair, and have piercing mouthparts for feeding. Although there are more than 540 described species of Anoplura and despite the potential economical and medical implications of sucking louse infestations, this study represents the first attempt to examine higher-level anopluran relationships using molecular data. In this study, we use molecular data to reconstruct the evolutionary history of 65 sucking louse taxa with phylogenetic analyses and compare the results to findings based on morphological data. We also estimate divergence times among anopluran taxa and compare our results to host (mammal) relationships. Results This study represents the first phylogenetic hypothesis of sucking louse relationships using molecular data and we find significant conflict between phylogenies constructed using molecular and morphological data. We also find that multiple families and genera of sucking lice are not monophyletic and that extensive taxonomic revision will be necessary for this group. Based on our divergence dating analyses, sucking lice diversified in the late Cretaceous, approximately 77 Ma, and soon after the Cretaceous-Paleogene boundary (ca. 65 Ma) these lice proliferated rapidly to parasitize multiple mammalian orders and families. Conclusions The diversification time of sucking lice approximately 77 Ma is in agreement with mammalian evolutionary history: all modern mammal orders are hypothesized to have diverged by 75 Ma thus providing suitable habitat for the colonization and radiation of sucking lice. Despite the concordant timing of diversification events

Head lice and the use of spinosad.

PubMed

Villegas, Susan C; Breitzka, Robin L

2012-01-01

Head lice infestations are responsible for social and economic distress. Despite a reported increase in resistance, permethrin 1% is still the first-line treatment of head lice. Alternative topical pediculicidal agents include malathion and benzyl alcohol, but resistance is of growing concern. In 2011, a new pediculicide, spinosad, was introduced. Our aim was to review the clinical pharmacology, efficacy, tolerability, and current place in therapy of spinosad for the treatment of head lice. Pertinent articles and abstracts were identified through searches of MEDLINE/Ebsco and MEDLINE/Ovid from 1948 to September 2011 and International Pharmaceutical Abstracts from 1966 to September 2011. Two reports described 3 trials of spinosad used for the treatment of head lice. One study (n = 120) demonstrated efficacy of both spinosad 0.5% and spinosad 1% compared with placebo, with 82.5% and 86.1% of patients free of live lice 14 days after treatment, respectively, compared with 25.6% in the placebo group (P < 0.001 for each treatment). The difference between the spinosad 0.5% and 1% treatment groups was not significant. Two trials (n = 1038) comparing spinosad 0.9% with permethrin 1% reported greater efficacy for spinosad with absence of live lice 14 days after 1 or 2 treatments for 84.6% and 86.7%, respectively, of primary cases compared with 44.9% and 42.9% with permethrin (P < 0.001 for both studies). The most common reported adverse events were eye and scalp irritation, but they were not statistically significant (P = 0.329 and P = 0.395, respectively). Only application-site erythema reactions showed statistical significance, with 6.8% in the permethrin group versus 3.1% in the spinosad group (P = 0.007). Although limited, the available literature suggests that spinosad is an effective and well-tolerated agent for the treatment of head lice. In a time of increasing resistance, spinosad has demonstrated superior performance compared with permethrin. A review of the

Worldwide Endemicity of a Multidrug-Resistant Staphylococcus capitis Clone Involved in Neonatal Sepsis.

PubMed

Butin, Marine; Martins-Simões, Patricia; Rasigade, Jean-Philippe; Picaud, Jean-Charles; Laurent, Frédéric

2017-03-01

A multidrug-resistant Staphylococcus capitis clone, NRCS-A, has been isolated from neonatal intensive care units in 17 countries throughout the world. S. capitis NRCS-A prevalence is high in some neonatal intensive care units in France. These data highlight the worldwide endemicity and epidemiologic relevance of this multidrug-resistant, coagulase-negative staphylococci clone.

Salmon lice – impact on wild salmonids and salmon aquaculture

PubMed Central

Torrissen, O; Jones, S; Asche, F; Guttormsen, A; Skilbrei, O T; Nilsen, F; Horsberg, T E; Jackson, D

2013-01-01

Salmon lice, Lepeophtheirus salmonis, are naturally occurring parasites of salmon in sea water. Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids. Salmon lice originating from farms negatively impact wild stocks of salmonids, although the extent of the impact is a matter of debate. Estimates from Ireland and Norway indicate an odds ratio of 1.1:1-1.2:1 for sea lice treated Atlantic salmon smolt to survive sea migration compared to untreated smolts. This is considered to have a moderate population regulatory effect. The development of resistance against drugs most commonly used to treat salmon lice is a serious concern for both wild and farmed fish. Several large initiatives have been taken to encourage the development of new strategies, such as vaccines and novel drugs, for the treatment or removal of salmon lice from farmed fish. The newly sequenced salmon louse genome will be an important tool in this work. The use of cleaner fish has emerged as a robust method for controlling salmon lice, and aquaculture production of wrasse is important towards this aim. Salmon lice have large economic consequences for the salmon industry, both as direct costs for the prevention and treatment, but also indirectly through negative public opinion. PMID:23311858

Lice update: new solutions to an old problem.

PubMed

Wadowski, Lisa; Balasuriya, Lily; Price, Harper N; O'Haver, Judith

2015-01-01

An estimated 6 to 12 million children are affected by lice annually in the United States.(1) Knowledge of the various treatment options for this diagnosis is essential. This paper aims to provide an overview of the myriad therapeutic options available for lice infestations in children. U.S. Food and Drug Administration-approved drugs, off-label drug therapies, over-the counter-products, and herbal remedies are all discussed in detail. Clinicians may use this information to teach patients and families about the latest available care for the eradication of head lice in pediatric patients. Copyright © 2015 Elsevier Inc. All rights reserved.

Excretion of living Borrelia recurrentis in feces of infected human body lice.

PubMed

Houhamdi, Linda; Raoult, Didier

2005-06-01

Louse-borne relapsing fever (LBRF), caused by Borrelia recurrentis, is 1 of the most dangerous arthropod-borne diseases. Infection is thought to occur through louse crushing. Lice feces have not been shown to contain living borreliae. We infected 800 body lice by feeding them on a rabbit made spirochetemic by the injection of 2 x 106 borreliae. The life span of infected lice was not shortened. Once infected, lice remained infected for life but did not transmit borreliae to their progeny or to nurse rabbits. B. recurrentis infection was observed throughout lice and spread into hemolymph on day 5 after infection. We describe 2 unprecedented phenomena. In hemolymph, B. recurrentis formed clumps of aggregated borreliae. Using immunofluorescence assay, transmission electron microscopy, and culture, we detected borreliae excreted in lice feces beginning on day 14 after infection. We conclude that, similar to epidemic typhus and trench fever, transmission of LBRF may be caused by lice feces.

Lousy chicks: Chewing lice from the Imperial Shag, Leucocarbo atriceps.

PubMed

Leonardi, María Soledad; Quintana, Flavio

2017-12-01

Forty-one imperial shag chicks were sampled for lice during the breeding season of 2014 in Punta León, Argentina. We found 2 lice species, Pectinopygus turbinatus infesting the body and Piagetiella caputincisum present in the oral cavity of the birds. This constitutes the first host record for P. turbinatus and the first record for the continental Argentina for P. caputincisum . Ninety-three percent of the chicks were infested by at least one lice species. P . turbinatus was present in all of the lousy chicks, while P. caputincisum infested 84.2% of them. The mean intensity was 29.5 and the range 1-129. There was no difference in prevalence, mean intensity or mean abundance between louse species. However, we found differences among the pattern of infestation of each species. Imperial shag chicks were infested by their parents during their first days of life by P. turbinatus , mainly in nymphal stage and by P. caputincisum as adult lice. Our results showed differences among lice species that could be related to the restrictions that lice from seabirds faced during their life cycle.

Chewing lice (Insecta: Phthiraptera) associated with vertebrates in Mexico.

PubMed

SÁnchez-Montes, Sokani; Colunga-Salas, Pablo; Álvarez-Castillo, LucÍa; GuzmÁn-Cornejo, Carmen; Montiel-Parra, Griselda

2018-01-15

The chewing lice (Insecta: Phthiraptera: Amblycera and Ischnocera) of Mexico have been little studied and many publications include isolated records. This paper summarizes current knowledge of chewing lice recorded from Mexico resulting from an exhaustive search of the literature published from 1866 to 2017. We found 342 louse species associated with 206 bird and 28 mammal species. As a result, we provide a checklist of the chewing lice recorded from Mexico, including a host-parasite list and their geographical distribution within the country.

Synergistic activity of antibiotics combined with ivermectin to kill body lice.

PubMed

Sangaré, Abdoul Karim; Rolain, Jean Marc; Gaudart, Jean; Weber, Pascal; Raoult, Didier

2016-03-01

Ivermectin and doxycycline have been found to be independently effective in killing body lice. In this study, 450 body lice were artificially fed on a Parafilm™ membrane with human blood associated with antibiotics (doxycycline, erythromycin, rifampicin and azithromycin) alone and in combination with ivermectin. Fluorescence in situ hybridisation and spectral deconvolution were performed to evaluate bacterial transcriptional activity following antibiotic intake by the lice. In the first series, a lethal effect of antibiotics on lice was observed compared with the control group at 18 days (log-rank test, P≤10(-3)), with a significant difference between groups in the production of nits (P=0.019, Kruskal-Wallis test). A high lethal effect of ivermectin alone (50ng/mL) was observed compared with the control group (log-rank test, P≤10(-3)). Fluorescence of bacteriocytes in lice treated with 20μg/mL doxycycline was lower than in untreated lice (P<0.0001, Kruskal-Wallis test). In the second series with antibiotic-ivermectin combinations, a synergistic lethal effect on treated lice (log-rank test, P<10(-6)) was observed compared with the control group at 18 days, associated with a significant decrease in the production of nits (P≤0.001, Kruskal-Wallis test). Additionally, survival of lice in the combination treatment groups compared with ivermectin alone was significant (log-rank test, P=0.0008). These data demonstrate that the synergistic effect of combinations of antibiotics and ivermectin could be used to achieve complete eradication of lice and to avoid selection of a resistant louse population. Copyright © 2016 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Epidemiological aspects of Pediculosis capitis and treatment evaluation in primary-school children in Iran.

PubMed

Motovali-Emami, Mohammad; Aflatoonian, Mohammad Reza; Fekri, Alireza; Yazdi, Mahbobeh

2008-01-15

This study was undertaken to assess the prevalence of and epidemiological factors associated with, head lice infections in Iranian primary schools in 2006 and evaluate data on the therapeutic efficacy of lindane shampoo. A total of 40586 children (19774 boys (48.72%) and 20812 girls (51.28%)] from 198 Governmentprimary schools in Kerman, were screened for head lice between March and June 2006. The diagnosis of head lice infestation was confirmed by clinical inspection of scalp and hair for the presence of adult lice nymphal stage, or eggs (nit) by line-toothed head lice comb. All children infested with lice were treated with lindane shampoo (1% gamma benzene hexachloride). The overall prevalence of head lice infestation was 1.8%. The prevalence of infestation was significantly higher in girls (2.9%) than in boys (0.6%) (p = 0.000). The infestation rate was greater among pupils who were living in rural areas (4.6%) than in urban areas (1.5%). Of the 721 children with a positive examination result, 424 pupils (58.8%) were reported as having been infested with head lice in the previous 6 months. Mother's education level was a significant risk factor in this model (p < 0.05). At 2 weeks after the primary treatment, the success rates of treatment were 49%. Comprehensive survey in our work showed the better future of the disease and related factors. Education campaigns by health care officials, physicians and teachers are expected to be helpful for head lice control. It is essential that governments should be supported form cooperation between the school authorities and public health centers to successful control head lice infestation in primary school. Also there is an urgent need to identify safe, novel insecticides for proved efficacy.

[Trichophyton violaceum : Main cause of tinea capitis in children at Mbarara Regional Referral Hospital in Uganda].

PubMed

Wiegand, C; Mugisha, P; Mulyowa, G K; Elsner, P; Hipler, U C; Gräser, Y; Uhrlaß, S; Nenoff, P

2016-09-01

Tinea capitis is caused by anthropophilic, zoophilic or geophilic dermatophytes of the genera Microsporum or Trichophyton. The aim of this study was to analyze the clinical presentation of tinea capitis among children in western Uganda. From February to June 2012, skin and hair samples were obtained from 115 patients aged from 1 to 16 years presenting at Mbarara Regional Referral Hospital (MUSC) with clinically suspected tinea capitis. Conventional mycological diagnostics comprised Blancophor preparation and cultivation of fungi for species identification. Tinea capitis among the children included in the MUSC study was mainly noninflammatory showing mostly a seborrhoeic pattern or "black dot" and "gray patch" form and highly inflammatory kerion celsi. Blancophor preparation identified 82.6 % positive and 17.4 % negative samples. Cultural species differentiation showed Trichophyton (T.) violaceum as the causative agent for tinea capitis in 56.6 % of the patients. In 13 %, Microsporum (M.) audouinii was isolated followed by T. soudanense (2.6 %), and T. rubrum (1.7 %). In addition, moulds (contamination?) such as Scopulariopsis brevicaulis, Aspergillus niger, and Fusarium oxysporum were found as well as mixed infections. The anthropophilic dermatophyte T. violaceum represents the most frequent cause of tinea capitis in western Uganda. For successful management oral antifungal therapy is necessary together with supportive topical treatment.

[Lice in Mali: frequency of infestation, genotyping, infection rate and case management].

PubMed

Sangaré, A K; Doumbo, S N; Koné, A K; Thera, M A; Dabo, A; Brouqui, P; Raoult, D; Doumbo, O K

2015-01-01

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.

Head Lice in Norwegian Households: Actions Taken, Costs and Knowledge

PubMed Central

Rukke, Bjørn Arne; Birkemoe, Tone; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben

2012-01-01

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

Head lice in Norwegian households: actions taken, costs and knowledge.

PubMed

Rukke, Bjørn Arne; Birkemoe, Tone; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben

2012-01-01

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. A questionnaire was answered by 6203 households from five geographically separated municipalities in Norway. 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. 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.

Velopharyngeal closure and the longus capitis muscle.

PubMed

Yamawaki, Y; Nishimura, Y; Suzuki, Y

1996-09-01

The dynamic mechanism of velopharyngeal function not only in normal individuals but also in patients with velopharyngeal insufficiency, which is mainly related to cleft palate, has been the subject of considerable interest and controversy. Recently, in order to clarify velopharyngeal movement in the valvular action on phonation we examined dynamic MR images of this area taken in the transverse plane in parallel with the muscle sling of levator veli palatini. In cases in whom the closure pattern in that plane is circular, detailed observation revealed a very interesting result; that is, the longus capitis muscle, one of the group of anterior vertebral muscles, is directly involved in velopharyngeal valving function. It has not previously been reported that the longus capitis muscle acts as one of the velopharyngeal closure muscles, in addition to levator veli palatini. The present study demonstrated that contraction of the muscle contributed to velopharyngeal closure by forward movement of the pharyngeal wall.

Fleas and lice of mammals in New Mexico

Treesearch

Paulette L. Ford; Richard A. Fagerlund; Donald W. Duszynski; Paul J. Polechla

2004-01-01

All available records are compiled for three orders of ectoparasites of mammals in New Mexico: fleas (Siphonaptera), sucking lice (Anoplura), and chewing lice (Mallophaga). We have drawn from records at the University of New Mexico's Museum of Southwestern Biology, the Vector Control Program of the New Mexico Environment Department, the Environmental Health...

Thermo-orientation and the movement of feather-feeding lice on hosts.

PubMed

Harbison, Christopher W; Boughton, Rachel M

2014-08-01

Temperature variation on the host is known to influence ectoparasite distributions. Ectoparasites may also use temperature gradients between host regions when moving on the host; however, tests are rare. Feather-feeding wing lice (Phthiraptera: Ischnocera) spend the majority of their time on the flight feathers of their avian hosts where they insert their bodies between feather barbs to escape host preening. However, because wing lice feed on downy abdominal feathers, they must repeatedly migrate between the flight feathers and body regions of their hosts. We performed a series of experiments that tested thermo-orientation in wing lice and evaluated its potential use during louse migrations between host regions. We found that wing lice can rapidly and accurately locate nearby heat targets that approximate host temperatures (37 C), demonstrating a capacity for directed thermo-orientation. We next tested the preference of wing lice for temperatures found along migration routes between bird flight feathers and their body regions. Wing lice could distinguish between temperatures found within distinct bird regions, and lice that had recently fed preferred the cooler temperatures (32 C), similar to those within bird flight feathers where they typically reside. However, when starved for 18-20 hr, wing lice shifted their preferences toward temperatures typical of bird body regions where they feed (36 C), demonstrating an ability to use thermal cues when moving between bird regions. We discuss the use of thermal cues during louse migration and microhabitat selection, as well as other potential impacts of thermo-orientation on host-parasite interactions.

Tinea Capitis in Infants

PubMed Central

Michaels, Brent D.

2012-01-01

Tinea capitis is a reasonably common infection among the pediatric population; however, it is still a relatively rare entity among infants less than one year of age. As such, a high index of suspicion is necessary for diagnosis among infants and an appropriate diagnostic work up should be employed in any case where a dermatophyte infection is suspected. Several methods are available for diagnosis. In addition, proper identification of the specific dermatophyte genera involved should be considered as treatment options may be altered based on the causative pathogen identified. PMID:22468173

Tinea Capitis: Current Status.

PubMed

Hay, R J

2017-02-01

Tinea capitis remains a common childhood infection in many parts of the world. Yet knowledge of the underlying pathogenetic mechanisms and the development of effective immunity have shown striking advances, and new methods of diagnosis ranging from dermoscopy to molecular laboratory tests have been developed even though they have not been assimilated into routine practice in many centres. Treatment is effective although it needs to be given for at least 1 month. What is missing, however, is a systematic approach to control through case ascertainment and therapy.

Relationship of farm salmon, sea lice, and wild salmon populations.

PubMed

Marty, Gary D; Saksida, Sonja M; Quinn, Terrance J

2010-12-28

Increased farm salmon production has heightened concerns about the association between disease on farm and wild fish. The controversy is particularly evident in the Broughton Archipelago of Western Canada, where a high prevalence of sea lice (ectoparasitic copepods) was first reported on juvenile wild pink salmon (Oncorhynchus gorbuscha) in 2001. Exposure to sea lice from farmed Atlantic salmon (Salmo salar) was thought to be the cause of the 97% population decline before these fish returned to spawn in 2002, although no diagnostic investigation was done to rule out other causes of mortality. To address the concern that sea lice from fish farms would cause population extinction of wild salmon, we analyzed 10-20 y of fish farm data and 60 y of pink salmon data. We show that the number of pink salmon returning to spawn in the fall predicts the number of female sea lice on farm fish the next spring, which, in turn, accounts for 98% of the annual variability in the prevalence of sea lice on outmigrating wild juvenile salmon. However, productivity of wild salmon is not negatively associated with either farm lice numbers or farm fish production, and all published field and laboratory data support the conclusion that something other than sea lice caused the population decline in 2002. We conclude that separating farm salmon from wild salmon--proposed through coordinated fallowing or closed containment--will not increase wild salmon productivity and that medical analysis can improve our understanding of complex issues related to aquaculture sustainability.

Relationship of farm salmon, sea lice, and wild salmon populations

PubMed Central

Marty, Gary D.; Saksida, Sonja M.; Quinn, Terrance J.

2010-01-01

Increased farm salmon production has heightened concerns about the association between disease on farm and wild fish. The controversy is particularly evident in the Broughton Archipelago of Western Canada, where a high prevalence of sea lice (ectoparasitic copepods) was first reported on juvenile wild pink salmon (Oncorhynchus gorbuscha) in 2001. Exposure to sea lice from farmed Atlantic salmon (Salmo salar) was thought to be the cause of the 97% population decline before these fish returned to spawn in 2002, although no diagnostic investigation was done to rule out other causes of mortality. To address the concern that sea lice from fish farms would cause population extinction of wild salmon, we analyzed 10–20 y of fish farm data and 60 y of pink salmon data. We show that the number of pink salmon returning to spawn in the fall predicts the number of female sea lice on farm fish the next spring, which, in turn, accounts for 98% of the annual variability in the prevalence of sea lice on outmigrating wild juvenile salmon. However, productivity of wild salmon is not negatively associated with either farm lice numbers or farm fish production, and all published field and laboratory data support the conclusion that something other than sea lice caused the population decline in 2002. We conclude that separating farm salmon from wild salmon—proposed through coordinated fallowing or closed containment—will not increase wild salmon productivity and that medical analysis can improve our understanding of complex issues related to aquaculture sustainability. PMID:21149706

PREVALENCE OF HEAD LICE INFESTATION IN PRIMARY SCHOOL CHILDREN IN PORT HARCOURT.

PubMed

Okoh, B A N; Alikor, E A D

2013-08-01

Head lice infestation affects mainly school-aged children and prevalence varies from region to region. Head lice infestation is of public health concern and screening is integrated into the School Health Programme. To determine the prevalence of head lice infestation in primary school-aged children in Port Harcourt, Nigeria. Cross-sectional descriptive study. A stratified multi-staged sampling technique was used to recruit pupils between six and 12 years of age, from thirteen primary schools located in three School Districts in the area. The heads of the pupils were inspected for head lice and nits with the aid of a battery operated Robi lice comb, magnifying glass and a torch as light source. A total of 1350 pupils were studied, 743 (55%) females and 607 (45%) males giving a female to male ratio of 1.2:1. Ten (0.7%) of the pupils had head lice infestation while five (0.4%) had evidence of past head lice infestation. The number of infested pupils among the younger age group (six to nine years) was seven (0.8%) and is higher, though not statistically significant, than that in the older age group (ten to twelve years) which was three (0.6%) (p = 0.453). No male was found to be infested while ten (1.3%) females were infested and the observed gender difference was statistically significant (p = 0.002). Head lice infestation still exists in Primary School children in Nigeria, therefore, screening for head lice infestation should still remain a part of the School Health Programme.

Acute Peritonitis Caused by Staphylococcus capitis in a Peritoneal Dialysis Patient.

PubMed

Basic-Jukic, Nikolina

Acute peritonitis remains the most common complication of peritoneal dialysis (PD), with coagulase-negative staphylococci (CoNS) reported to account for more than 25% of peritonitis episodes (1). Staphylococcus capitis is a gram-positive, catalase-positive CoNS that was originally identified as a commensal on the skin of the human scalp (2). Advancement of microbiological technologies for bacterial identification enables diagnosis of previously unknown causes of acute peritonitis. This is the first reported case of acute peritonitis in a PD patient caused by S. capitis. Copyright © 2017 International Society for Peritoneal Dialysis.

Body Lice as Tools for Diagnosis and Surveillance of Reemerging Diseases

PubMed Central

Roux, Veronique; Raoult, Didier

1999-01-01

Body lice are vectors of three bacteria which cause human disease: Rickettsia prowazekii, the agent of epidemic typhus; Bartonella quintana, the agent of trench fever; and Borrelia recurrentis, the agent of relapsing fever. A recrudescence of body lice is being observed as the numbers of individuals living under social conditions which predispose individuals to infestation have increased. Because this phenomenon may lead to the reemergence of infections transmitted by body lice, we aimed to assess the occurrence and prevalence of the three agents described above in more than 600 body lice collected from infested individuals in the African countries of Congo, Zimbabwe, and Burundi, in France, in Russia, and in Peru. The presence of the three bacteria in each louse was determined by specific PCR amplification, and the identities of the organisms detected were confirmed by determination of the nucleotide base sequences of the amplification products. Using this approach, we were able to confirm the presence of R. prowazekii in lice collected from refugees in Burundi, among whom typhus was epidemic, and the presence of B. quintana in lice collected from all locations except the Congo. B. recurrentis was never found. Molecular approaches are convenient tools for the detection and identification of bacterial DNA in body lice and for the epidemiological study of louse-borne bacteria from countries where no medical and biological laboratory facilities are available. PMID:9986818

Body lice as tools for diagnosis and surveillance of reemerging diseases.

PubMed

Roux, V; Raoult, D

1999-03-01

Body lice are vectors of three bacteria which cause human disease: Rickettsia prowazekii, the agent of epidemic typhus; Bartonella quintana, the agent of trench fever; and Borrelia recurrentis, the agent of relapsing fever. A recrudescence of body lice is being observed as the numbers of individuals living under social conditions which predispose individuals to infestation have increased. Because this phenomenon may lead to the reemergence of infections transmitted by body lice, we aimed to assess the occurrence and prevalence of the three agents described above in more than 600 body lice collected from infested individuals in the African countries of Congo, Zimbabwe, and Burundi, in France, in Russia, and in Peru. The presence of the three bacteria in each louse was determined by specific PCR amplification, and the identities of the organisms detected were confirmed by determination of the nucleotide base sequences of the amplification products. Using this approach, we were able to confirm the presence of R. prowazekii in lice collected from refugees in Burundi, among whom typhus was epidemic, and the presence of B. quintana in lice collected from all locations except the Congo. B. recurrentis was never found. Molecular approaches are convenient tools for the detection and identification of bacterial DNA in body lice and for the epidemiological study of louse-borne bacteria from countries where no medical and biological laboratory facilities are available.

Fluoroscopy and Sonographic Guided Injection of Obliquus Capitis Inferior Muscle in an Intractable Occipital Neuralgia

PubMed Central

Kim, Ok Sun; Jeong, Seung Min; Ro, Ji Young; Kim, Duck Kyoung; Koh, Young Cho; Ko, Young Sin; Lim, So Dug; Kim, Hae Kyoung

2010-01-01

Occipital neuralgia is a form of headache that involves the posterior occiput in the greater or lesser occipital nerve distribution. Pain can be severe and persistent with conservative treatment. We present a case of intractable occipital neuralgia that conventional therapeutic modalities failed to ameliorate. We speculate that, in this case, the cause of headache could be the greater occipital nerve entrapment by the obliquus capitis inferior muscle. After steroid and local anesthetic injection into obliquus capitis inferior muscles under fluoroscopic and sonographic guidance, the visual analogue scale was decreased from 9-10/10 to 1-2/10 for 2-3 weeks. The patient eventually got both greater occipital neurectomy and partial resection of obliquus capitis inferior muscles due to the short term effect of the injection. The successful steroid and local anesthetic injection for this occipital neuralgia shows that the refractory headache was caused by entrapment of greater occipital nerves by obliquus capitis inferior muscles. PMID:20552081

Tinea capitis and tinea faciei in the Zurich area - an 8-year survey of trends in the epidemiology and treatment patterns.

PubMed

Kieliger, S; Glatz, M; Cozzio, A; Bosshard, P P

2015-08-01

Tinea capitis and tinea faciei are dermatophyte infections of the scalp and glabrous skin of the face affecting mainly prepubertal children. During the past 30 years, a significant increase and a change in the pattern of infectious agents has been noted for tinea capitis. The aim of this study was to determine trends in the current epidemiological situation of tinea capitis and tinea faciei in the Zurich area, Switzerland and adjacent Central and Eastern Switzerland. Consecutive cases diagnosed between 2006 and 2013 were studied retrospectively. A total of 90 tinea capitis and 40 tinea faciei cases were observed. Anthropophilic isolates (primarily Trichophyton violaceum and Microsporum audouinii) accounted for 76% of tinea capitis cases. In contrast, zoophilic isolates (primarily T. interdigitale) were responsible for 73% of tinea faciei cases. The peak incidence in both conditions was in 4-8 year-old children. While the annual number of tinea faciei cases remained stable over the past 8 years, a trend for an increase in T. violaceum-positive tinea capitis has been observed. This was mainly due to patients of African ethnicity. Anthropophilic isolates accounted for three quarters of tinea capitis and one quarter of tinea faciei cases. T. violaceum-positive tinea capitis was primarily linked to patients of African ethnicity. Tinea capitis caused by Microsporum spp. was more refractory to therapy and needed longer treatment than Trichophyton spp.-induced infection. © 2014 European Academy of Dermatology and Venereology.

Statistical modelling of sea lice count data from salmon farms in the Faroe Islands.

PubMed

Gislason, H

2018-06-01

Fiskaaling regularly counts the number of sea lice in the attached development stages (chalimus, mobiles and adult) for the salmon farms in the Faroe Islands. A statistical model of the data is developed. In the model, the sea-lice infection is represented by the chalimus (or mobile) lice developing into adult lice and is used to simulate past and current levels of adult lice-including treatments-as well as to predict the adult sea lice level 1-2 months into the future. Time series of the chalimus and adult lice show cross-correlations that shift in time and grow in size with temperature. This implies in situ the temperature-dependent development times of about 56 down to 42 days and the inverted development times (growth rates) of 0.018 up to 0.024 lice/day at 8-10°C. The temperature dependence DT=α1T+α2α3=17,840T+7.439-2.128is approximated byD1T=105.2-6.578T≈49 days at the mean temperature 8.5°C-similar to DchaT=100.6-6.507T≈45 days from EWOS data. The observed development times at four sites for a year (2010-11) were 49, 50, 51 and 52 days, respectively. Finally, we estimate the sea lice production from fish farms to discuss approaches to control the sea lice epidemics-preferably by natural means. This study is useful for understanding sea lice levels and treatments, and for in situ analysis of the sea-lice development times and growth rates. © 2017 John Wiley & Sons Ltd.

Substantial variation in the extent of mitochondrial genome fragmentation among blood-sucking lice of mammals.

PubMed

Jiang, Haowei; Barker, Stephen C; Shao, Renfu

2013-01-01

Blood-sucking lice of humans have extensively fragmented mitochondrial (mt) genomes. Human head louse and body louse have their 37 mt genes on 20 minichromosomes. In human pubic louse, the 34 mt genes known are on 14 minichromosomes. To understand the process of mt genome fragmentation in the blood-sucking lice of mammals, we sequenced the mt genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, H. apri, which diverged from human lice approximately 65 Ma. The 37 mt genes of the pig lice are on nine circular minichromosomes; each minichromosome is 3-4 kb in size. The pig lice have four genes per minichromosome on average, in contrast to two genes per minichromosome in the human lice. One minichromosome of the pig lice has eight genes and is the most gene-rich minichromosome found in the sucking lice. Our results indicate substantial variation in the rate and extent of mt genome fragmentation among different lineages of the sucking lice.

Substantial Variation in the Extent of Mitochondrial Genome Fragmentation among Blood-Sucking Lice of Mammals

PubMed Central

Jiang, Haowei; Barker, Stephen C.; Shao, Renfu

2013-01-01

Blood-sucking lice of humans have extensively fragmented mitochondrial (mt) genomes. Human head louse and body louse have their 37 mt genes on 20 minichromosomes. In human pubic louse, the 34 mt genes known are on 14 minichromosomes. To understand the process of mt genome fragmentation in the blood-sucking lice of mammals, we sequenced the mt genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, H. apri, which diverged from human lice approximately 65 Ma. The 37 mt genes of the pig lice are on nine circular minichromosomes; each minichromosome is 3–4 kb in size. The pig lice have four genes per minichromosome on average, in contrast to two genes per minichromosome in the human lice. One minichromosome of the pig lice has eight genes and is the most gene-rich minichromosome found in the sucking lice. Our results indicate substantial variation in the rate and extent of mt genome fragmentation among different lineages of the sucking lice. PMID:23781098

Basal cell carcinoma induced by therapeutic radiation for tinea capitis-clinicopathological study.

PubMed

Oshinsky, Shlomit; Baum, Sharon; Huszar, Monica; Debby, Assaf; Barzilai, Aviv

2018-02-21

An increased prevalence of aggressive histological subtypes, such as micronodular and morpheaform, has been seen, irrespective of the clinical course, in basal cell carcinoma (BCC) following irradiation for tinea capitis. The aim of this study was to assess the histopathological features of BCCs among patients irradiated for tinea capitis and correlate them with the clinical course. The medical records and BCC biopsy specimens of individuals who were previously irradiated for tinea capitis were reviewed. Demographic data and clinical characteristics were retrieved. Biopsy specimens were evaluated for histological subtype classification and additional histopathological features. A telephone survey was conducted to assess the clinical behaviour of the tumours. Thirty-one patients (17 male; 14 female) were included. The average age at time of first biopsy was 56 years. The total number of lesions was 185, with 80% of subjects showing multiple lesions. The nodular subtype was the most prevalent, followed by superficial, micronodular and mixed tumours. One-third of the BCCs could be classified as aggressive histologically. Stromal fibroplasia and melanin deposits were common. There was no mortality related to BCC. None of the 17 patients who completed the survey had evidence of local invasiveness or metastases. BCCs following radiation therapy for tinea capitis show unique histological characteristics related to aggressive behaviour. These aggressive features did not reflect the clinical behaviour in the current cohort. © 2018 John Wiley & Sons Ltd.

Akirins in sea lice: first steps towards a deeper understanding.

PubMed

Carpio, Yamila; García, Claudia; Pons, Tirso; Haussmann, Denise; Rodríguez-Ramos, Tania; Basabe, Liliana; Acosta, Jannel; Estrada, Mario Pablo

2013-10-01

Sea lice (Copepoda, Caligidae) are the most widely distributed marine pathogens in the salmon industry. Vaccination could be an environmentally friendly alternative for sea lice control; however, research on the development of such vaccines is still at an early stage of development. Recent results have suggested that subolesin/akirin/my32 are good candidate antigens for the control of arthropod infestations, including sea lice, but background knowledge about these genes in crustaceans is limited. Herein, we characterize the my32 gene/protein from two important sea lice species, Caligus rogercresseyi and Lepeophtheirus salmonis, based on cDNA sequence isolation, phylogenetic relationships, three dimensional structure prediction and expression analysis. The results show that these genes/proteins have the main characteristics of akirins from invertebrates. In addition, immunization with purified recombinant my32 from L. salmonis elicited a specific antibody response in mice and fish. These results provide an improvement to our current knowledge about my32 proteins and their potential use as vaccine candidates against sea lice in fish. Copyright © 2013 Elsevier Inc. All rights reserved.

Factors in Etiology and Predisposition of Adult Tinea Capitis and Review of Published Literature.

PubMed

Khosravi, Ali Reza; Shokri, Hojjatollah; Vahedi, Ghasem

2016-06-01

Tinea capitis is a common fungal infection in children but is less frequently encountered in adults, especially in immunocompromised individuals. To determine the incidence of tinea capitis in adults, the predisposing factors and causative species. A retrospective study was conducted over a period of 5 years, from 2010 to 2015, on cases of tinea capitis diagnosed in the Department of Dermatology and Mycology Research Center in Tehran, Iran. The information was collected from the patients including age, gender, location of the lesions, results of direct examination and culture, cause of immunosuppression and the prescribed treatment. Twenty-five (20.6 %) patients (10 men and 15 women) with a mean age of 45.28 years were affected by tinea capitis among a total number of 121 positive cases. Most of these adults (80 %) had a grade of immunodeficiency due to the underlying syndromes or diseases, and the rest were immunocompetent. Trichophyton species were isolated from 84 % of these adult patients, indicating Trichophyton violaceum (T. violaceum) as the most common fungal agent. Treatment with oral terbinafine or itraconazole was successful in all these cases. The results showed that most cases affecting the adult population were caused by species of the genus Trichophyton. T. violaceum was the most common dermatophyte of adult patients. Thus, it is important to consider tinea capitis as a differential diagnosis in immunocompromised adults, even though it is considered to be rare in adults.

The control of sea lice in Atlantic salmon by selective breeding.

PubMed

Gharbi, Karim; Matthews, Louise; Bron, James; Roberts, Ron; Tinch, Alan; Stear, Michael

2015-09-06

Sea lice threaten the welfare of farmed Atlantic salmon and the sustainability of fish farming across the world. Chemical treatments are the major method of control but drug resistance means that alternatives are urgently needed. Selective breeding can be a cheap and effective alternative. Here, we combine experimental trials and diagnostics to provide a practical protocol for quantifying resistance to sea lice. We then combined quantitative genetics with epidemiological modelling to make the first prediction of the response to selection, quantified in terms of reduced need for chemical treatments. We infected over 1400 young fish with Lepeophtheirus salmonis, the most important species in the Northern Hemisphere. Mechanisms of resistance were expressed early in infection. Consequently, the number of lice per fish and the ranking of families were very similar at 7 and 17 days post infection, providing a stable window for assessing susceptibility to infection. The heritability of lice numbers within this time window was moderately high at 0.3, confirming that selective breeding is viable. We combined an epidemiological model of sea lice infection and control on a salmon farm with genetic variation in susceptibility among individuals. We simulated 10 generations of selective breeding and examined the frequency of treatments needed to control infection. Our model predicted that substantially fewer chemical treatments are needed to control lice outbreaks in selected populations and chemical treatment could be unnecessary after 10 generations of selection. Selective breeding for sea lice resistance should reduce the impact of sea lice on fish health and thus substantially improve the sustainability of Atlantic salmon production. © 2015 The Author(s).

Treatment of Pediculosis Capitis

PubMed Central

Verma, Prashant; Namdeo, Chaitanya

2015-01-01

An endeavour to delineate the salient details of the treatment of head lice infestation has been made in the present article. Treatment modalities including over the counter permethrin and pyrethrin, and prescription medicines, including malathion, lindane, benzyl alcohol, spinosad are discussed. Salient features of alternative medicine and physical treatment modalities are outlined. The problem of resistance to treatment has also been taken cognizance of. PMID:26120148

In Vitro and In Vivo Evaluation of Infestation Deterrents Against Lice

PubMed Central

Yoon, Kyong Sup; Ketzis, Jennifer K.; Andrewes, Samuel W.; Wu, Christopher S.; Honraet, Kris; Staljanssens, Dorien; Rossel, Bart; Marshall Clark, J.

2015-01-01

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

In Vitro and In Vivo Evaluation of Infestation Deterrents Against Lice.

PubMed

Yoon, Kyong Sup; Ketzis, Jennifer K; Andrewes, Samuel W; Wu, Christopher S; Honraet, Kris; Staljanssens, Dorien; Rossel, Bart; Marshall Clark, J

2015-09-01

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.

[Mycological and epidemiological aspects of tinea capitis in the Sousse region of Tunisia].

PubMed

Saghrouni, F; Bougmiza, I; Gheith, S; Yaakoub, A; Gaïed-Meksi, S; Fathallah, A; Mtiraoui, A; Ben Saïd, M

2011-01-01

Tinea capitis continues to be considered a public health problem in Tunisia. The purpose of our study was to investigate trends in the incidence and the mycological and epidemiological aspects of tinea capitis in the Sousse region (Central Tunisia). Our work is a retrospective study concerning all scalp samples taken by the parasitology laboratory of the Farhat Hached Hospital in Sousse, Tunisia, over a 26-year period (1983-2008). A total of 10,505 specimens were examined. Of these, 5593 were positive with positive direct examination and/or positive culture. The average incidence was 215 cases per year. Patients were aged under 12 years in 89.3% of cases. A total of 175 cases of tinea capitis in adults were diagnosed. Ten dermatophyte species were isolated: Trichophyton (T.) violaceum (66.7%), Microsporum (M.) canis (29.3%), T. schoenleinii (1.6%), T. mentagrophytes (1.1%), T. verrucosum (0.6%), T. tonsurans (0.2%), T. rubrum (0.2%), M. gypseum (0.1%), M. audouinii (0.03%) and M. nanum (0.01%). Our study showed a decrease in the annual incidence of tinea capitis over the study period with an evident decrease in trichophytic tinea and disappearance of favus giving way to microsporic and inflammatory tinea. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Network centrality and seasonality interact to predict lice load in a social primate

PubMed Central

Duboscq, Julie; Romano, Valeria; Sueur, Cédric; MacIntosh, Andrew J.J.

2016-01-01

Lice are socially-transmitted ectoparasites. Transmission depends upon their host’s degree of contact with conspecifics. While grooming facilitates ectoparasite transmission via body contact, it also constrains their spread through parasite removal. We investigated relations between parasite burden and sociality in female Japanese macaques following two opposing predictions: i) central females in contact/grooming networks harbour more lice, related to their numerous contacts; ii) central females harbour fewer lice, related to receiving more grooming. We estimated lice load non-invasively using the conspicuous louse egg-picking behaviour performed by macaques during grooming. We tested for covariation in several centrality measures and lice load, controlling for season, female reproductive state and dominance rank. Results show that the interaction between degree centrality (number of partners) and seasonality predicted lice load: females interacting with more partners had fewer lice than those interacting with fewer partners in winter and summer, whereas there was no relationship between lice load and centrality in spring and fall. This is counter to the prediction that increased contact leads to greater louse burden but fits the prediction that social grooming limits louse burden. Interactions between environmental seasonality and both parasite and host biology appeared to mediate the role of social processes in louse burden. PMID:26915589

Network centrality and seasonality interact to predict lice load in a social primate.

PubMed

Duboscq, Julie; Romano, Valeria; Sueur, Cédric; MacIntosh, Andrew J J

2016-02-26

Lice are socially-transmitted ectoparasites. Transmission depends upon their host's degree of contact with conspecifics. While grooming facilitates ectoparasite transmission via body contact, it also constrains their spread through parasite removal. We investigated relations between parasite burden and sociality in female Japanese macaques following two opposing predictions: i) central females in contact/grooming networks harbour more lice, related to their numerous contacts; ii) central females harbour fewer lice, related to receiving more grooming. We estimated lice load non-invasively using the conspicuous louse egg-picking behaviour performed by macaques during grooming. We tested for covariation in several centrality measures and lice load, controlling for season, female reproductive state and dominance rank. Results show that the interaction between degree centrality (number of partners) and seasonality predicted lice load: females interacting with more partners had fewer lice than those interacting with fewer partners in winter and summer, whereas there was no relationship between lice load and centrality in spring and fall. This is counter to the prediction that increased contact leads to greater louse burden but fits the prediction that social grooming limits louse burden. Interactions between environmental seasonality and both parasite and host biology appeared to mediate the role of social processes in louse burden.

Chewing Lice of Swan Geese (Anser cygnoides): New Host-Parasite Associations.

PubMed

Choi, Chang-Yong; Takekawa, John Y; Prosser, Diann J; Smith, Lacy M; Ely, Craig R; Fox, Anthony D; Cao, Lei; Wang, Xin; Batbayar, Nyambayar; Natsagdorj, Tseveenmayadag; Xiao, Xiangming

2016-10-01

Chewing lice (Phthiraptera) that parasitize the globally threatened swan goose Anser cygnoides have been long recognized since the early 19th century, but those records were probably biased towards sampling of captive or domestic geese due to the small population size and limited distribution of its wild hosts. To better understand the lice species parasitizing swan geese that are endemic to East Asia, we collected chewing lice from 14 wild geese caught at 3 lakes in northeastern Mongolia. The lice were morphologically identified as 16 Trinoton anserinum (Fabricius, 1805), 11 Ornithobius domesticus Arnold, 2005, and 1 Anaticola anseris (Linnaeus, 1758). These species are known from other geese and swans, but all of them were new to the swan goose. This result also indicates no overlap in lice species between older records and our findings from wild birds. Thus, ectoparasites collected from domestic or captive animals may provide biased information on the occurrence, prevalence, host selection, and host-ectoparasite interactions from those on wild hosts.

Chewing Lice of Swan Geese (Anser cygnoides): New Host-Parasite Associations

PubMed Central

Choi, Chang-Yong; Takekawa, John Y.; Prosser, Diann J.; Smith, Lacy M.; Ely, Craig R.; Fox, Anthony D.; Cao, Lei; Wang, Xin; Batbayar, Nyambayar; Natsagdorj, Tseveenmayadag; Xiao, Xiangming

2016-01-01

Chewing lice (Phthiraptera) that parasitize the globally threatened swan goose Anser cygnoides have been long recognized since the early 19th century, but those records were probably biased towards sampling of captive or domestic geese due to the small population size and limited distribution of its wild hosts. To better understand the lice species parasitizing swan geese that are endemic to East Asia, we collected chewing lice from 14 wild geese caught at 3 lakes in northeastern Mongolia. The lice were morphologically identified as 16 Trinoton anserinum (Fabricius, 1805), 11 Ornithobius domesticus Arnold, 2005, and 1 Anaticola anseris (Linnaeus, 1758). These species are known from other geese and swans, but all of them were new to the swan goose. This result also indicates no overlap in lice species between older records and our findings from wild birds. Thus, ectoparasites collected from domestic or captive animals may provide biased information on the occurrence, prevalence, host selection, and host-ectoparasite interactions from those on wild hosts. PMID:27853128

Shared Vulnerability: A Theory of Caring for Children with Persistent Head Lice

ERIC Educational Resources Information Center

Gordon, Shirley C.

2007-01-01

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…

Evolution of tinea capitis in the Nanchang area, Southern China: a 50-year survey (1965-2014).

PubMed

Zhan, Ping; Geng, Chengfang; Li, Zhihua; Jin, Yun; Jiang, Qing; Tao, Li; Luo, Yunpeng; Xiong, Zhiwei; Wu, Shaoxi; Li, Dongmei; Liu, Weida; de Hoog, G Sybren

2015-05-01

Tinea capitis remains a common public health problem worldwide especially in developing areas. Aetiologic agents and clinical pattern vary with geography and history of socioeconomic conditions. Three community surveys and a prospective study were carried out over the past 50 years (1965-2014) in the Qingyunpu District of Nanchang, Southern China. Clinical presentation and spectrum of aetiological agents were monitored to understand the evolution of tinea capitis. In 1965 favus was highly epidemic and Trichophyton schoenleinii presented as the overwhelming aetiological agents of scalp infection in the study area, with a prevalence of 3.41% of the population. During a governmental campaign to eliminate tinea capitis initiated in mid of 1960s, favus was successfully controlled and the prevalence decreased to less than 0.01% in 1977. After that period, clinical presentation and spectrum of fungi changed with social development. Trichophyton schoenleinii was replaced by Trichophyton violaceum and Trichophyton mentagrophytes. Nowadays, the species corresponds with a dominant black dot type of tinea capitis in the Nanchang area. The prevalence of causative agents of tinea capitis is not only related to geography but also to socioeconomic factors. Multiple factors have to be considered for the management for control of this disease. © 2015 Blackwell Verlag GmbH.

[Tinea capitis in the University Hospital of Constantine (Algeria)].

PubMed

Benmezdad, A; Moulahem, T; Benyezzar, M; Djaballah, M; Beldjoudi, W; Fendri, A H

2012-12-01

Although benign, tinea capitis are a public health problem and a frequent complaint in children. In Algeria, these disorders have long been known; their high frequency was related to unfavorable social conditions of people both in cities than in rural areas. Our aim is the study of tinea capitis diagnosed in the laboratory of Parasitology and Mycology of the University Hospital of Constantine through a retrospective review of 15 consecutive years from 1997 to 2011. Currently the clinical and biological differ from those described by ancient authors; dermatophytic flora has evolved significantly and favus, once quite common in our country, is hardly ever found. In addition, we are witnessing a resurgence of zoophilic tinea particularly those caused by Microsporum canis. Copyright © 2012. Published by Elsevier SAS.

Walk or ride? Phoretic behaviour of amblyceran and ischnoceran lice.

PubMed

Bartlow, Andrew W; Villa, Scott M; Thompson, Michael W; Bush, Sarah E

2016-04-01

Phoresy is a behaviour where one organism hitches a ride on another more mobile organism. This is a common dispersal mechanism amongst relatively immobile species that specialise on patchy resources. Parasites specialise on patchily distributed resources: their hosts. Although host individuals are isolated in space and time, parasites must transmit between hosts or they will die with their hosts. Lice are permanent obligate ectoparasites that complete their entire life cycle on their host. They typically transmit when hosts come into direct contact; however, lice are also capable of transmitting phoretically. Yet, phoresy is rare amongst some groups of lice. Fundamental morphological differences have traditionally been used to explain the phoretic differences amongst different suborders of lice; however, these hypotheses do not fully explain observed patterns. We propose that a more fundamental natural history trait may better explain variation in phoresy. Species able to disperse under their own power should be less likely to engage in phoresy than more immobile species. Here we experimentally tested the relationship between independent louse mobility and phoresy using a system with four species of lice (Phthiraptera: Ischnocera and Amblycera) that all parasitize a single host species, the Rock Pigeon (Columba livia). We quantified the relative ability of all four species of lice to move independently off the host, and we quantified their ability to attach to, and remain attached to, hippoboscid flies (Pseudolynchia canariensis). Our results show that the most mobile louse species is the least phoretic, and the most phoretic species is quite immobile off the host. Our findings were consistent with the hypothesis that phoretic dispersal should be rare amongst species of lice that are capable of independent dispersal; however other factors such as interspecific competition may also play a role. Copyright © 2016 Australian Society for Parasitology Inc. Published by

Transmission dynamics of parasitic sea lice from farm to wild salmon.

PubMed

Krkosek, Martin; Lewis, Mark A; Volpe, John P

2005-04-07

Marine salmon farming has been correlated with parasitic sea lice infestations and concurrent declines of wild salmonids. Here, we report a quantitative analysis of how a single salmon farm altered the natural transmission dynamics of sea lice to juvenile Pacific salmon. We studied infections of sea lice (Lepeophtheirus salmonis and Caligus clemensi) on juvenile pink salmon (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) as they passed an isolated salmon farm during their seaward migration down two long and narrow corridors. Our calculations suggest the infection pressure imposed by the farm was four orders of magnitude greater than ambient levels, resulting in a maximum infection pressure near the farm that was 73 times greater than ambient levels and exceeded ambient levels for 30 km along the two wild salmon migration corridors. The farm-produced cohort of lice parasitizing the wild juvenile hosts reached reproductive maturity and produced a second generation of lice that re-infected the juvenile salmon. This raises the infection pressure from the farm by an additional order of magnitude, with a composite infection pressure that exceeds ambient levels for 75 km of the two migration routes. Amplified sea lice infestations due to salmon farms are a potential limiting factor to wild salmonid conservation.

Transmission dynamics of parasitic sea lice from farm to wild salmon

PubMed Central

Krkošek, Martin; Lewis, Mark A; Volpe, John P

2005-01-01

Marine salmon farming has been correlated with parasitic sea lice infestations and concurrent declines of wild salmonids. Here, we report a quantitative analysis of how a single salmon farm altered the natural transmission dynamics of sea lice to juvenile Pacific salmon. We studied infections of sea lice (Lepeophtheirus salmonis and Caligus clemensi ) on juvenile pink salmon (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) as they passed an isolated salmon farm during their seaward migration down two long and narrow corridors. Our calculations suggest the infection pressure imposed by the farm was four orders of magnitude greater than ambient levels, resulting in a maximum infection pressure near the farm that was 73 times greater than ambient levels and exceeded ambient levels for 30 km along the two wild salmon migration corridors. The farm-produced cohort of lice parasitizing the wild juvenile hosts reached reproductive maturity and produced a second generation of lice that re-infected the juvenile salmon. This raises the infection pressure from the farm by an additional order of magnitude, with a composite infection pressure that exceeds ambient levels for 75 km of the two migration routes. Amplified sea lice infestations due to salmon farms are a potential limiting factor to wild salmonid conservation. PMID:15870031

Head lice predictors and infestation dynamics among primary school children in Norway

PubMed Central

Birkemoe, Tone; Lindstedt, Heidi Heggen; Ottesen, Preben; Soleng, Arnulf; Næss, Øyvind; Rukke, Bjørn Arne

2016-01-01

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

[Physicians' knowledge in Israel on the biology and control of head lice].

PubMed

Mumcuoglu, Kosta Y; Mumcuoglu, Michael; Danilevich, Maria; Gilead, Leon

2008-10-01

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.

Head lice predictors and infestation dynamics among primary school children in Norway.

PubMed

Birkemoe, Tone; Lindstedt, Heidi Heggen; Ottesen, Preben; Soleng, Arnulf; Næss, Øyvind; Rukke, Bjørn Arne

2016-02-01

Health providers need to know which measures to take and children to prioritize in order to decrease costs associated with head lice infestations. 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. 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. 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. 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. © The Author 2015. Published by Oxford University Press.

Prevalence of Tinea Capitis Infection Among Primary School Children in a Rural Setting in South-West Nigeria

PubMed Central

Ayanlowo, Olusola; Oladele, Rita; Balogun, Mobolanle

2014-01-01

Dermatophyte infection is a common skin disorder. Tinea capitis, infection of the scalp and hair shaft, is the most common dermatophytosis in children aged between six months and pre-pubertal age. The aim of the study was to determine the prevalence, causative agents and to identify predisposing factors among primary school children in a rural community in Sagamu, Ogun state, Nigeria. This was a descriptive cross sectional study. Interviewer administered questionnaire was used. Following a physical examination, children with a clinical diagnosis of tinea capitis had scalp and hair scrapings for microscopy and culture. Tinea capitis was confirmed in 15.4%. Trichophyton mentagrophyte (51.7%) and Microsporum aoudouinii (20.7%) were the most prevalent organisms in this study. The most common predisposing factors were carrying of objects on the scalp; sharing of hair clippers, scissors, combs, towels and fomites. Low socioeconomic status coupled with overcrowding and poor hygiene was the major determinant of tinea capitis among the children. Tinea capitis remains a common infection among Nigerian school children. Health promotion and health education interventions are recommended to promote good hygiene, better living conditions, early identification and treatment. PMID:28299118

Prevalence of Tinea Capitis Infection Among Primary School Children in a Rural Setting in South-West Nigeria.

PubMed

Ayanlowo, Olusola; Akinkugbe, Ayesha; Oladele, Rita; Balogun, Mobolanle

2014-02-04

Dermatophyte infection is a common skin disorder. Tinea capitis , infection of the scalp and hair shaft, is the most common dermatophytosis in children aged between six months and pre-pubertal age. The aim of the study was to determine the prevalence, causative agents and to identify predisposing factors among primary school children in a rural community in Sagamu, Ogun state, Nigeria. This was a descriptive cross sectional study. Interviewer administered questionnaire was used. Following a physical examination, children with a clinical diagnosis of tinea capitis had scalp and hair scrapings for microscopy and culture. Tinea capitis was confirmed in 15.4%. Trichophyton mentagrophyte (51.7%) and Microsporum aoudouinii (20.7%) were the most prevalent organisms in this study. The most common predisposing factors were carrying of objects on the scalp; sharing of hair clippers, scissors, combs, towels and fomites. Low socioeconomic status coupled with overcrowding and poor hygiene was the major determinant of tinea capitis among the children. Tinea capitis remains a common infection among Nigerian school children. Health promotion and health education interventions are recommended to promote good hygiene, better living conditions, early identification and treatment.

Knowledge, attitudes and practices regarding head lice infestations in rural Nigeria.

PubMed

Heukelbach, Jorg; Ugbomoiko, Uade Samuel

2011-09-14

Head lice infestations are common in sub-Saharan Africa, but knowledge, attitudes and practices have never been studied in this region. This population-based study was conducted in a small rural community (population = 590) in Kwara State, Central Nigeria. Inhabitants of the community were interviewed regarding head lice infestations, using a pre-tested structured questionnaire, and examined regarding the presence of active pediculosis. Of the 496 participants included, 367 (74.0%) had experienced head lice infestations, but only 26 (11.1%) of the individuals older than 15 years knew the correct mode of transmission. Of 142 individuals with active pediculosis, only 1 (0.7%) felt ashamed. Treatment was most commonly done by grooming (46.3%), followed by combing (27.2%). Only 4.6% used pediculicides, and 21.8% did not apply any treatment. Opinions about difficulties in controlling head lice were asked in three groups: biological, technical and social. In the first group, the most common difficulty noted was detecting head lice (52.1%), followed by possible resistance that would lengthen the time of infestation (38.9%). Technical constraints included concerns on the safety and effectiveness of products (48.7%) and difficulties in obtaining treatment (46.2%). Social contraints included difficulty in treating children (24.4%), lack of knowledge (23.5%), and the social behavior of children (22.2%). Head lice were not perceived as an important disease in a rural Nigerian community, and feelings about the infestation were mostly indifferent. Despite its common occurrence, knowledge on head lice was limited.  

Spinosad for the treatment of head lice infestations.

PubMed

Villegas, S C

2012-09-01

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. Copyright 2012 Prous Science, S.A.U. or its licensors. All rights reserved.

Prevalence and risk factors of tinea capitis and tinea pedis in school children in Turkey.

PubMed

Balci, Elcin; Gulgun, Mustafa; Babacan, Oguzhan; Karaoglu, Abdulbaki; Kesik, Vural; Yesilkaya, Sirzat; Turker, Turker; Tok, Duran; Koc, Ayse Nedret

2014-05-01

To evaluate the prevalence and risk factors of tinea capitis and tinea pedis in school children in Turkey. The study included 8122 students from 24 schools in the rural and urban areas around Kayseri,Turkey. We asked every student for their personal identification and also for their sanitation in order to get an idea about dermatophytosis. Samples taken from suspicious lesions were collected and inoculated onto Sabouraud dextrose agar slants. For identification of grown fungi, macroscopic appearance of colonies, microscopic examination and biochemical tests were used. There were 41 (0.5%) suspicious lesions in feet and 31 (0.3%) in scalp and 22 (0.2%) students were diagnosed as tinea pedis and 9 (0.1%) as tinea capitis by fungal culture. The predominant etiologic agents in feet were Trichophyton rubrum 8 (36%), Trichophyton mentagrophytes 1 (4%), Rhodotorula 8 (36%), Trichosporon 2 (9%), Candida glabrata 2 (9%), Candida albicans 1 (4%), while Trichophyton verrucosum 8 (88%) and Trichophyton mentagrophytes 1 (12%) were identified in scalp samples. School settlement was found as risk factors on the frequency of tinea pedis and capitis. Age and gender were also found as risk factors on the frequency of tinea pedis. The results of this study demonstrate a low prevalence of tinea capitis and tinea pedis in school children of central Anatolia of Turkey. School settlement is a very important factor affecting the prevalence of tinea capitis and pedis in school children in central Anatolia of Turkey.

[Current approaches to overcoming permethrin resistance in lice].

PubMed

Lopatina, Iu V

2013-01-01

The paper gives information on pediculosis morbidity worldwide. It summarizes the data available in the literature on the resistance of head and clothes lice to pyrethroids and on the mechanisms of this resistance. The formation of head and clothes louse populations resistant to pyrethroids is shown to be a global problem. New groups of chemical substances that are alternatives to pyrethroids and the mechanisms of their action on lice are considered.

Intractable occipital neuralgia caused by an entrapment in the semispinalis capitis.

PubMed

Son, Byung-Chul; Kim, Deok-Ryeong; Lee, Sang-Won

2013-09-01

Occipital neuralgia is a rare pain syndrome characterized by periodic lancinating pain involving the occipital nerve complex. We present a unique case of entrapment of the greater occipital nerve (GON) within the semispinalis capitis, which was thought to be the cause of occipital neuralgia. A 66-year-old woman with refractory left occipital neuralgia revealed an abnormally low-loop of the left posterior inferior cerebellar artery on the magnetic resonance imaging, suggesting possible vascular compression of the upper cervical roots. During exploration, however, the GON was found to be entrapped at the perforation site of the semispinalis capitis. There was no other compression of the GON or of C1 and C2 dorsal roots in their intracranial course. Postoperatively, the patient experienced almost complete relief of typical neuralgic pain. Although occipital neuralgia has been reported to occur by stretching of the GON by inferior oblique muscle or C1-C2 arthrosis, peripheral compression in the transmuscular course of the GON in the semispinalis capitis as a cause of refractory occipital neuralgia has not been reported and this should be considered when assessing surgical options for refractory occipital neuralgia.

Intractable Occipital Neuralgia Caused by an Entrapment in the Semispinalis Capitis

PubMed Central

Kim, Deok-ryeong; Lee, Sang-won

2013-01-01

Occipital neuralgia is a rare pain syndrome characterized by periodic lancinating pain involving the occipital nerve complex. We present a unique case of entrapment of the greater occipital nerve (GON) within the semispinalis capitis, which was thought to be the cause of occipital neuralgia. A 66-year-old woman with refractory left occipital neuralgia revealed an abnormally low-loop of the left posterior inferior cerebellar artery on the magnetic resonance imaging, suggesting possible vascular compression of the upper cervical roots. During exploration, however, the GON was found to be entrapped at the perforation site of the semispinalis capitis. There was no other compression of the GON or of C1 and C2 dorsal roots in their intracranial course. Postoperatively, the patient experienced almost complete relief of typical neuralgic pain. Although occipital neuralgia has been reported to occur by stretching of the GON by inferior oblique muscle or C1-C2 arthrosis, peripheral compression in the transmuscular course of the GON in the semispinalis capitis as a cause of refractory occipital neuralgia has not been reported and this should be considered when assessing surgical options for refractory occipital neuralgia. PMID:24278663

Osseous spurs at the fovea capitis femoris-a frequent finding in asymptomatic volunteers.

PubMed

Bensler, Susanne; Agten, Christoph A; Pfirrmann, Christian W A; Sutter, Reto

2018-01-01

To investigate the different morphologic types of the fovea capitis femoris and the spectrum of osseous spurs/osteophytes of the fovea in asymptomatic volunteers and patients with hip osteoarthritis. Sixty-five patients (mean age 63.6 years) with radiographically confirmed osteoarthritis of the hip and 59 asymptomatic healthy volunteers (mean age 33.9 years) underwent non-contrast MRI of the hip joint. Two radiologists independently evaluated all images. Fovea morphology (standard type, diamond type, flat type, triangular type) as well as the frequency, size and location of spurs/osteophytes of the fovea were assessed. Descriptive and inferential statistics were applied. The most frequent morphologic type of the fovea capitis femoris was the standard type for both asymptomatic volunteers (average 45%) and patients (average 49%). Osseous spurs were detected in 70% of the asymptomatic volunteers, and 97% of the patients had osteophytes. Spur size at all locations was significantly smaller in asymptomatic volunteers (range 1-2 mm) than osteophyte size in patients (range 1-4 mm) (p ≤ 0.035). In volunteers and patients, the spurs/osteophytes were most frequently located at the anterior border of the fovea capitis femoris. Smaller osseous spurs (<2 mm) at the border of the fovea capitis femoris are very common in asymptomatic volunteers and do not seem to be pathologic.

Reinterpreting the origins of flamingo lice: cospeciation or host-switching?

PubMed Central

Johnson, Kevin P; Kennedy, Martyn; McCracken, Kevin G

2006-01-01

The similarity of the louse faunas of flamingos and ducks has been used as evidence that these two groups of birds are closely related. However, the realization that ducks actually are more closely related to Galliformes caused many workers to reinterpret this similarity in parasite faunas as host switching from ducks to flamingos. Recent unexpected phylogenetic results on the relationships of waterbirds and their lice call for a reinterpretation of the origins of the lice of the enigmatic flamingos. Here, we bring together new evidence on the phylogenetic relationships of flamingos and their lice and show that the lice of flamingos and grebes are closely related because their hosts share a common ancestor (cospeciation). We also demonstrate that the similarity of the louse faunas of flamingos and ducks is a result of host switching from flamingos to ducks, rather than from ducks to flamingos. PMID:17148381

Acute prurigo simplex in humans caused by pigeon lice.

PubMed

Stolf, Hamilton Ometto; Reis, Rejane d'Ávila; Espósito, Ana Cláudia Cavalcante; Haddad Júnior, Vidal

2018-03-01

Pigeon lice are insects that feed on feathers of these birds; their life cycle includes egg, nymph and adult and they may cause dermatoses in humans. Four persons of the same family, living in an urban area, presented with widespread intensely pruritic erythematous papules. A great number of lice were seen in their house, which moved from a nest of pigeons located on the condenser of the air-conditioning to the dormitory of one of the patients. Even in urban environments, dermatitis caused by parasites of birds is a possibility in cases of acute prurigo simplex. Pigeon lice are possible etiological agents of this kind of skin eruption, although they are often neglected, even by dermatologists.

Acute prurigo simplex in humans caused by pigeon lice*

PubMed Central

Stolf, Hamilton Ometto; Reis, Rejane d'Ávila; Espósito, Ana Cláudia Cavalcante; Haddad Júnior, Vidal

2018-01-01

Pigeon lice are insects that feed on feathers of these birds; their life cycle includes egg, nymph and adult and they may cause dermatoses in humans. Four persons of the same family, living in an urban area, presented with widespread intensely pruritic erythematous papules. A great number of lice were seen in their house, which moved from a nest of pigeons located on the condenser of the air-conditioning to the dormitory of one of the patients. Even in urban environments, dermatitis caused by parasites of birds is a possibility in cases of acute prurigo simplex. Pigeon lice are possible etiological agents of this kind of skin eruption, although they are often neglected, even by dermatologists. PMID:29723376

Chewing lice of swan geese (Anser cygnoides): New host-parasite associations

USGS Publications Warehouse

Choi, Chang-Yong; Takekawa, John Y.; Prosser, Diann J.; Smith, Lacy M.; Ely, Craig R.; Fox, Anthony D.; Cao, Lei; Wang, Xin; Batbayar, Nyambayar; Natsagdorj, Tseveenmayadag; Xiao, Xiangming

2016-01-01

Chewing lice (Phthiraptera) that parasitize the globally threatened swan goose Anser cygnoides have been long recognized since the early 19th century, but those records were probably biased towards sampling of captive or domestic geese due to the small population size and limited distribution of its wild hosts. To better understand the lice species parasitizing swan geese that are endemic to East Asia, we collected chewing lice from 14 wild geese caught at 3 lakes in northeastern Mongolia. The lice were morphologically identified as 16 Trinoton anserinum (Fabricius, 1805), 11 Ornithobius domesticus Arnold, 2005, and 1 Anaticola anseris (Linnaeus, 1758). These species are known from other geese and swans, but all of them were new to the swan goose. This result also indicates no overlap in lice species between older records and our findings from wild birds. Thus, ectoparasites collected from domestic or captive animals may provide biased information on the occurrence, prevalence, host selection, and host-ectoparasite interactions from those on wild hosts.

Comparative cophylogenetics of Australian phabine pigeons and doves (Aves: Columbidae) and their feather lice (Insecta: Phthiraptera)

USGS Publications Warehouse

Sweet, Andrew D.; Chesser, R. Terry; Johnson, Kevin P.

2017-01-01

Host–parasite coevolutionary histories can differ among multiple groups of parasites associated with the same group of hosts. For example, parasitic wing and body lice (Insecta: Phthiraptera) of New World pigeons and doves (Aves: Columbidae) differ in their cophylogenetic patterns, with body lice exhibiting higher phylogenetic congruence with their hosts than wing lice. In this study, we focus on the wing and body lice of Australian phabine pigeons and doves to determine whether the patterns in New World pigeons and doves are consistent with those of pigeons and doves from other regions. Using molecular sequence data for most phabine species and their lice, we estimated phylogenetic trees for all three groups (pigeons and doves, wing lice and body lice), and compared the phabine (host) tree with both parasite trees using multiple cophylogenetic methods. We found a pattern opposite to that found for New World pigeons and doves, with Australian wing lice showing congruence with their hosts, and body lice exhibiting a lack of congruence. There are no documented records of hippoboscid flies associated with Australian phabines, thus these lice may lack the opportunity to disperse among host species by attaching to hippoboscid flies (phoresis), which could explain these patterns. However, additional sampling for flies is needed to confirm this hypothesis. Large differences in body size among phabine pigeons and doves may also help to explain the congruence of the wing lice with their hosts. It may be more difficult for wing lice than body lice to switch among hosts that vary more dramatically in size. The results from this study highlight how host–parasite coevolutionary histories can vary by region, and how local factors can shape the relationship.

Evaluating the effect of synchronized sea lice treatments in Chile.

PubMed

Arriagada, G; Stryhn, H; Sanchez, J; Vanderstichel, R; Campistó, J L; Rees, E E; Ibarra, R; St-Hilaire, S

2017-01-01

The sea louse is considered an important ectoparasite that affects farmed salmonids around the world. Sea lice control relies heavily on pharmacological treatments in several salmon-producing countries, including Chile. Among options for drug administration, immersion treatments represent the majority of antiparasitic control strategies used in Chile. As a topical procedure, immersion treatments do not induce a long lasting effect; therefore, re-infestation from neighbouring farms may undermine their efficacy. Synchronization of treatments has been proposed as a strategy to improve immersion treatment performance, but it has not been evaluated so far. Using a repeated-measures linear mixed-effect model, we evaluated the impact of treatment synchronization of neighbouring farms (within 10km seaway distance) on the adult lice mean abundance from weeks 2 to 8 post-treatment on rainbow trout and Atlantic salmon farms in Chile, while controlling for external and internal sources of lice before the treatments, and also for environmental and fish-related variables. Results indicate that treatment synchronization was significantly associated with lower adult lice levels from weeks 5 to 7 after treatment. This relationship appeared to be linear, suggesting that higher levels of synchronization may result in lower adult sea lice levels during these weeks. These findings suggest that synchronization can improve the performance of immersion delousing treatments by keeping sea lice levels low for a longer period of time. Our results may be applicable to other regions of the world where immersion treatments are widely used. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Clinicoepidemiological and Mycological Study of Tinea Capitis in the Pediatric Population of Kashmir Valley: A Study from a Tertiary Care Centre.

PubMed

Bhat, Yasmeen J; Zeerak, Sumaya; Kanth, Farhat; Yaseen, Atiya; Hassan, Iffat; Hakak, Rubina

2017-01-01

Tinea capitis is a superficial fungal infection that predominantly affects the pediatric population. The etiological factors vary from region to region, and the exact incidence remains obscure. The clinicoepidemiological and mycological aspects of this dermatophytosis were studied in a tertiary care centre in Kashmir valley. To determine the clinicoepidemiological aspects and mycological findings of dermatophytes involved in tinea capitis cases in Kashmir valley. Wood's lamp examination, KOH examination, and fungal culture were performed in one hundred fifty clinically diagnosed cases of tinea capitis with patients' age upto 14 years over a period of 6 months. The epidemiological factors associated with the disease were also evaluated. Tinea capitis was predominant in the 3-6 and 6-9 years age groups with a male preponderance. Grey patch tinea capitis was the most common variant. KOH positivity was 76%, and Trichophyton tonsurans was the most common fungal isolate. Tinea capitis is a very common fungal infection in our setting. Early detection and diagnosis is mandatory to prevent its spread in the community as well as the development of scarring alopecia in the affected individual.

Insights About Head Lice Transmission From Field Data and Mathematical Modeling.

PubMed

Toloza, Ariel Ceferino; Laguna María, Fabiana; Ortega-Insaurralde, Isabel; Vassena, Claudia; Risau-Gusman, Sebastián

2018-02-22

Head lice infest millions of school-age children every year, both in developed and developing countries. However, little is known about the number of lice transferred among children during school activities, because direct methods to study this are almost impossible to implement. This issue has been addressed following an indirect method, which consist in collecting data of real infestation from several children groups and using a mathematical model of lice colonies to infer how the infestation observed might have evolved. By determining the events that would most likely lead to infestations as those observed, we find that severe infestations are most likely initiated by a relatively large number of lice transferred at the same moment or within relatively short time spans. In turn, analysis of the data obtained from screenings of the same groups of children a few days apart shows evidence of such transmission events. Interestingly, only children with severe infestations could harbor the lice necessary for this type of transmission. Thus, they play the same role as 'superspreaders' in epidemiology. As part of our experimental study it is also shown that a simple procedure of combing can be very effective to remove all mobile lice, and thus could be used as an effective preventive measure against those severe infestations that are responsible for the spread of pediculosis.

Permethrin and malathion resistance in head lice: results of ex vivo and molecular assays.

PubMed

Bouvresse, Sophie; Berdjane, Zohra; Durand, Rémy; Bouscaillou, Julie; Izri, Arezki; Chosidow, Olivier

2012-12-01

Treatment of head lice infestation relies on the application of topical insecticides. Overuse of these products has led to the emergence of resistance to pyrethroids and malathion worldwide. Permethrin resistance in head lice is mostly conferred by the knockdown resistance (kdr) trait. To evaluate the occurrence of permethrin- and malathion-resistant head lice in Paris. A prospective survey was conducted in 74 elementary schools. Live lice collected on schoolchildren were randomly selected and submitted to ex vivo bioassays or underwent individual DNA extraction. A fragment of kdr-like gene was amplified and compared with wild-type sequences. Live head lice were detected in 574 children. Ex vivo assays showed no surviving lice after a 1-hour contact with malathion while most lice died after a 1-hour exposure to permethrin and piperonyl butoxide (85.7%, 95% confidence interval [CI]: 83.9-87.5). Among the 670 lice with workable DNA sequences, 661 lice (98.7%, 95% CI 97.7-99.3) had homozygous kdr mutations. The findings of this large-scale survey of the occurrence of insecticide-resistant head lice indicated a major insecticide pressure in the study population, but it was not sufficient to draw conclusions about other populations. The presence of T917I-L920F mutations in kdr gene may not correlate with treatment failure in prospective studies. The high occurrence of kdr mutant allele suggests that insecticide resistance was already strongly established in the studied population. This finding must be interpreted with caution as it may not be predictive of treatment failure. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Dermoscopy as a useful supportive tool for the diagnosis of pityriasis amiantacea-like tinea capitis.

PubMed

Errichetti, Enzo; Stinco, Giuseppe

2016-07-01

Clinical distinction between pityriasis amiantacea-like tinea capitis and pityriasis amiantacea due to noninfectious inflammatory diseases is a troublesome task, with a significant likelihood of diagnostic errors/delays and prescription of inappropriate therapies. We report a case of pityriasis amiantacea-like tinea capitis with its dermoscopic findings in order to highlight the usefulness of dermoscopy in improving the recognition of such a condition.

Epidemiology of tinea capitis in northeast Iran: a retrospective analysis from 1998 to 2012.

PubMed

Afshar, Parvaneh; Vahedi, Lale; Ghasemi, Maryam; Mardanshahi, Alireza

2016-06-01

Tinea capitis is a common disease of the pediatric population. This disease typically follows one of several clinical patterns, i.e., scaling, hair loss, and/or inflammatory lesions, which are usually caused predominantly by two dermatophytic genera: Microsporum and Trichophyton. The aim of this study was to investigate tinea capitis and its etiological agents in Sari city of Mazandaran province, Iran. We studied the spectrum of tinea capitis by means of a retrospective analysis involving 1745 patients referred to both the Reference Laboratory of Medical Mycology (RLMM) and Bo Ali Sina Hospital at Sari, Iran (1998-2012). Specimens were assessed by standard mycological techniques based on macroscopic and microscopic morphology. Among the patients, 480 (27.5%; 61 males and 39% females) were confirmed through a mycological examination. The peak incidence was in the 5-14 years age group. Endothrix (263 cases; 54.8%) was the most frequent clinical feature by direct exam. The predominant causative agents of tinea capitis were T. tonsurans (186 cases; 38.8%) and T. violaceum (119 cases; 24.8%), followed by T. mentagrophytes (46 cases; 9.6%), T. schoenleinii (28; 5.8%), T. rubrum (20 cases; 4.2%), M. gypseum (15 cases; 3.1%), T. verrucosum (14 cases; 2.9%), and Epidermophyton floccosum (1 cases; 0.2%). The present study showed that tinea capitis is mainly due to the anthropophilic species, and the most common species were T. tonsurans and T. violaceum. Owing to the high frequency of anthropophilic species, future studies may be useful in the development of preventive and educational strategies to reduce healthcare expenditure. © 2015 The International Society of Dermatology.

Dermatoscopic findings as a complementary tool in the differential diagnosis of the etiological agent of tinea capitis.

PubMed

Schechtman, Regina Casz; Silva, Nanashara Diane Valgas; Quaresma, Maria Victória; Bernardes Filho, Fred; Buçard, Alice Mota; Sodré, Celso Tavares

2015-01-01

Tinea capitis is a scalp infection caused by fungi. In Brazil, the main causative agents are Microsporum canis and the Trichophyton tonsurans. Etiological diagnosis is based on suggestive clinical findings and confirmation depends on the fungus growth in culture. However, it is not always possible to perform this test due to lack of availability. We reveal the dermoscopic findings that enable distinction between the main causative agents of Tinea capitis, M. canis and T. tonsurans. The association of clinical and dermatoscopic findings in suspected Tinea capitis cases may help with the differential diagnosis of the etiological agent, making feasible the precocious, specific treatment.

In vitro antifungal susceptibility of Trichophyton violaceum isolated from tinea capitis patients.

PubMed

Deng, S; de Hoog, G S; Verweij, P E; Zoll, J; Ilkit, M; Morsali, F; Abliz, P; Wang, X; Zhan, P; Yang, L; Hasimu, H; Liao, W; Pan, W; Seyedmousavi, S

2015-04-01

Trichophyton violaceum is an anthropophilic dermatophyte that is endemic to parts of Africa and Asia and is sporadic in Europe. T. violaceum mainly causes tinea capitis in both children and adolescents. Although the infections caused by T. violaceum are of considerable medical importance, its antifungal susceptibility profile remains poorly examined. In this study, we tested the in vitro antifungal susceptibility of a set of clinical T. violaceum isolates obtained from tinea capitis patients, using the CLSI broth microdilution method. We tested eight antifungals and used isolates collected from Western China (21), Eastern China (12), the Middle East (1), Europe (20), South Africa (7) and Canada (1). The geometric means of the MICs of the antifungals for all isolates were as follows (in increasing order): posaconazole, 0.021 mg/L; terbinafine, 0.023 mg/L; voriconazole, 0.062 mg/L; amphotericin B, 0.20 mg/L; itraconazole, 0.34 mg/L; caspofungin, 0.56 mg/L; fluconazole, 4.23 mg/L; and flucytosine, 8.46 mg/L. No statistically significant differences in the susceptibility profiles of T. violaceum were detected within the geographical regions tested. Posaconazole, terbinafine and voriconazole were shown to be the most potent antifungal agents against T. violaceum isolates obtained from tinea capitis patients worldwide. These results might help clinicians in developing appropriate therapies that have a high probability of successfully treating tinea capitis due to T. violaceum. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Comparative cophylogenetics of Australian phabine pigeons and doves (Aves: Columbidae) and their feather lice (Insecta: Phthiraptera).

PubMed

Sweet, Andrew D; Chesser, R Terry; Johnson, Kevin P

2017-05-01

Host-parasite coevolutionary histories can differ among multiple groups of parasites associated with the same group of hosts. For example, parasitic wing and body lice (Insecta: Phthiraptera) of New World pigeons and doves (Aves: Columbidae) differ in their cophylogenetic patterns, with body lice exhibiting higher phylogenetic congruence with their hosts than wing lice. In this study, we focus on the wing and body lice of Australian phabine pigeons and doves to determine whether the patterns in New World pigeons and doves are consistent with those of pigeons and doves from other regions. Using molecular sequence data for most phabine species and their lice, we estimated phylogenetic trees for all three groups (pigeons and doves, wing lice and body lice), and compared the phabine (host) tree with both parasite trees using multiple cophylogenetic methods. We found a pattern opposite to that found for New World pigeons and doves, with Australian wing lice showing congruence with their hosts, and body lice exhibiting a lack of congruence. There are no documented records of hippoboscid flies associated with Australian phabines, thus these lice may lack the opportunity to disperse among host species by attaching to hippoboscid flies (phoresis), which could explain these patterns. However, additional sampling for flies is needed to confirm this hypothesis. Large differences in body size among phabine pigeons and doves may also help to explain the congruence of the wing lice with their hosts. It may be more difficult for wing lice than body lice to switch among hosts that vary more dramatically in size. The results from this study highlight how host-parasite coevolutionary histories can vary by region, and how local factors can shape the relationship. Copyright © 2017 Australian Society for Parasitology. All rights reserved.

Detection and culture of Bartonella quintana, Serratia marcescens, and Acinetobacter spp. from decontaminated human body lice.

PubMed

La Scola, B; Fournier, P E; Brouqui, P; Raoult, D

2001-05-01

As part of a survey for trench fever among homeless people in Marseilles, France, we attempted isolation of Bartonella quintana from body lice. A decontamination protocol of immersion in 70% ethanol with 0.2% iodine was devised and was tested with a laboratory colony of body lice. Lice which had been experimentally contaminated with either Escherichia coli, Staphylococcus epidermidis, or Acinetobacter spp. were successfully decontaminated, and this process did not prevent the culture of B. quintana from these lice. One hundred sixty-one lice obtained from homeless patients were studied by the protocol. B. quintana was isolated on axenic medium from 15 of 161 body lice and was detected in 41 of 161 lice by PCR. Acinetobacter spp. and Serratia marcescens were also isolated from body lice. The sensitivities of PCR and culture of B. quintana were 98 and 36%, respectively. These procedures may be useful for epidemiologic studies of trench fever and for the recovery of strains for characterization and comparison.

Socioeconomic status, family background and other key factors influence the management of head lice in Norway.

PubMed

Rukke, Bjørn Arne; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben; Birkemoe, Tone

2014-05-01

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

Why infest the loved ones--inherent human behaviour indicates former mutualism with head lice.

PubMed

Rózsa, Lajos; Apari, Péter

2012-05-01

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.

Changes in base composition bias of nuclear and mitochondrial genes in lice (Insecta: Psocodea).

PubMed

Yoshizawa, Kazunori; Johnson, Kevin P

2013-12-01

While it is well known that changes in the general processes of molecular evolution have occurred on a variety of timescales, the mechanisms underlying these changes are less well understood. Parasitic lice ("Phthiraptera") and their close relatives (infraorder Nanopsocetae of the insect order Psocodea) are a group of insects well known for their unusual features of molecular evolution. We examined changes in base composition across parasitic lice and bark lice. We identified substantial differences in percent GC content between the clade comprising parasitic lice plus closely related bark lice (=Nanopsocetae) versus all other bark lice. These changes occurred for both nuclear and mitochondrial protein coding and ribosomal RNA genes, often in the same direction. To evaluate whether correlations in base composition change also occurred within lineages, we used phylogenetically controlled comparisons, and in this case few significant correlations were identified. Examining more constrained sites (first/second codon positions and rRNA) revealed that, in comparison to the other bark lice, the GC content of parasitic lice and close relatives tended towards 50 % either up from less than 50 % GC or down from greater than 50 % GC. In contrast, less constrained sites (third codon positions) in both nuclear and mitochondrial genes showed less of a consistent change of base composition in parasitic lice and very close relatives. We conclude that relaxed selection on this group of insects is a potential explanation of the change in base composition for both mitochondrial and nuclear genes, which could lead to nucleotide frequencies closer to random expectation (i.e., 50 % GC) in the absence of any mutation bias. Evidence suggests this relaxed selection arose once in the non-parasitic common ancestor of Phthiraptera + Nanopsocetae and is not directly related to the evolution of the parasitism in lice.

The role of body size in host specificity: reciprocal transfer experiments with feather lice.

PubMed

Bush, Sarah E; Clayton, Dale H

2006-10-01

Although most parasites show at least some degree of host specificity, factors governing the evolution of specificity remain poorly understood. Many different groups of host-specific parasites show a striking correlation between parasite and host body size, suggesting that size reinforces specificity. We tested this hypothesis by measuring the relative fitness of host-specific feather lice transferred to pigeons and doves that differ in size by an order of magnitude. To test the general influence of size, we transferred unrelated groups of wing and body lice, which are specialized for different regions of the host. Lice were transferred in both directions, from a large native host species, the rock pigeon (Columba livia), to several progressively smaller hosts, and from a small native host species, the common ground dove (Columbina passerina), to several larger hosts. We measured the relative fitness (population size) of lice transferred to these novel host species after two louse generations. Neither wing lice nor body lice could survive on novel host species that were smaller in size than the native host. However, when host defense (preening behavior) was blocked, both groups survived and reproduced on all novel hosts tested. Thus, host defense interacted with host size to govern the ability of lice to establish on small hosts. Neither wing lice nor body lice could survive on larger hosts, even when preening was blocked. In summary, host size influenced the fitness of both types of feather lice, but through different mechanisms, depending on the direction of the transfer. Our results indicate that host switching is most likely between hosts of similar body size. This finding has important implications for studies of host-parasite coevolution at both the micro- and macroevolutionary scales.

Head Lice: Information for Parents

MedlinePlus

... Address What's this? Submit What's this? Submit Button Information For: Parents Schools Listen to audio/Podcast Related ... General Public. Contact Us Parasites Home Head Lice Information for Parents Language: English (US) Español (Spanish) Recommend ...

Head Lice: Prevention and Control

MedlinePlus

... and General Public. Contact Us Parasites Home Prevention & Control Language: English (US) Español (Spanish) Recommend on Facebook ... that can be taken to help prevent and control the spread of head lice: Avoid head-to- ...

Chewing Lice (Phthiraptera) of Several Species of Wild Birds in Iran, with New Records

PubMed Central

Dik, Bilal; Halajian, Ali

2013-01-01

Background: Although there are about 520 species of birds in Iran, but only some of them have been checked for ectoparasites so far.The aim of this study was to check some more available species of the birds of Iran for lice. Methods: This study was performed between 2008–2010 in northern Iran. For this purpose we tried to check some of the wild bird species available and mostly not checked before to identify the lice of them.The birds were found in some of the houses of hunters keeping as trap for catching more birds, some of the bird keepers and a few dead birds from taxidermists. In this way we could check 79 birds of 6 species. Results: We identified 11 lice species on the birds and overall 15.2 % of the examined birds were infested by the lice. Nine lice species including Aquanirmus podicipis, Pseudomenopon dolium, Ardeicola sp, Ciconiphilus decimfasciatus; Menacanthus sp, Austromenopon transversum, Pectinopygus gyricornis, Colpocephalum turbinatum and Hohorstiella lata were recorded for the first time on the birds in Iran. One specimen of Menacanthus sp was found on the purple Heron (Ardea purpurea) that is a new host report for this lice. Conclusion: Although the infection rate was not very high in the birds, but 11 species of lice in 6 studied birds species in this study, shows there are still other lice species that exist in the birds and should be identified and added to Iran lice fauna list. PMID:23785698

Tinea capitis favosa misdiagnosed as tinea amiantacea

PubMed Central

Anane, Sonia; Chtourou, Olfa

2012-01-01

Introduction Favus of the scalp or tinea capitis favosa is a chronic dermatophyte infection of the scalp. In almost cases, favus is caused by Trichophyton schoenleinii, anthropophilic dermatophyte. It is characterized by the presence of scutula and severe alopecia. Besides the classic clinical type of tinea capitis favosa, there are many variant of clinical form which may persist undiagnosed for many years. In this work, we report an atypical form of favus to Trichophyton schoenleinii which was misdiagnosed as tinea amiantacea. Case-report An 11-year old girl came to the outpatient department of dermatology (day 0) with history of tinea amiantacea treated unsuccessfully with keratolytic shampoo (day – 730). She presented a diffuse scaling of the scalp with thick scaly patches and without scutula or alopecia. A diagnosis of tinea favosa by T. schoenleinii was made by mycological examination. She was treated with griseofulvin and ketoconazole in the form of foaming gel for twelve weeks. Despite treatment, clinical evolution was marked by appearance of permanent alopecia patches. The follow-up mycological examination was negative. Conclusion Because of ultimate evolution of favus into alopecia, we emphasize the importance of mycological examination in case of diffuse scaling. PMID:24432210

Fossil Liposcelididae and the lice ages (Insecta: Psocodea)

PubMed Central

Grimaldi, David; Engel, Michael S

2005-01-01

Fossilized, winged adults belonging to the psocopteran family Liposcelididae are reported in amber from the mid-Cretaceous (ca 100 Myr) of Myanmar (described as Cretoscelis burmitica, gen. et sp. n.) and the Miocene (ca 20 Myr) of the Dominican Republic (Belaphopsocus dominicus sp. n.). Cretoscelis is an extinct sister group to all other Liposcelididae and the family is the free-living sister group to the true lice (order Phthiraptera, all of which are ectoparasites of birds and mammals). A phylogenetic hypothesis of relationships among genera of Liposcelididae, including fossils, reveals perfect correspondence between the chronology of fossils and cladistic rank of taxa. Lice and Liposcelididae minimally diverged 100 Myr, perhaps even in the earliest Cretaceous 145 Myr or earlier, in which case the hosts of lice would have been early mammals, early birds and possibly other feathered theropod dinosaurs, as well as haired pterosaurs. PMID:16537135

Chewing lice from wild birds in northern Greece.

PubMed

Diakou, Anastasia; Pedroso Couto Soares, José Bernardo; Alivizatos, Haralambos; Panagiotopoulou, Maria; Kazantzidis, Savas; Literák, Ivan; Sychra, Oldřich

2017-10-01

Greece represents an important area for wild birds due to its geographical position and habitat diversity. Although the bird species in Greece are well recorded, the information about the chewing lice that infest them is practically non-existent. Thus, the aim of the present study was to record the species of lice infesting wild birds in northern Greece and furthermore, to associate the infestation prevalence with factors such as the age, sex, migration and social behaviour of the host as well as the time of the year. In total 729 birds, (belonging to 9 orders, 32 families and 68 species) were examined in 7 localities of northern Greece, during 9 ringing sessions from June 2013 until October 2015. Eighty (11%) of the birds were found to be infested with lice. In 31 different bird species, 560 specimens of lice, belonging to 33 species were recorded. Mixed infestations were recorded in 11 cases where birds were infested with 2-3 different lice species. Four new host-parasite associations were recorded i.e. Menacanthus curuccae from Acrocephalus melanopogon, Menacanthus agilis from Cettia cetti, Myrsidea sp. from Acrocephalus schoenobaenus, and Philopretus citrinellae from Spinus spinus. Moreover, Menacanthus sinuatus was detected on Poecile lugubris, rendering this report the first record of louse infestation in this bird species. The statistical analysis of the data collected showed no association between parasitological parameters (prevalence, mean and median intensity and mean abundance) in two different periods of the year (breeding vs post-breeding season). However, there was a statistically significant difference in the prevalence of infestation between a) migrating and sedentary passerine birds (7.4% vs 13.2%), b) colonial and territorial birds (54.5% vs 9.6%), and c) female and male birds in breeding period (2.6% vs 15.6%). Copyright © 2017. Published by Elsevier B.V.

Diffuse alopecia in an adolescent female: tinea capitis.

PubMed

Koch, Ellen; English, Joseph C

2014-02-01

"Black dot" tinea capitis is a common cause of alopecia in young patients. It is most commonly caused by a dermatophyte infection with Trichophyton tonsurans. This entity can be easily distinguished from alopecia areata with the use of hair/scalp dermoscopy. The use of oral terbinafine is effective in resolving the infection.

Clinicoepidemiological and Mycological Study of Tinea Capitis in the Pediatric Population of Kashmir Valley: A Study from a Tertiary Care Centre

PubMed Central

Bhat, Yasmeen J.; Zeerak, Sumaya; Kanth, Farhat; Yaseen, Atiya; Hassan, Iffat; Hakak, Rubina

2017-01-01

Background: Tinea capitis is a superficial fungal infection that predominantly affects the pediatric population. The etiological factors vary from region to region, and the exact incidence remains obscure. The clinicoepidemiological and mycological aspects of this dermatophytosis were studied in a tertiary care centre in Kashmir valley. Aim: To determine the clinicoepidemiological aspects and mycological findings of dermatophytes involved in tinea capitis cases in Kashmir valley. Materials and Methods: Wood's lamp examination, KOH examination, and fungal culture were performed in one hundred fifty clinically diagnosed cases of tinea capitis with patients’ age upto 14 years over a period of 6 months. The epidemiological factors associated with the disease were also evaluated. Results: Tinea capitis was predominant in the 3–6 and 6–9 years age groups with a male preponderance. Grey patch tinea capitis was the most common variant. KOH positivity was 76%, and Trichophyton tonsurans was the most common fungal isolate. Conclusion: Tinea capitis is a very common fungal infection in our setting. Early detection and diagnosis is mandatory to prevent its spread in the community as well as the development of scarring alopecia in the affected individual. PMID:28405548

Newly described features resulting from high-magnification dermoscopy of tinea capitis.

PubMed

Lacarrubba, Francesco; Verzì, Anna Elisa; Micali, Giuseppe

2015-03-01

Recent studies have reported "comma hairs" as a typical dermoscopic feature of tinea capitis observed at low magnification (×10). The aim of this study was to evaluate the dermoscopic aspects of tinea capitis at high magnification (×150) and its diagnostic role. Five children (2 boys and 3 girls; aged 4-10 years) with multiple scaly patches of alopecia underwent scalp dermoscopy, direct microscopic examinations, and mycological cultures of skin scrapings. Using low magnification (×30), typical comma hairs, "Morse code-like" hairs, and "zigzag" hairs were observed. When using high magnification (×150), additional features were horizontal white bands that appear as empty bands that are likely related to localized areas of fungal infection. These horizontal white bands are usually multiple and may cause the hair to bend and break. We also identified a new dermoscopic feature consisting of translucent, easily deformable hairs that look weakened and transparent and show unusual bends; they are likely the result of a massive fungal invasion involving the whole hair shaft. Direct microscopic examination showed fungal infection and results of mycological culture were positive for Microsporum canis in all cases. The identification of new findings using higher-magnification dermoscopy may enhance the diagnosis of tinea capitis and be of help to better understand some pathogenetic mechanisms.

Treatment outcomes for tinea capitis in a skin of color population.

PubMed

Bhanusali, Dhaval; Coley, Marcelyn; Silverberg, Jonathan I; Alexis, Andrew; Silverberg, Nanette B

2012-07-01

Tinea capitis periodically undergoes demographic shifts in causative dermatophyte and therapeutic response to oral anti-fungal therapy. To determine prevalent fungal species and response to standard antifungal therapy in inner-city children of color. An IRB-approved chart review of demographic, clinical, diagnostic, and therapeutic data was conducted for children and young adults (0 to 18 years of age) who had scalp fungal culture performed for scalp hyperkeratosis and/or alopecia over a 2.5 year time-period. Supplemental parental phone interview was performed for missing data points. A total of 84 patients with final diagnosis of tinea capitis were identified-52% male, 60.6% African-American, 28.2% Hispanic, and 9.9% Caucasian. Complete resolution at 4 weeks was uncommon in all demographic groups (Hispanic: 11.7%, African-American: 41.3%). The Hispanic group and the youngest patients (aged less than 4 years) were less likely to respond to initial therapy, but the results were not significant. Of the 80 tinea capitis patients initially treated with griseofulvin, 41 out of 54 children (76%) had complete response to micronized suspension +/- crushed tablet (33% required shift to tablets from suspension) and 20 out of 26 (76.9%) cleared on crushed tablets alone. Of the 19 griseofulvin failures, 5 cleared on fluconazole suspension, 7 on terbinafine sprinkles, 3 on itraconazole therapy, and 4 were lost to follow-up. Of the 47 patients who could be evaluated long-term after a single course of oral griseofulvin at 6 weeks or greater, 38 had documented long-term mycological cure (80.8%) and 42 had long-term clinical cure (89%). Trichophyton tonsurans (n=40) was the most prevalent causative species identified on culture, followed by Alternaria species (n=10) and Microsporum canis (n=1). Retrospective chart review: patient population has a high rate of usage of over-the-counter antifungal creams and shampoos, affecting culture results. Tinea capitis is still the most common

Epidemiology of pediculosis capitis among schoolchildren in the eastern area of Bangkok, Thailand.

PubMed

Rassami, Watcharawit; Soonwera, Mayura

2012-11-01

To determine the prevalence of infestation with head lice in primary schoolchildren in the eastern area of Bangkok, Thailand. The present study was to determine the head lice infestation (Pediculosis) levels in primary schoolchildren, during May, 2011 to July, 2011, A total of 3 747 schoolchildren aged 5-12 years old from 12 selected primary school of Ladkrabang district, the eastern area of Bangkok were examined for head lice. Pediculosis was defined as the presence of at least on living adult, nymph and viable egg. The overall head lice infestation rate was 23.32% and infestation rate was higher in girls (47.12%) than in boys (0%). The infestation rate among schoolchildren varied from 12.62% to 29.76%. The infestation rate among girls varied from 26.07% (12 years old group) to 55.89% (8 years old group). Pediculosis is a common public health problem affecting primary schoolchildren in eastern area of Bangkok and those levels are epidemic importance.

Epidemiology of pediculosis capitis among schoolchildren in the eastern area of Bangkok, Thailand

PubMed Central

Rassami, Watcharawit; Soonwera, Mayura

2012-01-01

Objective To determine the prevalence of infestation with head lice in primary schoolchildren in the eastern area of Bangkok, Thailand. Methods The present study was to determine the head lice infestation (Pediculosis) levels in primary schoolchildren, during May, 2011 to July, 2011, A total of 3 747 schoolchildren aged 5-12 years old from 12 selected primary school of Ladkrabang district, the eastern area of Bangkok were examined for head lice. Pediculosis was defined as the presence of at least on living adult, nymph and viable egg. Results The overall head lice infestation rate was 23.32% and infestation rate was higher in girls (47.12%) than in boys (0%). The infestation rate among schoolchildren varied from 12.62% to 29.76%. The infestation rate among girls varied from 26.07% (12 years old group) to 55.89% (8 years old group). Conclusions Pediculosis is a common public health problem affecting primary schoolchildren in eastern area of Bangkok and those levels are epidemic importance. PMID:23569868

Safety and efficacy of terbinafine in a pediatric Iranian cohort of patients with Tinea capitis

PubMed Central

Sabzghabaee, Ali M.; Mansouri, Parwin; Mohammadi, Mahboobeh

2009-01-01

Background and objectives Tinea capitis is a common infection of the scalp and hair shaft caused by dermatophyte fungi that mainly affects prepubescent children. Systemic therapy is required for treatment and to prevent spread. The aim of present study was to assess the effect of terbinafine for Tinea capitis treatment in children. Methods Thirty Iranian pediatric patients with a clinical diagnosis of Tinea capitis were enrolled in the study. The Study was conducted in a general and referral teaching hospital (Imam Medical Centre – Tehran, Iran) from 2006 to 2007. Eligible patients with less than 20 kg of body weight were given 62.5 mg terbinafine, and for patients between 20 and 40 kg the dose was 125 mg, on the first visit. All patients had the second clinical visit and second samples for microscopic study were taken. For each patient, direct mycology test (KOH test) and mycological culture were carried out before the study was started and after second, fourth, fifth, sixth and eighth weeks. Probable drug’s adverse effects were also recorded. Results Based on the results of mycological culture of patients’ lesions, Microsporum canis and Trichophyton sheonlini were considered as major causes of Tinea capitis in these children. Out of 30 study patients, KOH test of 93% in the 5th week and 100% in the 6th week was negative. All patients healed completely from signs of infection, after six weeks. Also, no severe side effects were seen in any patients. Conclusion According to the results of this study, the use of terbinafine is an effective therapy in Iranian cases of Tinea capitis in children without severe side effects. PMID:23964167

Demystifying pediculosis: school nurses taking the lead.

PubMed

Pontius, Deborah J

2014-01-01

The treatment of Pediculosis capitis, or head lice, is fraught with misinformation, myths, and mismanagement. Common myths include the need to exclude children from school, the need to remove all visible nits ("no-nit" policies), the need for massive environmental cleaning, that head lice live for long periods of time, and that schools are a common location for lice transmission. Head lice are a common childhood nuisance, causing embarrassment and emotional trauma in both children and families. This article explores and challenges the commonly held beliefs about the identification, management, and treatment of Pediculosis by presenting current recommended evidence-based practice. It also challenges pediatric nurses, and school nurses in particular, in alignment with the National Association of School Nurses (NASN) Position Statement on Pediculosis Management in the School Setting, to act as change agents for reasonable and effective school policies and practices.

Efficacy of spray formulations containing binary mixtures of clove and eucalyptus oils against susceptible and pyrethroid/ malathion-resistant head lice (Anoplura: Pediculidae).

PubMed

Choi, Han-Young; Yang, Young-Cheol; Lee, Si Hyeock; Clark, J Marshall; Ahn, Young-Joon

2010-05-01

The control efficacy of clove, Eugenia caryophyllata, and eucalyptus, Eucalyptus globulus, essential oils and 15 formulations containing these essential oils alone (8, 12, and 15% sprays) and their binary mixtures (7:3, 5:5, and 3:7 by weight) against adult females of insecticide-susceptible KR-HL and dual malathion- and permethrin-resistant BR-HL strains of head louse, Pediculus humanus capitis (De Geer), was examined by using contact plus fumigant and human hair wig (placed over the head of mannequin) mortality bioassays. In contact plus fumigant mortality bioassay, essential oils from eucalyptus (0.225 mg/cm2) and clove (1.149 mg/cm2) were less effective than either d-phenothrin (0.0029 mg/cm2) or pyrethrum (0.0025 mg/cm2) based on 6-h median lethal concentration values. However, the efficacies of eucalyptus and clove oils were almost identical against females fromn both strains, despite high levels of resistance of the BR-HL females to d-phenothrin (resistance ratio, 667) and pyrethrum (resistance ratio, 754). In human hair wig mortality bioassay, eucalyptus oil spray treatment gave better control efficacy than either spray treatment with clove oil alone or their binary mixtures. Thus, eucalyptus applied as 8% sprays (15 or 20 ml) appears to provide effective protection against pediculosis even to insecticide-resistant head louse populations. Once the safety issues resolved, covering the treated hair and scalp with bath shower cap or hat would ensure the fumigant action of the essential oil.

Adamson's Fringe, Horatio George Adamson, and Kligman's Experiments and Observations on Tinea Capitis

PubMed Central

Joshi, Rajiv

2011-01-01

Adamson's fringe is located at the upper margin of the keratogenous zone of the hair follicle where the nucleated hair shaft cornifies completely and gets converted to hard anucleated keratin. It marks also the area of complete keratinization of the cuticle and Henle's layer of the inner root sheath and the beginning of the stem of the follicle. In Tinea capitis, dermatophytic infection of the hair shaft is restricted to this zone and the fungi do not penetrate further down the infected hair in the bulb of the follicle. The fungi in Adamson's words form “a fringe of mycelium surrounding the hair shaft and project below the lower margin of the sheath of spores around the root-stem.” Horatio George Adamson (1865--1955), a British dermatologist first described this phenomenon, in 1895, and this article describes Adamson's fringe with a short biography of Adamson and discusses Kligman's experiments and observations on Tinea capitis which validated the observations of Adamson and the concept of Adamson's Fringe and described the pathogenesis in Tinea capitis. PMID:21769230

Use of scanning electron microscopy to confirm the identity of lice infesting communally grazed goat herds.

PubMed

Sebei, P J; McCrindle, C M E; Green, E D; Turner, M L

2004-06-01

Lice have been described on goats in commercial farming systems in South Africa but not from flocks on communal grazing. During a longitudinal survey on the causes of goat kid mortality, conducted in Jericho district, North West Province, lice were collected from communally grazed indigenous goats. These lice were prepared for and viewed by scanning electron microscopy, and micro-morphological taxonomic details are described. Three species of lice were found in the study area and identified as Bovicola caprae, Bovicola limbatus and Linognathus africanus. Sucking and biting lice were found in ten of the 12 herds of goats examined. Lice were found on both mature goats and kids. Bovicola caprae and L. africanus were the most common biting and sucking lice respectively in all herds examined. Scanning electron microscopy revealed additional features which aided in the identification of the louse species. Photomicrographs were more accurate aids to identification than the line drawings in the literature and facilitated identification using dissecting microscope.

Treatment of tinea capitis - griseofulvin versus fluconazole - a comparative study.

PubMed

Shemer, Avner; Plotnik, Ira Bernstein; Davidovici, Batya; Grunwald, Marcelo H; Magun, Ronen; Amichai, Boaz

2013-08-01

To compare the efficacy and safety of fluconazole and griseofulvin in the treatment of tinea capitis. Patients with tinea capitis (n = 113) with positive fungal cultures entered the study. The patients were divided into four groups with different treatment regimes. Two groups received griseofulvin 15 or 25 mg/kg/day and two groups received fluconazole 4 or 6 mg/kg/day, all for up to 12 weeks. Griseofulvin was found to be slightly better than fluconazole. The lower doses for both griseofulvin and fluconazole required significantly longer treatment duration until mycological cure than the higher doses, independent of the fungus type. Since no significant difference was found between the drugs, it is suggested that the choice should be based on tolerability, availability and cost of the drugs. © The Authors • Journal compilation © Blackwell Verlag GmbH, Berlin.

Estimating costs of sea lice control strategy in Norway.

PubMed

Liu, Yajie; Bjelland, Hans Vanhauwaer

2014-12-01

This paper explores the costs of sea lice control strategies associated with salmon aquaculture at a farm level in Norway. Diseases can cause reduction in growth, low feed efficiency and market prices, increasing mortality rates, and expenditures on prevention and treatment measures. Aquaculture farms suffer the most direct and immediate economic losses from diseases. The goal of a control strategy is to minimize the total disease costs, including biological losses, and treatment costs while to maximize overall profit. Prevention and control strategies are required to eliminate or minimize the disease, while cost-effective disease control strategies at the fish farm level are designed to reduce the losses, and to enhance productivity and profitability. Thus, the goal can be achieved by integrating models of fish growth, sea lice dynamics and economic factors. A production function is first constructed to incorporate the effects of sea lice on production at a farm level, followed by a detailed cost analysis of several prevention and treatment strategies associated with sea lice in Norway. The results reveal that treatments are costly and treatment costs are very sensitive to treatment types used and timing of the treatment conducted. Applying treatment at an early growth stage is more economical than at a later stage. Copyright © 2014 Elsevier B.V. All rights reserved.

The survey of tinea capitis and scalp dermatophyte carriage in nursing home residents.

PubMed

Lin, Chien-Yio; Lo, Hsiu-Jung; Tu, Ming-Gene; Ju, Yu-Ming; Fan, Yun-Chen; Lin, Chih-Chao; Chiang, Ya-Ting; Yang, Yun-Liang; Chen, Kai-Ting; Sun, Pei-Lun

2018-02-01

Tinea capitis is a contagious dermatophyte infection of scalp and associated hairs. On the other hand, asymptomatic carriage is a status of positive dermatophyte scalp culture, but without signs or symptoms of tinea capitis, and no evidence of hair shaft invasion confirmed by direct microscopy. Tinea capitis and asymptomatic carriage mostly occur in children, but adult females are becoming another population in recent decades. In this study, we focused on the prevalence and related fungi of tinea capitis and asymptomatic carriage in elderly by the shampoo brush method, as well as the source of transmission, in 10 nursing home residents. Two hundred and thirteen residents were screened, and 186 isolates were identified, of which only three were dermatophytes (1.4%). The scalp dermatophyte isolates were identified as Trichophyton rubrum by morphological characters and sequences comparisons in all three cases. After revisiting, these cases were proved to be asymptomatic carriers by negative microscopic and culture examination; however, two cases were found to have concurrent tinea pedis and onychomycosis, which were identified as T. rubrum and Trichophyton interdigitale. The source of the T. rubrum scalp carriage may come from tinea elsewhere on the body of the same subject or from other people in the same institute. Finding and treating the source of carriage, as well as treating scalp carriage patients according to the colony counts, may help prevent disease spreading. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Correlated evolution of host and parasite body size: tests of Harrison's rule using birds and lice.

PubMed

Johnson, Kevin P; Bush, Sarah E; Clayton, Dale H

2005-08-01

Large-bodied species of hosts often harbor large-bodied parasites, a pattern known as Harrison's rule. Harrison's rule has been documented for a variety of animal parasites and herbivorous insects, yet the adaptive basis of the body-size correlation is poorly understood. We used phylogenetically independent methods to test for Harrison's rule across a large assemblage of bird lice (Insecta: Phthiraptera). The analysis revealed a significant relationship between louse and host size, despite considerable variation among taxa. We explored factors underlying this variation by testing Harrison's rule within two groups of feather-specialist lice that share hosts (pigeons and doves). The two groups, wing lice (Columbicola spp.) and body lice (Physconelloidinae spp.), have similar life histories, despite spending much of their time on different feather tracts. Wing lice showed strong support for Harrison's rule, whereas body lice showed no significant correlation with host size. Wing louse size was correlated with wing feather size, which was in turn correlated with overall host size. In contrast, body louse size showed no correlation with body feather size, which also was not correlated with overall host size. The reason why body lice did not fit Harrison's rule may be related to the fact that different species of body lice use different microhabitats within body feathers. More detailed measurements of body feathers may be needed to explore the precise relationship of body louse size to relevant components of feather size. Whatever the reason, Harrison's rule does not hold in body lice, possibly because selection on body size is mediated by community-level interactions between body lice.

Clinical response and safety of malathion shampoo for treatment of head lice in a primary school.

PubMed

Wananukul, Siriwan; Chatproedprai, Susheera; Tempark, Therdpong; Wananukul, Winai

2011-04-01

Help eradicate or at least alleviating head lice in a primary school with malathion shampoo and to study clinical response and safety of malathion shampoo. All students were examined by using a fine-toothed lice comb to help detect live lice. Direct visual examination and the collection of nits for microscopic examination were performed to differentiate viable nits from empty nits. Diagnosis of head lice was made by the presence of lice. All students that had lice and/or nits were treated with malathion shampoo. Malathion shampoo was also provided for all family members. Pediculocidal efficacy was by the presence or absence of live lice. Blood for red blood cell cholinesterase activity was drawn in 32 volunteers before treatment and after the second treatment. At the first visit, 629 students were examined and 48 students had live head lice. The infestation rate was 13% in girls and 1.3% in boys. The cure rate was 93% after the first treatment. The reported side effects were nausea, a burning sensation, and irritation that was found in five (4%), 10 (7%) and three (2%) students respectively. The mean of RBC cholinesterase activity before and after two applications showed significant changes (p = 0.03). It was -7.5 +/- 4.1% reduction from the initial, but all were in the normal range. There was no report of clinical manifestation of malathion toxicity. Malathion shampoo is safe and effective in the treatment of head lice. There is significant skin absorption so a scalp examination for head lice should be done before subsequent application to avoid unnecessary exposure.

Prevalence of tinea capitis and the causative agent among school children in Gondar, North West Ethiopia.

PubMed

Ali, Jemal; Yifru, Sisay; Woldeamanuel, Yimtubezinash

2009-10-01

Tinea capitis is a worldwide public health problem that poses specific therapeutic challenge. This dermatophytosis of the scalp is characteristically a fungal infection affecting children between 5 and 15 years of age. A decision on treatment of tinea capitis requires identification of the specific causative fungal agent or at least establishment of the prevalence of a given dermatophyte in a given community. to estimate the prevalence of tinea capitis, assess predisposing risk factors and identify the causative fungal agent in school children in north Gonder zone, Northwest Ethiopia. This was a cross sectional study conducted in two elementary schools in Gondar town. Clinico-dermatological data and questionnaire on socio-demographic information, living and hygienic conditions were collected. Mycological investigation was done by microscopic examination culture. A total of 372 students were screened for Tinea capitis infection, 262 from Meseret elementary school and 110 from Chechela elementary school. Among these, 61% (n = 227) were female and 39% (n = 145) were male. The median age was 10 years old, 98% of the study subjects were within the age range of 5 to 15. From the screened 372 children 47.5% (n = 177) were clinically suspected for Tinea capitis and 174 scalp samples were collected Microscopic examination in KOH (10%)-wet-mount preparation revealed 65.5% (n = 14) had fungal elements (hyphae and/or arthroconidia) in their clinical samples. Out of 174 specimen 50.0% (87) were culture positive. 33.9% (59) were contaminated and in 16.0% (28) were culture negative. From the positive samples 86.2% (75) were identified as Trichophyton violaceum. The rest 13.8% (12) were further sub-cultured at 37 degrees C and studied morphologically, and identified as Trichophyton verrucosum. A high prevalence of Tinea capitis caused by T. violaceum was found in school children in Gondar. Ethiopia. Provisions for prevention and control should be set in the schools focused on

Predicting the effectiveness of depth-based technologies to prevent salmon lice infection using a dispersal model.

PubMed

Samsing, Francisca; Johnsen, Ingrid; Stien, Lars Helge; Oppedal, Frode; Albretsen, Jon; Asplin, Lars; Dempster, Tim

2016-07-01

Salmon lice is one of the major parasitic problems affecting wild and farmed salmonid species. The planktonic larval stages of these marine parasites can survive for extended periods without a host and are transported long distances by water masses. Salmon lice larvae have limited swimming capacity, but can influence their horizontal transport by vertical positioning. Here, we adapted a coupled biological-physical model to calculate the distribution of farm-produced salmon lice (Lepeophtheirus salmonis) during winter in the southwest coast of Norway. We tested 4 model simulations to see which best represented empirical data from two sources: (1) observed lice infection levels reported by farms; and (2) experimental data from a vertical exposure experiment where fish were forced to swim at different depths with a lice-barrier technology. Model simulations tested were different development time to the infective stage (35 or 50°-days), with or without the presence of temperature-controlled vertical behaviour of lice early planktonic stages (naupliar stages). The best model fit occurred with a 35°-day development time to the infective stage, and temperature-controlled vertical behaviour. We applied this model to predict the effectiveness of depth-based preventive lice-barrier technologies. Both simulated and experimental data revealed that hindering fish from swimming close to the surface efficiently reduced lice infection. Moreover, while our model simulation predicted that this preventive technology is widely applicable, its effectiveness will depend on environmental conditions. Low salinity surface waters reduce the effectiveness of this technology because salmon lice avoid these conditions, and can encounter the fish as they sink deeper in the water column. Correctly parameterized and validated salmon lice dispersal models can predict the impact of preventive approaches to control this parasite and become an essential tool in lice management strategies. Copyright

Chewing lice (Phthiraptera) species of wild birds in northwestern Turkey with a new host record☆

PubMed Central

Girisgin, Ahmet Onur; Dik, Bilal; Girisgin, Oya

2013-01-01

The goal of this study was to identify the chewing lice species of migratory and non-migratory wild birds in the province of Bursa, which is located in northwestern Turkey, between August 2009 and November 2012. Sixty-eight birds brought to the animal hospital in need of medical intervention, which belonged to 25 species, 20 genera and 15 families in 10 orders, were examined for ectoparasites. To sample for the presence of chewing lice, an insecticide was pulverised on the feathers of each bird over a white piece of paper, and then all of the lice were collected and placed in tubes containing 70% alcohol. The lice specimens were cleared in 10% KOH for 24 h, mounted in Canada balsam and identified using a light microscope. Forty (58.8%) out of 68 birds examined were infested with at least one species of chewing lice, and a total of 29 lice species were found on the birds. This study represents the first documentation in Turkey of 9 of these lice species and also provides the first worldwide record of Degeeriella nisus on the Common buzzard (Buteo buteo). PMID:24533339

Dermatoscopic fi ndings as a complementary tool in the differential diagnosis of the etiological agent of tinea capitis*

PubMed Central

Schechtman, Regina Casz; Silva, Nanashara Diane Valgas; Quaresma, Maria Victória; Bernardes Filho, Fred; Buçard, Alice Mota; Sodré, Celso Tavares

2015-01-01

Tinea capitis is a scalp infection caused by fungi. In Brazil, the main causative agents are Microsporum canis and the Trichophyton tonsurans. Etiological diagnosis is based on suggestive clinical findings and confirmation depends on the fungus growth in culture. However, it is not always possible to perform this test due to lack of availability. We reveal the dermoscopic findings that enable distinction between the main causative agents of Tinea capitis, M. canis and T. tonsurans. The association of clinical and dermatoscopic findings in suspected Tinea capitis cases may help with the differential diagnosis of the etiological agent, making feasible the precocious, specific treatment. PMID:26312662

Using state-space models to predict the abundance of juvenile and adult sea lice on Atlantic salmon.

PubMed

Elghafghuf, Adel; Vanderstichel, Raphael; St-Hilaire, Sophie; Stryhn, Henrik

2018-04-11

Sea lice are marine parasites affecting salmon farms, and are considered one of the most costly pests of the salmon aquaculture industry. Infestations of sea lice on farms significantly increase opportunities for the parasite to spread in the surrounding ecosystem, making control of this pest a challenging issue for salmon producers. The complexity of controlling sea lice on salmon farms requires frequent monitoring of the abundance of different sea lice stages over time. Industry-based data sets of counts of lice are amenable to multivariate time-series data analyses. In this study, two sets of multivariate autoregressive state-space models were applied to Chilean sea lice data from six Atlantic salmon production cycles on five isolated farms (at least 20 km seaway distance away from other known active farms), to evaluate the utility of these models for predicting sea lice abundance over time on farms. The models were constructed with different parameter configurations, and the analysis demonstrated large heterogeneity between production cycles for the autoregressive parameter, the effects of chemotherapeutant bath treatments, and the process-error variance. A model allowing for different parameters across production cycles had the best fit and the smallest overall prediction errors. However, pooling information across cycles for the drift and observation error parameters did not substantially affect model performance, thus reducing the number of necessary parameters in the model. Bath treatments had strong but variable effects for reducing sea lice burdens, and these effects were stronger for adult lice than juvenile lice. Our multivariate state-space models were able to handle different sea lice stages and provide predictions for sea lice abundance with reasonable accuracy up to five weeks out. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Comparison of the proliferation and excretion of Bartonella quintana between body and head lice following oral challenge.

PubMed

Kim, J H; Previte, D J; Yoon, K S; Murenzi, E; Koehler, J E; Pittendrigh, B R; Lee, S H; Clark, J M

2017-06-01

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.

Incidence and prevalence of head lice in a district health authority area.

PubMed

Harris, J; Crawshaw, J G; Millership, S

2003-09-01

There are very few recent studies of the incidence and prevalence of head lice in the UK. A population-based questionnaire survey was carried out in a district health authority area. Two hundred and four of 235 primary schools (87%) agreed to participate. A total of 21,556 of 43,889 (49%) questionnaires were returned by parents. Overall 438 children had head lice at the time of the survey, giving a prevalence of 2.03%; 8,059 had had lice at some time in the last year giving an annual incidence of 37.4%.

Pubic "Crab" Lice Prevention and Control

MedlinePlus

... and General Public. Contact Us Parasites Home Prevention & Control Recommend on Facebook Tweet Share Compartir Pubic ("crab") ... that can be taken to help prevent and control the spread of pubic ("crab") lice: All sexual ...

The Mitochondrial Genome of the Guanaco Louse, Microthoracius praelongiceps: Insights into the Ancestral Mitochondrial Karyotype of Sucking Lice (Anoplura, Insecta)

PubMed Central

Li, Hu; Barker, Stephen C.

2017-01-01

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

The head and body lice of humans are genetically distinct (Insecta: Phthiraptera, Pediculidae): evidence from double infestations.

PubMed

Leo, N P; Hughes, J M; Yang, X; Poudel, S K S; Brogdon, W G; Barker, S C

2005-07-01

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.

Vertical transmission of feather lice between adult blackbirds Turdus merula and their nestlings: a lousy perspective.

PubMed

Brooke, M de L

2010-12-01

There is limited information about the natural history of the transmission of feather lice (Phthiraptera) from parent birds to their young. This article therefore examines the transmission of 4 species of feather lice from parent blackbirds to their nestlings in an English population, and addresses questions formulated from the perspective of the lice. The lice that disperse onto the several young in the nest were mostly found on the larger chicks, those with higher survival prospects. The lice dispersing to chicks were overwhelmingly nymphs, which cannot be sexed morphologically, and so the prediction that the adult lice dispersing would be disproportionately female, potential founders of a new population, was only supported for the most numerous species, Brueelia merulensis. There was no evidence that louse dispersal to chicks was density dependent and more likely when the parents were more heavily infested. Finally, I predicted that lice might aggregate on female blackbirds, which undertake more brooding, to increase their chance of transmission to nestlings. For 1 louse species, B. merulensis, prevalence, but not louse intensity, was higher on female than male blackbirds. For 2 other louse species, Philopterus turdi and Menacanthus eurysternus, no differences between male and female blackbirds were detected.

Fragmented mitochondrial genomes in two suborders of parasitic lice of eutherian mammals (Anoplura and Rhynchophthirina, Insecta)

PubMed Central

Shao, Renfu; Barker, Stephen C; Li, Hu; Song, Simon; Poudel, Shreekanta; Su, Yuan

2015-01-01

Parasitic lice (order Phthiraptera) infest birds and mammals. The typical animal mitochondrial (mt) genome organization, which consists of a single chromosome with 37 genes, was found in chewing lice in the suborders Amblycera and Ischnocera. The sucking lice (suborder Anoplura) known, however, have fragmented mt genomes with 9–20 minichromosomes. We sequenced the mt genome of the elephant louse, Haematomyzus elephantis – the first species of chewing lice investigated from the suborder Rhynchophthirina. We identified 33 mt genes in the elephant louse, which were on 10 minichromosomes. Each minichromosome is 3.5–4.2 kb in size and has 2–6 genes. Phylogenetic analyses of mt genome sequences confirm that the elephant louse is more closely related to sucking lice than to the chewing lice in the Amblycera and Ischnocera. Our results indicate that mt genome fragmentation is shared by the suborders Anoplura and Rhynchophthirina. Nine of the 10 mt minichromosomes of the elephant louse differ from those of the sucking lice (Anoplura) known in gene content and gene arrangement, indicating that distinct mt karyotypes have evolved in Anoplura and Rhynchophthirina since they diverged ~92 million years ago. PMID:26617060

Aspergillus niger - a possible new etiopathogenic agent in Tinea capitis? Presentation of two cases.

PubMed

Chokoeva, Anastasiya Atanasova; Zisova, Liliya; Chorleva, Kristina; Tchernev, Georgi

2016-01-01

Tinea capitis is generally considered as the most frequent fungal infection in childhood, as it accounts for approximately 92% of all mycosis in children. The epidemiology of this disease varies widely ranging from antropophillic, zoophilic, and geophillic dermatophytes, as the main causative agent in different geographic areas, depending on several additional factors. Nowadays, the etiology is considered to vary with age, as well with gender, and general health condition. The former reported extraordinary Tinea capitis case reports have been replaced by original articles and researches dealing with progressively changing patterns in etiology and clinical manifestation of the disease. This fact is indicative that under the umbrella of the well-known disease there are facts still hidden for future revelations. Herein, we present two rare cases of Tinea capitis in children, which totally differ from the recently established pattern, in their clinical presentation, as well as in the etiological aspect, as we discuss this potential new etiological pattern of the disease, focusing on our retrospective and clinical observation. Collected data suggest that pathogenic molds should be considered as a potential source of infection in some geographic regions, which require total rationalization of the former therapeutic conception, regarding the molds' higher antimitotic resistance compared to dermatophytes. Molds-induced Tinea capitis should be also considered in clinically resistant and atypical cases, with further investigations of the antifungal susceptibility of the newest pathogens in the frame of the old disease. Further investigations are still needed to confirm or reject this proposal. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

Apes, lice and prehistory.

PubMed

Weiss, Robin A

2009-01-01

Although most epidemic human infectious diseases are caused by recently introduced pathogens, cospeciation of parasite and host is commonplace for endemic infections. Occasional host infidelity, however, provides the endemic parasite with an opportunity to survive the potential extinction of its host. Such infidelity may account for the survival of certain types of human lice, and it is currently exemplified by viruses such as HIV.

Human phthiriasis. Can dermoscopy really help dermatologists? Entodermoscopy: a new dermatological discipline on the edge of entomology.

PubMed

Scanni, G

2012-02-01

The diagnosis of human phtiriasis (often referred to as the "crab" or the "pubic louse") can be more difficult than other types of pediculosis (Pediculus corporis and Pediculus capitis) because this insect has a smaller body of 1.2 x 0.8 mm, may be lighter in color, not as mobile and therefore harder to see to the naked eye. Can dermoscopy aid to perform a better analysis of the skin? The clinical experience developed in two patients gives an affirmative answer, moreover adding useful information of insect and its eggs already known to entomologists but never used in dermatological diagnosis. The identification in vivo can distinguish Phthirus pubis from other skin signs while the conical shape of the operculum and the wide fixing sleeve of egg to hair, tells what species of louse is infesting, even if the insect is unavailable or nits are elsewhere from the pubic area. Entodermoscopy, provided that dermatologists have some knowledge of entomology, therefore promises advantages over standard microscopic examination.

Prevalence of tinea capitis in Southeastern Austria between 1985 and 2008: up-to-date picture of the current situation.

PubMed

Binder, Barbara; Lackner, Helmut Karl; Poessl, Birgit Dorothea; Propst, Erika; Weger, Wolfgang; Smolle, Josef; Ginter-Hanselmayer, Gabriele

2011-05-01

Tinea capitis is the most common dermatophyte infection in childhood, but may rarely occur in adults and the elderly. Causative agents vary within different geographical areas as well as during decades. The aim of this study was to evaluate the prevalence and causative agents of tinea capitis in Southeastern Austria. Retrospective analysis of 714 patients diagnosed with tinea capitis seen at the outpatient Department of Dermatology/Medical University of Graz during the time period 1985-2008 was carried out. A total of 517 of the 714 patients were children, 21 adults and in the case of 176 patients age was not available. Microsporum canis was found in 84.4%. Trichophyton soudanense tinea capitis is seen since 1998, Trichophyton tonsurans for the first time in 2008. Tinea capitis has become very important for the public health. Besides an increasing incidence, there is a change in age of the patients affected and with the pattern of causative agents as a result of immigration movements and lifestyle habits mainly influenced by domestic pets. Our situation reflects nearly the epidemiology of the bordering countries of Austria mainly in the Southeastern surroundings. These epidemiological changes are a challenge for general practitioners, dermatologists and veterinarians to work close together for advice on control, early diagnosing and adequate treatment. © 2009 Blackwell Verlag GmbH.

Detection of Acinetobacter baumannii in human head and body lice from Ethiopia and identification of new genotypes.

PubMed

Kempf, Marie; Abdissa, Alemseged; Diatta, Georges; Trape, Jean-François; Angelakis, Emmanouil; Mediannikov, Oleg; La Scola, Bernard; Raoult, Didier

2012-09-01

Acinetobacter baumannii has previously been detected and genotyped in human body lice. The objectives of this study were to determine the presence of this bacterium in head and body lice collected from healthy individuals in Ethiopia by molecular methods and to characterize the genotype. Human lice from locations at different altitudes in Ethiopia were screened for the presence of Acinetobacter sp by targeting the rpoB gene. Acinetobacter baumannii was detected and genotyped using recA PCR amplification. A total of 115 head and 109 body lice were collected from 134 healthy individuals. Acinetobacter sp were found in 54 head (47%) and 77 body (71%) lice. The recA gene was sequenced for 60 of the Acinetobacter sp and 67% were positive for A. baumannii; genotype 1 was retrieved the most frequently. Our study is the first to show the presence of A. baumannii in human body lice, and also in head lice, in Ethiopia. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Ecomorphology of parasite attachment: experiments with feather lice.

PubMed

Bush, Sarah E; Sohn, Edward; Clayton, Dale H

2006-02-01

The host specificity of some parasites can be reinforced by morphological specialization for attachment to mobile hosts. For example, ectoparasites with adaptations for attaching to hosts of a particular size might not be able to remain attached to larger or smaller hosts. This hypothesis is suggested by the positive correlation documented between the body sizes of many parasites and their hosts. We adopted an ecomorphological approach to test the attachment hypothesis. We tested the ability of host-specific feather lice (Phthiraptera: Ischnocera) to attach to 6 novel species of pigeons and doves that vary in size by nearly 2 orders of magnitude. Surprisingly, Rock Pigeon lice (Columbicola columbae) remained attached equally well to all 6 novel host species. We tested the relative importance of 3 factors that could facilitate louse attachment: whole-body insertion, tarsal claw use, and mandible use. Insertion, per se, was not necessary for attachment. However, insertion on coarse feathers of large hosts allowed lice to access feather barbules with their mandibles. Mandible use was a key component of attachment regardless of feather size. Attachment constraints do not appear to reinforce host specificity in this system.

Selection of suitable reference genes for gene expression studies in Staphylococcus capitis during growth under erythromycin stress.

PubMed

Cui, Bintao; Smooker, Peter M; Rouch, Duncan A; Deighton, Margaret A

2016-08-01

Accurate and reproducible measurement of gene transcription requires appropriate reference genes, which are stably expressed under different experimental conditions to provide normalization. Staphylococcus capitis is a human pathogen that produces biofilm under stress, such as imposed by antimicrobial agents. In this study, a set of five commonly used staphylococcal reference genes (gyrB, sodA, recA, tuf and rpoB) were systematically evaluated in two clinical isolates of Staphylococcus capitis (S. capitis subspecies urealyticus and capitis, respectively) under erythromycin stress in mid-log and stationary phases. Two public software programs (geNorm and NormFinder) and two manual calculation methods, reference residue normalization (RRN) and relative quantitative (RQ), were applied. The potential reference genes selected by the four algorithms were further validated by comparing the expression of a well-studied biofilm gene (icaA) with phenotypic biofilm formation in S. capitis under four different experimental conditions. The four methods differed considerably in their ability to predict the most suitable reference gene or gene combination for comparing icaA expression under different conditions. Under the conditions used here, the RQ method provided better selection of reference genes than the other three algorithms; however, this finding needs to be confirmed with a larger number of isolates. This study reinforces the need to assess the stability of reference genes for analysis of target gene expression under different conditions and the use of more than one algorithm in such studies. Although this work was conducted using a specific human pathogen, it emphasizes the importance of selecting suitable reference genes for accurate normalization of gene expression more generally.

Estimating the cost of sea lice to salmon aquaculture in eastern Canada.

PubMed Central

Mustafa, A; Rankaduwa, W; Campbell, P

2001-01-01

Parasitic sea lice are serious problems in aquaculture. The true cost of these parasites is unknown. We demonstrate the economic burden imposed by sea lice, so that researchers, aquatic specialists, and policy makers can approximate the economic cost of this problem and work towards developing alternative control methods. PMID:11195524

Evaluation of emamectin benzoate and substance EX against salmon lice in sea-ranched Atlantic salmon smolts.

PubMed

Skilbrei, Ove Tommy; Espedal, Per Gunnar; Nilsen, Frank; Garcia, Enrique Perez; Glover, Kevin A

2015-04-08

Experimental releases of Atlantic salmon smolts treated with emamectin benzoate (EB) against salmon lice have previously been used to estimate the significance of salmon lice on the survival of migrating smolts. In recent years, the salmon louse has developed reduced sensitivity to EB, which may influence the results of such release experiments. We therefore tested the use of 2 anti-lice drugs: EB was administered to salmon smolts in high doses by intra-peritoneal injection and the prophylactic substance EX (SubEX) was administered by bathing. A third, untreated control group was also established. Salmon were challenged with copepodids of 2 strains of salmon lice (1 EB-sensitive strain and 1 with reduced EB-sensitivity) in mixed-group experimental tanks. At 31 d post-challenge, the numbers of pre-adult lice on treated fish were around 20% compared with the control fish, with minor or no differences between the 2 treatments and lice strains. Both treatments therefore appeared to give the smolts a high degree of protection against infestation of copepodids of salmon lice. However, significantly lower growth of the EB-treatment group indicates that bathing the fish in SubEX is less stressful for smolts than intra-peritoneal injection of EB.

Emergence of African species of dermatophytes in tinea capitis: A 17-year experience in a Montreal pediatric hospital.

PubMed

Marcoux, Danielle; Dang, Julie; Auguste, Hedwige; McCuaig, Catherine; Powell, Julie; Hatami, Afshin; Maari, Catherine; Le Meur, Jean-Baptiste

2018-05-01

An increase in dermatophyte infections caused by African species is reported in countries receiving African immigrants. Our goal was to determine the epidemiologic and clinical characteristics of tinea capitis in children infected with African species of dermatophytes in Montreal, Canada. Demographic and clinical data from medical records of children infected with African species of dermatophytes were retrieved retrospectively (2000-2016) at Sainte-Justine University Hospital Center. In Montreal, the number of tinea capitis cases caused by African species of dermatophytes increased sixfold over 17 years. African immigrant children (84%), men and boys (61%), and preschoolers (2-5 years old) (51%) were the most frequently affected in our 315 cases. Family contamination was frequent (45%). Referring physicians prescribed systemic antifungal treatment in 39% of cases and pediatric dermatologist consultants in 90%. Treatment failure to oral terbinafine occurred in 39% of Microsporum audouinii infections. In Montreal, there was a significant increase in tinea capitis caused by African species of dermatophytes. Microsporum audouinii is highly transmissible and often resistant to oral terbinafine. Recognizing tinea capitis trends in a given environment will improve patient care. © 2018 Wiley Periodicals, Inc.

[Ecological niches of sucking lice (Phthiraptera: Anoplura) and their coevolution relationship with small mammal hosts in Yunnan, China].

PubMed

Meng, Yan-Fen; Guo, Xian-Guo; Men, Xing-Yuan; Wu, Dian

2008-02-28

To investigate the ecological niches of sucking lice (Phthiraptera: Anoplura) on the body surface of small mammal hosts and the co-evolutionary relationship between lice and mammal hosts in Yunnan Province. Thirty species of small mammals were captured and used as 30 resource sequences. The distribution and composition of the dominant 22 species of sucking lice on the body surface of the 30 species small mammal hosts were analyzed as the utilization proportion for each resource sequence. The niche breadth and proportional similarity were measured. SPSS 13.0 statistical software was used for analyzing the niche overlap matrix of sucking lice by hierarchical clustering analysis, and a dendrogram was made. The niche breadth was narrow for most species of sucking louse. Among the detected species, Hoplopleura pacifica showed the widest niche breadth, but only 0.1536. Indices of niche proportional similarity of most sucking lice were relatively small from 0.0005 to 0.4695. The 22 species of sucking lice were classified into 16 niche overlap groups, by lambda = 5.5, through a hierarchical clustering analysis for the niche overlaps, and the clustering process of most sucking lice was late. The sucking lice have a high specificity for hosts, of which different species show an apparent niche divergence on host selection. The results reveal a high coevolution between sucking lice and the mammal hosts.

Randomized, investigator-blinded, controlled clinical study with lice shampoo (Licener®) versus dimethicone (Jacutin® Pedicul Fluid) for the treatment of infestations with head lice.

PubMed

Semmler, Margit; Abdel-Ghaffar, Fathy; Gestmann, Falk; Abdel-Aty, Mohammed; Rizk, Ibrahim; Al-Quraishy, Saleh; Lehmacher, Walter; Hoff, Norman-Philipp

2017-07-01

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

Tinea Capitis in the form of Concentric Rings in an HIV Positive Adult on Antiretroviral Treatment

PubMed Central

Narang, Kirti; Pahwa, Manish; Ramesh, V

2012-01-01

Dermatophyte infection may present in the form of concentric rings caused by Trichophyton concentricum, known as Tinea Imbricata. In immunosuppressed patients, there are reports of lesions in the form of concentric rings caused by dermatophytes other than Trichophyton concentricum too, mostly by Trichophyton tonsurans, known as Tinea indesiciva or Tinea pseudoimbricata. We report a case of tinea capitis in a HIV-positive adult woman on antiretroviral therapy, who presented with concentric rings of papules and pustules with slight scaling on the scalp along with diffuse thinning of hair. Both Potassium hydroxide mount and culture showed the presence of Dermatophytes. Tinea capitis is considered rare in adults, but new cases are being reported in immunocompromised as well as in immunocompetent patients. The pertinent features of this case are: HIV-positive adult female on antiretroviral therapy, presenting with tinea capitis in the form of concentric rings; culture from the lesion grew Microsporum audouinii; responding to oral Terbinafine. PMID:22837564

[Tinea capitis in the military hospital Avicenna (Morocco): Review of 8 years (2006-2013)].

PubMed

El Mezouari, E; Hocar, O; Atarguine, H; Akhdari, N; Amal, S; Moutaj, R

2016-03-01

Tinea capitis are due to fungal infection by dermatophytes. They are common in developing countries including Morocco. The objective of this study intended to describe the epidemiology, clinical and mycological profile of tinea capitis in Avicenna military hospital of Marrakech. This is a retrospective study over an 8-year period (from 1st January 2006 to 31st December 2013). All patients targeted through this study presented to the laboratory with the suspicion of tinea capitis, they were under a detailed investigation with a careful mycological analysis; diagnosis of tinea capitis was established as the direct examination and/or the sampling proved positive. Of the 334 patients investigated, 216 had a TC with an overall prevalence of 64.67%. The average age was 6 years. The M/F sex ratio was 0.55. The isolated dermatophytes were Microsporum canis with 105 cases (63.26%), Trichophyton violaceum in 44 cases (26.51%), T. mentographytes in 8 cases (4.81%), M. langeronii in 5 cases (3.01%), T. verrucosum in 3 cases (1.8%) and T. schoenleinii in 1 case (0.61%). The contact with animals was found in 40% of cases and immunosupression in 3.47% of cases. We verify through our investigation that tineas predominate among school age children with a female predominance. The epidemiological profile of TC in our study is similar to that of other studies in Moroccan and Maghrebian countries investigations. The TC is relatively a mild infection but can be confused with other dermatoses not easy to diagnose. For this reason, their treatment necessitates a mycological analysis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Keep Your Wits Not Your Nits: A Rational Approach to Head Lice from the National Pediculosis Association. Second Edition.

ERIC Educational Resources Information Center

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…

Comparative effects of mites and lice on the reproductive success of rock doves (Columba livia).

PubMed

Clayton, D H; Tompkins, D M

1995-02-01

We report experimental data comparing the effects of Mesostigmatid mites and Ischnoceran lice on the reproductive performance of a single group of captive rock doves (Columba livia). Several components of host reproductive success were compared for the two groups, including number of eggs laid, hatching success, nestling growth rates, fledging success, post-fledging body mass and survival. Adult body mass and survival were also compared. There was a dramatic difference in the effects of the mites and lice. The former drove host reproductive success to zero, mainly by agitating adults and causing them to incubate eggs less faithfully. Nestling growth rates and post-fledging survival were also significantly reduced by mites. Lice showed no effect on reproductive success whatsoever, even though the feather damage they cause is known to have energetic consequences (Booth, Clayton & Block, 1993). Neither parasite had a significant effect on adult birds. Although Ischnocera are found on most species of birds, our results for lice constitute the first experimental test of the impact of Ischnocera on avian reproductive success (preliminary report by Clayton & Tompkins, 1994). We discuss reasons for the different effects of mites and lice, including the relationship of horizontal (mites) and vertical (lice) transmission to the evolution of virulence.

Distribution of chewing lice upon the polygynous peacock Pavo cristatus.

PubMed

Stewart, I R; Clark, F; Petrie, M

1996-04-01

An opportunistic survey of louse distribution upon the peacock Pavo cristatus was undertaken following a cull of 23 birds from an English zoo. After complete skin and feather dissolution, 2 species of lice were retrieved, Goniodes pavonis and Amyrsidea minuta. The distribution of both louse species could be described by a negative binomial model. The significance of this is discussed in relation to transmission dynamics of lice in the atypical avian mating system found in the peacock, which involves no male parental care.

A fixed-dose approach to conducting emamectin benzoate tolerance assessments on field-collected sea lice, Lepeophtheirus salmonis.

PubMed

Whyte, S K; Westcott, J D; Elmoslemany, A; Hammell, K L; Revie, C W

2013-03-01

In New Brunswick, Canada, the sea louse, Lepeophtheirus salmonis, poses an on-going management challenge to the health and productivity of commercially cultured Atlantic salmon, Salmo salar. While the in-feed medication, emamectin benzoate (SLICE® ; Merck), has been highly effective for many years, evidence of increased tolerance has been observed in the field since late 2008. Although bioassays on motile stages are a common tool to monitor sea lice sensitivity to emamectin benzoate in field-collected sea lice, they require the collection of large numbers of sea lice due to inherent natural variability in the gender and stage response to chemotherapeutants. In addition, sensitive instruments such as EC(50) analysis may be unnecessarily complex to characterize susceptibility subsequent to a significant observed decline in efficacy. This study proposes an adaptation of the traditional, dose-response format bioassay to a fixed-dose method. Analysis of 657 bioassays on preadult and adult stages of sea lice over the period 2008-2011 indicated a population of sea lice in New Brunswick with varying degrees of susceptibility to emamectin benzoate. A seasonal and spatial effect was observed in the robustness of genders and stages of sea lice, which suggest that mixing different genders and stages of lice within a single bioassay may result in pertinent information being overlooked. Poor survival of adult female lice in bioassays, particularly during May/June, indicates it may be prudent to consider excluding this stage from bioassays conducted at certain times of the year. This work demonstrates that fixed-dose bioassays can be a valuable technique in detecting reduced sensitivity in sea lice populations with varying degrees of susceptibility to emamectin benzoate treatments. © 2013 Blackwell Publishing Ltd.

The drivers of sea lice management policies and how best to integrate them into a risk management strategy: An ecosystem approach to sea lice management.

PubMed

Jackson, D; Moberg, O; Stenevik Djupevåg, E M; Kane, F; Hareide, H

2018-06-01

The control of sea lice infestations on cultivated Atlantic salmon is a major issue in many regions of the world. The numerous drivers which shape the priorities and objectives of the control strategies vary for different regions/jurisdictions. These range from the animal welfare and economic priorities of the producers, to the mitigation of any potential impacts on wild stocks. Veterinary ethics, environmental impacts of therapeutants, and impacts for organic certification of the produce are, amongst others, additional sets of factors which should be considered. Current best practice in both EU and international environmental law advocates a holistic ecosystem approach to assessment of impacts and risks. The issues of biosecurity and ethics, including the impacts on the stocks of species used as cleaner fish, are areas for inclusion in such a holistic ecosystem assessment. The Drivers, Pressures, State, Impacts, Responses (DPSIR) process is examined as a decision-making framework and potential applications to sea lice management are outlined. It is argued that this is required to underpin any integrated sea lice management (ISLM) strategy to balance pressures and outcomes and ensure a holistic approach to managing the issue of sea lice infestations on farmed stock on a medium to long-term basis. © 2017 The Authors. Journal of Fish Diseases Published by John Wiley & Sons Ltd.

Effect of timing of count events on estimates of sea lice abundance and interpretation of effectiveness following bath treatments.

PubMed

Gautam, R; Vanderstichel, R; Boerlage, A S; Revie, C W; Hammell, K L

2017-03-01

Effectiveness of sea lice bath treatment is often assessed by comparing pre- and post-treatment counts. However, in practice, the post-treatment counting window varies from the day of treatment to several days after treatment. In this study, we assess the effect of post-treatment lag time on sea lice abundance estimates after chemical bath treatment using data from the sea lice data management program (Fish-iTrends) between 2010 and 2014. Data on two life stages, (i) adult female (AF) and (ii) pre-adult and adult male (PAAM), were aggregated at the cage level and log-transformed. Average sea lice counts by post-treatment lag time were computed for AF and PAAM and compared relative to treatment day, using linear mixed models. There were 720 observations (treatment events) that uniquely matched pre- and post-treatment counts from 53 farms. Lag time had a significant effect on the estimated sea lice abundance, which was influenced by season and pre-treatment sea lice levels. During summer, sea lice were at a minimum when counted 1 day post-treatment irrespective of pre-treatment sea lice levels, whereas in the spring and autumn, low levels were observed for PAAM over a longer interval of time, provided the pre-treatment sea lice levels were >5-10. © 2016 John Wiley & Sons Ltd.

A new shampoo based on neem (Azadirachta indica) is highly effective against head lice in vitro.

PubMed

Heukelbach, Jörg; Oliveira, Fabíola A S; Speare, Richard

2006-09-01

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.

Sea trout adapt their migratory behaviour in response to high salmon lice concentrations.

PubMed

Halttunen, E; Gjelland, K-Ø; Hamel, S; Serra-Llinares, R-M; Nilsen, R; Arechavala-Lopez, P; Skarðhamar, J; Johnsen, I A; Asplin, L; Karlsen, Ø; Bjørn, P-A; Finstad, B

2018-06-01

Sea trout face growth-mortality trade-offs when entering the sea to feed. Salmon lice epizootics resulting from aquaculture have shifted these trade-offs, as salmon lice might both increase mortality and reduce growth of sea trout. We studied mortality and behavioural adaptations of wild sea trout in a large-scale experiment with acoustic telemetry in an aquaculture intensive area that was fallowed (emptied of fish) synchronically biannually, creating large variations in salmon lice concentrations. We tagged 310 wild sea trout during 3 years, and gave half of the individuals a prophylaxis against further salmon lice infestation. There was no difference in survival among years or between treatments. In years of high infestation pressure, however, sea trout remained closer to the river outlet, used freshwater (FW) habitats for longer periods and returned earlier to the river than in the low infestation year. This indicates that sea trout adapt their migratory behaviour by actively choosing FW refuges from salmon lice to escape from immediate mortality risk. Nevertheless, simulations show that these adaptations can lead to lost growth opportunities. Reduced growth can increase long-term mortality of sea trout due to prolonged exposure to size-dependent predation risk, lead to lower fecundity and, ultimately, reduce the likelihood of sea migration. © 2017 The Authors. Journal of Fish Diseases Published by John Wiley & Sons Ltd.

Microsporum audouinii tinea capitis in a Swiss school: assessment and management of patients and asymptomatic carriers.

PubMed

Donghi, Davide; Hauser, Valérie; Bosshard, Philipp P

2011-04-01

We report three cases involving 7- to 8-year-old children from a Swiss school who had refractory tinea capitis due to an unusual strain of Microsporum audouinii which perforates hair in vitro. The patients showed no response to modern oral antifungal drugs like terbinafine and fluconazole. After switching to oral griseofulvin, two of the patients had a complete recovery, while the third was cured after the introduction of oral itraconazole. Given the high potential for contagion of this anthropophilic dermatophyte, all family members and three entire school classes were screened using the 'toothbrush technique'. Three family members and five class-mates were found to be asymptomatic carriers of M. audouinii and were consequently treated to avoid further transmission or reinfection of the treated patients. This is the first report of an outbreak of M. audouinii in Switzerland and underlines the importance of screening all contacts of patients with M. audouinii tinea capitis. Further, the effectiveness of griseofulvin in Microsporum tinea capitis has been corroborated, while newer antimycotic drugs like fluconazole or terbinafine failed.

Clinical specificities of Tinea capitis in Georgia population.

PubMed

Kudava, Kh

2013-11-01

The aim of the study was to reveal peculiarities of the clinical symptoms and forms of Tinea capitis caused by etiological agents that are common in our country. The study was conducted on 176 ambulatory patients who approached the National Centre in 2009-2013. Inclusion criterion was simultaneous presence of clinical symptoms and positive result of microscopic study. For cultural examination was used Sabouraud's dextrose agar with the antibiotic chloramphenicol. Clinical manifestations were divided into inflammatory and non-inflammatory (i.e. slightly manifested inflammatory signs) lesions. 85(48,3%) inflammatory and 91(51,7%) non-inflammatory cases of Tinea capitis were revealed. Clinical forms were distributed in following way: kerion 73 (41,5%), grey patch with single lesions 71 (40,3%), seborrheic dermatitis-like form 14 (8%), agminate folliculites 12 (6,8%) and black-dot dermatophytosis 6 (3,4%). In 41(89,1%) of the cases etiological agent of the kerion was Trichophyton mentagrophytes; in 41(85,4%) of the cases etiological agent for the grey patch with single lesions was Microsporum canis. Important clinical and etiological relationship was revealed between kerion and Trichophyton mentagrophytes, as well as between grey patch with single lesions and Microsporum canis. In case of inflammatory forms (predominantly kerion) caused by Trichophyton verrucosum and Trichophyton mentagrophytes ID reaction was manifested by disseminated follicular papules.

Recent updates in oral terbinafine: its use in onychomycosis and tinea capitis in the US.

PubMed

Van Duyn Graham, Lauren; Elewski, Boni E

2011-11-01

Onychomycosis and tinea capitis are prevalent fungal diseases that are difficult to cure and usually require systemic treatment. Onychomycosis has high recurrence rates and can significantly affect a patient's quality of life. Oral terbinafine has been approved for onychomycosis for 20 years in Europe and 15 years in the United States. Over these past 20 years, numerous studies show that oral terbinafine is a safe and efficacious treatment for onychomycosis. More recently, oral terbinafine also has been approved for tinea capitis. Once difficult to treat, terbinafine has revolutionised treatment of these fungal diseases. It has minimal side effects and its limited drug interactions make it an excellent treatment option for patients with co-morbidities. This review discusses oral terbinafine and new insights into the treatment of onychomycosis and tinea capitis. Recent publications have enhanced our knowledge of the mechanisms of oral terbinafine and its efficacy in treating onychomycosis. Oral terbinafine vs. other antifungal therapeutic options are reviewed. Overall, terbinafine remains a superior treatment for dermatophyte infections because of its safety, fungicidal profile, once daily dosing, and its ability to penetrate the stratum corneum. © 2011 Blackwell Verlag GmbH.

[Pediculosis capitis: a questionnaire survey in 4 schools of the Bordeaux Academy 1990-1991].

PubMed

Courtiade, C; Labrèze, C; Fontan, I; Taïeb, A; Maleville, J

1993-01-01

A questionnaire survey of head lice treatment was conducted in four schools--each including a nursery and an elementary school--in the Bordeaux area. Two schools were situated in the centre of the city, one in a suburban area and one in a rural area (50 km from the city). Four-page questionnaires were filled in anonymously by the parents in April 1991; 840 answers were obtained (80 p. 100 response rate). Between January 1990 and March 1991, 48.7 p. 100 of children had at least one episode of head lice infestation (infestation rates varied from 38.8 to 62.6 p. 100 depending on the schools); 30.5 p. 100 of children were contaminated for the first time during that period. Lice were detected by the parents in 95 p. 100 of the cases. The prevalence of lice was higher in females (60 p. 100) than in males (40 p. 100). The highest prevalence was noted in the suburban school where 17 p. 100 of the parents were unemployed at the time of the survey. The peak age for head lice was 7, but 19.4 p. 100 of nursery school children aged 2-4 years had been contaminated at least once. Impetigo was rare (1.2 p. 100), and pruritus was noted in only 14.2 p. 100 of the cases. Most children had been contaminated at school. Curative treatment was counselled by a chemist in 87 p. 100 of the cases. Pyrethrins were used in 81 p. 100, and the shampoo (Hegor) plus spray (Paraspecial Poux) association was the most frequent, totalling two-thirds of prescriptions.(ABSTRACT TRUNCATED AT 250 WORDS)

Environment-related and host-related factors affecting the occurrence of lice on rodents in Central Europe.

PubMed

Stanko, Michal; Fričová, Jana; Miklisová, Dana; Khokhlova, Irina S; Krasnov, Boris R

2015-06-01

We studied the effects of environment- (habitat, season) and host-related (sex, body mass) factors on the occurrence of four species of lice (Insecta:Phthiraptera:Anoplura) on six rodent species (Rodentia:Muridae). We asked how these factors influence the occurrence of lice on an individual host and whether different rodent-louse associations demonstrate consistent trends in these effects. We found significant effects of at least one environment-related and at least one host-related factor on the louse occurrence in five of six host-louse associations. The effect of habitat was significant in two associations with the occurrence of lice being more frequent in lowland than in mountain habitats. The effect of season was significant in five associations with a higher occurrence of infestation during the warm season in four associations and the cold season in one association. Host sex affected significantly the infestation by lice in three associations with a higher frequency of infestation in males. Host body mass affected the occurrence of lice in all five associations, being negative in wood mice and positive in voles. In conclusion, lice were influenced not only by the host- but also by environment-related factors. The effects of the latter could be mediated via life history parameters of a host.

The changing war on sea lice: the rise of non-drug based treatments

USDA-ARS?s Scientific Manuscript database

Sea lice are likely the single most economically costly pathogen that has faced the salmon farming industry over the past 40 years. Estimates of the global cost of sea lice to the industry have grown from $480 million USD in 2006 to $742 million USD in 2012. Not only has the cost to industry increas...

Head lice infestations (Anoplura: Pediculidae) in Saudi and non-Saudi school-aged children.

PubMed

Bosely, Hanan Aboalkasem; El-Alfy, Nadia M

2011-04-01

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.

The identification and grading of the psychosocial impact of Tinea capitis in primary school children in a semi-urban area of Rivers State, Nigeria.

PubMed

Fienemika, Agnes E; Okeafor, Chukwuma U

2017-01-01

Tinea capitis is a fungal skin disease, which is not life-threatening but could affect the psychosocial life of those suffering from it. Thus, this study sought to identify and grade the psychosocial impact related to Tinea capitis in primary school children. This was a cross-sectional study involving primary school children in Emohua Local Government Area of Rivers State. These children had been clinically diagnosed with Tinea capitis. The Children Dermatology Life Quality Index instrument was used to identify the presence of a psychosocial impact, which was graded as none, mild, moderate, and severe. The Statistical Package for Social Sciences version 20 software was used for analysis, and statistical significance was set at P < 0.05. A total of 184 children aged 6-12 years with Tinea capitis participated in the study. The mean age of the children was 9.5 ± 2.9 years. The male-to-female ratio was 2.5:1. More than half of the children (58.2%, n = 127) had mild-to-severe psychosocial impact. The psychosocial impact was significantly higher (P = 0.02) among the female children (61.5%; n = 32) than the male children (41.7%; n = 20). In addition, female children with Tinea capitis were 2.2 times more likely to suffer a psychosocial impact than their male counterparts (odds ratio = 2.2; 95% confidence interval: 1.16-4.32). There were no significant differences in the psychosocial impact across the age categories (P = 0.859). Tinea capitis has a psychosocial impact on the daily lives of school children, with more than half of the children experiencing mild-to-severe grades of psychosocial impact. Collaboration between mental health physicians and pediatric dermatologists is encouraged to address the effect of Tinea capitis on the psychosocial life of school children, especially the female children.

Overcoming health inequalities by using the Bug Busting 'whole-school approach' to eradicate head lice.

PubMed

Ibarra, Joanna; Fry, Frances; Clarice, Wickenden; Olsen, Alice; Vander Stichele, Robert H; Lapeere, Hilde; Maryan, Jenner; Franks, Andrea; Smith, Jane L

2007-10-01

The aim of this paper was to illustrate the socially inclusive nature of the Bug Busting 'whole-school approach' to head louse eradication. In the UK, Belgium and Denmark, persistent head lice in families of all socio-economic status (SES) is a problem. Since 1995 in the UK and 1998 elsewhere, an educational programme intended to teach families how to detect and treat head lice by using the Bug Busting wet combing method has been organized in some areas. Local schools lead this community strategy for prevention, known as a 'whole-school approach' (UK). We describe five studies applying the Bug Busting approach, four set in districts where some disadvantaged families live (UK and Belgium) and a fifth set in Denmark. Feasibility and consumer satisfaction are examined. One UK study analyses data on area prescribing for head lice and the impact in a deprived locality of raising the profile of Bug Busting. We find parental education in Bug Busting enables families of all SES to participate in a 'whole-school approach' to head lice. Best results are obtained when each family has a Bug Buster Kit. This provides all the combs necessary with full instructions on their use with ordinary shampoo and conditioner to detect lice, eradicate an infestation mechanically, or to check the success of any treatment. In the UK, the promotion of the Bug Busting approach is reducing primary care expenditure on treatment for head lice and professional time spent with worried parents. As a result, healthcare providers can give time to the few families who require one-to-one guidance. Incorporation of the Bug Busting approach to head lice into clinical practice in school communities contributes to sustainable control whilst overcoming health inequalities in participating families.

Tinea capitis in Botswana

PubMed Central

Thakur, Rameshwari

2013-01-01

Background Tinea capitis (TC) is a common dermatophyte infection of the scalp that can also involve the eyebrows and eyelashes. Aim This study aimed to find the causative fungus responsible for TC in Botswana and determine its association with the clinical types of TC. Methods Samples for potassium hydroxide 10% mounts and fungal cultures were collected in a microbiology laboratory at the National Health Laboratory, Gaborone, Botswana. Dermasel agar and Sabouraud dextrose agar were inoculated with the samples. Lactophenol cotton blue mounts were prepared from the culture-positive samples to study the morphological characteristics. Results Trichophyton violaceum was found to be the predominant causative organism of TC. Trichophyton tonsurans was isolated from one patient. Both are anthropophilic species. Conclusion TC was found to be most common in those aged 1–15 years (81%). Of 17 patients in this age group, 16 were younger than 10 years old and one was 14 years old. T. violaceum was the most common dermatophyte species isolated. PMID:23386791

Tinea capitis in Botswana.

PubMed

Thakur, Rameshwari

2013-01-01

Tinea capitis (TC) is a common dermatophyte infection of the scalp that can also involve the eyebrows and eyelashes. This study aimed to find the causative fungus responsible for TC in Botswana and determine its association with the clinical types of TC. Samples for potassium hydroxide 10% mounts and fungal cultures were collected in a microbiology laboratory at the National Health Laboratory, Gaborone, Botswana. Dermasel agar and Sabouraud dextrose agar were inoculated with the samples. Lactophenol cotton blue mounts were prepared from the culture-positive samples to study the morphological characteristics. Trichophyton violaceum was found to be the predominant causative organism of TC. Trichophyton tonsurans was isolated from one patient. Both are anthropophilic species. TC was found to be most common in those aged 1-15 years (81%). Of 17 patients in this age group, 16 were younger than 10 years old and one was 14 years old. T. violaceum was the most common dermatophyte species isolated.

Effects of sex and locality on the abundance of lice on the wild rodent Oligoryzomys nigripes.

PubMed

Fernandes, Fernanda Rodrigues; Cruz, Leonardo Dominici; Linhares, Arício Xavier

2012-10-01

Various factors can affect the parasite distribution on a host. In this study, the influence of sex, body size, and locality of a rodent host, Oligoryzomys nigripes, on lice abundance was investigated. A generalized linear model indicated that the sex and locality of O. nigripes significantly contributed to the variation in lice abundance on the host. The male bias of lice parasitizing the rodent host O. nigripes may be associated with intersexual differences in physiology and behavior, while locality differences in lice abundance may be associated with differences in host density and diversity between the two localities sampled. Studies of host-parasite associations improve the understanding of the ecology of infectious diseases, as well as the evolution of these host-parasite interactions.

Effect of permethrin-impregnated underwear on body lice in sheltered homeless persons: a randomized controlled trial.

PubMed

Benkouiten, Samir; Drali, Rezak; Badiaga, Sékéné; Veracx, Aurélie; Giorgi, Roch; Raoult, Didier; Brouqui, Philippe

2014-03-01

The control of body lice in homeless persons remains a challenge. To determine whether the use of long-lasting insecticide-treated underwear provides effective long-term protection against body lice in homeless persons. A randomized, double-blind, placebo-controlled trial was conducted in February and December 2011 in 2 homeless shelters (Madrague Ville and Forbin) in Marseille, France. Of the 125 homeless persons screened for eligibility, 73 body lice-infested homeless persons, 18 years or older, were enrolled. Body lice-infested homeless persons were randomly assigned to receive 0.4% permethrin-impregnated underwear or an identical-appearing placebo for 45 days, in a 1:1 ratio, with a permuted block size of 10. Visits were scheduled at days 14 and 45. Data regarding the presence or absence of live body lice were collected. The primary and secondary end points were the proportions of homeless persons free of body lice on days 14 and 45, respectively. Mutations associated with permethrin resistance in the body lice were also identified. Significantly more homeless persons receiving permethrin-impregnated underwear than homeless persons receiving the placebo were free of body lice on day 14 in the intent-to-treat population (28% vs 9%; P = .04), with a between-group difference of 18.4 percentage points (95% CI, 1.4-35.4), and in the per-protocol population (34% vs 11%; P = .03), with a between-group difference of 23.7 percentage points (95% CI, 3.6-43.7). This difference was not sustained on day 45. At baseline, the prevalence of the permethrin-resistant haplotype was 51% in the permethrin group and 44% in the placebo group. On day 45, the permethrin-resistant haplotype was significantly more frequent in the permethrin group than in the placebo group (73% vs 45%, P < .001). Permethrin-impregnated underwear is more efficient than placebo at eliminating body louse infestations by day 14; however, this difference was not sustained on day 45. The use of permethrin

Sensitivity assessment of sea lice to chemotherapeutants: Current bioassays and best practices.

PubMed

Marín, S L; Mancilla, J; Hausdorf, M A; Bouchard, D; Tudor, M S; Kane, F

2017-12-18

Traditional bioassays are still necessary to test sensitivity of sea lice species to chemotherapeutants, but the methodology applied by the different scientists has varied over time in respect to that proposed in "Sea lice resistance to chemotherapeutants: A handbook in resistance management" (2006). These divergences motivated the organization of a workshop during the Sea Lice 2016 conference "Standardization of traditional bioassay process by sharing best practices." There was an agreement by the attendants to update the handbook. The objective of this article is to provide a baseline analysis of the methodology for traditional bioassays and to identify procedures that need to be addressed to standardize the protocol. The methodology was divided into the following steps: bioassay design; material and equipment; sea lice collection, transportation and laboratory reception; preparation of dilution; parasite exposure; response evaluation; data analysis; and reporting. Information from the presentations of the workshop, and also from other studies, allowed for the identification of procedures inside a given step that need to be standardized as they were reported to be performed differently by the different working groups. Bioassay design and response evaluation were the targeted steps where more procedures need to be analysed and agreed upon. © 2017 John Wiley & Sons Ltd.

Mycological profile of tinea capitis in schoolchildren in rural southern Ethiopia.

PubMed

Pérez-Tanoira, R; Marín, I; Berbegal, L; Prieto-Pérez, L; Tisiano, G; Cuadros, J; Górgolas, M; Ramos, J M

2017-04-01

Tinea capitis is a known common infection among schoolchildren in developing countries that is still underreported in Ethiopia. The aim of this study was to examine the epidemiologic and etiologic profile of tinea capitis among school-aged children in a rural area in southern Ethiopia. We collected demographic and clinicodermatological data from school children aged 3-12 years with tinea infections. Pathologic specimens were taken for potassium hydroxide (KOH) mount and mycological culture. Dermatophyte species were identified by macroscopic examination of the colony and microscopic examination of fungal cultures. A total of 634 schoolchildren were screened in the study; 128 cases were suspected for tinea capitis based on clinical examination of which 99 patients (mean age 6.7 years within a range of 4-12 years), who were subsequently positive, either based on KOH examination or showed growth of dermatophytes on culture, were included in our study. The ratio of males to females was 3:1. A total of 88 patients (89.9%) had a culture positive for dermatophytes. The zoophilic species Trichophyton verrucosum was the most prevalent isolate (n = 29 cases), followed by the anthropophilic species T. tonsurans (n = 27). The other Trichophyton species implicated were T. mentagrophytes (n = 14), as well as T. schoenleinii, T. soudanense, and T. violaceum. Only 11 of the isolates belonged to the genus Microsporum: M. audouinii (n = 8), M. ferrugineum (n = 2), and M. gallinae (n = 1). T. verrucosum, followed by T. tonsurans were the most frequent causative agents in this study. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Optimization and field use of a bioassay to monitor sea lice Lepeophtheirus salmonis sensitivity to emamectin benzoate.

PubMed

Westcott, Jillian D; Stryhn, Henrik; Burka, John F; Hammell, K Larry

2008-04-01

A bioassay for sea lice Lepeophtheirus salmonis sensitivity towards emamectin benzoate (EMB) was validated for field use. A probit regression model with natural responsiveness was used for the number of affected (moribund or dead) sea lice in bioassays involving different concentrations of EMB. Bioassay optimization included an evaluation of the inter-rater reliability of sea lice responsiveness to EMB and an evaluation of gender-related differences in susceptibility. Adoption of a set of bioassay response criteria improved the concordance (evaluated using the concordance correlation coefficient) between raters' assessments and the model estimation of EC50 values (the 'effective concentration' leading to a response of 50% of the lice not prone to natural response). An evaluation of gender-related differences in EMB susceptibility indicated that preadult stage female sea lice exhibited a significantly larger sensitivity towards EMB in 12 of 19 bioassays compared to preadult males. In order to evaluate sea lice sensitivity to EMB in eastern Canada, the intensive salmon farming area in the Bay of Fundy in southwestern New Brunswick was divided into 4 distinct regions based on industry health management practices and hydrographics. A total of 38 bioassays were completed from 2002 to 2005 using populations of preadult stage sea lice collected from Atlantic salmon Salmo salar farms within the 4 described regions. There was no significant overall effect of region or year on EC50 values; however, analysis of variance indicated a significant effect of time of year on EC50 values in 2002 and a potential effect in 2004 to 2005. Although the range of EC50 values obtained in this 3 yr study did not appear sufficient to affect current clinical success in the control of sea lice, the results suggest a seasonal- or temperature-associated variation in sensitivity to EMB. This will need to be considered if changes in EMB efficacy occur in the future.

Size matters for lice on birds: Coevolutionary allometry of host and parasite body size.

PubMed

Harnos, Andrea; Lang, Zsolt; Petrás, Dóra; Bush, Sarah E; Szabó, Krisztián; Rózsa, Lajos

2017-02-01

Body size is one of the most fundamental characteristics of all organisms. It influences physiology, morphology, behavior, and even interspecific interactions such as those between parasites and their hosts. Host body size influences the magnitude and variability of parasite size according to Harrison's rule (HR: positive relationship between host and parasite body sizes) and Poulin's Increasing Variance Hypothesis (PIVH: positive relationship between host body size and the variability of parasite body size). We analyzed parasite-host body size allometry for 581 species of avian lice (∼15% of known diversity) and their hosts. We applied phylogenetic generalized least squares (PGLS) methods to account for phylogenetic nonindependence controlling for host and parasite phylogenies separately and variance heterogeneity. We tested HR and PIVH for the major families of avian lice (Ricinidae, Menoponidae, Philopteridae), and for distinct ecological guilds within Philopteridae. Our data indicate that most families and guilds of avian lice follow both HR and PIVH; however, ricinids did not follow PIVH and the "body lice" guild of philopterid lice did not follow HR or PIVH. We discuss mathematical and ecological factors that may be responsible for these patterns, and we discuss the potential pervasiveness of these relationships among all parasites on Earth. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Meta-analysis of randomized, controlled trials comparing griseofulvin and terbinafine in the treatment of tinea capitis.

PubMed

Tey, Hong Liang; Tan, Andy Soon Leong; Chan, Yuin Chew

2011-04-01

Griseofulvin has been the standard treatment for tinea capitis but newer antifungal agents, particularly terbinafine, are increasingly being used because of their shorter duration of treatment and more consistent absorption rates. We sought to compare the efficacy of oral griseofulvin and oral terbinafine in the treatment of tinea capitis. A search of MEDLINE, EMBASE, Cochrane Central Register of Clinical Trials, and the Cochrane Skin Group Ongoing Skin Trials Register was performed up to January 2010 for randomized controlled trials comparing griseofulvin and terbinafine in the treatment of tinea capitis in immunocompetent patients. The primary outcome measure was the complete cure rate. The mycological and clinical cure rates and adverse effects were secondary outcome measures. Pooling of treatment effect was accomplished using a random effects model and the I(2) test was used to check for heterogeneity among the studies. Seven studies involving 2163 subjects were included. There was no significant difference in efficacy between griseofulvin (mean duration of treatment 8 weeks, range 6-12 weeks) and terbinafine (mean duration of treatment 4 weeks, range 2-6 weeks); odds ratio = 1.22 favoring terbinafine (95% confidence interval [CI] = 0.785-1.919; P = .37). In the pooled analysis of 5 studies in which Trichophyton species were the predominant (≥65%) pathogenic dermatophyte, terbinafine showed a trend toward greater efficacy (odds ratio 1.49; 95% CI = 0.975-2.277; P = .065). Subgroup analysis revealed that terbinafine was more efficacious than griseofulvin in treating Trichophyton species (1.616; 95% CI = 1.274-2.051; P < .001) and griseofulvin was more efficacious than terbinafine in treating Microsporum species (0.408; 95% CI = 0.254-0.656; P < .001). Both griseofulvin and terbinafine demonstrated good safety profiles in the studies. Data on efficacy of griseofulvin and terbinafine for separate groups of Trichophyton and Microsporum species were not available

[Emergence of Microsporum audouinii and Trichophyton tonsurans as causative organisms of tinea capitis in the Dominican Republic].

PubMed

Arenas, R; Torres, E; Amaya, M; Rivera, E R; Espinal, A; Polanco, M; Fernández, R; Isa-Isa, R

2010-05-01

Tinea capitis affects mainly children. The frequency and causative organism vary from region to region. To provide epidemiological and mycological data on tinea capitis collected in urban and rural areas of the Dominican Republic. Samples were obtained from 118 patients with tinea capitis. Sixty-three of these were from 2 schools in urban areas of the Dominican capital Santo Domingo (53%) and 55 were from rural schools on the border with Haiti (47%). The study included 84 boys (71. 18%) and 34 girls (28. 81%). The urban sample comprised mainly boys (84. 12%). The most represented age ranges were 6 to 8 years (47. 45%), 3 to 5 years (24. 59%), and 9 to 11 years (16. 94%). Microsporum audouinii (39. 68%), Trichophyton tonsurans (23. 80%), Microsporum canis (19. 04%), and Trichophyton violaceum (1. 58%) were isolated from children in urban areas, whereas T. tonsurans (87%) and Trichophyton mentagrophytes (2%) were isolated from those in rural areas. Overall, T. tonsurans (61. 16%), M. audouinii (24. 27%), and M canis (11. 65%) were the most frequently isolated causative organisms, whereas T. violaceum and T. mentagrophytes were rarely reported. In urban areas of the Dominican Republic, tinea capitis was found mainly in boys, but in rural areas it was evenly distributed among boys and girls. The emergence of M. audouinii and an increase in T. tonsurans were found while M. canis continued to be present at lower frequencies. On the rural border with Haiti, there was a significant predominance of T. tonsurans.

Scanning and transmission electron microscopic observation of the parasitic form of Trichophyton violaceum in the infected hair from tinea capitis.

PubMed

Zhuang, Kaiwen; Ran, Xin; Lei, Song; Zhang, Chaoliang; Lama, Jebina; Ran, Yuping

2014-01-01

Trichophyton violaceum is a pathogen of tinea capitis and usually cause infection of scalp and hair in children. To investigate the parasitic form of T. violaceum in the human hair tissue, the infected hair strands were collected from a 9-year-old boy with tinea capitis due to T. violaceum and observed under both the scanning electron microscope (SEM) and transmission electron microscope (TEM). The SEM and TEM findings revealed that T. violaceum parasitically lives in the hair shaft in various forms and the morphological transformation of the fungus from hyphae into arthrospores was noted. The involved hair shaft was damaged to the great extent and its ultrastructural changes were evident. Those morphological characteristics of T. violaceum and the three-dimensional ultastructure changes of infected hairs give a better knowledge about the host-fungus relationship in tinea capitis. © 2014 Wiley Periodicals, Inc.

Selective breeding program for sea lice Lepeophtheirus salmonis (Kroyer 1838) at the USDA's National Cold Water Marine Aquaculture Center

USDA-ARS?s Scientific Manuscript database

Sea lice are likely the most economically costly pathogen that has faced the salmon farming industry over the past 40 years. Recent economic estimates put the annual cost of sea lice at $742 million USD in 2012. With the rise of resistance to multiple drugs used to treat sea lice, there has been a s...

New records and a new species of chewing lice (Phthiraptera, Amblycera, Ischnocera) found on Columbidae (Columbiformes) in Pakistan

PubMed Central

Naz, Saima; Sychra, Oldrich; Rizvi, Syed Anser

2012-01-01

Abstract The chewing lice (Phthiraptera) of Columbidae (Columbiformes) from Pakistan are studied. Six species of chewing lice with new host records are recorded and one new species of the genus Colpocephalum is described from Columba livia in the Karachi region. All the columbid chewing lice from Pakistan are keyed out and the new species is illustrated and compared with the closest allied species. PMID:22451786

Sea lice infestations on farmed Atlantic salmon in Scotland and the use of ectoparasitic treatments.

PubMed

Revie, C W; Gettinby, G; Treasurer, J W; Grant, A N; Reid, S W J

A recently compiled national database on sea lice infestations on farmed Atlantic salmon, contains detailed records for the period 1996 to 2000 from over 30 commercial sites on the west coast of Scotland. The data indicate that the two prevalent species of lice, Lepeophtheirus salmonis and Caligus elongatus, have different trends in abundance and distinctive seasonal patterns of infestation on farmed salmon. For the economically important species L salmonis, its abundance on fish varies with the time of the production cycle, the time of year and the particular year. Weekly fluctuations in sea lice counts indicate that treatment can be very effective in controlling infestations but that the counts recover rapidly and regular treatments are necessary to ensure control. A comparison of sites using medium or large numbers of treatments suggests that they do not reduce sea lice infestations to the same levels. There is also evidence that sites using treatments based on different chemical constituents had significantly different levels of infestation.

Reduced taxonomic richness of lice (Insecta: Phthiraptera) in diving birds.

PubMed

Felsõ, B; Rózsa, L

2006-08-01

Avian lice occupy different habitats in the host plumage that the physical environment outside the host body may affect in several ways. Interactions between host plumage and water may be an important source of such effects. Here, we use a comparative approach to examine the effect of a host's diving behavior on the taxonomic richness of its lice. Louse genera richness was significantly lower in clades of diving birds than on their nondiving sister clades. Species richness of host and body mass did not differ significantly between these clades; thus, these factors did not bias our results. This study suggests that the hosts' diving behavior can effectively influence ectoparasite communities.

Chewing lice (Phthiraptera) from wild birds in southern Portugal.

PubMed

Tomás, André; Palma, Ricardo L; Rebelo, Maria Teresa; da Fonseca, Isabel Pereira

2016-06-01

This study was carried out to determine chewing louse species of wild birds in the Ria Formosa Natural Park, located in southern Portugal. In addition, the hypothesis that bird age, avian migration and social behaviour have an impact on the louse prevalence was tested. Between September and December of 2013, 122 birds (belonging to 10 orders, 19 families, 31 genera and 35 species) captured in scientific ringing sessions and admitted to the Wildlife Rehabilitation and Investigation Centre of Ria Formosa were examined for lice. Twenty-six (21.3%) birds were found to be infested with at least one chewing louse species. The chewing lice identified include 18 species. Colonial birds (34.9%) and migratory birds (29.5%) had statistically significant higher prevalence than territorial birds (6.8%) and resident birds (13.1%), respectively. This paper records 17 louse species for the first time in southern Portugal: Laemobothrion maximum, Laemobothrion vulturis, Actornithophilus piceus lari, Actornithophilus umbrinus, Austromenopon lutescens, Colpocephalum heterosoma, Colpocephalum turbinatum, Eidmanniella pustulosa, Nosopon casteli, Pectinopygus bassani, Pseudomenopon pilosum, Trinoton femoratum, Trinoton querquedulae, Craspedorrhynchus platystomus, Degeeriella fulva, Falcolipeurus quadripustulatus, Lunaceps schismatus. Also a nymph of the genus Strigiphilus was collected from a Eurasian eagle-owl. These findings contribute to the knowledge of avian chewing lice from important birds areas in Portugal. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Using biological-physical modelling for informing sea lice dispersal in Loch Linnhe, Scotland.

PubMed

Salama, N K G; Dale, A C; Ivanov, V V; Cook, P F; Pert, C C; Collins, C M; Rabe, B

2018-06-01

Sea lice are a constraint on the sustainable growth of Scottish marine salmonid aquaculture. As part of an integrated pest management approach, farms coordinate procedures within spatial units. We present observations of copepodids being at relatively greater density than nauplii in upper waters, which informs the development of surface layer sea lice transmission modelling of Loch Linnhe, Scotland, for informing farm parasite management. A hydrodynamic model is coupled with a biological particle-tracking model, with characteristics of plankton sea lice. Simulations are undertaken for May and October 2011-2013, forced by local wind data collected for those periods. Particles are continually released from positions representing farm locations, weighted by relative farm counts, over a 2-week period and tracked for a further 5 days. A comparison is made between modelled relative concentrations against physical and biological surveys to provide confidence in model outputs. Connectivity between farm locations is determined in order to propose potential coordination areas. Generally, connectivity depends on flow patterns in the loch and decreases with increased farm separation. The connectivity indices are used to estimate the origins of the sea lice population composition at each site, which may influence medicinal regimens to avoid loss of efficacy. © 2017 John Wiley & Sons Ltd.

Tinea capitis in schoolchildren in southern Ivory Coast.

PubMed

Fulgence, Kassi Kondo; Abibatou, Konate; Vincent, Djohan; Henriette, Vanga; Etienne, Angora Kpongbo; Kiki-Barro, Pulchérie Christiane; Yavo, William; Koné, Moussa; Hervé Menan, Eby Ignace

2013-04-01

Fungal infections of the scalp commonly affect the pediatric population. These infections are caused by dermatophytes that are able to invade the keratinized structures of skin, hair, and nails. This study aimed to analyze the epidemiology of fungal scalp infections in southern Ivory Coast during 2008-2009. From October 2008 to July 2009, 17,745 children ranging in age from 4-16 years, attending urban and rural primary schools in seven towns in Ivory Coast, were examined clinically for tinea capitis. Hair stumps and scales were collected from children who showed symptoms suggestive of scalp ringworm. Samples were exposed to direct microscopic examination using 30% potassium hydroxide solution and cultivation on Sabouraud's dextrose agar with or without actidione. Of the 17,745 children who were clinically examined, a total of 2645 exhibited symptoms suggestive of scalp ringworm. Positive cultures for fungi were found in 2458, yielding an overall prevalence of tinea capitis of 13.9%. The majority of infections occurred in males (74.0%). The most commonly affected age group involved children ranging from 9-12 years (n = 1335, 54.3%), followed by those in the range of 4-8 years (n = 936, 38.1%). Trichophyton soudanense, Microsporum langeronii, and Trichophyton mentagrophytes were the most prevalent etiologic agents (56.7%, 21.4% and 19.7%, respectively). Other species were occasionally isolated, including Trichophyton violaceum (1.4%) and Trichophyton rubrum (0.8%). Epidemiological surveys are an essential tool for developing strategies for infection control. © 2013 The International Society of Dermatology.

Association between sea lice (Lepeophtheirus salmonis) infestation on Atlantic salmon farms and wild Pacific salmon in Muchalat Inlet, Canada.

PubMed

Nekouei, Omid; Vanderstichel, Raphael; Thakur, Krishna; Arriagada, Gabriel; Patanasatienkul, Thitiwan; Whittaker, Patrick; Milligan, Barry; Stewardson, Lance; Revie, Crawford W

2018-03-05

Growth in salmon aquaculture over the past two decades has raised concerns regarding the potential impacts of the industry on neighboring ecosystems and wild fish productivity. Despite limited evidence, sea lice have been identified as a major cause for the decline in some wild Pacific salmon populations on the west coast of Canada. We used sea lice count and management data from farmed and wild salmon, collected over 10 years (2007-2016) in the Muchalat Inlet region of Canada, to evaluate the association between sea lice recorded on salmon farms with the infestation levels on wild out-migrating Chum salmon. Our analyses indicated a significant positive association between the sea lice abundance on farms and the likelihood that wild fish would be infested. However, increased abundance of lice on farms was not significantly associated with the levels of infestation observed on the wild salmon. Our results suggest that Atlantic salmon farms may be an important source for the introduction of sea lice to wild Pacific salmon populations, but that the absence of a dose response relationship indicates that any estimate of farm impact requires more careful evaluation of causal inference than is typically seen in the extant scientific literature.

Sea lice infestations on juvenile chum and pink salmon in the Broughton Archipelago, Canada, from 2003 to 2012.

PubMed

Patanasatienkul, Thitiwan; Sanchez, Javier; Rees, Erin E; Krkosek, Martin; Jones, Simon R M; Revie, Crawford W

2013-07-22

Juvenile pink salmon Oncorhynchus gorbuscha and chum salmon O. keta were sampled by beach or purse seine to assess levels of sea lice infestation in the Knight Inlet and Broughton Archipelago regions of coastal British Columbia, Canada, during the months of March to July from 2003 to 2012. Beach seine data were analyzed for sea lice infestation that was described in terms of prevalence, abundance, intensity, and intensity per unit length. The median annual prevalence for chum was 30%, ranging from 14% (in 2008 and 2009) to 73% (in 2004), while for pink salmon, the median was 27% and ranged from 10% (in 2011) to 68% (in 2004). Annual abundance varied from 0.2 to 5 sea lice per fish with a median of 0.47 for chum and from 0.1 to 3 lice (median 0.42) for pink salmon. Annual infestation followed broadly similar trends for both chum and pink salmon. However, the abundance and intensity of Lepeophtheirus salmonis and Caligus clemensi, the 2 main sea lice species of interest, were significantly greater on chum than on pink salmon in around half of the years studied. Logistic regression with random effect was used to model prevalence of sea lice infestation for the combined beach and purse seine data. The model suggested inter-annual variation as well as a spatial clustering effect on the prevalence of sea lice infestation in both chum and pink salmon. Fish length had an effect on prevalence, although the nature of this effect differed according to host species.

[Hormonal treatment of hypophyseal dwarfism, a cause of epiphyseolisthesis capitis femoris? (author's transl)].

PubMed

Möhler, W; Rütt, A

1981-02-01

Two cases of hypophyseal proportional dwarfism which were treated by hormones are reported. After the treatment had been finished the epiphyseal cartilage remained persistent over a long period. Moreover, in both patients an epiphyseolisthesis capitis femoris occurred in their third decennium. A causal nexus is discussed.

Head lice prevalence among households in Norway: importance of spatial variables and individual and household characteristics

PubMed Central

RUKKE, BJØRN ARNE; BIRKEMOE, TONE; SOLENG, ARNULF; LINDSTEDT, HEIDI HEGGEN; OTTESEN, PREBEN

2011-01-01

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

Head lice prevalence among households in Norway: importance of spatial variables and individual and household characteristics.

PubMed

Rukke, Bjørn Arne; Birkemoe, Tone; Soleng, Arnulf; Lindstedt, Heidi Heggen; Ottesen, Preben

2011-09-01

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.

Epidemiological description of the sea lice (Caligus rogercresseyi) situation in southern Chile in August 2007.

PubMed

Hamilton-West, Christopher; Arriagada, Gabriel; Yatabe, Tadaishi; Valdés, Pablo; Hervé-Claude, Luis Pablo; Urcelay, Santiago

2012-05-01

Salmon sea lice represent one of the most important threats to salmon farming throughout the world. Results of private monitoring efforts have shown an increase in the number of positive cages and cage-level abundance of sea lice in southern Chile since 2004. As a consequence, the Chilean Fisheries Service implemented an Official Surveillance Program in the main salmon production area of southern Chile to assess the situation of sea lice in fish farms. Results showed that the prevalence of sea lice in the fish farms was 53.4%, ranging from 3.5% in Puerto Aysén to 100% in the Seno de Reloncaví zone. The average sea lice abundance was 11.8 per fish (Geometrical mean (GM)=8.61, 95% CI (2.1-6.9)). The highest levels were found in Seno de Reloncaví (GM=24.99, 95% CI (15.9-39.2)), Hornopirén (GM=14.7, 95% CI (10.4-20.8)) and Chiloé norte (GM=9.75, 95% CI (1-1.9)), and the lowest loads were observed in Puerto Aysén (GM=1.35, 95%CI (1-1.9)) and Puerto Cisnes (GM=1.67, 95%CI (1.1-2.6)). Salmo salar and Oncorhynchus mykiss had the highest abundance levels (GM=6.93, 95% CI (5.7-8.5), and (GM=5.55, 95% CI (3.6-8.5), respectively). O. kisutch showed lower levels (GM=1.34, 95% CI (1-1.7)), apparently being more resistant to infestation. Sea lice in farmed salmon are widely distributed in different zones of southern Chile, and are becoming a serious threat to this industry. Prevalence and abundance levels were found to be generally high, decreasing in southern zones. Copyright © 2011 Elsevier B.V. All rights reserved.

The Chewing Lice (Insecta, Phthiraptera) Fauna of the Swainson's Warbler, Limnothlypis swainsonii (Aves, Parulidae).

PubMed

Valim, Michel P; Reiley, Bryan M

2015-09-01

We examined Swainson's warblers (Limnothlypis swainsonii (Audubon, 1834), Aves: Parulidae) for lice fauna during 2 yr at three study sites in Arkansas, USA. A total of 66 individuals were examined; eight birds (10.6%) were parasitized with 16 lice of two new species belonging to two genera Myrsidea Waterson, 1915 (Amblycera: Menoponidae) and Brueelia Kéler, 1936 (Ischnocera: Philopteridae). Parasitological parameter data are given on the prevalence of lice on Swainson's warblers. Species descriptions and illustrations are provided for Myrsidea bensoni sp. nov. and Brueelia limnothlypiae sp. nov.; including a key for females of the genus Myrsidea that parasitize Parulidae (Passeriformes). © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cathelicidin (LL-37) level in the scalp hair of patients with tinea capitis.

PubMed

Abdelaal, Nagwa H; Rashed, Laila A; Ibrahim, Sahar Y; Abd El Halim, Mona H; Ghoneim, Noha; Saleh, Noha A; Saleh, Marwah A

2017-10-01

Antimicrobial peptides (AMPs) are considered an important first line of defense against pathogens. Cathelicidin LL-37 was upregulated in response to fungal infection. In this work we aimed to evaluate cathelicidin LL-37 in the hair of tinea capitis and compare it to normal controls. Hair samples were collected from 30 children and 30 controls aged from 2 to10 years old, and the level of cathelicidin LL-37 in the hair was detected by quantitative real-time PCR. The 30 patients were further subdivided into three subgroups according to their clinical type. Ten patients were scaly type, 10 patients were black dots type, and 10 patients were kerion type. Cathelicidin level in patients ranged from 6.0 to 17.5 with mean ± SD (11.3 ± 2.3) and in control ranged from 1.02 to 6.2, with mean ± SD (2.8 ± 1.5). There was a significant difference between the patients and controls regarding the cathelicidin level; P value was 0. The mean cathelicidin level was lowest in the kerion type10.73 ± 2.6 and highest in the black dot type 12.05 ± 2.76. However, there was no significant difference between the cathelicidin level of the different clinical types of tinea capitis; P value was 0.58. In conclusion, the level of cathelicidin LL-37 in hair specimens of human tinea capitis was significantly higher than controls. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Understanding and Managing Head Lice | NIH MedlinePlus the Magazine

MedlinePlus

... to share hats, combs, or brushes with others. Policies regarding school attendance for children with head lice vary. Sources: National Library of Medicine, Centers for Disease Control and Prevention, ...

Faster the better: a reliable technique to sample anopluran lice in large hosts.

PubMed

Leonardi, María Soledad

2014-06-01

Among Anoplura, the family Echinophthiriidae includes those species that infest mainly the pinnipeds. Working with large hosts implies methodological considerations as the time spent in the sampling, and the way in that the animal is restrained. Previous works on echinophthiriids combined a diverse array of analyses including field counts of lice and in vitro observations. To collect lice, the authors used forceps, and each louse was collected individually. This implied a long manipulation time, i.e., ≈60 min and the need to physically and/or chemically immobilize the animal. The present work described and discussed for the first a sample technique that minimized the manipulation time and also avoiding the use of anesthesia. This methodology implied combing the host's pelage with a fine-tooth plastic comb, as used in the treatment of human pediculosis, and keeping the comb with the lice retained in a Ziploc® bag with ethanol. This technique was used successfully in studies of population dynamic, habitat selection, and transmission pattern, being a reliable methodology. Lice are collected entirely and are in a good condition to prepare them for mounting for studying under light or scanning electron microscopy. Moreover, the use of the plastic comb protects from damaging taxonomically important structures as spines being also recommended to reach taxonomic or morphological goals.

A pilot study of the use of oral ivermectin to treat head lice in primary school students in Australia.

PubMed

Currie, Marian J; Reynolds, Graham J; Glasgow, Nicholas J; Bowden, Francis J

2010-01-01

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.

Transcriptome identification of putative genes involved in protein catabolism and innate immune response in human body louse (Pediculicidae: Pediculus humanus).

PubMed

Pedra, Joao H F; Brandt, Amanda; Li, Hong-Mei; Westerman, Rick; Romero-Severson, Jeanne; Pollack, Richard J; Murdock, Larry L; Pittendrigh, Barry R

2003-11-01

Genomics information relating to human body lice is surprisingly scarce, and this has constrained studies of their physiology, immunology and vector biology. To identify novel body louse genes, we used engorged adult lice to generate a cDNA library. Initially, 1152 clones were screened for inserts, edited for removal of vector sequences and base pairs of poor quality, and viewed for splicing variations, gene families and polymorphism. Computational methods identified 506 inferred open reading frames including the first predicted louse defensin. The inferred defensin aligns well with other insect defensins and has highly conserved cysteine residues, as are known for other defensin sequences. Two cysteine and five serine proteinases were categorized according to their inferred catalytic sites. We also discovered seven putative ubiquitin-pathway genes and four iron metabolizing deduced enzymes. Finally, glutathione-S-transferases and cytochrome P450 genes were among the detoxification enzymes found. Results from this first systematic effort to discover human body louse genes should promote further studies in Phthiraptera and lice.

An unusual presentation: trichomycosis (trichobacteriosis) capitis in an infant.

PubMed

Takcı, Zennure; Karadağ, Ayşe Serap

2014-01-01

Trichomycosis (trichobacteriosis) is an asymptomatic superficial bacterial colonization of the hair shaft that is clinically characterized by pale yellowish, reddish or blackish sticky, cylindrical concretions surrounding the hair shaft in the axillary or pubic region. As far as we know, the first and only case of trichomycosis capitis was reported in a 8-year-old boy in 2011. We encountered no cases of trichomycosis in infancy in the literature. The current case displays an atypical presentation of trichobacteriosis involving head hair in a 10-month-old male infant.

Severe pediculosis capitus: a case of "crusted lice" with autoeczematization.

PubMed

Connor, Cody J; Selby, John C; Wanat, Karolyn A

2016-03-16

Pediculosis humanus capitus infestations are common and classically present with intense pruritus of the scalp. Although many treatment options are available, lice are becoming more resistant to conventional therapies and severe clinical presentations are bound to become more prevalent. We present a case of treatment-resistant pediculosis capitus resulting in diffuse autoeczematization of the torso and extremities and severe crusting and scaling of the scalp, which we called "crusted lice." This eruption differs from the well-described id reaction known as "pediculid" and represents a more dramatic manifestation of rampant infestation. This paper provides an up-to-date review of treatment options available for pediculosis humanus capitus, including newer medications like the ones that eventually led to resolution of our patient's extreme infestation.

Inflammatory tinea capitis mimicking dissecting cellulitis in a postpubertal male: a case report and review of the literature.

PubMed

Stein, Loretta L; Adams, Erin G; Holcomb, Katherine Z

2013-09-01

Tinea capitis in postpubertal patients is unusual and may be misdiagnosed as dissecting cellulitis. We report a case of a healthy 19-year-old Hispanic male presenting with a 2-month history of a large, painful subcutaneous boggy plaque on the scalp with patchy alopecia, erythematous papules, cysts and pustules. Although initially diagnosed as dissecting cellulitis, potassium hydroxide evaluation (KOH preparation) of the hair from the affected region was positive. A punch biopsy of the scalp demonstrated endothrix consistent with tinea capitis, but with a brisk, deep mixed inflammatory infiltrate as can be seen with chronic dissecting cellulitis. Fungal culture revealed Trichophyton tonsurans, and a diagnosis of inflammatory tinea capitis was made. The patient was treated over the course of 17 months with multiple systemic and topical antifungal medications, with slow, but demonstrable clinical and histopathological improvement. A rare diagnosis in adults, clinicians should have a high index of suspicion for this condition in an adult with an inflammatory scalp disorder not classic for dissecting cellulitis or with a recalcitrant dissecting cellulitis. Prompt, appropriate diagnosis and treatment is necessary to prevent the long-term complications of scarring alopecia. © 2013 Blackwell Verlag GmbH.

Ovicidal Efficacy of Abametapir Against Eggs of Human Head and Body Lice (Anoplura: Pediculidae).

PubMed

Bowles, Vernon M; Yoon, Kyong Sup; Barker, Stephen C; Tran, Christopher; Rhodes, Christopher; Clark, Marshall J

2017-01-01

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 LC 50 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. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America.

Unstable pyrethroid resistance in sheep body lice Bovicola ovis (Schrank), (Phthiraptera: Trichodectidae) and its implications for lice control on sheep.

PubMed

Levot, Garry

2012-04-30

A retrospective study in which the 18 years treatment history of a mob of sheep hosting a pyrethroid resistant strain of sheep body lice was compared with the coincidental changes in that strain's response to cypermethrin, provided a unique opportunity to investigate the stability of pyrethroid resistance in this species. Resistance levels remained very high (resistance factors (RF)=75-145) for at least five years following the cessation of pyrethroid treatments but within ten years had dropped to only 5, a level similar to many normal field strains and certainly not indicative of high-level resistance. Resumption of pyrethroid treatment of sheep infested with these lice caused a coincidental increase in resistance to an extreme level (RF=321) within two years. Wool producers considering a return to pyrethroid use to control louse infestations should be aware that such a strategy may not be sustainable in the long term and that in Australia effective registered alternative treatments are available. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Pubic Lice (Pthirus pubis): History, Biology and Treatment vs. Knowledge and Beliefs of US College Students

PubMed Central

Anderson, Alice L.; Chaney, Elizabeth

2009-01-01

Pubic lice (Pthirus pubis) maintain a worldwide parasitic population infesting two to over 10 percent of human populations, continuing a presence that has been constant since early evidence 10,000 years ago. Outbreaks in the 1970s have been recorded, but incomplete records preclude description of a definitive population cycle. Current levels of infestation in a US college student population were investigated in this study. Knowledge and opinions of students were also recorded in an online survey administered to college students taking a basic health course at a mid-sized East Coast University. In a group of 817 students, 35 reported experience with pubic lice or other STD infection. Knowledge, beliefs, and treatment attitudes were examined for the 782 students who did not have experience with either pubic lice or STD infection. These students deemed antibiotics as a viable treatment for pubic lice infestation. They also indicated negative attitudes toward the use of pesticide crèmes, which are the most useful prescription. Symptoms and transmission myths in student answers are described. PMID:19440402

Commercial trials using emamectin benzoate to control sea lice Lepeophtheirus salmonis infestations in Atlantic salmon Salmo salar.

PubMed

Stone, J; Sutherland, I H; Sommerville, C; Richards, R H; Varma, K J

2000-06-19

Two trials were conducted at commercial salmon farms to evaluate the efficacy of emamectin benzoate (Slice, 0.2% aquaculture pre-mix, Schering-Plough Animal Health) as a treatment for sea lice Lepeophtheirus salmonis (Krøyer) and Caligus elongatus Nordmann infestations in Atlantic salmon Salmo salar L. Trials were carried out in 15 m2 commercial sea pens, at temperatures of 5.5 to 7.5 degrees C and 10.8 to 13.8 degrees C. Each pen was stocked with 14,000 to 17,500 fish with mean weights of 0.44 to 0.74 and 1.33 to 1.83 kg. Fish were naturally infested with sea lice at the start of each trial. At Day -1, samples of 10 or 15 fish were taken from each pen to determine pre-treatment numbers of lice. Emamectin benzoate was administered in feed, to 4 replicate pens, at a dose of 50 micrograms kg-1 biomass d-1 for 7 consecutive days (Days 0 to 6). Sea lice were counted again, between Days 7 and 77, and comparisons made with untreated control fish. Despite adverse weather conditions, wide variations in fish weights and exposure to new infestations, treatment was effective against chalimus and motile stages of L. salmonis. In the autumn trial, efficacy at Day 27 was 89%, and lice numbers remained lower on treated fish than on control fish 64 d from the start of treatment. In the winter trial, reductions in lice numbers at low temperatures were slower but good efficacy was achieved by Day 35. Although control fish had to be treated with hydrogen peroxide at Day 21, fish treated only with emamectin benzoate on Days 0 to 6 still had 89% fewer lice than control fish at Day 35. There were very few C. elongatus present, but at the end of both trials numbers were lower on treated fish. No adverse effects were associated with treatment of fish with emamectin benzoate.

Efficacy of neem seed extract shampoo on head lice of naturally infected humans in Egypt.

PubMed

Abdel-Ghaffar, Fathy; Semmler, Margit

2007-01-01

Sixty heavily lice-infested male and female children (4-15 years) were selected and subjected to the treatment with a neem seed extract shampoo. Twenty to thirty milliliter of the shampoo were thoroughly mixed with completely wet hair and rubbed in to reach the skin of the scalp. After 5, 10, 15 and 30 min, the shampoo was washed out and the hair basically combed. Head lice were collected and examined. The neem seed extract shampoo proved to be highly effective against all stages of head lice. No obvious differences regarding the efficacy of the shampoo were observed between an exposure time of 10, 15 or 30 min. No side effects, such as skin irritation, burning sensations, or red spots on the scalp, forehead or neck, respectively, were observed.

Origin of Clothing Lice Indicates Early Clothing Use by Anatomically Modern Humans in Africa

PubMed Central

Toups, Melissa A.; Kitchen, Andrew; Light, Jessica E.; Reed, David L.

2011-01-01

Clothing use is an important modern behavior that contributed to the successful expansion of humans into higher latitudes and cold climates. Previous research suggests that clothing use originated anywhere between 40,000 and 3 Ma, though there is little direct archaeological, fossil, or genetic evidence to support more specific estimates. Since clothing lice evolved from head louse ancestors once humans adopted clothing, dating the emergence of clothing lice may provide more specific estimates of the origin of clothing use. Here, we use a Bayesian coalescent modeling approach to estimate that clothing lice diverged from head louse ancestors at least by 83,000 and possibly as early as 170,000 years ago. Our analysis suggests that the use of clothing likely originated with anatomically modern humans in Africa and reinforces a broad trend of modern human developments in Africa during the Middle to Late Pleistocene. PMID:20823373