Acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) is a major global public health problem. The aim of this study is to determine the prevalence of HIV-1 infection in four municipalities of Pará State (Marabá, Parauapebas, Curionópolis, and Canaã dos Carajás), in northern, Brazil. The municipalities are located in the Carajás Complex iron mining area. The employment opportunities result in extensive migratory flow of people. A total of 4771 serum samples were obtained from 2005 to 2014 and were sent to Evandro Chagas Institute, Belém-Pará, where they were tested by enzyme-linked immunosorbent assay, with reactive samples confirmed by Western blot analysis. The samples were from individuals from 23 Brazilian states and the Federal District, mainly Maranhão (39.53%) and other municipalities of Pará (34.25%). The total positivity rate was 0.48% (23/4771). The rate was 0.47% (14/2975) in males and 0.50% (9/1796) in females. Of these, 0.33% (14/4275) were from asymptomatic individuals whose serum were collected during the serological survey, 1.81% (9/497) were from cases featuring clinical symptoms including fever/diarrhea/jaundice, which were included in febrile, diarrheal, and icteric syndromes analyzed during the study. The findings indicated the presence of HIV-1 infection in the general population studied. The majority of cases (60.9%, 14 of 23 positive cases) were asymptomatic.

中文翻译：

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2005-2014 年巴西亚马逊帕拉州一个具有强烈迁徙流动的铁矿区人类免疫缺陷病毒 1 感染的流行率和流行病学特征

由人类免疫缺陷病毒 (HIV) 引起的获得性免疫缺陷综合征 (AIDS) 是一个主要的全球公共卫生问题。本研究的目的是确定巴西北部帕拉州的四个城市（马拉巴、帕劳阿佩巴斯、库里奥诺波利斯和卡纳多斯卡拉哈斯）的 HIV-1 感染率。自治市位于 Carajás Complex 铁矿区。就业机会导致广泛的人口迁移。从 2005 年到 2014 年，共采集了 4771 份血清样本，并将其送往贝伦帕拉州的 Evandro Chagas 研究所，在那里通过酶联免疫吸附试验进行检测，并通过蛋白质印迹分析确认反应样本。样本来自巴西 23 个州和联邦区的个人，主要是马拉尼昂 (39.53%) 和帕拉州的其他城市 (34.25%)。总阳性率为 0.48% (23/4771)。男性为 0.47% (14/2975)，女性为 0.50% (9/1796)。其中，0.33%（14/4275）来自在血清学调查期间采集血清的无症状个体，1.81%（9/497）来自具有发热/腹泻/黄疸等临床症状的病例，包括发热、腹泻，以及研究期间分析的黄疸综合征。研究结果表明，在所研究的一般人群中存在 HIV-1 感染。大多数病例（60.9%，23 例阳性病例中的 14 例）无症状。81% (9/497) 来自具有发热/腹泻/黄疸等临床症状的病例，这些病例包括在研究期间分析的发热、腹泻和黄疸综合征中。研究结果表明，在所研究的一般人群中存在 HIV-1 感染。大多数病例（60.9%，23 例阳性病例中的 14 例）无症状。81% (9/497) 来自具有发热/腹泻/黄疸等临床症状的病例，这些病例包括在研究期间分析的发热、腹泻和黄疸综合征中。研究结果表明，在所研究的一般人群中存在 HIV-1 感染。大多数病例（60.9%，23 例阳性病例中的 14 例）无症状。