Laboratório de Pesquisa Clínica em Dermatozoonoses em Animais Domésticos, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Laboratório de Pesquisa Clínica e Vigilância em Leishmanioses, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
PLoS One. 2020 Sep 1;15(9):e0238188. doi: 10.1371/journal.pone.0238188. eCollection 2020.
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.
内脏利什曼病由原生动物利什曼原虫引起，是一种人畜共患病。家犬是城市地区的主要储存宿主。本研究旨在评估血清阳性的雄性和雌性犬的生殖道中利什曼原虫的频率、活性感染和负荷，以及鉴定与这种原生动物相关的组织学生殖道改变。我们研究了来自巴西同一流行地区的 45 只雄性和 25 只雌性血清阳性的未去势利什曼原虫感染犬。使用单重 qPCR 和寄生虫学检测（组织病理学、免疫组织化学和寄生虫培养）检查睾丸、附睾、前列腺、外阴、阴道和子宫的组织样本。后两者用于检测活性感染（能够繁殖并引起病变的寄生虫）。44 只（98%）雄性和 25 只（100%）雌性犬的生殖道中存在利什曼原虫（附睾：98%；外阴：92%；阴道：92%；睾丸：91%；子宫：84%；前列腺：66%）。69%的雄性和 64%的雌性生殖道中证实存在活性感染（子宫中为 32%）。睾丸、外阴、附睾和阴道中的寄生虫负荷相似，前列腺中的负荷较低。只有阴道中的寄生虫负荷与临床症状的数量显著相关。除前列腺外，所有器官均以肉芽肿性炎症为主。只有在睾丸和附睾中，这些器官中的寄生虫负荷较高的犬的炎症浸润明显更为强烈。感染雄性和雌性犬的生殖道中利什曼原虫的高频率、活性感染的检测和负荷的相似性表明，该寄生虫具有通过两性进行性传播的潜力，并且在研究区域内，雌性可能具有垂直传播的潜力。此外，由于在子宫中经常观察到活动性利什曼原虫感染，因此垂直传播可能很频繁。
