Focal persistence of soil-transmitted helminthiases in impoverished areas in the State of Piaui, Northeastern Brazil.

This study aims to describe the prevalence, distribution, and factors associated with soil-transmitted helminthiases (STHs) in rural localities in Piaui, Brazil. Two cross-sectional surveys (n=605 subjects; 172 families) were carried out in order to obtain socio-demographic, anthropometric, spatial and parasitological data. Parasites were evaluated using Kato-Katz and centrifugal sedimentation techniques. Eggs were measured to assess infection with zoonotic Strongylida parasites. Kernel maps were constructed with Q-GIS. The prevalence of hookworm infection was 12.4% (75/605). Other helminthes found were Trichuris trichiura (n=1; 0.2%) and Hymenolepis nana (n=1; 0.2%). The hookworm positivity rate was significantly lower among subjects who had used albendazole when compared with individuals who had not used anthelmintics or had used antiprotozoal drugs in the last 6 months (8/134 [6.0%] vs. 59/415 [14.2%]; p=0.009). A total of 39/172 (22.7%) families had at least one infected member. The association between the number of dwellers and hookworm positivity in the family was present in a logistic regression multivariate model. Assessment of worm burdens showed 92.2% light, 6.2% moderate, and 1.6% heavy infections. Hookworm eggs (n=34) measured 57.2 - 75.4 µm in length and 36.4 - 44.2 µm in width (mean ± SD = 65.86 ± 4.66 µm L and 40.05 ± 1.99 µm W), commensurate with human hookworms. Hotspots suggest that transmission has a focal pattern. STHs persist in impoverished rural areas in Northeastern Brazil where currently available control strategies (mass drug administration) apparently do not allow the elimination of the infection.

An entomoepidemiological investigation of Chagas disease in the state of Ceará, Northeast Region of Brazil.

The seroprevalence of Chagas disease in humans and the presence of triatomines were investigated in a rural locality in the State of Ceará, Brazil, an historically endemic region. Approximately 80% of the surveyed residents agreed to undergo serological tests. Intradomestic and peridomestic environments were searched for triatomines in both the dry and rainy seasons. The prevalence rate of Chagas disease was 1.2% and the majority of individuals confirmed with the disease over 50 years of age. A total of 761 specimens of triatomines were captured, most of which were from colonies composed of nymphs and adult bugs, and the majority of specimens were obtained in the dry season. Triatoma brasiliensis was the predominant species. Analysis using light microscopy revealed that 28.6% of the insects were Trypanosoma cruzi positive. Results suggest that peridomestic man-made structures, such as animal shelters, improper storage of timber and uninhabited dwellings contribute to the high rate of triatomine infestation in the area.

An entomoepidemiological investigation of Chagas disease in the state of Ceará, Northeast Region of Brazil / Investigação entomoepidemiológica da doença de Chagas no Estado do Ceará, Nordeste do Brasil / Investigación entomoepidemiológica de la enfermedad de Chagas en el estado de Ceará, noreste de Brasil

The seroprevalence of Chagas disease in humans and the presence of triatomines were investigated in a rural locality in the State of Ceará, Brazil, an historically endemic region. Approximately 80% of the surveyed residents agreed to undergo serological tests. Intradomestic and peridomestic environments were searched for triatomines in both the dry and rainy seasons. The prevalence rate of Chagas disease was 1.2% and the majority of individuals confirmed with the disease over 50 years of age. A total of 761 specimens of triatomines were captured, most of which were from colonies composed of nymphs and adult bugs, and the majority of specimens were obtained in the dry season. Triatoma brasiliensis was the predominant species. Analysis using light microscopy revealed that 28.6% of the insects were Trypanosoma cruzi positive. Results suggest that peridomestic man-made structures, such as animal shelters, improper storage of timber and uninhabited dwellings contribute to the high rate of triatomine infestation in the area.

A presença de triatomíneos e a soroprevalência da infecção chagásica humana foram investigadas em uma localidade rural do Estado do Ceará, Brasil, região endêmica histórica da doença de Chagas. Os triatomíneos foram pesquisados nos domicílios, nos períodos de seca e de chuva. A soroprevalência encontrada no período foi de 1,2%, maior entre pessoas com mais de 50 anos de idade, e sem diferença significativa em relação ao sexo. Foram capturados 761 espécimes de triatomíneos, em colônias compostas de ninfas e insetos adultos, com predominância de Triatoma brasiliensis, especialmente no período de seca. O exame do conteúdo intestinal dos insetos revelou que 28,6% eram Trypanosoma cruzi positivos. Os resultados sugerem que os abrigos de animais e armazenamento inadequado de materiais no peridomicílio, particularmente amontoados de madeiras, bem como moradias desabitadas, contribuem para o alto índice de infestação de triatomíneos na localidade.

Se investigó la presencia de insectos y seroprevalencia en la infección humana por Trypanosoma cruzi, en un área rural del estado de Ceará, Brasil, región endémica histórica de la enfermedad Chagas. Se informó sobre la presencia de insectos en los hogares durante los períodos de sequía y lluvia. La seroprevalencia en el período fue un 1,2%, mayor entre las personas de más de 50 años de edad, y no hubo diferencias significativas en relación al sexo. Se capturaron 761 ejemplares de insectos en colonias compuestas por ninfas y adultos de insectos, principalmente, Triatoma brasiliensis, especialmente durante la estación seca. El examen del contenido intestinal de los insectos reveló que un 28,6% eran T. cruzi positivo. Los resultados sugieren que los refugios de animales y el almacenamiento inadecuado de materiales fuera del hogar, especialmente pilas de madera y casas deshabitadas, contribuyen a la alta tasa de infestación de insectos en la localidad.