Estudio seroepidemiológico y entomológico sobre la enfermedad de Chagas en un área infestada por Triatoma maculata (Erichson 1848) en el centro-occidente de Venezuela An entomological and seroepidemiological study of Chagas' disease in an area in central-western Venezuela infested with Triatoma maculata (Erichson 1848)

En el presente trabajo se realizó un estudio seroepidemiológico, entomológico y de factores de riesgo para la infestación de las viviendas en un área infestada por Triatoma maculata (Parroquia Xaguas, Municipio Urdaneta, Estado Lara, Venezuela). Se muestrearon 140 viviendas, 509 personas y 110 cánidos, a los cuales se les determinó anticuerpos séricos anti-Trypanosoma cruzi mediante ELISA y MABA, utilizando antígenos recombinantes. La infección por Tr. cruzi de los triatominos fue determinada por microscopía óptica y PCR. Los resultados mostraron una seroprevalencia en humanos de 1,57% y en cánidos de 6,36%. De los 545 triatominos capturados 97,98% fueron T. maculata, 1,65% Eratyrus mucronatus y 0,37% Panstrongylus geniculatus; con índices vectoriales de infección 0,36%, infestación 16,4%, colonización 39,1%, coinfestación 8,6% y dispersión 100%. La presencia de vectores en el domicilio y peridomicilio estuvo asociada a la presencia de gallinas, desorden en el peridomicilio, caprinos, gallineros y/o distribución del domicilio. Los resultados permiten concluir que T. maculata es el vector predominante en la región, con capacidad de infestar y colonizar el domicilio y estaría involucrado en la transmisión de la enfermedad de Chagas.<br>This article presents a study on seroepidemiological, entomologic, and risk factors for domiciliary infestation in a circumscribed area infested with Triatoma maculata in Parroquia Xaguas, Urdaneta Municipality, Lara State, Venezuela. One hundred and forty households, 509 persons, and 110 dogs were sampled. Serum anti-Trypanosoma cruzi antibodies were determined by means of ELISA and MABA techniques using recombinant antigens. Tr. cruzi infection in the triatomines was determined by direct microscopy and PCR. According to the results, 1.57% of humans and 6.36% of dogs were positive for serum anti-Tr. cruzi antibodies. Triatomine species were: 97.98% T. maculata, 1.65% Eratyrus mucronatus, and 0.37% Panstrongylus geniculatus. Vector indices were: 0.36% vector infection, 16.4% household infestation, 39.1% household colonization, 8.6% household co-infestation, and 100% vector dispersion. Domiciliary and peridomiciliary infestation was associated with the presence of chickens and disorderly goat corrals, chicken coops, and domiciliary distribution. The results strongly suggest that T. maculata is the predominant Tr. cruzi vector in the area and that due to its capacity to infest and colonize human dwellings, it could be involved in Chagas' disease transmission

Epidemiologia da doença de Chagas em quatro localidades rurais de Jaguaruana, Estado do Ceará: soroprevalência da infecção, parasitemia e aspectos clínicos Epidemiology of Chagas disease in four rural localities in Jaguaruana, State of Ceará: seroprevalence of infection, parasitemia and clinical characteristics

Um estudo transversal sobre a doença de Chagas realizado com o exame da população de quatro localidades (nº= 541 habitantes) do município de Jaguaruana, estado do Ceará, mostrou: a soroprevalência da infecção chagásica em 3,1%, avaliada pelos testes de imunofluorescência indireta, hemaglutinação indireta e ELISA, maior entre as pessoas com mais de 50 anos e sem diferença em relação ao sexo; a parasitemia positiva em 11,8% (2/17) soropositivos, determinada pelo xenodiagnóstico indireto e em 75% (9/12) pela reação em cadeia da polimerase (p<0,05); a cardiopatia em 41% (7/17) dos soropositivos e em 11,8% (2/17) dos controles soronegativos (p< 0,05), avaliada por anamnese, exame físico e eletrocardiograma de repouso. A análise desses resultados mostrou que as prevalências da parasitemia positiva e da cardiopatia chagásica crônica são semelhantes às da Caatinga do Piauí e maiores do que no Sertão da Paraíba, apesar de historicamente, todas essas áreas apresentarem o Triatoma brasiliensis e o Triatoma pseudomaculata como principais responsáveis pela transmissão da infecção chagásica.<br>A cross-sectional study on Chagas disease that examined the populations of four localities (nº = 541 inhabitants) in the municipality of Jaguaruana, State of Ceará, showed seroprevalence of Chagas infection of 3.1%, as assessed by indirect immunofluorescence, indirect hemagglutination and ELISA tests. The rate was higher among adults over 50 years old, without any difference in relation to sex. Positive parasitemia was found in 11.8% (2/17) of the seropositive individuals by means of indirect xenodiagnosis and in 75% (9/12) by means of the polymerase chain reaction (p < 0.05). Cardiopathy was found by means of anamnesis, physical examination and resting electrocardiogram in 41% (7/17) of the seropositive individuals and in 11.8% (2/17) of the seronegative controls (p < 0.05). Analysis of these results showed that the prevalences of positive parasitemia and chronic Chagas cardiopathy were similar to those in the Caatinga area of Piauí and greater than in the Sertão area of Paraíba, although all these areas historically presented Triatoma brasiliensis and Triatoma pseudomaculata as the primary vectors responsible for Chagas infection transmission