Fichet-Calvet Elisabeth, Lecompte Emilie, Koivogui Lamine, Daffis Stéphane, ter Meulen Jan
Department of Systematics and Evolution, Museum National d'Histoire Naturelle, Paris, France.
Vector Borne Zoonotic Dis. 2008 Spring;8(1):41-8. doi: 10.1089/vbz.2007.0118.
We recently reported increased prevalence of Lassa virus (LASV) infection in Mastomys natalensis during the rainy season in Guinea, West Africa. Here, the association of LASV prevalence with fecundity, fertility, and the age structure of the rodent population was analyzed using data from the previous study. The animals reproduced throughout the year, but highest fecundity was observed during the rainy season. Accordingly, the rodent population was aged at the beginning and young at the end of the rainy season. Lassa virus infection was observed in all age groups, including the very young, which is compatible with vertical transmission. However, since the prevalence of infection showed a trend with increasing age in the younger age groups, horizontal transmission by yet unknown mechanisms may also play a role in LASV transmission. Multivariate analysis did not show an association of LASV prevalence with any demographic variable studied. Rodent behavior influencing virus transmissibility and contaminated environment may therefore be responsible for spatial and seasonal variations in LASV prevalence in M. natalensis.
我们最近报告称，在西非几内亚的雨季期间，南非乳鼠感染拉沙病毒（LASV）的患病率有所上升。在此，利用先前研究的数据，分析了LASV患病率与该啮齿动物种群的繁殖力、生育力和年龄结构之间的关联。这些动物全年繁殖，但在雨季观察到最高繁殖力。相应地，啮齿动物种群在雨季开始时年龄较大，在雨季结束时较为年轻。在所有年龄组中都观察到了拉沙病毒感染，包括非常年幼的个体，这与垂直传播相符。然而，由于在较年轻年龄组中感染患病率呈现出随年龄增长的趋势，通过尚不清楚的机制进行的水平传播可能也在LASV传播中起作用。多变量分析未显示LASV患病率与所研究的任何人口统计学变量之间存在关联。因此，影响病毒传播性的啮齿动物行为和受污染的环境可能是导致南非乳鼠中LASV患病率出现空间和季节变化的原因。
