Avaliação de novas abordagens para controle e diagnóstico da leishmaniose visceral no Brasil

Abstract

Visceral leishmaniasis is a serious and chronic disease with a geographic spread in Brazil due to the absence of a treatment that eliminates the parasite, ineffective control measures, and diagnostic methods with low accuracy. The study aimed to evaluate the systemic insecticidal activity of a single oral dose of fluralaner against Lutzomyia longipalpis, as well as evaluate the mid-infrared as an alternative for Leishmania infantum detection in canine serum samples. Mongrel dogs were recruited and randomized into two groups, fluralaner (n = 4) and control (n = 4), and female specimens of Lu. longipalpis were allowed to feed on all dogs before treatment, on day one post-treatment, and then monthly until 1-year post-treatment. In addition, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) combined with multivariate analysis was employed to distinguish samples from dogs infected with L. infantum in different clinical forms (n = 29) from healthy animals (n = 30). After data analysis, there was 100% mortality of Lu. longipalpis for up to five months after treatment initiation. The efficacy of fluralaner ranged from 100% on day 1 to 68% at six months with a decrease to 1.4% at one-year post-treatment. ATR-FTIR was efficient in differentiating samples from infected and uninfected dogs with 100% sensitivity and specificity using the successive projections algorithm with linear discriminant analysis (SPA-LDA), SPA with support vector machine (SPA-SVM), and the genetic algorithm with LDA (GA-LDA). These satisfactory results suggest that fluralaner may be used as a control strategy for VL in endemic areas, as well as spectroscopy associated with multivariate analysis demonstrates its potential as an alternative tool for the VL diagnosis in dogs.