Background

Visceral leishmaniasis (VL) caused by Leishmania infantum became a disease of urban areas in Brazil in the last 30 years and there has been an increase in asymptomatic L. infantum infection with these areas.

Methodology/Principal findings

A retrospective study of human VL was performed in the state of Rio Grande do Norte, Brazil, for the period of 1990–2014. The data were divided into five-time periods. For all VL cases, data on sex, age, nutritional status and childhood vaccination were collected. Geographic information system tools and statistical models were used to analyze the dispersion of human VL. The mean annual incidence of VL was 4.6 cases/100,000 inhabitants, with total 3,252 cases reported. The lethality rate was 6.4%. Over time the annual incidence of VL decreased in the 0–4 years (p<0.0001) and 5–9 (p <0.0001) age groups, but increased in ages 20–39 (p<0.001) and >40 years (p<0.0001). VL occurred more often in males (β₂ = 2.5; p<0.0001). The decreased incidence of VL in children was associated with improved nutritional status and childhood immunizations including measles, poliomyelitis, BCG, and hepatitis B. Human VL correlated temporally and geographically with canine L. infantum infection (p = 0.002, R² = 0.438), with rainfall and with Lutzomyia longipalpis density (r = 0.762). Overall, the incidence of VL decreased, while VL-AIDS increased, especially between 2010–2014. VL was more frequently found in areas that lacked urban infrastructure, detected by lack of garbage collection and sewers, whereas HIV infection was associated with higher levels of schooling and evidence of higher socioeconomic status.

Conclusion/Significance

The demographics of VL in northeastern Brazil have changed. Disease incidence has decreased in children and increased in adults. They were associated with improvements in nutrition, socioeconomic status and immunization rates. Concurrent VL-AIDS poses a serious challenge for the future.

中文翻译：

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巴西东北部内脏利什曼病的人口统计学变化：未来的经验教训

背景

在过去的30年中，婴儿利什曼原虫引起的内脏利什曼病（VL）成为巴西城市地区的一种疾病，无症状L增多。这些区域有婴儿感染。

方法/主要发现

在1990-2014年期间，在巴西北里奥格兰德州对人类VL进行了回顾性研究。数据分为五个时间段。对于所有VL病例，收集了有关性别，年龄，营养状况和儿童接种疫苗的数据。地理信息系统工具和统计模型用于分析人类VL的扩散。VL的平均年发病率为4.6例/ 100000居民，报告的总数为3,252例。致死率是6.4％。随着时间的流逝，VL的年发病率在0–4岁（p <0.0001）和5–9（p <0.0001）年龄组中降低，但在20–39岁（p <0.001）和> 40岁（p < 0.0001）。VL男性更常发生（β ₂= 2.5; p <0.0001）。儿童VL发生率的降低与营养状况的改善和儿童免疫接种的改善有关，包括麻疹，脊髓灰质炎，卡介苗和乙型肝炎。人的VL在时间和地理上与犬L相关。婴儿期（p = 0.002，R ² = 0.438），降雨和长足的Lutzomyia longipalpis密度（r = 0.762）。总体而言，VL的发病率下降，而VL-AIDS的发病率上升，尤其是在2010-2014年之间。VL在缺乏城市基础设施的地区更常见，这是由于缺乏垃圾收集和下水道而发现的，而HIV感染则与较高的学历和较高的社会经济地位有关。

结论/意义

巴西东北部的VL人口结构发生了变化。儿童的疾病发病率下降，成人的发病率上升。它们与营养，社会经济地位和免疫率的提高有关。并发VL-AIDS对未来构成了严峻的挑战。