Demby A H, Inapogui A, Kargbo K, Koninga J, Kourouma K, Kanu J, Coulibaly M, Wagoner K D, Ksiazek T G, Peters C J, Rollin P E, Bausch D G
Special Pathogens Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases (NCID), Centers for Disease Control and Prevention (CDC), Atlanta, GA 30333, USA.
Vector Borne Zoonotic Dis. 2001 Winter;1(4):283-97. doi: 10.1089/15303660160025912.
Rodents of the genus Mastomys form the reservoir for Lassa virus (LV), an arenavirus that causes a potentially severe hemorrhagic illness, Lassa fever (LF). Although Mastomys rodents exist throughout sub-Saharan Africa, areas of human LF appear to be quite focal. The distribution of small mammals and LV-infected Mastomys has been assessed in only a few countries. We conducted a survey of small mammals in selected regions of Guinea to assess the degree to which LV poses a public health risk in that country. A total of 1,616 small mammals, including 956 (59%) Mastomys, were captured from 444 households and seven bush sites. Mastomys made up > 90% of the captured animals in the savannah, savannah-forest transition, and forest regions of Guinea, while Mus musculus dominated in coastal and urban sites. Animals were analyzed via enzyme-linked immunosorbent assay (ELISA) for LV-specific antigen (blood and spleen homogenate) and IgG antibody (blood only). Virus isolation from spleen homogenates was also performed on a subset of animals. Lassa antibody and antigen were found in 96 (11%) and 46 (5%), respectively, of 884 tested Mastomys. Antibody and antigen were essentially mutually exclusive and showed profiles consistent with vertical transmission of both LV and antibody. LV was isolated only from Mastomys. ELISA antigen constituted an acceptable surrogate for virus isolation, with a sensitivity and specificity when performed on blood of 78% (95% confidence interval: 68-83%) and 98% (95-99%), respectively. The proportion of LV-infected Mastomys per region ranged from 0 to 9% and was highest in the savannah and forest zones. The proportion of infected animals per village varied considerably, even between villages in close proximity. Infected animals tended to cluster in relatively few houses, suggesting the existence of focal "hot spots" of LV-infected Mastomys that may account for the observed heterogeneous distribution of LF.
多乳鼠属啮齿动物是拉沙病毒（LV）的宿主，拉沙病毒是一种沙粒病毒，可引发潜在的严重出血性疾病——拉沙热（LF）。尽管多乳鼠在撒哈拉以南非洲地区均有分布，但人类拉沙热的发病区域似乎相当集中。仅在少数几个国家评估过小哺乳动物和感染拉沙病毒的多乳鼠的分布情况。我们在几内亚的选定地区开展了一项小型哺乳动物调查，以评估拉沙病毒在该国构成公共卫生风险的程度。从444户家庭和7个丛林地点共捕获了1616只小型哺乳动物，其中包括956只（59%）多乳鼠。在几内亚的稀树草原、稀树草原 - 森林过渡区和森林地区，捕获的动物中多乳鼠占比超过90%，而小家鼠在沿海和城市地区占主导地位。通过酶联免疫吸附测定（ELISA）分析动物的拉沙病毒特异性抗原（血液和脾脏匀浆）和IgG抗体（仅血液）。还对一部分动物的脾脏匀浆进行了病毒分离。在884只接受检测的多乳鼠中，分别有96只（11%）和46只（5%）检测到拉沙抗体和抗原。抗体和抗原基本相互排斥，且显示出与拉沙病毒和抗体垂直传播一致的特征。仅从多乳鼠中分离出了拉沙病毒。ELISA抗原可作为病毒分离的可接受替代指标，对血液进行检测时，其敏感性和特异性分别为78%（95%置信区间：68 - 83%）和98%（95 - 99%）。每个地区感染拉沙病毒的多乳鼠比例在0%至9%之间，在稀树草原和森林地带最高。每个村庄感染动物的比例差异很大，即使是相邻村庄之间也是如此。感染动物往往集中在相对较少的房屋中，这表明存在拉沙病毒感染的多乳鼠的局部“热点”，这可能解释了观察到的拉沙热分布不均的现象。
