In-house serological ELISA as a leishmaniosis diagnostic test: development and applications in canines from the western border of Brazil

Leishmaniosis is a great public health problem affecting both humans and animals. The disease is caused by the protozoan Leishmania spp., which has a complex cycle involving a phlebotomine vector. The ELISA test (Enzyme-Linked Immunosorbent Assay) along with a chromatographic immunoassay was defined by the Brazil Health Ministry as the confirmatory screening protocol in 2011. Uruguaiana city is 630 km away from Porto Alegre, which makes it difficult to send samples and diagnose leishmaniasis, as well as receive quick results. In view of this, the present study evaluated an in-house indirect ELISA method compared to indirect immunofluorescence assay (IFA) and dual-path platform chromatographic immunoassay (DPP-BioManguinhos®) for the detection of an immune response to Leishmania spp. in canine species. The serological evaluation included 48 canines from the western border of Brazil (Uruguaiana and Barra do Quaraí city). Among the 48 canine samples tested, 18 were positive when using the ELISA technique, 19 were positive with IFA, and 17 were positive with rapid test DPP®. The ELISA technique showed a sensitivity/specificity of 83.3%/86.7% when compared to IFA and 100%/96.8% compared to DPP®. The present study showed a prevalence of 37.5%, demonstrating that the infection circulates in the studied population. It can be concluded that the ELISA technique was valuable for use in field conditions when performing screening tests in endemic areas. RESUMO: A leishmaniose é um grande problema de saúde pública que afeta tanto humanos quanto animais. A doença é causada pelo protozoário Leishmania spp., que possui um ciclo complexo envolvendo um vetor flebotomíneo. O teste ELISA (Enzyme-Linked Immunosorbent Assay), juntamente com um imunoensaio cromatográfico, foi definido pelo Ministério da Saúde do Brasil como protocolo de triagem confirmatória em 2011. A cidade de Uruguaiana fica a 630 km de Porto Alegre, o que dificulta o envio de amostras e o diagnóstico da leishmaniose, além da demora para obter os resultados. Diante disso, o presente estudo teve como objetivo avaliar um método de ELISA indireto in-house comparado ao ensaio de imunofluorescência indireta (IFA) e imunoensaio cromatográfico de plataforma de dupla via (DPP-BioManguinhos®) para a detecção de uma resposta imune contra Leishmania spp. na espécie canina. A avaliação sorológica incluiu 48 caninos da fronteira oeste do Brasil (cidade de Uruguaiana e Barra do Quaraí). Das 48 amostras caninas testadas, 18