Dietze R, Barros G B, Teixeira L, Harris J, Michelson K, Falqueto A, Corey R
Núcleo de Doenças Infecciosas-Universidade Federal do Espírito Santo, Vitória, Brazil.
Clin Infect Dis. 1997 Nov;25(5):1240-2. doi: 10.1086/516096.
In Brazil, where Leishmania chagasi causes endemic American visceral leishmaniasis (AVL), the spread and maintenance of human disease are attributed to canine reservoirs. However, despite measures directed toward the elimination of infected canines, the incidence of human disease continues to increase. To evaluate the role of infected canines in the acquisition of AVL by humans, we undertook a controlled intervention study in three similar, but isolated, valleys of Pancas, Espírito Santo, Brazil. In the two experimental (intervention) valleys, infected dogs were eliminated whereas in the control valley, seropositive canines remained untouched. During the 12-month study period, human seropositivity rates, as measured by dot enzyme-linked immunosorbent assay, increased from 15% to 54% in the intervention valleys and from 14% to 54% in the control valley. The elimination of infected canines in the intervention valleys did not result in a statistically significant difference between the incidences of human serological conversion in the intervention and control valleys at either 6 (20% and 22%, respectively; P = .5961) or 12 months (26% and 27%, respectively; P = .9442). The role of humans as a significant reservoir for AVL is proposed as an explanation for the study results.
在巴西，恰加斯利什曼原虫引发美洲内脏利什曼病（AVL）的地方流行，人类疾病的传播和持续存在归因于犬类宿主。然而，尽管采取了针对消灭受感染犬类的措施，但人类疾病的发病率仍在持续上升。为了评估受感染犬类在人类感染AVL中的作用，我们在巴西圣埃斯皮里图州潘卡斯的三个相似但相互隔离的山谷中进行了一项对照干预研究。在两个实验（干预）山谷中，受感染的狗被消灭，而在对照山谷中，血清反应呈阳性的犬类未受影响。在为期12个月的研究期间，通过斑点酶联免疫吸附测定法测得的人类血清反应阳性率，在干预山谷中从15%升至54%，在对照山谷中从14%升至54%。在干预山谷中消灭受感染犬类，在6个月（分别为20%和22%；P = 0.5961）或12个月（分别为26%和27%；P = 0.9442）时，干预山谷和对照山谷中人类血清学转换发生率之间均未产生统计学上的显著差异。研究结果的一种解释是，提出人类作为AVL的重要宿主的作用。
