背景:拉沙病毒(LASV),急性病毒性出血性疾病拉沙热(LF)的原因,是西非特有的。人类感染主要发生在暴露于啮齿动物宿主的被感染粪便或尿液后,纳塔尔人。塞拉利昂接触LASV的患病率是粗略估计的,并且在很大程度上是未知的。这项横断面研究旨在建立塞拉利昂三个行政区的LASVIgG抗体的基线血清阳性率,并确定血清阳性和LASV暴露的潜在危险因素。
结果:在2015年至2018年之间,来自凯内马的10,642名参与者,Tonkolili,和PortLoko地区参加了这项横断面研究。以前的LASV和LF流行病学研究支持将这些地区分类为“地方性”,\"\"出现,\"和\"非地方性\",分别。通过ELISA检测干血斑样本的LASV抗体,以确定参与者的血清阳性。表明以前接触过LASV。对每个参与者进行调查,以评估与LASV暴露风险较高相关的人口和环境因素。LASV抗体的总血清阳性率为16.0%。在凯内马,洛科港,和Tonkolili区,血清效价为20.1%,14.1%,和10.6%,分别。在多变量分析中,如果他们居住在凯内马区,LASV血清阳性的可能性更大,不管性别,年龄,或职业。环境因素导致LASV暴露风险增加,包括不良的住房建设和靠近灌木丛,林区,拒绝。
结论:在这项研究中,我们确定了三个地区的基线LASV血清阳性率,这将为未来的流行病学提供信息。生态,以及塞拉利昂LF和LASV的临床研究。LASV和LF在两个空间上分布的异质性,和时间,会使疗效试验和干预方案的设计变得困难。对LASV的患病率进行更多的研究并确定潜在的高流行区域将大大提高对LF的认识并改善与LASV相关的针对性控制程序。
Lassa virus (LASV), the cause of the acute viral hemorrhagic illness Lassa fever (LF), is endemic in West Africa. Infections in humans occur mainly after exposure to infected excrement or urine of the rodent-host, Mastomys natalensis. The prevalence of exposure to LASV in Sierra Leone is crudely estimated and largely unknown. This cross-sectional
study aimed to establish a baseline point seroprevalence of IgG antibodies to LASV in three administrative districts of Sierra Leone and identify potential risk factors for seropositivity and LASV exposure.
Between 2015 and 2018, over 10,642 participants from Kenema, Tonkolili, and Port Loko Districts were enrolled in this cross-sectional
study. Previous LASV and LF epidemiological studies support classification of these districts as \"endemic,\" \"emerging,\" and \"non-endemic\", respectively. Dried blood spot samples were tested for LASV antibodies by ELISA to determine the seropositivity of participants, indicating previous exposure to LASV. Surveys were administered to each participant to assess demographic and environmental factors associated with a higher risk of exposure to LASV. Overall seroprevalence for antibodies to LASV was 16.0%. In Kenema, Port Loko, and Tonkolili Districts, seroprevalences were 20.1%, 14.1%, and 10.6%, respectively. In a multivariate analysis, individuals were more likely to be LASV seropositive if they were living in Kenema District, regardless of sex, age, or occupation. Environmental factors contributed to an increased risk of LASV exposure, including poor housing construction and proximity to bushland, forested areas, and refuse.
In this
study we determine a baseline LASV seroprevalence in three districts which will inform future epidemiological, ecological, and clinical studies on LF and the LASV in Sierra Leone. The heterogeneity of the distribution of LASV and LF over both space, and time, can make the design of efficacy trials and intervention programs difficult. Having more studies on the prevalence of LASV and identifying potential hyper-endemic areas will greatly increase the awareness of LF and improve targeted control programs related to LASV.