ABSTRACT Chagas disease is an important endemic morbidity in Latin America affecting millions of people in the American continent. It is caused by the protozoan Trypanosoma cruzi, and transmitted through the feces of the insect vector belonging to the subfamily Triatominae. The present conducted an entomological survey of triatomines and analyzed entomological indicators, such as the rate of infestation, colonization, triatomine density and natural infection in rural communities in the municipality of Campinas do Piaui, Piaui State, in the Northeast region of Brazil. Data on the search of triatomines performed in 167 domiciliary units (DUs), harvested during the period of February to July 2019, in 12 rural communities were analyzed. The capture of triatomines occurred in all studied communities, being 76 the number of positive DUs, of the 167 surveyed, presenting a global rate of infestation of 45.51%. Two triatomines species were collected: Triatoma brasiliensis (98.49%) and T. pseudomaculata (1.51%), the first was found in the domiciliary and peridomiciliary areas, while the second was captured only in peridomiciliary areas. The index of colonization was 17.1%. Natural infection was observed only in 5.44% of T. brasiliensis samples. The entomological survey was conducted in rural communities, showingthe risk of transmission of Chagas disease to the local population, requiring continuous entomological surveillance and vector control.

Neste estudo foi detectada infecção por Leishmania spp. em Rhipicephalus sanguineus (R. sanguineus) de cães naturalmente infectados por Leishmania (Leishmania) infantum = L. (L.) infantum. Foram utilizados 35 cães de ambos os sexos e idades desconhecidas, sorologicamente positivos pelas técnicas de reação de imunofluorescência indireta (RIFI), enzyme-linked immunosorbent assay (ELISA) e Quick Test-DPP (Dual Path Plataform), e com exame parasitológico positivo em biópsia de pele ou punção de medula óssea esternal e 10 cães domiciliados negativos, como controle. Os carrapatos que infestavam esses cães foram coletados em pool de 10 fêmeas adultas por animal. A Reação em Cadeia pela Polimerase (PCR = Polymerase Chain Reaction) foi realizada com primers para Leishmania spp., que amplificaram 720pb. O resultado das 35 amostras processadas revelou a amplificação de oito amostras (8/35 - 22,9%). Conclui-se que a presença do DNA do parasita sugere que carrapatos podem estar participando do ciclo zoonótico da leishmaniose visceral canina na cidade de Teresina, Piauí.

In this study, we detected Leishmania spp. infection in R. sanguineus collected from dogs that were naturally infected with L. (L.) infantum. We examined 35 dogs of both sexes and unknown ages. The infected dogs were serologically positive by the immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), and Quick Test-DPP (Dual Path Platform), as well as parasitological examination of a positive skin biopsy or sternal bone marrow aspiration. Ten negative dogs were included as controls. The ticks that infested these dogs were collected in pools of 10 adult females per animal. The PCR was performed with specific primers for Leishmania spp., which amplified a 720-bp fragment. Of the 35 analyzed samples, a product was observed in eight samples (8/35; 22.9%). We conclude that the presence of parasite DNA suggests that ticks participate in the zoonotic cycle of canine visceral leishmaniasis, in the city of Teresina, Piauí.

Com o objetivo de investigar aspectos da infecção e morbidade da doença de Chagas no município de João Costa, Piauí, Brasil, realizamos pesquisa sorológica para detectar Ig G anti-T. cruzi em 2.080 moradores através dos testes de imunofluorescência indireta, hemaglutinação indireta e ELISA. Em seguida, 189 pacientes soropositivos e 141 soronegativos foram avaliados pelo exame clínico e eletrocardiograma (ECG), enquanto a parasitemia foi pesquisada em 106 chagásicos pelo xenodiagnóstico indireto e teste da reação polimerásica em cadeia (PCR). A soropositividade total para Ig G anti-T.cruzi foi de 9,8%, com variação de 0,5% em menores de 10 anos a 39,4% em maiores de 59 anos, independentemente do sexo. O percentual de ECG alterados foi de 41,3% entre os chagásicos e de 15,6% entre os não-chagásicos (p < 0,05). A positividade do teste da PCR foi de 74,5% e a do xenodiagnóstico de 15,1% (p < 0,05). Apesar da elevada prevalência da infecção na população investigada, o baixo valor nos menores de 10 anos pode ser indicador de redução da transmissão por triatomíneos. A alta proporção de participação do componente etiológico exclusivamente chagásico na prevalência da cardiopatia indica a gravidade da doença de Chagas na região estudada.

In order to investigate aspects of the infection and morbidity of Chagas' disease in the municipality of João Costa, Piauí State, Brazil, we carried out a serological survey to detect anti-Trypanosoma cruzi antibodies in 2,080 individuals, by indirect immunofluorescence, indirect hemagglutination and ELISA. A total of 189 seropositive and 141 seronegative patients were evaluated by anamnesis, physical exam and electrocardiogram (EKG). The parasitaemia of 106 chagasic patients was evaluated by indirect xenodiagnosis and PCR (polymerase chain reaction). The total seropositivity was 9.8%, with intervals of 0.5% in patients younger than 10 years old, and 39.4% among patients older than 59 years old, independently of the sex. The PCR and xenodiagnosis were positive, respectively in 74.5% and 15.1% of the seropositive patients (p < 0.05). The rate of abnormal EKG was 41.3% in chagasic and 15.6% in non-chagasic patients (p < 0.05). In spite of the high prevalence of infection in the investigated population, the low rate of seropositivity among children is indicative of a possible decrease of the active transmission mediated by triatomines. The high proportion of the chagasic component on the cardiopathy prevalence is indicative of the high morbidity of Chagas' disease in the studied region.