Aspectos epidemiológicos da leishmaniose visceral canina na zona rural do semiárido paraibano e análise de técnicas de diagnóstico

Abstract

Visceral leishmaniasis is caused by Leishmania infantum in Brazil. It is a chronic diseaseand often a fatal zoonosis and considered as a serious worldwide public health problemand recognized by the World Health Organization as one of seventeen "NeglectedTropical Diseases". This study was conducted in 2012 in the county of Patos, in ParaíbaState semiarid region. The main purposes were to estimate the prevalence and the riskfactors of canine visceral leishmaniasis (CVL), and to evaluate the performance of serologicaltests. Serological prevalence was determined using three techniques (ELISA, IFAand DPP chromatographic immunoassay - Dual Path Platform). ELISA was the goldenstandard, since it is the confirmatory test for CVL as established by the Brazilian Ministryof Health. In total, 362 blood samples were collected and were considered positiveif positive by two serological assays. Positive samples were tested by PCR and qPCR. Anepidemiological questionnaire was applied to the dog owner to identify risk factors associatedwith CVL. The seroprevalence was 11.33% (41/362). Chromatographic immunoassay- DPP showed a sensitivity of 58% (95%, CI: 0.43 to 0.72) and specificity of 96%(95%, CI: 0.93-0.98) , with a Kappa index of 0.5. The IFA had a sensitivity of 85% (95%,CI: 0.72 to 0.94), specificity of 99% (95%, CI: 0.98 to 1) and Kappa value of 0.8. The riskfactor identified in the multivariate analysis was gender (OR=2.15 [1.09 to 4.21]), maledogs having 2.15 times more chance of being infected. The increased likelihood can possiblybe explained by the use of male dogs for hunting and as guard dogs, two factorsthat increase dog contact to infected sandflies. Due to the prevalence rates, it should berecommended control measures against canine visceral leishmaniasis. The results demonstratedthat the Chromatographic immunoassay (DPP-Dual Path Platform) is not thebest technique for screening positive animals due to its low sensitivity, suggesting itsreplacement by ELISA.