Correlation between chronic inflammation, immunostaining and parasite load in the genital system of female dogs naturally infected with Leishmania infantum

Abstract

The aim of the present study was to investigate the correlations among chronic inflammatory reaction, immunostaining and parasite load in the genital system of female dogs naturally infected with Leishmania infantum . Animals (n = 10) used in this study were from the Department of Vector Control and Animal Surveillance of the municipality of Caruaru, state of Pernambuco, Brazil. Fragments of the vulva, vagina, cervix, uterine body, uterine horns and ovaries were submitted to histopathological analysis, immunohistochemistry (IHC) and DNA detection of amastigotes by qPCR. Correlations were found between the IHC findings and chronic inflammatory infiltrate related to L. Infantum only in the vulva and vagina; whereas, the same inflammatory reactions without immunostaining were observed in all organs, except the ovaries. L. Infantum DNA was detected in all organs of genital system, with no difference in parasite load observed among the different organs. No correlation was reported between parasite load and inflammatory lesions in the organs evaluated, except for the uterine body, in which an inverse correlation was detected. In conclusion, the vulva and vagina were the major sites of lesions and immunostaining for L. Infantum amastigotes in the genital system of female dogs. Moreover, parasite load exerted no influence on the intensity of the lesions in the organs evaluated.

Frequency, active infection and load of Leishmania infantum and associated histological alterations in the genital tract of male and female dogs

“…Previous studies involving dogs with parasitological confirmation of L . infantum have also reported a high frequency of positive results in the genital tract of males (94.7%) and females (90.0%) by IHC and qPCR [ 13 , 14 ]. In another study involving dogs with parasitological confirmation that originated from the same area as the animals of the present study, the frequencies of positive results in the genital tract were 90% among males and 80% among females [ 11 ].…”

“…These authors [ 13 ] observed a lower frequency of positive results in the prostate (78.9%), but higher than that found in the present study. In bitches, studies found a higher frequency of positive results in the uterus (80%), followed by the vagina (70%) and vulva (60%) [ 14 ]. These results differ from the present study in which the frequencies of positive results were much higher in the vulva and vagina compared to the uterus.…”

“…In the female genital tract, the L . infantum load was reported to be lower than in the male genital tract and was more intense in the vulva and vagina, but was not associated with inflammatory intensity in these organs [ 14 ]. Some authors suggest tropism of L .…”

“…However, other studies found a high frequency of parasitism in the genital tract of females, suggesting tropism of L . infantum also for the female genital tract and the possibility of venereal transmission from female to male [ 11 , 14 ]. The detection of vaginal secretion contaminated with L .…”

“…However, studies on the frequency of L . infantum in the genital tract of dogs that simultaneously evaluate parasite load, the presence of active infection and histological alterations associated with this parasite are scarce [ 13 , 14 ]. In addition, these studies have evaluated small populations and only males or females from different endemic areas.…”