Walter Reed Army Institute of Research, Silver Spring, Maryland 20009, USA.
Vector Borne Zoonotic Dis. 2012 Jul;12(7):558-63. doi: 10.1089/vbz.2010.0081. Epub 2012 Mar 27.
A representative, two-stage probability sampling design was used to select 40 villages in northern Azerbaijan with populations of <500 people to screen for evidence of prior infection with Francisella tularensis. Informed consent was provided, and samples were obtained from 796 volunteers and tested for the presence of immunoglobulin G antibodies using enzyme-linked immunosorbent assay. F. tularensis seropositivity was prevalent (15.5% of volunteers), but there was minimal reporting of signs and symptoms consistent with clinical tularemia, suggesting that mild or asymptomatic infection commonly occurs. Frequently seeing rodents around the home was a risk factor for seropositivity (POR = 1.6, p = 0.03), controlling for age and gender. Geospatial analysis identified associations between village-level tularemia prevalence and suitable tick habitats, annual rainfall, precipitation in the driest quarter, and altitude. This study contributes to the growing understanding of the geographic distribution of tularemia and provides further information on the climatic and landscape conditions that increased the potential for exposure to this pathogen. The potential occurrence of asymptomatic or mild F. tularensis infection warrants further study.
本研究采用具有代表性的两阶段概率抽样设计，在阿塞拜疆北部选择了 40 个人口少于 500 人的村庄，以筛查土拉弗朗西斯菌（Francisella tularensis）既往感染的证据。在获得知情同意后，从 796 名志愿者中采集样本，并使用酶联免疫吸附试验检测 IgG 抗体的存在情况。土拉弗朗西斯菌血清阳性率较高（15.5%的志愿者），但与临床土拉菌病一致的体征和症状报告较少，这表明轻度或无症状感染较为常见。家中经常看到啮齿动物是血清阳性的危险因素（POR=1.6，p=0.03），该因素控制了年龄和性别。地理空间分析确定了村庄层面土拉菌病流行率与合适的蜱栖息地、年降雨量、最干旱季度的降雨量和海拔之间的关联。本研究有助于更好地了解土拉菌病的地理分布，并提供了更多关于增加接触该病原体潜在风险的气候和景观条件的信息。无症状或轻度土拉弗朗西斯菌感染的潜在发生情况值得进一步研究。
