Epidemiology and morbidity of scabies and pediculosis capitis in resource-poor communities in Brazil

Ivermectin: panacea for resource-poor communities?

The 2014 Gairdner Global Health Award was conferred for discovery of the unique microorganism that is the sole source of the endectocidal avermectins, and the Public sector/Private sector Partnership that developed innovative biopharmaceuticals with immeasurably beneficial impact on public health worldwide. Ivermectin is already labelled a 'wonder drug', essential for campaigns to eliminate two disfiguring and devastating tropical diseases. New uses for it are identified regularly, including possible antibacterial, antiviral, and anticancer potential. Hundreds of millions of people are taking ivermectin to combat various diseases and afflictions, and mass administration of ivermectin in polyparasitised poor communities around the world is increasingly recognised as a mechanism to easily and cost-effectively improve overall health and quality of life for everyone.

Dermatologic conditions in teenage adolescents in Nigeria

Background

Skin disorders are common in adolescents, and the impact on quality of life can be enormous, particularly when viewed against the backdrop of the visibility of skin diseases and the psychologically vulnerable period of adolescence. However, few studies have documented the magnitude of skin disorders in this subset of individuals. We therefore estimated the point prevalence and pattern of dermatologic conditions in adolescents attending various secondary schools in Calabar, Southern Nigeria.

Methods

Using a structured questionnaire, relevant sociodemographic information was obtained from 1,447 teenage adolescents from eight secondary schools. Thereafter, a whole body examination was conducted to determine the presence and types of skin disorders seen.

Results

Skin diseases were seen in 929 students. The point prevalence was higher in males (72.1%) than in females (58.3%). Private schools had a higher prevalence than public schools. The six most common dermatoses were acne vulgaris, pityriasis versicolor, nevi, tinea, miliaria, and keloid/hypertrophic scars, and accounted for over 80% of the dermatoses seen.

Conclusion

The point prevalence of dermatoses in senior secondary school adolescents was 64.2%. Although a large number of skin disorders were observed, only a handful accounted for a significant proportion of the diseases seen. This increases the ease of training community health workers in the recognition and treatment of common skin diseases. Age, race, and climatic factors are important determinants of skin diseases in adolescents in Nigeria.

Advances in studies of disease-navigating webs: Sarcoptes scabiei as a case study

The discipline of epidemiology is the study of the patterns, causes and effects of health and disease conditions in defined anima populations. It is the key to evidence-based medicine, which is one of the cornerstones of public health. One of the important facets of epidemiology is disease-navigating webs (disease-NW) through which zoonotic and multi-host parasites in general move from one host to another. Epidemiology in this context includes (i) classical epidemiological approaches based on the statistical analysis of disease prevalence and distribution and, more recently, (ii) genetic approaches with approximations of disease-agent population genetics. Both approaches, classical epidemiology and population genetics, are useful for studying disease-NW. However, both have strengths and weaknesses when applied separately, which, unfortunately, is too often current practice. In this paper, we use Sarcoptes scabiei mite epidemiology as a case study to show how important an integrated approach can be in understanding disease-NW and subsequent disease control.

Scabies community prevalence and mass drug administration in two Fijian villages

BACKGROUND

Scabies has been estimated to affect approximately 300 million people worldwide each year. Scabies rates are high and pose a significant public health problem in Fiji. Community-based comparison treatment trials have not been undertaken. We estimated scabies prevalence and compared the efficacy and tolerability of mass drug administration (MDA) of benzyl benzoate lotion (BB) or oral ivermectin (IVM) in two villages in Fiji.

METHODS

A prospective MDA trial was undertaken in two Fijian villages, comparing three daily applications of BB with single dose IVM or permethrin cream for those aged under two years. The therapies were offered to all community members regardless of the presence of scabies or its symptoms. The difference in prevalence was measured before and after the intervention and absolute risk reduction (ARR) and relative risk (RR) calculated.

RESULTS

In the BB group, there were 572 eligible participants, of whom 435 (76%) enrolled and 201 (46%) returned for follow-up. In the IVM group, there were 667 eligible participants, of whom 325 (49%) enrolled and 126 (39%) returned. Scabies prevalence was lower after the intervention in both groups. It fell from 37.9 to 20.0% (ARR 18.0%; RR 0.52) in the BB group and from 23.7 to 9.5% (ARR 14.2%; RR 0.40) in the IVM group.

CONCLUSIONS

Our study provides proof of principle that MDA for scabies can reduce scabies prevalence at the community level, and that there was no significant difference in this trial between BB and oral IVM.

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.

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.

Impact of scabies in resource-poor communities

PURPOSE OF REVIEW

Features of endemic scabies are specific in resource-poor and underprivileged communities, with implications for control measures on the community level. In this review, these special aspects are addressed.

RECENT FINDINGS

Scabies is endemic in many resource-poor communities, with a prevalence of 20% and higher. Transmission is influenced by social attitudes, migration, access to healthcare services, housing conditions, hygiene conditions, and crowding. Endemic scabies occurs with severe infestations, complications, and sequels, mainly in children. Sleep loss as a result of scabies-related itching is common. Complications include secondary infections by group A streptococci and acute poststreptococcal glomerulonephritis. Shame, restriction of leisure activities, and stigmatization are common. Treatment of scabies includes a variety of topical compounds, but control on the community level is not an easy task. As ivermectin kills a variety of other parasites, this oral drug is increasingly used for mass treatment. Intervention should address socioemotional aspects using an integrated approach with professionals from different areas, and the community.

SUMMARY

Scabies is a neglected disease and needs to be perceived as an important public health problem causing morbidity in many resource-poor communities. Future work on epidemiology, clinical aspects, transmission dynamics, socioeconomic aspects, and sustainable control in resource-poor communities is needed.

The neglected navigating web of the incomprehensibly emerging and re-emerging Sarcoptes mite

Parasite presence in any ecosystem generates complex navigating webs (Parasite-NW) within the system, through which parasites move from one to another host. The appropriate assimilation of parasite navigating web is pivotal for a better understanding of pathogen flow in the ecosystem, with implications for disease control. Sarcoptes mite has been approached from medical, veterinary, entomological, physiological and, recently, molecular sides, to understand its epidemiological navigating web between isolates from different hosts and geographical regions. The obtained conclusions are still a matter of debate. Sarcoptes navigating web (Sarcoptes-NW) is intricate and uncertain, with unexplainable pathogenic flow. In this review we summarize by which routes, under what conditions and at what levels the Sarcoptes mite moves among its hosts.

Scratching the itch: new tools to advance understanding of scabies

Scabies remains a significant public health problem worldwide. Research into aspects of Sarcoptes scabiei biology and host-parasite interactions has been impeded by an inability to maintain mites in vitro and by limited access to parasite material and infected subjects. The generation of comprehensive expressed sequence tag libraries has enabled the initial characterisation of molecules of interest to diagnostics, vaccines, and drug resistance. The recent development and utilisation of animal models, combined with next-generation technologies, is anticipated to lead to new strategies to prevent, diagnose, and treat scabies, ultimately improving skin health in both human and veterinary settings. This article will summarise recent molecular and immunologic advances on scabies, and will address priorities for the exciting 'next chapter' of scabies research.

Controlling scabies in madrasahs (Islamic religious schools) in Bangladesh

OBJECTIVES

To assess the effectiveness of a scabies control programme in reducing the prevalence of scabies in urban Bangladesh madrasahs, where the condition is extremely common.

STUDY DESIGN

A controlled trial involving four intervention madrasahs (total students 2359) and four control madrasahs (total students 2465) in Dhaka Metropolitan Area.

METHODS

A baseline scabies sample survey was carried out on 40 and 44 students of four intervention and four control madrasahs, respectively. Another 40 students of the intervention madrasahs were administered a pre-intervention test on scabies knowledge. This was followed by mass treatment of all students, teachers and staff of the eight madrasahs with topical 5% permethrin cream. The subsequent intervention involved daily monitoring of students for five key personal hygiene practices, weekly 10-min scabies health education classes, supply of simple and inexpensive products to students to prevent cross-infestation to/from peers (e.g. plastic bags, clothes hangers), and chemotherapy of new students detected with scabies. After 4 months of the intervention, the prevalence of scabies, personal hygiene practices and scabies knowledge were assessed in students of the intervention madrasahs.

RESULTS

Before the intervention, the prevalence of scabies was 61% and 62% in intervention and control madrasahs, respectively (P = 1.00). After mass scabies treatment in all eight madrasahs and 4 months of intervention, the prevalence of scabies was reduced to 5% and 50% in intervention and control madrasahs, respectively (P < 0.001). There were significant improvements in all five personal hygiene practices at the intervention madrasahs. Mean test scores for scabies knowledge were 40% before the intervention and 99% after the intervention in the four intervention madrasahs. The cost of this programme was US$1.60 per student, and primarily included products such as plastic bags and clothes hangers, and health education material.

CONCLUSIONS

This programme demonstrates a pragmatic and cost-effective way to control scabies in a residential institutional setting. It is recommended that this programme should be scaled up to all residential madrasahs in Bangladesh.

Prevalence of pediculosis capitis in children from a rural school in Yucatan, Mexico

We conducted an analytical cross-sectional survey to estimate the prevalence of and factors associated with active head lice infestation. In total 140 children, aged 6 to 16-years, from a public school in rural Yucatan, Mexico, were examined by wet-combing. A structured questionnaire was used to collect information on individuals and the conditions in the surrounding environment. Head lice infestation was found in 19 out of the 140 children tested (13.6%) and this was associated with both lower income (OR 9.9, 95% CI 2.15-45.79, p = 0.003) and a higher frequency of hair washing (OR 8, 95% CI 1.58-50, p = 0.012). Intersectoral control programs that take into account the socioeconomic differences of children should be implemented.

Canine and feline parasitic zoonoses in China

Canine and feline parasitic zoonoses have not been given high priority in China, although the role of companion animals as reservoirs for zoonotic parasitic diseases has been recognized worldwide. With an increasing number of dogs and cats under unregulated conditions in China, the canine and feline parasitic zoonoses are showing a trend towards being gradually uncontrolled. Currently, canine and feline parasitic zoonoses threaten human health, and cause death and serious diseases in China. This article comprehensively reviews the current status of major canine and feline parasitic zoonoses in mainland China, discusses the risks dogs and cats pose with regard to zoonotic transmission of canine and feline parasites, and proposes control strategies and measures.

Scabies in the developing world--its prevalence, complications, and management

Scabies remains one of the commonest of skin diseases seen in developing countries. Although its distribution is subject to a cycle of infection, with peaks and troughs of disease prevalence, this periodicity is often less obvious in poor communities. Scabies is a condition that affects families, particularly the most vulnerable; it also has the greatest impact on young children. Largely through the association with secondary bacterial infection caused by group A streptococci and Staphylococcus aureus, the burden of disease is compounded by nephritis, rheumatic fever and sepsis in developing countries. However, with a few notable exceptions, it remains largely neglected as an important public health problem. The purpose of this review is to provide an update on the current position of scabies with regard to its complications and control in resource-poor countries.

Acute morbidity associated with scabies and other ectoparasitoses rapidly improves after treatment with ivermectin

In resource-poor settings, scabies is associated with considerable morbidity. Which factors determine morbidity and how rapidly it recedes after specific treatment is not known. Patients with scabies were recruited in three urban slums in Fortaleza, Northeast Brazil. Diagnosis was established according to dermatoscopy, skin scraping, or adhesive film test. Severity of scabies-associated morbidity was assessed semiquantitatively. Patients and close contacts were treated with oral ivermectin (200 μg/kg, repeated after 7 days) and followed up for 2 weeks. Ninety-five patients were included in the study. Papules were the most common lesion type (98.9%). Excoriations due to scratching were observed in 43.2% and bacterial superinfection in 24.2%. Predilection sites were the arms (82.1%) and the abdomen (81.1%). At baseline, 36.3% of patients complained about intense or severe itching. Intense or severe itch decreased to 6.3% 2 weeks after treatment (p=0.02). Whereas 37.5% of the patients complained about intense or severe itch-related sleep disturbances at baseline, only 8.8% reported the symptom 2 weeks after treatment (p=0.35). At baseline, the degree of itching was correlated with the degree of sleep disturbance (ρ=0.64; p<0.001). One week after the first dose of ivermectin, the intensity of itching and of sleep disturbance decreased significantly (p<0.001). In patients living in resource-poor setting, scabies was associated with considerable morbidity. Treatment with ivermectin rapidly reconstituted health in almost all cases.

Prevalence of Pediculus humanus capitis infestation among kindergarten children in Bahía Blanca city, Argentina

The human head louse, Pediculus humanus capitis De Geer (Anoplura: Pediculidae), is a worldwide public health concern. This human obligate ectoparasite usually infests school age children. The aim of this work was to investigate the prevalence of head lice in kindergarten children from Bahia Blanca. In addition, the influence of risk factors for pediculosis infestation, such as gender, hair characteristics, and socioeconomic class, was studied in relation to the prevalence of this ectoparasite. From a total of 220 pupils examined (125 girls and 95 boys), 94 showed pediculosis. The overall prevalence of head lice infestation was 42.7 %. Pediculosis was more frequent in girls (53.6 %) than in boys (28.4 %) and in medium, long, and very long hairs. No differences were found between socioeconomic classes. This indicated that head lice are relatively common in kindergarten children from Bahía Blanca.

Impaired quality of life in adults and children with scabies from an impoverished community in Brazil

BACKGROUND

Scabies is highly prevalent in resource-poor communities in developing countries and is associated with considerable morbidity in this setting. How the parasitic skin disease impairs the quality of life of patients has rarely been investigated.

METHODOLOGY

A modified Dermatology Life Quality Index (mDLQI) was developed to assess the quality of life in adults and children with scabies living in an urban slum in Fortaleza, capital of Ceará State, Brazil. A total of 105 patients with scabies (58 children and 57 adults) were included in the study. The diagnosis was made by dermatoscopy, skin scraping, and adhesive film test.

RESULTS

Feelings of shame was the restriction most frequently noted (adults 77.2% and children 46.6%). Other types of quality of life impairment were the need to dress differently (35.1 vs. 29.3%), restriction on leisure activities (24.6 vs. 36.8%), social exclusion (24.6 vs. 17.9%), stigmatization (21.1 vs. 25.0%), teasing (only children: 26.3%), and problems with sexual partners (only adults: 10.9%). Women and girls perceived more restrictions than men and boys. mDLQI scores indicated that 13.9% of the patients noticed a large or very large effect on their life, 65.2% considered their quality of life lightly or moderately reduced by scabies, and 20.9% did not feel any restrictions. The degree of impairment increased parallel to the degree of itching and severity of scabies (P=0.003).

LIMITATIONS

Owing to active case finding, most of the patients were in an early phase of scabies, and clinical pathology was not very pronounced.

CONCLUSION

Scabies considerably impaired the quality of life in adults and children living in poverty in an urban slum. Females particularly suffered from restrictions.

Risk factors for delayed diagnosis of scabies in hospitalized patients from long-term care facilities

Background

Delayed diagnosis of scabies can cause an institutional outbreak, which causes considerably economic burden to control. This study was to find the risk factors for delayed diagnosis of scabies in hospitalized patients from long-term care facilities.

Methods

We conducted a retrospective analysis of the hospitalized patients from long-term care facilities, diagnosed to have scabies between January 2006 and December 2008. A stepwise logistic regression analysis was performed to determine the risk factors for delayed diagnosis of scabies.

Results

A total of 706 episodes with scabies were identified retrospectively in 399 hospitalized patients from long-term care facilities. Of these, 44 episodes were considered as delayed diagnosis of scabies. These patients were more associated with chronic usage of steroid (73% vs. 10%, P < 0.001) and had longer duration of hospitalization than the others (30 vs. 13 days, P < 0.001). After logistic regression, steroid therapy was the risk factor of delayed diagnosis of scabies (odds ratio: 23.493).

Conclusions

In the patients from long-term care facilities, clinical physicians should pay more attention to those with chronic usage of steroid to avoid delayed diagnosis of scabies.

Keywords

Scabies; Delayed diagnosis; Risk factor; Long-term care facility

Parental attitudes towards head lice infestation in Greece

BACKGROUND

Pediculosis capitis constitutes a growing problem worldwide and is usually considered as an inconvenience. Parents often handle this infestation on their own initiative.

OBJECTIVE

We conducted a survey in order to depict the parental attitudes towards head lice infestation in Greece.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Epidemiology of scabies prevalence in the U.K. from general practice records

BACKGROUND

Scabies is a contagious parasitic infestation which causes an allergic reaction to just a few mites.

OBJECTIVES

To examine the epidemiology of scabies consultations in the U.K. by age, sex, region of the country and time.

METHODS

Data were obtained from the THIN (The Health Information Network) database provided by EPIC U.K. in which each consultation episode is coded according to a 'READ' code. Data were available for 1997-2005 inclusive (9 years) for approximately 8·5% of the U.K. population from 12 regions of the U.K. We used harmonic analysis to model the data over time and derived cycle amplitudes and phases for each region in the U.K.

RESULTS

There was a significantly greater infestation rate among females with a relative risk of 1·24 (P < 0·001) relative to males. The age group 10-19 years had the highest infestation rates (with rates of 4·55 per 1000 and 5·92 per 1000 for males and females, respectively). The middle age groups had the smallest infestation rates. A cycle with length of between 15 and 17 years was derived, and the phase times of the cycles for each region suggested a progression of the disease originating from the North East, spreading to Northern parts of the U.K. and then to the Midlands and the South.

CONCLUSIONS

The study confirms earlier studies with regard to the age/sex distribution of scabies. We suggest a contagious pattern of spread of scabies infestation in the U.K. with an epidemic cycle length of 15-17 years.

Sarcoptes-World Molecular Network (Sarcoptes-WMN): integrating research on scabies

Parasites threaten human and animal health globally. It is estimated that more than 60% of people on planet Earth carry at least one parasite, many of them several different species. Unfortunately, parasite studies suffer from duplications and inconsistencies between different investigator groups. Hence, groups need to collaborate in an integrated manner in areas including parasite control, improved therapy strategies, diagnostic and surveillance tools, and public awareness. Parasite studies will be better served if there is coordinated management of field data and samples across multidisciplinary approach plans, among academic and non-academic organizations worldwide. In this paper we report the first 'Living organism-World Molecular Network', with the cooperation of 167 parasitologists from 88 countries on all continents. This integrative approach, the 'Sarcoptes-World Molecular Network', seeks to harmonize Sarcoptes epidemiology, diagnosis, treatment, and molecular studies from all over the world, with the aim of decreasing mite infestations in humans and animals.

Prevalence of head lice and hygiene practices among women over twelve years of age in Sindh, Balochistan, and North West Frontier Province: National Health Survey of Pakistan, 1990-1994

BACKGROUND

Head lice infestation is an infection of the scalp and skin which causes blood loss, discomfort, and social and psychological distress with the possibility of secondary bacterial infections occurring at scratch sites. In Pakistan, although some small scale studies have been conducted to investigate prevalence of head lice in school children and the general population, no population based estimates have been reported. The National Health Survey of Pakistan (NHSP 1990 - 94) was a nationally representative health examination survey of the Pakistani population. The NHSP is the first population based household survey to collect data on the prevalence of head lice in adult women in Pakistan. In this paper we use data from the NHSP to present an epidemiological profile of personal hygiene practices and head lice infestation among women aged 12 years or older in three provinces of Pakistan; Balochistan, Sindh and North West Frontier Province (NWFP).

RESULTS

Overall about 7% women aged 12 years and older suffered from head lice infestation. Multivariable logistic regression analysis identified factors independently associated with presence of head lice. Age less than 16 years and crowding at home were associated with higher infestation-rates. The impact of household socio-economic status on infestation rates among women was different in urban and rural settings; urban women with low socio-economic status were more vulnerable than similar women in rural settings. Bathing infrequently in summer was associated with higher prevalence rates only in Sindh, possibly due to the fact that among the three provinces Sindh has a hotter and more humid summer.

CONCLUSIONS

The results of our analysis of NHSP indicate high levels of head lice infestation among girls and women in the three Provinces. The epidemiological profile of hygienic practices of women indicated that NWFP and Balochistan as compared to Sindh, and rural as compared to urban areas were less developed with respect to access to water supply and soap for maintaining personal hygiene. Simple and cost-effective measures such as provision of water and soap, and improving awareness regarding maintaining personal hygiene can contribute significantly towards improving public health status of the women in Pakistan.

Arthropod-borne diseases associated with political and social disorder

The living conditions and the crowded situations of the homeless, war refugees, or victims of a natural disaster provide ideal conditions for the spread of lice, fleas, ticks, flies and mites. The consequence of arthropod infestation in these situations is underestimated. Along with louse-borne infections such as typhus, trench fever, and relapsing fever, the relationship between Acinetobacter spp.-infected lice and bacteremia in the homeless is not clear. Murine typhus, tungiasis, and myiasis are likely underestimated, and there has been a reemergence of bed bugs. Attempted eradication of the body louse, despite specific measures, has been disappointing, and infections with Bartonella quintana continue to be reported. The efficacy of ivermectin in eradicating the human body louse, although the effect is not sustained, might provide new therapeutic approaches. Arthropod-borne diseases continue to emerge within the deprived population. Public health programs should be engaged rapidly to control these pests and reduce the incidence of these transmissible diseases.

Efficacy of chemical and botanical over-the-counter pediculicides available in Brazil, and off-label treatments, against head lice ex vivo

BACKGROUND

There is a lack of reliable data on the efficacy of over-the-counter (OTC) pediculicides in Brazil.

METHODS

We performed ex vivo assays of eight marketed pediculicides: 1% permethrin (Kwell, Clean Hair, Keltrina, Nedax), 0.02% deltamethrin (Deltacid, Pediderm), and two "natural" products (Piolho e Lêndea, Pilogenio). We also tested 5% permethrin (Keltrina Plus), traditional home remedies and an ivermectin-based product used in veterinary medicine. Head lice (49-52 per group) were immersed in the compound for 3 min and washed after 20 min to simulate the typical in vivo treatment protocol. Lice were examined for activity up to 24 h using stringent criteria for survival.

RESULTS

Of the permethrin containing products, highest mortality was observed with Kwell and Clean Hair (97.9 and 90.2% after 4 h). Keltrina, Nedax, Keltrina Plus, and the two deltamethrin-based products showed only a low efficacy of <60% after 4 h. With exception of pure coconut oil (80% mortality after 4 h), home remedies showed a very low efficacy, and both marketed products killed few lice. The ivermectin-based product caused a mortality of 100% after 4 h.

CONCLUSIONS

Most Brazilian OTC products did not show a satisfactory efficacy against head lice. Resistance may be present. Ivermectin and coconut oil are promising compounds for topical treatment. Laboratory-based tests should be used to assess resistance patterns and to identify formulations of the active ingredient that increase the efficacy. Standardized testing should be performed before a product is licensed for head lice treatment.

Head lice

Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2002 clinical report on head lice was published by the American Academy of Pediatrics, patterns of resistance to products available over-the-counter and by prescription have changed, and additional mechanical means of removing head lice have been explored. 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.

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

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 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.

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 time, control measures should include the treatment of all household contacts. Mass treatment with ivermectin may reduce the incidence of head lice infestation and associated morbidity in resource-poor communities.

A new two-phase dimeticone pediculicide shows high efficacy in a comparative bioassay

BACKGROUND

Dimeticones kill head lice by physical means. Here we assessed in a comparative bioassay the ex vivo efficacy of "NYDA sensitiv", a new two-phase dimeticone-based pediculicide similar to a product established on the market, but without fragrances.

METHODS

We compared efficacy of the new product to a positive dimeticone control group, a sample of four other insecticidal and natural head lice products marketed in Germany, and an untreated control. In a bioassay, lice were exposed ex vivo to products and examined for activity for up to 24 hours, following a standard protocol.

RESULTS

After 6 and 24 hours, 13.7 and 88.5% of untreated control lice did not show major vital signs. In contrast, no lice showed major vital signs 5 minutes after treatment with the new product or the control dimeticone group (NYDA). This effect persisted at all observation points (100% efficacy). Efficacy of 0.5% permethrin (Infectopedicul) ranged between 76 and 96% in evaluations between 5 min and 6 hours. All lice treated with a coconut-based compound (mosquito Läuseshampoo) did not show major vital signs after 5 min, but mortality was only 58% after one hour. Pyrethrum extract (Goldgeist forte) showed an efficacy of 22 - 52% between 5 min and 3 hours after treatment; after 6 hours, 76% of lice were judged dead. An oxyphthirine-based compound (Liberalice DUO LP-PRO) killed 22 - 54% of lice in the first 6 hours.

CONCLUSIONS

The two-phase dimeticone compound NYDA sensitiv is highly efficacious. The removal of fragrances as compared to an established dimeticone product did not affect in vitro efficacy.

Epidermal parasitic skin diseases: a neglected category of poverty-associated plagues

Epidermal parasitic skin diseases (EPSD) are a heterogeneous category of infectious diseases in which parasite-host interactions are confined to the upper layer of the skin. The six major EPSD are scabies, pediculosis (capitis, corporis and pubis), tungiasis and hookworm-related cutaneous larva migrans. We summarize the current knowledge on EPSD and show that these diseases are widespread, polyparasitism is common, and significant primary and secondary morbidity occurs. We show that poverty favours the presence of animal reservoirs, ensures ongoing transmission, facilitates atypical methods of spreading infectious agents and increases the chances of exposure. This results in an extraordinarily high prevalence and intensity of infestation of EPSD in resource-poor populations. Stigma, lack of access to health care and deficient behaviour in seeking health care are the reasons why EPSD frequently progress untreated and why in resource-poor populations severe morbidity is common. The ongoing uncontrolled urbanization in many developing countries makes it likely that EPSD will remain the overriding parasitic diseases for people living in extreme poverty. We advocate integrating control of EPSD into intervention measures directed against other neglected diseases such as filariasis and intestinal helminthiases.

Epidemiology of Pediculosis capitis in elementary schools of Buenos Aires, Argentina

The infestation with the human obligate ectoparasite Pediculus humanus capitis De Geer is a common public health problem affecting mainly schoolchildren worldwide. The aim of the present study was to investigate the infestation levels of head lice in elementary schools from Buenos Aires with resistant levels to permethrin >100. A total of 1,856 children aged 3-13 years old from eight selected elementary schools were examined for head lice. Pediculosis was observed in all the studied schools. The overall infestation rate was 29.7%. Girls were statistically significant more infested than boys, with infestation rate values of 36.1% and 26.7%, respectively (P < 0.0001). Only 42 of the infested girls (12%) and 23 of the infested boys (11.4%) had >10 lice on their hair. The proportions of infested children-both girls and boys-in each age group were not found to differ significantly from one another. The infestation rate among schools varied from 19.12% to 42.74%. This indicated that pediculosis is relatively common in elementary schools from Buenos Aires, and those levels are of epidemic importance. The differences of pediculosis among the studied schools could be explained by the different control strategies applied by parents or advisors to eradicate head lice.

The epidemiology of scabies in an impoverished community in rural Brazil: presence and severity of disease are associated with poor living conditions and illiteracy

BACKGROUND

We sought to study the epidemiology of scabies and to identify risk factors of severe disease in an impoverished rural community in northeast Brazil.

METHODS

The study was designed as a repeated cross-sectional study based on two door-to-door surveys. One survey was carried out in the rainy season, the other in the dry season. The inhabitants of the community were examined for the presence of scabies and demographic, socioeconomic, and behavioral risk factors were assessed. Risk factors were analyzed using bivariate and multivariate regression analysis.

RESULTS

The overall prevalence was 9.8% with no significant variation between seasons and the incidence was estimated to be 196/1000 person-years. The highest prevalence (18.2%) was observed in children younger than 4 years. Risk factors in the bivariate analysis were young age, presence of many children in the household, illiteracy, low family income, poor housing, sharing clothes and towels, and irregular use of shower. Age younger than 15 years, illiteracy, sharing of clothes, and living in the community for more than 6 months remained significant independent risk factors in multivariate regression analysis.

LIMITATIONS

We used a clinical case definition; specificity and sensitivity were not verified. Men were underrepresented in the study population.

CONCLUSIONS

In this impoverished community scabies is an important health problem characterized by continuous transmission throughout the year. The parasitic skin disease is embedded in a complex web of causation characterized by poor living conditions and a low level of education.

Seasonal fluctuations of head lice infestation in Germany

Pediculosis capitis is one of the most frequent infectious diseases in childhood. If not diagnosed and treated rapidly, considerable clinical pathology may develop. The ubiquitous parasitic skin disease is characterized by a lack of sound epidemiological data, and factors which influence disease occurrence are still enigmatic. To investigate whether, in Germany, head lice infestation follows a seasonal pattern, we analyzed the weekly head lice consultations at the Health Department of Braunschweig City, Lower Saxony, for a period of 5 years, and compared the data with the units of pediculocides sold by two wholesalers to German pharmacies during a period of 2 and 3 years, respectively. The number of consultations did not show a clear seasonality, although there was a tendency of fewer consultations during school holidays, and an increase when schools opened again after Christmas, Easter, summer, and autumn holidays. In contrast, the number of packages of pediculocides sold followed a distinct seasonal rhythm with a maximum between calendar week 34 and 40, i.e., from mid September to end of October. In Germany, occurrence of pediculosis capitis varies according to the season of the year with a maximum in late summer and early autumn.

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

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.

Self-diagnosis of active head lice infestation by individuals from an impoverished community: high sensitivity and specificity

To compare sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of self-diagnosis for head lice infestation with visual inspection, we conducted a study in an urban slum in Brazil. Individuals were asked about active head lice infestation (self-diagnosis); we performed visual inspection and thereafter wet combing (gold standard). Of the 175 individuals included, 77 (44%) had an active head lice infestation. For self-diagnosis, sensitivity (80.5%), specificity (91.8%), PPV (88.6%) and NPV (85.7%) were high. Sensitivity of visual inspection was 35.1%. Public health professionals can use self-diagnosis as a diagnostic tool, to estimate accurately prevalence of pediculosis in a community, and to monitor ongoing intervention strategies.

Escabiose na cabeça e pescoço: nós a estamos reconhecendo?

Apesar de o acometimento de cabeça e pescoço de crianças mais velhas e adultos na escabiose ser conhecido, a literatura é pobre em sua descrição. Estudados 124 pacientes com escabiose clássica com cinco anos de idade ou mais, para pesquisa, descrição e registro fotográfico das lesões de cabeça e pescoço. Esses locais foram acometidos em 35,8% dos casos, e as lesões mais encontradas foram crostas hemáticas, pápulas eritematosas com e sem escoriações ou crostas sobrepostas e descamação adjacente.

Infection in the elderly

Many functional, demographic, and immunologic changes associated with aging are responsible for increasing the incidence and severity of infectious diseases in the elderly. Management is complicated by age-related organ system changes. Because many of the elderly are on multiple medications for underlying illnesses, antimicrobial therapy needs to be chosen keeping drug interactions and adverse events in mind. Common infections seen in the elderly are infections of skin and soft tissue, urinary tract, respiratory tract, and gastrointestinal tract. Organized and well-funded programs to address infectious disease issues in the elderly are the only way to improve care.

Slum health: from understanding to action

The defining physical and legal characteristics of slums profoundly affect the health of these communities and may also serve as potential targets for immediate intervention.

Skin disease is common in rural Nepal: results of a point prevalence study

BACKGROUND

Skin problems are the commonest reason for people accessing healthcare services in Nepal but there is little information about the prevalence of skin disease.

OBJECTIVES

To perform a point prevalence study of skin disease in the Terai region of Nepal.

METHODS

Five villages were randomly selected in Bara District in the Terai region of Nepal, and 878 people were examined.

RESULTS

The number of individuals identified as having a skin disease was 546. The point prevalence of identifiable skin abnormalities was 62.2% (546 of 878) (with 95% exact confidence intervals 58.9-65.4%). A wide range of dermatoses was identified. The six most prevalent were dermatophyte infections (11.4%), followed by pityriasis versicolor (8.9%), acne (7.7%), melasma (6.8%), eczema (5.6%) and pityriasis alba (5.2%). Overall, treatable skin infections and infestations were by far the commonest skin diseases identified.

CONCLUSIONS

Our study has demonstrated a very high point prevalence (62.2%) of skin disease in rural Nepal. This study represents the first formal survey of skin disease in Nepal and demonstrates a large burden of disease, in particular treatable infections.

[Tungiasis: a neglected disease causing severe morbidity in a shantytown in Fortaleza, State of Ceará]

The parasitic skin disease tungiasis, caused by the jigger flea Tunga penetrans, is endemic in low-income communities in Brazil. In this study, inhabitants of a shantytown in Fortaleza, northeastern Brazil, who had an elevated parasite load, were identified. The number of lesions, localization, staging and associated diseases were recorded. The 142 individuals identified were living in extremely precarious housing conditions. A total of 3,445 lesions located on the feet were counted (median = 17 lesions; maximum = 98 lesions). Almost without exception, the individuals had nail deformation and edema, and more than 70% presented with pain and fissures. There was nail loss in 46%; deformation of the digits in 25%; abscesses in 42%; and complaints of walking difficulty in 59%. Our data show that tungiasis in this low-income urban community typical of northeastern Brazil was associated with severe morbidity. Tungiasis needs to be recognized as a public health problem in this study area and other similar endemic areas.

Clinical features and associated morbidity of scabies in a rural community in Alagoas, Brazil

OBJECTIVE

To describe the clinical characteristics of scabies and the associated morbidity in an impoverished rural community in northeast Brazil.

METHOD

A door-to-door survey was made to examine twice the population of an endemic area; first at the end of the rainy season, and a second time in the dry season 4 months later.

RESULTS

In total, 2005 individuals were examined. The overall prevalence of scabies was 9.8% (95% CI 8.5-11.2). Predilection sites with similar relative frequencies in all age groups were the abdomen (83.7%) and the inguinal area/inner part of the thighs (66.3%). Hands, feet, genitals and the scalp/neck/face were significantly more often affected in children <7 years (all P < 0.03). Fifty-five per cent of the patients showed scabies lesions simultaneously at > or = 12 distinct topographic areas. Papular lesions were most commonly found, followed by papular-crusted lesions. Vesicles were significantly more often observed in children (P = 0.04). Sixty-four per cent of the patients had three or more types of lesions. Local lymphadenopathy was present in 53.6% and superinfection in 36.7% of the cases. The number of topographic areas affected, as well as the proportion of superinfected lesions, was inversely correlated with age (rho = -0.22, P = 0.002 and rho = -0.358, P < 0.05, respectively). The quantity of skin surface infested, the proportion of superinfected lesions and the presence of a superinfected lesion distal to an enlarged lymphnode were predictors of lymphadenopathy. Seventy-two per cent of the patients suffered from sleep disorders, mainly because of itching.

CONCLUSION

Scabies is associated with considerable morbidity in this endemic community. Predilection sites, clinical presentation, quantity of skin surface affected and proportion of secondary infected lesions show a dichotomy between children and adults.

Nosocomial scabies

Scabies is a parasitic dermatosis with a worldwide distribution. This infestation affects millions of people annually and may cause large nosocomial outbreaks with considerable morbidity among patients and healthcare workers. Immunocompromised or elderly institutionalized patients admitted with unrecognized crusted scabies are the main source of nosocomial transmission. Factors that facilitate the development of hospital-acquired scabies and nosocomial epidemics are: poor knowledge of scabies epidemiology, unfamiliarity of healthcare workers with atypical presentations, long incubation period, diagnostic delay and incomplete monitoring. Within hospitals, containment of an outbreak relies on the strict implementation of appropriate infection control measures and treatment administration to contacts. It is associated with a considerable working and economic burden.

Morbidity assessment in sand flea disease (tungiasis)

Tungiasis, caused by the sand flea Tunga penetrans, is a health problem in many impoverished communities in Latin America, the Caribbean, and sub-Saharan Africa. Sand flea disease is associated with a broad spectrum of clinical and histological pathology. The factors determining the disease burden in endemic communities are not well understood, and severity of clinical pathology has never been assessed quantitatively. Thus, two severity scores were developed: one for acute disease and one for chronic sequels. These scores were evaluated in a cohort of 70 severely infested patients living in a shantytown in Fortaleza, a capital city in Northeast Brazil. Patients were examined during a period of 25 days and followed-up after a twice daily application of a plant-based repellent to prevent reinfestation. The severity score for acute disease symptoms significantly correlated with the infestation rate and the number of embedded fleas. It turned zero when reinfestation was prevented. The score for chronic disease also significantly correlated with the infestation rate. Tungiasis is associated with considerable acute and chronic morbidity. The degree of acute morbidity is directly related to the number of embedded sand fleas. When transmission is interrupted, the chronic morbidity reflects the infestation rates individuals have experienced in the past.

Scabies

Scabies is a neglected parasitic disease that is a major public health problem in many resource-poor regions. It causes substantial morbidity from secondary infections and post-infective complications such as acute post-streptococcal glomerulonephritis. Disease control requires treatment of the affected individual and all people they have been in contact with, but is often hampered by inappropriate or delayed diagnosis, poor treatment compliance, and improper use of topical compounds such as permethrin, lindane, or benzyl benzoate. In addition to concerns over toxicity with such compounds, parasite resistance seems to be increasing. Oral ivermectin is an alternative that has been used successfully in community control programmes. Plant derivatives such as turmeric, neem, and tea tree oil are also promising future treatments. The disease is strongly associated with poverty and overcrowding, and the associated stigma can ostracise affected individuals. Treatment of scabies in poor countries needs to integrate drug treatment programmes with efforts to improve the socioeconomic conditions and education programmes to reduce stigma. We expect the future to bring more sensitive and specific clinical and laboratory-based diagnostic methods, as well as new therapeutic strategies.