Banca de QUALIFICAÇÃO: ROSEANE OLIVEIRA FEITOSA

Evaluation of biological samples in the serological and molecular diagnosis of dogs with natural infection by Leishmania Infantum from the city of Recife

 Canine leishmaniasis, conjunctival smear, tears, serology

Visceral leishmaniasis (VL) is caused by the protozoan Leishmania infantum and transmitted by the bite of infected female sand flies during a blood meal. Dogs are considered the main reservoir hosts in urban environments, due to their intimate relationship with humans and high skin parasitism. Although parasitological diagnosis is the gold standard, the use of molecular techniques has become increasingly relevant due to their high sensitivity and specificity. The study aimed to evaluate different biological samples in the serological and molecular diagnosis of dogs with natural infection by Leishmania Infantum from the city of Recife. The study used 14 domiciled dogs, residents of the city of Recife, adults, of both sexes, ages and different breeds, treated at the parasitic diseases clinic at the Federal Rural University of Pernambuco (UFRPE), with a positive parasitological diagnosis and without prior treatment. for Lcan. All dogs underwent blood collection for serological tests, DPP and RIFI, and conjunctival swab and tear collection for molecular diagnosis, using PCR. For the PCR results, the conjunctival swab detected a greater number of positive samples. Statistically, the conjunctival swab demonstrated better performance than the tear strip. Of the animals where the RIFI titer was equal to or greater than 1/160, the conjunctival swab PCR detected positive samples satisfactorily, however without statistical difference. Therefore, the use of less invasive techniques, such as the conjunctival swab, represents less cost and good sensitivity for diagnosis, through PCR. This was the first study using PCR with a filter paper strip to collect tears for the molecular diagnosis of Lcan.