Pediculosis capitis

The Impact of the COVID-19 Pandemic on the Prevalence of Head Lice Infestation among Children Attending Schools and Kindergartens in Poland

Pediculosis capitis predominantly affects child populations. During the COVID-19 pandemic, various types of social limitations such as social isolation and limitations on educational facilities' functionalities were introduced worldwide, including in Poland. The impact of these pandemic restrictions on the prevalence of pediculosis capitis has not been extensively investigated so far. Existing data on this topic are limited mainly to indirect evaluation methods, such as online surveys or Internet analysis. In this study, we directly examined a cohort of over five thousand children to assess the influence of COVID-19 pandemic restrictions on the prevalence of head lice infestation among school and kindergarten attendees in Poland. Our findings demonstrate that the restrictions imposed during the COVID-19 pandemic led to a decrease in the number of children infested with head lice compared to pre-pandemic data. These results confirm that head lice infestations remain an ongoing epidemiological concern and warrant continued monitoring.

Head Lice Infestation in Pre-High School Girls, Lak Hok Suburban Area, Pathum Thani Province, in Central Thailand

This is a cross-sectional descriptive survey to determine the prevalence of lice infestation in a pre-high school, Lak Hok subdistrict, Pathum Thani Province, in central part of Thailand. The knowledge, attitudes, and practices of parents/guardians toward head lice in female children during February-April 2020 were evaluated. A total of 83 out of 111 parents (74.8%) agreed to complete consent forms and questionnaires. The prevalence of pediculosis found in this study was 68.7%. The infestation was found in the primary school level (87.5%), which was significantly higher than pre-primary school (29.6%; p < 0.05). Itching scalp was revealed in 93.0% of pediculosis. The results showed that occupation, religion, education, and income showed no significant difference between lice infested and non-infested students (p > 0.05). There was no significant association between sex, occupation, religion, education, income, status of parents, and family size among lice infested and non-infested students (p > 0.05). The parents/guardians showed the middle level of knowledge concerning with pediculosis capitis (66.8%). The lack of knowledge leading, first, to the belief that pediculosis does not need any treatment (89.2%), followed by boys getting head lice more frequently than girls (85.5%), and the belief that sharing infested combs, brushes, or hair ribbons does not result in lice transmission (79.9%). More than 75% of the parents/guardians had experienced infestation of head lice and showed themselves willing and able to diagnose and treat their family. However, 50.6% of them did not feel shame when their children were infested with head lice. Children washing their hair by themselves were found to be a significant factor in infestation (88.5%). High rate of pediculosis in this suburban school needs more intensive care by parents/guardians and teachers. Furthermore, improvement strategies to prevent and control lice in the school need to be more specifically planned and scheduled by teachers and health administrators.

The Efficacy and Biopharmaceutical Properties of a Fixed-Dose Combination of Disulfiram and Benzyl Benzoate

Scabies and hair lice are parasitic diseases that affect human skin and hair, respectively. The incidence and resistances of these infections are increasing. Tenutex^® (disulfiram and benzyl benzoate emulsion) is an alternative to standard insecticides to avoid resistances. The aim of the work is to evaluate the transdermal absorption and the in vitro efficacy against scabies and hair lice after different exposition times. Dermatomed human skin was used to assess the dermal absorption using a validated High Performance Liquid Chromatography (HPLC) method. HEK001 keratinocytes were used to evaluate the cytotoxicity of benzyl benzoate. Only benzyl benzoate was able to cross the skin, but it did not show cytotoxicity at any of the tested concentrations. The product efficacy was tested on Psoroptes ovis after direct contact and after administration on sheep skin explants at different contact times. Permethrin/malathion-resistant strains of Pediculus humanis capitis adults and eggs were directly exposed to Tenutex, and the vitality and hatchability, respectively, were evaluated. The anti-scabies study demonstrated that exposure for 6 or 24 h completely eradicated the parasite. The pediculicidal activity of Tenutex exhibited superior efficacy than standard treatment on resistant lice. The positive results obtained suggest that Tenutex^® is a good treatment option, especially in drug resistance situations.

Human pediculosis, a global public health problem

Background

Human pediculosis is caused by hematophagous lice, which are transmitted between individuals via direct and/or indirect contact. Despite the public health importance of louse infestation, information concerning the global burden of pediculosis and the epidemiological landscape of louse-borne diseases is limited. The aim of this review was to summarize the biology, epidemiology, diagnosis, and control of lice infestation in humans. We also discussed the latest advances in molecular taxonomy and molecular genetics of lice.

Methods

We searched five electronic bibliographic databases (PubMed, ScienceDirect, CNKI, VIP Chinese Journal Database, and Wanfang Data) and followed a standard approach for conducting scoping reviews to identify studies on various aspects of human lice. Relevant information reported in the identified studies were collated, categorized, and summarized.

Results

A total of 282 studies were eligible for the final review. Human pediculosis remains a public health issue affecting millions of people worldwide. Emerging evidence suggests that head lice and body lice should be considered conspecific, with different genotypes and ecotypes. Phylogenetic analysis based on mitochondrial (mt) cytb gene sequences identified six distinct clades of lice worldwide. In addition to the direct effect on human health, lice can serve as vectors of disease-causing pathogens. The use of insecticides plays a crucial role in the treatment and prevention of louse infestation. Genome sequencing has advanced our knowledge of the genetic structure and evolutionary biology of human lice.

Conclusions

Human pediculosis is a public health problem affecting millions of people worldwide, particularly in developing countries. More progress can be made if emphasis is placed on the use of emerging omics technologies to elucidate the mechanisms that underpin the physiological, ecological, and evolutionary aspects of lice.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-00986-w.

Head lice were also affected by COVID-19: a decrease on Pediculosis infestation during lockdown in Buenos Aires

Pediculosis is a worldwide disease affecting school-aged children produced by the presence of the head louse, Pediculus humanus capitis De Geer, an obligate ectoparasite on the human scalp feeding exclusively on blood. Transmission occurs primarily through direct physical head-to-head contact. In March 2020, the World Health Organization (WHO) declared the COVID-19 outbreak as a pandemic. COVID-19 is caused by SARS-CoV-2, a variant of the coronavirus. Therefore, on March 18, 2020, the Argentinean government established mandatory isolation for an indefinite period. This obligatory isolation interrupted regular classes avoiding direct contact between children, thus affecting the dispersal route of individuals and the evolution of head louse populations. In this study, we evaluated through an online survey how confinement affected the prevalence of lice during lockdown compared to the situation prior to confinement. The survey allowed to discriminate the different control strategies, the number of treatments, and the amount of insects recorded by parents. Data of 1118 children obtained from 627 surveys were analyzed. As the main result, it was observed that prevalence of lice decreased significantly from before (69.6%) to during (43.9%) COVID-19 lockdown. Moreover, head lice infestation was more effectively controlled in households with up to 2 children in comparison to households with 3 or more children. This is the first study that analyzed the prevalence of head lice during COVID-19 pandemic. In addition, this work demonstrated the impact of social distance in the population dynamics of head lice and how it could affect the control strategies in the future.

Genetic Diversity of Pediculus humanus capitis (Phthiraptera: Pediculidae) in Peninsular Malaysia and Molecular Detection of Its Potential Associated Pathogens

Pediculosis capitis caused by Pediculus humanus capitis (De Geer) is endemic all over the world, and children are mostly affected, particularly those living in overcrowded institutions. Several studies have shown that P. h. capitis carried human pathogenic bacteria, suggesting the potential role of head lice in the transmission of pathogens to humans. In this study, we determined the genetic diversity of head lice collected from welfare homes sheltering underprivileged children by using DNA barcoding and demonstrated the presence of Acinetobacter spp., Serratia marcescens, and Staphylococcus aureus in head lice, which have never been investigated before in Malaysia. Cox1 DNA barcoding identified the head lice, P. h. capitis collected from welfare homes across two geographical areas of Peninsular Malaysia as belonging to clades A, B, and D. Acinetobacter bacteria: Acinetobacter guillouiae, Acinetobacter junii, Acinetobacter baumannii, and Acinetobacter nosocomialis were detected in head lice belonging to clades A and also D. In addition, DNA from S. marcescens and S. aureus were also detected in both clades A and D. To our knowledge, this is the first report on the genetic diversity of head lice in Malaysia through DNA barcoding, as well as the first to provide molecular evidence on the type of bacteria occurring in head lice in Malaysia. It is anticipated that the DNA barcoding technique used in this study will be able to provide rapid and accurate identification of arthropods, in particular, medically important ectoparasites.

Scalp microbiota alterations in children with pediculosis

Pediculosis is a disease caused by the insect Pediculus humanus capitis that mainly occurs in childhood. A comparative study was carried out evaluating groups of schoolchildren with (group A) and without pediculosis (group B) to analyse the characteristics of the scalp microbiota. Samples were collected by swab using Stuart transport medium and incubate in Sabouraud dextrose agar with tetracycline to analyse the fungal microbiota and in blood agar to assess the bacterial microbiota. The isolates identity was confirmed by sequencing of the 16S and 18S regions of the ribosomal DNA gene for bacteria and fungi, respectively. The analysis of the 186 isolates led to the identification of 35 bacteria and 40 fungi in group A and 47 bacteria and 64 fungi in group B. The results indicate differences in bacterial and fungal species in the groups analysed. In the observed bacterial microbiota, Staphylococcus capitis occurred more frequently than Staphylococcus epidermidis in group A vs B. Among fungal isolates, Debaryomyces sp. was more frequent in group B vs A. Our findings showed scalp microbiota alterations in children with pediculosis, meriting future studies to analyse the relationship between these agents and their impact on human health.

Teaching children about hygiene: A primary prevention experience in Portugal

Background

Children's knowledge on hygiene is often considered to be provided by parents or schools. It is something with a direct impact on health and linked with socio-cultural factors. Primary care plays a vital role in health education and promotion, so focusing on hygiene habits is part of primary prevention.

Objectives

Improving the knowledge on hygiene and promoting healthy behaviors in students from the 4^th to the 6^th grade.

Materials and Methods

Longitudinal, prospective study. Hygiene habits were assessed through a questionnaire, followed by a brief health education session organized by healthcare professionals at schools. Hygiene habits were then reassessed using the original questionnaire.

Results

A total of 812 questionnaires (354 in the pre-session phase and 458 in the post-session phase) were collected, filled in by students with ages ranging between 8 and 16 (average, 10.8), being 52% boys. There were significant increases in the score in both genders, but this increase was slightly higher for boys, with an average increase of 0.98 points (P < 0.05, independent samples t test). The 9 year old group (in the first evaluation; 10 years old post-talk) had the highest increase in score, with an average increase of 1.33 points in the questionnaire.

Conclusion

Interventions conducted by healthcare professionals at schools have a positive effect for health education. The resulting scores revealed an improvement regarding hygiene habits namely in younger students. This may suggest that interventions on hygiene habits should take place at younger ages, so to have a greater impact in behavioral change.

Using human head lice to unravel neglect and cause of death

Despite the common association of human lice with abandoned or neglected people, no procedure to assess pediculosis, aimed to detect signs of neglect, exists. Investigating the two most common forms of head louse infestation, regular and severe, we define lice-markers of neglect and develop a protocol and survey form to record and assess pediculosis. The study of head lice from a deceased victim of neglect helped unravel time-length since death, frequency of exposure to neglect and the cause and circumstances related to the death. Nit-clusters are markers of neglect, indicating length and frequency of neglect episodes. In the case study used here that culminated in the death of the victim, sustained abandonment started circa 2 years before discovery. The lice suggested that death was caused by overconsumption of a powerful calcium channel blocker, an antihypertensive, an excess of which in lice food supply (blood) stops oogenesis. Despite hosting thousands of adult females on the hair, lice reproduction stopped and nits were no longer developed or deposited on the hairs at the root end. This short distance of the shaft with no nits provided a time estimation of overdosing of almost 2 months before death.

[Pediculus capitis in schoolchildren of the urban area of Nuevo León, México: Analyses of associated factors]

INTRODUCTION

Pediculosis capitis is a recurring problem affecting 6 to 12 millions of children annually; there are no epidemiological data on this subject in the state of Nuevo León, and there are few in México. Therefore, new contributions are needed to design control strategies based on factors that may predispose to head lice infestation.

OBJECTIVE

To determine the prevalence of Pediculus capitis in primary school children and to evaluate risk factors and individual or socioeconomic characteristics statistically associated with infestation.

MATERIALS AND METHODS

We included 840 schoolchildren from six municipalities after parents and children signed an informed consent. Ectoparasites were collected from infested children using a finetoothed comb. Participants were interviewed using a questionnaire on individual and socioeconomic variables including age, gender, education, hair characteristics, overcrowding, and siblings with pediculosis, among others.

RESULTS

The overall prevalence of head lice in schoolchildren was 28% (235/840), the highest prevalence was among girls (33.7%, 140/417), and children from the fifth grade (10-11 years old) were the most affected (6.2%; 52/840). Female gender, long hair and the father's education level were significantly associated with P. capitis.

CONCLUSION

Our results showed that the P. capitis prevalence in Nuevo León is one of the highest in Mexico, that it constitutes a real public health problem, and that there is need to establish prevention programs at home and school to decrease or to control P. capitis with the support of public health authorities.

Prevalence of head lice infestation and pediculicidal effect of permethrine shampoo in primary school girls in a low-income area in southeast of Iran

Background

Head lice infestation is a common public health problem that is most prevalent in primary school children throughout the world, especially in developing countries including different parts of Iran. This study aimed to determine the prevalence and risk factors associated with head lice infestation and pediculicidal effect of 1% permethrin shampoo in primary schools girls of Bashagard County, one of the low socioeconomic areas in southeast of Iran.

Methods

In this interventional study six villages with similar demographical situations were selected and randomly assigned into intervention and control areas. In each area 150 girl students aged 7–12 years were selected randomly and screened for head lice infestation by visual scalp examination. In intervention area, treatment efficacy of 1% permethrin shampoo was evaluated via re-examination for infestation after one, two, and three weeks. Pre-tested structured questionnaire was used to collect data on socio-demographic and associated factors of head lice infestation.

Results

The prevalence of head lice infestation was 67.3%. There was significant association between head lice infestation and school grade, family size, parents’ literacy, bathing facilities, frequency of hair washing, and use of shared articles (p < 0.05). The effectiveness of 1% permethrin shampoo for head lice treatment was 29.2, 68.9, and 90.3% after the first, second, and third weeks, respectively.

Conclusion

The head lice infestation is a health problem in primary school girls of Bashagard County. Improvement of socioeconomic status and providing appropriate educational programs about head lice risk factors and prevention can be effective for reduction of infestation in this area.

Trial registration

This trial has been registered and approved by Hormozgan University of Medical Sciences ethical committee (Trial No.764). Trial registration date: March 17 2014.

The efficacy of Australian essential oils for the treatment of head lice infestation in children: A randomised controlled trial

Background

The increase in resistance of head lice to neurotoxic pediculicides and public concern over their safety has led to an increase in alternative treatments, many of which are poorly researched or even untested.

Methods

A multicentre, randomised, assessor‐blind, parallel‐group trial (Trial 1) was conducted to compare the safety and efficacy of a head lice treatment containing Australian eucalyptus oil and Leptospermum petersonii (EO/LP solution; applied thrice with 7‐day intervals between applications) with a neurotoxic treatment containing pyrethrins and piperonyl butoxide (P/PB mousse; applied twice with a 7‐day interval) in children. A single‐blind, open trial (Trial 2) was conducted to assess the efficacy of EO/LP solution following a single application. In addition, skin irritancy and sensitisation tests using EO/LP solution were performed in adults and children. In vitro tests were performed to further assess the ovicidal and pediculicidal efficacy of EO/LP solution.

Results

EO/LP solution was found to be more than twice as effective in curing head lice infestation as P/PB mousse in per‐protocol participants (Trial 1; 83% vs 36%, P < 0.0001), and was also found to be 100% pediculicidal following a single application (Trial 2). Adverse events were limited to transient itching, burning or stinging. Further skin testing with the EO/LP solution reported no irritation or sensitisation in adults, or irritation in children. In vitro exposure of lice and eggs to the EO/LP solution resulted in 100% mortality.

Conclusion

The efficacy, safety and relative ease of use of the EO/LP solution make it a viable alternative in treating head lice.

[Randomised clinical trial to evaluate the efficacy and safety of a new pediculicide made with saponified olive oil in the eradication of Pediculus humanus capitis]

INTRODUCTION

The aim of the study was to evaluate the efficacy and safety of a new pediculicide in the eradication of Pediculus humanus capitis infestation.

MATERIAL AND METHODS

A randomised clinical trial was designed, in which children aged between 5 and 15 years diagnosed with pediculosis were selected. Treatment was administered on days 1 and 7 after selection, and they were evaluated in 4 visits (day 2, 7, 9, and 14). The product under evaluation with saponified olive oil was Inex Pediculicide Soap^®, which was compared with Paranix^®, with a similar mechanism of action. The primary efficacy endpoint was the eradication of the parasite by day 14 (louse-free rate), using an intention to treat analysis.

RESULTS

Six paediatricians from 5 Primary Health Care centres in the Community of Madrid (Spain) and one private clinic participated in the study. A total of 45 children were included, of which 75.6% were girls (n=34). The mean age was 7.1 years (95% CI 6.3-7.9). The large majority (80%) were middle class, and 82.2% had a history of previous pediculosis. The efficacy at 14 days was 76.2% (95% CI 52.8-91.8) in the group treated with Inex Pediculicide Soap^® group, and 79.2% (95% CI 57.9-92.9) in Paranix^® group (NNT=33.3). No adverse effects were observed with treatment.

CONCLUSIONS

The 2 products were effective and safe in the eradication therapy Pediculus humanus capitis, with no statistical differences.

Epidemiological comparative study of pediculosis capitis among primary school children in Fayoum and Minofiya governorates, Egypt

Pediculosis is a frequent public health problem. The pattern and prevalence of Pediculosis is dependent on many socio-demographic and economic factors. It is common in schoolchildren especially primary level; it may affect their learning performance. This study aimed to determine the prevalence of head louse among primary students, in Fayoum and Bagor districts, and explore the predisposing factors of head louse infestation in both public and private schools. The study was a cross-sectional descriptive study, conducted in two governorates: Fayoum and Minofiya governorates which represent upper and lower Egypt respectively during the academic year of 2012-2013. The students were selected from different grades with a total of 10,935 students. The prevalence of head lice in the study group was 16.7 %. The incidence was higher in public schools 20.7 % than private schools 9.04 % and in girls 25.8 % more than boys, especially covered hair girls 6.2 %. There was a socio-demographic influence of louse infestation on residence, presence of water supply, number of house rooms, and number of family member. It is concluded that head lice are a common childhood problem related to poor hygiene and socioeconomic status. There is a need for collaboration effort between family, school, community, and media, to create an environment that establishes healthy behaviors and health promotion.

Treatment of Pediculosis Capitis

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.

Molecular survey of the head louse Pediculus humanus capitis in Thailand and its potential role for transmitting Acinetobacter spp

BACKGROUND

Head louse infestation, which is caused by Pediculus humanus capitis, occurs throughout the world. With the advent of molecular techniques, head lice have been classified into three clades. Recent reports have demonstrated that pathogenic organisms could be found in head lice. Head lice and their pathogenic bacteria in Thailand have never been investigated. In this study, we determined the genetic diversity of head lice collected from various areas of Thailand and demonstrated the presence of Acinetobacter spp. in head lice.

METHODS

Total DNA was extracted from 275 head louse samples that were collected from several geographic regions of Thailand. PCR was used to amplify the head louse COI gene and for detection of Bartonella spp. and Acinetobacter spp. The amplified PCR amplicons were cloned and sequenced. The DNA sequences were analyzed via the neighbor-joining method using Kimura's 2-parameter model.

RESULTS

The phylogenetic tree based on the COI gene revealed that head lice in Thailand are clearly classified into two clades (A and C). Bartonella spp. was not detected in all the samples, whereas Acinetobacter spp. was detected in 10 samples (3.62%), which consisted of A. baumannii (1.45%), A. radioresistens (1.45%), and A. schindleri (0.72%). The relationship of Acinetobacter spp. and the head lice clades showed that Acinetobacter spp. was found in clade A and C.

CONCLUSIONS

Head lice in Thailand are classified into clade A and B based on the COI gene sequences. Pathogenic Acinetobacter spp. was detected in both clades. The data obtained from the study might assist in the development of effective strategies for head lice control in the future. Detection of pathogenic bacteria in head lice could raise awareness of head lice as a source of nosocomial bacterial infections.

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

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 biannual focus on head lice during the 2 years of investigation increased checking thoroughness, while checking frequency remained unchanged. Based on the results, we suggest new head lice management guidelines for health authorities.

Designing randomized-controlled trials to improve head-louse treatment: systematic review using a vignette-based method

Head-louse infestation remains a public health problem. Despite published randomized-controlled trials, no consensus-based clinical practice guidelines for its management emerged because of the heterogeneity of trial methodologies. Our study was undertaken to attempt to find an optimal trial framework: minimizing the risk of bias, while taking feasibility into account. To do so, we used the vignette-based method. A systematic review first identified trials on head-louse infestation; 49 were selected and their methodological constraints assessed. Methodological features were extracted and combined by arborescence to generate a broad spectrum of potential designs, called vignettes, yielding 357 vignettes. A panel of 48 experts then rated one-on-one comparisons of those vignettes to obtain a ranking of the designs. Methodological items retained for vignette generation were income level of the population, types of treatments compared, randomization unit, blinding, treatment-administration site, diagnosis method and criteria, and primary outcome measure. The expert panel selected vignettes with cluster randomization, centralized treatment administration, and blinding of the outcome assessor. The vignette method identified optimal designs to standardize future head-louse treatment trials, thereby obtaining valid conclusions and comparable data from future trials, and appears to be a reliable way to generate evidence-based guidelines.

Survey assessment on pediatricians' attitudes on head lice management

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 believe that no product is effective for prevention.

Conclusions

This is the first study that investigates the clinical practice of family pediatricians about the management and treatment of head lice globally, the Italian pediatricians surveyed proved to be quite informed on the head lice management. However, even in a country where pediatric assistance is free for everybody, a considerable proportion of parents do not seek advice to their own family pediatrician. Therefore, educations of parents, other than continuous updating of pediatricians, may contribute to a better management of head lice in the community.

Effect of households' social networks on lice infestation among vulnerable Mexican children: a qualitative comparative analysis

The prevalence of pediculosis is high among elementary and secondary school children, which favors the belief that infestation occurs more often in schools than in homes. This study explored the role of households' social networks in the transmission of head lice. Seventeen school children and their social networks (n = 22) from Acatlipa (Morelos, Mexico) participated in a prospective observational study during school vacation. The hair of all the school children was washed with shampoo containing permethrin at the beginning of the study and the incidence of pediculosis (O) was evaluated at the beginning of the school term (follow-up at 1.5 months). The sets included in the qualitative comparative analysis were sex (S), length of hair (H), baseline diagnostic of pediculosis (I) and degree (D) and infestation index (N) obtained through the analysis of social networks. The prevalence of pediculosis was the same at the beginning and the end of follow-up (17.6%). The degree of the school children's networks ranged between 2 and 14. There were 8 configurations, the most frequent being F*i*d*n*h. The most parsimonious configuration associated with the incidence of pediculosis was F*I*d*H (female, previous infestation, low degree and long hair), with a coverage of 0.344 and a consistency of 0.941. Indicators of social networks made it possible to identify the role of households' social networks in the transmission of lice. Individual actions such as the use of shampoo containing insecticides are temporary and, therefore, structural actions should be favored.

Skin diseases among schoolchildren in Ghana, Gabon, and Rwanda

OBJECTIVES

Skin diseases, especially skin infections, among schoolchildren in Africa can be a major health problem. The objective of this study was to determine the prevalences of skin diseases among children in rural and urban schools in three different African countries and to study the influence of socioeconomic level.

METHODS

Cross-sectional, population-based studies were performed in Ghana, Gabon, and Rwanda. Point prevalences of skin diseases were estimated on the basis of physical examination by at least one dermatologist.

RESULTS

A total of 4839 schoolchildren were seen. The overall prevalence of schoolchildren with any skin disease was high and amounted to 34.6% and 42.0% in two Ghanaian studies, 45.8% in Gabon, and 26.7% in Rwanda. In children with skin diseases, skin infections represented the greatest proportion of disease, accounting for 14.7% and 17.6% of skin disease in the Ghanaian studies, and 27.7% and 22.7% in Gabon and Rwanda, respectively. Diseases with the highest prevalence were tinea capitis and bacterial skin infections, especially in rural areas and in schools serving children living at lower socioeconomic levels.

CONCLUSIONS

The prevalences of skin diseases among African schoolchildren were high. Skin infections such as tinea capitis and pyoderma predominated.

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

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.

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

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.

Head lice prevalence among households in Norway: importance of spatial variables and individual and household characteristics

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.

Prevalence of pediculosis capitis among schoolchildren in Greece and risk factors: a questionnaire survey

Pediculosis capitis is a common problem worldwide. The aim of this study was to estimate the prevalence of pediculosis capitis in children of preschool or school age in Greece, as well as to investigate the potential risk factors. The study included children of preschool and school age from all over Greece, including urban, semi-urban, and rural areas of Greece. A questionnaire with both closed and open-type questions, which was constructed by the researcher and filled in by the children's parents, was used. A total of 5,084 questionnaires were distributed, of which 2,792 were adequately filled and subsequently evaluated. Descriptive statistics and logistic regression models were used. The median age of the children was 8 years (range: 3-13 yrs) and 54% of them were girls. Pediculosis was found to be prevalent in 12% of the tested population. The prevalence of the disease seems to be increased after the age of 10 years and the risk is higher in girls. The number of family members was correlated positively with the risk of being infected with pediculosis at least once. The children's gender, their age, and family size were correlated with the risk of infection.