Reservoir dynamics of rabies in Southeast Tanzania and the roles of cross-species transmission and domestic dog vaccination

Understanding the role of different species in the transmission of multi-host pathogens, such as rabies virus, is vital for effective control strategies. Across most of sub-Saharan Africa domestic dogs (Canis familiaris) are considered the reservoir for rabies, but the role of wildlife has been long debated. Here we explore the multi-host transmission dynamics of rabies across southeast Tanzania. Between January 2011 and July 2019 data on probable rabies cases were collected in the regions of Lindi and Mtwara. Hospital records of animal-bite patients presenting to healthcare facilities were used as sentinels for animal contact tracing. The timing, location and species of probable rabid animals was used to reconstruct transmission trees to infer who infected whom and the relative frequencies of within- and between-species transmission. During the study, 688 probable human rabies exposures were identified, resulting in 47 deaths. Of these exposures, 389 were from domestic dogs (56.5%) and 262 from jackals (38.1%). Over the same period 549 probable animal rabies cases were traced: 303 in domestic dogs (55.2%) and 221 in jackals (40.3%). Although dog-to-dog transmission was most commonly inferred (40.5% of transmission events), a third of inferred events involved wildlife-to-wildlife transmission (32.6%) and evidence suggested some sustained transmission chains within jackal populations. A steady decline in probable rabies cases in both humans and animals coincided with the implementation of widespread domestic dog vaccination during the first six years of the study. Following the lapse of this programme dog rabies cases began to increase in one of the northernmost districts. Synthesis and applications: In southeast Tanzania, despite a relatively high incidence of rabies in wildlife and evidence of wildlife-to-wildlife transmission, domestic dogs remain essential to the reservoir of infection. Continued dog vaccination alongside improved surveillance would allow a fuller understanding of the role of wildlife in maintaining transmission in this area. Nonetheless, dog vaccination clearly suppressed rabies in both domestic dog and wildlife populations, reducing both public health and conservation risks and, if sustained, has potential to eliminate rabies from this region.

明确不同物种在多宿主病原体（multi-host pathogen）、如狂犬病病毒（rabies virus）的传播过程中所扮演的角色，对于制定高效的传染病防控策略至关重要。在撒哈拉以南非洲大部分地区，家犬（Canis familiaris）被认为是狂犬病的储存宿主，但野生动物在该病传播中的作用长期以来存在诸多争议。本研究针对坦桑尼亚东南部地区的狂犬病多宿主传播动态展开探索。2011年1月至2019年7月期间，研究团队在林迪（Lindi）与姆特瓦拉（Mtwara）两个行政区收集疑似狂犬病病例的相关数据。本研究将前往医疗机构就诊的动物咬伤患者的医院记录，作为开展动物接触追踪的哨兵监测（sentinel）数据。研究人员通过疑似狂犬病动物的发病时间、发病地点及感染物种信息，重建传播树（transmission trees）以推断感染链，以及种内与种间传播的相对频率。研究期间共确认688例人类狂犬病暴露病例，其中47例最终死亡。在这些暴露案例中，389例（56.5%）由家犬导致，262例（38.1%）由胡狼（jackal）导致。同期共追踪到549例动物疑似狂犬病病例：其中家犬病例303例（55.2%），胡狼病例221例（40.3%）。尽管研究推断的传播事件中以家犬间传播最为常见（占总传播事件的40.5%），但仍有三分之一的传播事件（32.6%）涉及野生动物间传播，且有证据显示胡狼种群内部存在持续的传播链。研究前六年，随着大范围家犬疫苗接种计划的推行，人类与动物的疑似狂犬病病例数均呈现稳步下降趋势；该疫苗接种计划终止后，最北部的一个行政区内的家犬狂犬病病例数开始回升。综合与应用：在坦桑尼亚东南部地区，尽管野生动物狂犬病的发病率相对较高，且存在野生动物间传播的证据，但家犬仍是该病感染的核心储存宿主。持续推进家犬疫苗接种并完善监测体系，将有助于更全面地阐明野生动物在该地区维持狂犬病传播过程中所扮演的角色。尽管如此，家犬疫苗接种已显著抑制了家犬与野生动物种群中的狂犬病流行，同时降低了公共卫生与生物保护风险；若该计划得以持续推行，该区域有望实现狂犬病的消除。

搜集汇总

背景与挑战

背景概述

该数据集包含2011年至2019年坦桑尼亚东南部林迪和姆特瓦拉地区狂犬病传播动态的研究数据，重点分析跨物种传播和家犬疫苗接种的作用。数据表明，尽管野生动物（如豺）在传播中占一定比例，家犬仍是主要传染源，且大规模家犬疫苗接种显著降低了人类和动物的狂犬病病例。数据集支持狂犬病控制策略的评估，强调持续犬只接种和监测的重要性。