Tropical Medicine Institute, Pará Federal University, Belém, PA, Brazil.
Trans R Soc Trop Med Hyg. 2009 Dec;103(12):1250-6. doi: 10.1016/j.trstmh.2009.06.010. Epub 2009 Jul 16.
The objectives of this study were to identify individuals with symptomatic and/or asymptomatic infection due to Leishmania (L.) infantum chagasi; to study the two types of infection, both clinically and immunologically, and to determine the prevalence rate of infection at the beginning of the study. This was a cross-sectional study with a cohort of 946 individuals, of both genders, from the age of 1 year, living in the municipality of Barcarena, PA, Brazil, an area endemic for American visceral leishmaniasis (AVL). The leishmanin skin test (LST) and the indirect fluorescent test (IFAT), were used for the diagnosis of infection. One hundred and twenty cases of infection were diagnosed, with a prevalence rate of 12.6%; eight cases showed high seroreactivity (1280-10240, IgG) in IFAT and no LST reaction; four of these cases were typical AVL and four had subclinical oligosymptomatic infection. Using two immunological methods with a clinical examination of the infected individuals enabled the identification of five clinical-immunological profiles which may promote a better understanding of the interaction between L. (L.) i. chagasi and the human immune response: asymptomatic infection (AI) 73.4%; subclinical resistant infection (SRI) 15%; subclinical oligosymptomatic infection (SOI) 3%; symptomatic infection (AVL) 3% and indeterminate initial infection (III) 5%.
本研究的目的是确定患有查加斯利什曼原虫（L.）感染的有症状和/或无症状感染者；从临床和免疫学两方面研究两种类型的感染，并确定研究开始时的感染发生率。这是一项横断面研究，共纳入 946 名 1 岁以上的男女两性个体，他们来自巴西帕拉州巴卡雷纳市，该地区是美洲内脏利什曼病（AVL）的流行区。采用利什曼菌素皮肤试验（LST）和间接荧光抗体试验（IFAT）诊断感染。共诊断出 120 例感染病例，感染率为 12.6%；8 例 IFAT 检测呈高血清反应性（1280-10240，IgG）且无 LST 反应；其中 4 例为典型 AVL，4 例为亚临床寡症状感染。使用两种免疫学方法和对感染者的临床检查，确定了五种临床免疫表型，这可能有助于更好地了解 L.（L.）i.查加斯与人类免疫反应之间的相互作用：无症状感染（AI）73.4%；亚临床抵抗感染（SRI）15%；亚临床寡症状感染（SOI）3%；有症状感染（AVL）3%和初始感染不确定（III）5%。
