A simple method for rapid community assessment of tungiasis.

OBJECTIVE: To evaluate a rapid assessment method to estimate the overall prevalence of tungiasis and severity of disease in endemic communities. METHODS: We analysed data from 10 population-based surveys on tungiasis, performed in five endemic communities in Brazil and Nigeria between 2001 and 2008. To assess the association between occurrence of tungiasis on six defined topographic areas of the feet and the true prevalence/prevalence of severe disease, linear regression analyses were performed. Estimated prevalences were calculated for each of the 10 surveys and compared to true prevalences. We then selected the most useful topographic localization to define a rapid assessment method, based on the strength of association and operational aspects. RESULTS: In total, 7121 individuals of the five communities were examined. Prevalence of tungiasis varied between 21.1% and 54.4%. The presence of periungual lesions on the toes was identified as the most useful rapid assessment to estimate the prevalence of tungiasis (absolute errors: -4% to +3.6%; R(2 )=96%; P < 0.0001). Prevalence of severe tungiasis (>20 lesions) was also estimated by the method (absolute errors: -3.1% to +2.5%; R(2 )=76%; P = 0.001). CONCLUSION: Prevalence of tungiasis and prevalence of severe disease can be reliably estimated in communities with distinct cultural and geographical characteristics, by applying a simple and rapid epidemiological method. This approach will help to detect high-risk communities and to monitor control measures aimed at the reduction of tungiasis.

Leukocytosis and blood eosinophilia in a polyparasitised population in north-eastern Brazil.

It has long been known that leukocytosis and blood eosinophilia are common in the tropical environment, but data derived from population-based studies are scarce. A study was undertaken in a fishing village in north-east Brazil where both intestinal helminthiases and parasitic skin diseases are common. Of 409 individuals studied, 128 (31.3%) were infected with one intestinal helminth or ectoparasite species, 93 (22.7%) with two, 61 (14.9%) with three, 25 (6.1%) with four and 11 (2.7%) with more than four species; no parasites were found in 91 (22.2%) individuals. Leukocyte counts ranged between 3,300 cells/microl and 16,100 cells/microl (median, 7,200 cells/microl) and eosinophil counts between 40 cells/microl and 5,460 cells/microl (median, 455 cells/microl). Eosinophilia (>500/microl) was detected in 44.7% of the individuals, and hypereosinophilia (>1,000/microl) in 12.9%. Thirty-six (8.8%) individuals showed leukocytosis. While 75% of individuals with normal eosinophil counts were considered parasite-free, only 14% with eosinophilia and 11% with hypereosinophilia did not have enteroparasites or ectoparasites. Multivariate regression showed that the probability of eosinophilia and hypereosinophilia, but not of leukocytosis, increased with the number of parasite species present. The data show that eosinophilia occurs in almost one-half of the individuals from a resource-poor setting and that it is significantly associated with the presence of intestinal helminths, but not with the presence of ectoparasites.

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

BACKGROUND: Pediculosis capitis and scabies are common parasitic skin diseases, especially in resource-poor communities, but data on epidemiology and morbidity are scanty. OBJECTIVES: To assess the prevalence, seasonal variation and morbidity of pediculosis capitis and scabies in poor neighbourhoods in north-east Brazil. METHODS: The study comprised cross-sectional surveys of a representative population of an urban slum (n = 1460) in Fortaleza, the capital of Ceará State (Brazil) and a fishing community 60 km south of the city (n = 605). Study participants were examined for the presence of scabies and pediculosis capitis. In a longitudinal study in the slum, variation of prevalence in different seasons of the year was assessed. RESULTS: Prevalence of pediculosis capitis was 43.4% in the slum and 28.1% in the fishing community. Children aged 10-14 years and females were most frequently affected. Scabies was present in 8.8% of the population in the slum and in 3.8% of the population in the fishing community. There was no consistent pattern of age distribution. Superinfection was common in patients with scabies, and cervical lymphadenopathy in patients with pediculosis capitis. Multivariate analysis showed that age < or = 15 years, being of female sex and living in the urban slum were independent factors contributing to the simultaneous coinfestation with pediculosis capitis and scabies. The longitudinal data from the urban slum showed a characteristic seasonal variation of pediculosis capitis, but no fluctuation of scabies. CONCLUSIONS: Pediculosis capitis and scabies are hyperendemic in the study areas and are associated with considerable morbidity. There is an urgent need to develop control measures for these parasitic skin diseases in resource-poor communities. This is the first community-based study describing in detail the epidemiology and morbidity of scabies and head lice infestation in Brazil.

The animal reservoir of Tunga penetrans in severely affected communities of north-east Brazil.

Tungiasis is a zoonotic ectoparasitosis caused by the sand flea Tunga penetrans L. (Siphonaptera: Tungidae). This disease is hyperendemic in poor communities of north-east Brazil, causing considerable morbidity in affected human populations, but the animal reservoirs have not been investigated previously in Brazil. To assess the prevalence and intensity of T. penetrans infection in domestic and peri-domestic animals, as well as in the human population, we surveyed two typical communities of north-east Brazil: an urban slum and a traditional fishing village. In the slum we examined 849 humans, 121 cats, 82 dogs, 2 pigs, 2 rabbits, 1 monkey and 56 rodents, comprising 34 rats (Rattus rattus L.) and 22 mice (Mus domesticus L). In the fishing village we examined 505 humans, 68 dogs, 37 cats, 7 donkeys, 4 cattle, 3 pigs and 1 monkey. Tungiasis was common among dogs and cats of both communities, with respective prevalence rates of 67.1% (95% CI: 55.8-77.1) and 30.9% (95% CI: 20.2-43.3) in dogs, 49.6% (95% CI: 40.4-58.8) and 32.4% (95% CI: 18.0-49.8) in cats. Slum rats were 41.2% (95% CI: 24.6-59.3) infested, but the other animals were not. Human prevalence rates were 54.4% (95% CI: 51.0-57.8) in the slum and 52.1% (95% CI: 47.6-56.5) in the fishing village. High prevalence rates (range 31-67%) of tungiasis in humans, pets and rats (but apparently not other animals) indicate the need for an eco-epidemiological approach to control of this anthropo-zoonotic problem.