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

Abstract

Visceral leishmaniasis caused by the protozoan Leishmania infantum is a zoonosis. The domestic dog is the primary reservoir in urban areas. This study aimed to evaluate the frequency, active infection and load of L . infantum in the genital tract of male and female dogs seropositive for this parasite, as well as to identify histological genital alterations associated with this protozoan. We studied 45 male and 25 female L . infantum -seropositive noncastrated dogs from the same endemic area in Brazil. Tissue samples from the testis, epididymis, prostate, vulva, vagina, and uterus were examined by singleplex qPCR and parasitological tests (histopathology, immunohistochemistry, and parasitological culture). The latter were performed for the detection of active infection (parasites able to multiply and to induce lesions). Forty-four (98%) males and 25 (100%) females were positive for L . infantum in the genital tract (epididymis: 98%; vulva: 92%; vagina: 92%; testis: 91%; uterus: 84%; prostate: 66%). Active infection in the genital tract was confirmed in 69% of males and 64% of females (32% in the uterus). Parasite loads were similar in the testis, vulva, epididymis and vagina and lower in the prostate. Only the parasite load in the vagina was significantly associated with the number of clinical signs. Granulomatous inflammation predominated in all organs, except for the prostate. Only in the testis and epididymis was the inflammatory infiltrate significantly more intense among dogs with a higher parasite load in these organs. The high frequency, detection of active infection and similarity of L . infantum loads in the genital tract of infected males and females suggest the potential of venereal transmission of this parasite by both sexes and of vertical transmission by females in the area studied. Additionally, vertical transmission may be frequent since active L . infantum infection was a common observation in the uterus.

Anti-Brucella canis antibodies in dogs naturally infected with Leishmania infantum and associated histological alterations in the genital tract

“…Granulomatous inflammation observed in the genital tract is compatible with L. infantum and B. canis infections (Hollett 2006, Boechat et al 2020. This fact highlights the importance of including canine brucellosis in the differential histological diagnosis of CVL in the genital tract.…”

“…Despite the classical transmission of the parasite by the bite of infected phlebotomine sand fl ies, venereal and vertical transmission between dogs has been reported (Turchetti et al 2014). Infection with L. infantum can cause orchitis, epididymitis, prostatitis, vaginitis, and endometritis (Boechat et al 2020).…”

Leishmaniose Visceral: há possibilidade de transmissão sexual e vertical entre cães?

“…Atualmente, amastigotas de L. (L.) infantum vem sendo encontradas em órgãos genitais de cães e normalmente estão associadas a lesões inflamatórias nestes locais (Diniz et al, 2005;Silva et al, 2008). Diversos trabalhos demonstraram que há um tropismo do parasito para os órgãos do sistema reprodutivo dessa espécie animal e estudos recentes de Boechat et al (2016;2021) revelaram que a presença do protozoário no sistema reprodutivo de cães infectados independe do sexo (macho e fêmea) e dos sinais clínicos (assintomático e sintomático).…”

“…Acredita-se que a vulva, a vagina e o útero parecem ser os órgãos mais parasitados por Leishmania sp. em cadelas (Silva et al, 2008;Boechat et al, 2016;2021;Oliveira et al, 2016;Silva et al, 2021). Vale ressaltar que estes resultados foram realizados em áreas endêmicas da doença no Brasil, nos estados de Minas Gerais, Rio de Janeiro, São Paulo e Pernambuco.…”

“…Uma pesquisa revelou que apesar da ausência de lesões macroscópicas nos órgãos genitais femininos de cadelas infectadas por LV, houve a presença de infiltrado inflamatório granulomatoso em todo sistema reprodutivo desses animais, com exceção das tubas uterinas, e a presença de amastigotas de L. (L.) infantum foi visualizada no endométrio, ovários, mucosa vaginal, pele e mucosa da vulva e glândulas mamárias, inclusive foi possível observar uma maior carga parasitária e intensa reação inflamatória na vulva e mamas de cadelas infectadas (Boechat et al, 2016). Nesse trabalho, os autores mostraram uma certa preocupação com o encontro de amastigotas do parasito no lúmen da glândula mamária, o que pode indicar que sejam eliminadas pelo leite materno, consequentemente revelando uma possível transmissão mamária.…”