Rattus rattus was first reported from the West Nile Region of Uganda in 1961, an event that preceded the appearance of the first documented human plague outbreak in 1970. We investigated how invasive R. rattus and native small mammal populations, as well as their fleas, have changed in recent decades. Over an 18-month period, a total of 2,959 small mammals were captured, sampled, and examined for fleas, resulting in the identification of 20 small mammal taxa that were hosts to 5,109 fleas (nine species). Over three-fourths (75.8%) of captured mammals belonged to four taxa: R. rattus, which predominated inside huts, and Arvicanthis niloticus, Mastomys sp., and Crocidura sp., which were more common outside huts. These mammals were hosts for 85.8% of fleas collected, including the efficient plague vectors Xenopsylla cheopis and X. brasiliensis, as well as likely enzootic vectors, Dinopsyllus lypusus and Ctenophthalmus bacopus. Flea loads on small mammals were higher in certain environments in villages with a recent history of plague compared to those that lacked such a history. The significance of these results is discussed in relation to historical data, the initial spread of plague in the WNR and the continuing threat posed by the disease.

中文翻译：

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乌干达鼠疫三联征：侵入性黑鼠 (Rattus rattus)、本土小型哺乳动物及其跳蚤

Rattus rattus于 1961 年在乌干达西尼罗河地区首次报道，这一事件发生在 1970 年首次记录的人类鼠疫爆发之前。我们调查了入侵的R. rattus和本地小型哺乳动物种群，以及它们的跳蚤，近几十年来发生了变化。在 18 个月的时间里，共捕获、取样和检查了 2,959 只小型哺乳动物的跳蚤，从而确定了 20 个小型哺乳动物类群，它们是 5,109 种跳蚤（九种）的宿主。超过四分之三 (75.8%) 的捕获哺乳动物属于四个分类群：R. rattus，主要在小屋内，以及Arvicanthis niloticus、Mastomys sp.和Crocidurasp.，这是更常见的户外小屋。这些哺乳动物是所收集跳蚤的 85.8% 的宿主，包括有效的鼠疫载体Xenopsylla cheopis和X. brasiliensis，以及可能的地方动物载体Dinopsyllus lypusus和Ctenophthalmus bacopus。在最近有鼠疫病史的村庄的某些环境中，小型哺乳动物的跳蚤载量高于没有鼠疫病史的村庄。这些结果的重要性与历史数据、鼠疫在 WNR 的最初传播以及该疾病带来的持续威胁有关。