Conservation Genomics and EcoHealth, Institute for Evolutionary Ecology and Conservation Genomics, Ulm, Germany.
Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
Transbound Emerg Dis. 2022 Nov;69(6):3274-3284. doi: 10.1111/tbed.14679. Epub 2022 Aug 29.
Infections with tuberculosis (TB)-causing agents of the Mycobacterium tuberculosis complex threaten human, livestock and wildlife health globally due to the high capacity to cross trans-species boundaries. Tuberculosis is a cryptic disease characterized by prolonged, sometimes lifelong subclinical infections, complicating disease monitoring. Consequently, our understanding of infection risk, disease progression, and mortality across species affected by TB remains limited. The TB agent Mycobacterium suricattae was first recorded in the late 1990s in a wild population of meerkats inhabiting the Kalahari in South Africa and has since spread considerably, becoming a common cause of meerkat mortality. This offers an opportunity to document the epidemiology of naturally spreading TB in a wild population. Here, we synthesize more than 25 years' worth of TB reporting and social interaction data across 3420 individuals to track disease spread, and quantify rates of TB social exposure, progression, and mortality. We found that most meerkats had been exposed to the pathogen within eight years of first detection in the study area, with exposure reaching up to 95% of the population. Approximately one quarter of exposed individuals progressed to clinical TB stages, followed by physical deterioration and death within a few months. Since emergence, 11.6% of deaths were attributed to TB, although the true toll of TB-related mortality is likely higher. Lastly, we observed marked variation in disease progression among individuals, suggesting inter-individual differences in both TB susceptibility and resistance. Our results highlight that TB prevalence and mortality could be higher than previously reported, particularly in species or populations with complex social group dynamics. Long-term studies, such as the present one, allow us to assess temporal variation in disease prevalence and progression and quantify exposure, which is rarely measured in wildlife. Long-term studies are highly valuable tools to explore disease emergence and ecology and study host-pathogen co-evolutionary dynamics in general, and its impact on social mammals.
结核分枝杆菌复合体引起的结核病感染威胁着全球人类、家畜和野生动物的健康，因为它们具有跨越物种界限的高能力。结核病是一种隐匿性疾病，其特征是长时间、有时是终身的亚临床感染，使疾病监测变得复杂。因此，我们对受结核病影响的不同物种的感染风险、疾病进展和死亡率的理解仍然有限。分枝杆菌属的结核分枝杆菌 Suricattae 于 20 世纪 90 年代末在南非卡拉哈里地区的一个野生獴群中首次被记录，并在此后迅速传播，成为獴类死亡的常见原因。这为在野生种群中记录自然传播的结核病的流行病学提供了机会。在这里，我们综合了 3420 多只个体的 25 年以上的结核病报告和社会互动数据，以追踪疾病的传播，并量化结核病的社会接触、进展和死亡率。我们发现，大多数獴类在研究区域首次发现该病原体的 8 年内都曾接触过该病原体，接触率高达 95%的种群。大约四分之一接触过的个体发展到临床结核病阶段，随后在几个月内身体恶化并死亡。自出现以来，11.6%的死亡归因于结核病，尽管与结核病相关的死亡率可能更高。最后，我们观察到个体之间的疾病进展存在显著差异，这表明个体之间在结核病易感性和抵抗力方面存在差异。我们的研究结果表明，结核病的流行率和死亡率可能比以前报告的更高，尤其是在社会群体动态复杂的物种或群体中。长期研究，如本研究，可以评估疾病流行率和进展的时间变化，并量化在野生动物中很少测量的接触情况。长期研究是评估疾病出现和生态学以及研究宿主-病原体共同进化动态的高度有价值的工具，特别是对社会哺乳动物的影响。
