Abstract INTRODUCTION The control of
reservoirs for
Leishmania infantum -induced zoonotic
visceral leishmaniasis requires the identification of
dogs posing a
population risk. Here, we assessed the performance of several assays to identify
Lutzomyia longipalpis infectious
dogs.
METHODS We evaluated 99
dogs that were positive for
visceral leishmaniasis based on
parasite identification. Serological analyses were performed using an
enzyme-linked immunosorbent assay,
immunofluorescence antibody tests in 140 and 180 dilutions, rapid dual path platform tests,
immunochromatographic assay with a recombinant rK39
antigen, fast
agglutination screening tests, and direct
agglutination tests. We also performed
PCR to analyze peripheral
blood and
xenodiagnosis. RESULTS Forty-six
dogs infected at least one L. longipalpis specimen. Although the
serological test sensitivities were above 85% for detecting L. longipalpis infectious
dogs, none showed a satisfactory performance, as both
specificity (0.06 to 13%) and the area under the
receiver operating characteristic curve (45 to 53%) were low. The
PCR results were also weak, with a
sensitivity of 30%,
specificity of 72%, and an area under the
receiver operating characteristic curve of 51%. The infected L. longipalpis proportion was higher among asymptomatic
dogs than symptomatic
dogs. Among the symptomatic
dogs, those with ulceration-free
skin diseases were more infectious, with an
odds ratio of 9.3 (
confidence interval of 1.10 - 428.5). The larger the number of
insects fed, the greater the detected infectiousness. CONCLUSIONS Our study supports the imperative to develop novel
technologies for identifying the infectious
dogs that transmit L. infantum for the benefit of
public health.