Lushasi Kennedy, Hayes Sarah, Ferguson Elaine A, Changalucha Joel, Cleaveland Sarah, Govella Nicodem J, Haydon Daniel T, Sambo Maganga, Mchau Geofrey J, Mpolya Emmanuel A, Mtema Zacharia, Nonga Hezron E, Steenson Rachel, Nouvellet Pierre, Donnelly Christl A, Hampson Katie
Ifakara Health Institute, Ifakara, Tanzania.
Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.
J Appl Ecol. 2021 Nov;58(11):2673-2685. doi: 10.1111/1365-2664.13983.
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 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 south-east 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 were 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%), with the remainder in domestic cats and other wildlife species.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 6 years of the study. Following the lapse of this program, dog rabies cases began to increase in one of the northernmost districts. . In south-east 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.
了解不同物种在狂犬病病毒等多宿主病原体传播中的作用，对于制定有效的控制策略至关重要。在撒哈拉以南非洲的大部分地区，家犬被认为是狂犬病的宿主，但野生动物的作用长期以来一直存在争议。在此，我们探讨了坦桑尼亚东南部狂犬病的多宿主传播动态。
2011年1月至2019年7月期间，在林迪和姆特瓦拉地区收集了可能的狂犬病病例数据。将前往医疗机构就诊的动物咬伤患者的医院记录用作追踪动物接触情况的哨兵。利用可能感染狂犬病动物的时间、地点和物种来重建传播树，以推断谁感染了谁以及种内和种间传播的相对频率。
在研究期间，共确定了688例可能的人类狂犬病暴露病例，导致47人死亡。在这些暴露病例中，389例来自家犬（56.5%），262例来自豺（38.1%）。同一时期，追踪到549例可能的动物狂犬病病例：303例在家犬中（55.2%），221例在豺中（40.3%），其余病例在家猫和其他野生动物物种中。
虽然最常推断的是犬间传播（占传播事件的40.5%），但三分之一的推断事件涉及野生动物间传播（32.6%），并且有证据表明在豺种群中有一些持续的传播链。
在研究的前6年里，随着广泛开展家犬疫苗接种，人类和动物中可能的狂犬病病例稳步下降。该项目结束后，最北部的一个地区家犬狂犬病病例开始增加。在坦桑尼亚东南部，尽管野生动物中狂犬病发病率相对较高且存在野生动物间传播的证据，但家犬仍然是感染源的重要组成部分。持续进行犬类疫苗接种并加强监测，将有助于更全面地了解野生动物在该地区维持传播中的作用。尽管如此，犬类疫苗接种显然抑制了家犬和野生动物种群中的狂犬病，降低了公共卫生和保护风险，如果持续下去，有可能在该地区消除狂犬病。
