Background

The high rate of leprosy cases among children under 15 years of age in Brazil indicates ongoing transmission within the community. The identification of the new leprosy cases among contacts can help identify the source of infection and interrupt the transmission chain. This study aims to determine the detection rate of previously undiagnosed cases of leprosy among schoolchildren who are under 15 years of age living in Manaus, Amazonas, Brazil, and their possible source of infection by contact tracing.

Methodology/Principal findings

This was a school-based, cross-sectional study in which the identification of active leprosy cases was conducted in 277 out of 622 randomly selected public schools in Manaus, Amazonas, Brazil. Suspected cases of leprosy were referred to the Alfredo da Matta Foundation, a reference center for leprosy in Manaus. A total of 34,547 schoolchildren were examined, and 40 new leprosy cases were diagnosed. Among new cases, 57.5% were males, and 80.0% demonstrated paucibacillary leprosy. A total of 196 of 206 registered contacts were screened, and 52.5% of the newly diagnosed children’s cases had at least one positive household contact. In these contacts, grandparents (52.4%) were the most common co-prevalent cases, while 14.3% were uncles, 9.5% were parents and 9.5% were granduncles. Seven contacts (5.0%), including four siblings of child patients were newly diagnosed. Our data indicate that the prevalence is 11.58 per 10,000, which is 17 times higher than the registered rate.

Conclusions/Significance

This study suggests that the prevalence of leprosy among schoolchildren may have remained unchanged over the past thirty years. It also indicates that that active case finding is necessary for reaching the World Health Organization’s goals of zero detection among children, especially in endemic areas where the prevalence of leprosy is obscure. Moreover, we assert that all children must have their household contacts examined in order to identify the possible source of infection and interrupt the disease’s transmission. Novel strategies to reinforce contact tracing associated with large-scale strategies of chemo- and immune-prophylaxis should be expanded to prevent the perpetuation of the disease cycle.

中文翻译：

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亚马逊地区小学生中的麻风病：通过接触追踪进行主动搜索和可能感染源的横断面研究

背景

在巴西15岁以下的儿童中，麻风病发病率很高，这表明社区内仍在继续传播艾滋病毒。在接触者之间识别新的麻风病病例可以帮助识别感染源并中断传播链。这项研究旨在确定居住在巴西马瑙斯，亚马逊州，巴西的15岁以下学童中以前未被诊断出的麻风病的检出率，以及他们可能的接触者追踪来源。

方法/主要发现

这是一项基于学校的横断面研究，在巴西亚马孙州马瑙斯的622所随机选择的公立学校中，有277所进行了麻风病活动病例的鉴定。麻风病疑似病例转交给了玛瑙斯麻风病咨询中心阿尔弗雷多·达·马塔基金会（Alfredo da Matta Foundation）。总共检查了34,547名学童，并诊断出40例新的麻风病病例。在新发病例中，男性占57.5％，表现出脓疱性麻风病占80.0％。筛选了206个注册联系人中的196个，新诊断的儿童病例中有52.5％至少有一个积极的家庭联系人。在这些接触中，祖父母（52.4％）是最常见的共同流行病例，叔叔为14.3％，父母为9.5％，外公为9.5％。七个联系人（5.0％），新诊断出包括四名儿童患者的兄弟姐妹。我们的数据表明，患病率为每10,000人11.58，这是注册率的17倍。

结论/意义

这项研究表明，在过去的30年中，小学生中麻风的患病率可能没有变化。它还表明，要在儿童中实现世界卫生组织的零检出目标，特别是在麻风流行不明显的流行地区，积极寻找病例是必要的。此外，我们断言所有儿童都必须接受家庭接触检查，以查明可能的感染源并中断疾病的传播。应扩大与化学和免疫预防的大规模策略相关的加强接触者追踪的新策略，以防止疾病周期的延续。