Antonopoulos Alistair, Giannelli Alessio, Morgan Eric R, Charlier Johannes
Kreavet, Kruibeke, Belgium.
Queen's University, Belfast, UK.
Zoonoses Public Health. 2025 Aug;72(5):465-477. doi: 10.1111/zph.13226. Epub 2025 May 30.
Toxocariasis is a neglected zoonosis caused by ascarid nematodes of canids and felids. It is a global problem, affecting individuals in high, low, and middle-income countries. The burden of disease has previously been estimated at > 90,000 DALYs lost per year due to toxocariasis, and $2.5 billion annually in economic impact. Transmission of toxocariasis depends on interactions and contact between humans and the definitive animal hosts, mediated by environmental contamination with long-lived parasite eggs. This can complicate control measures, requiring the adoption of a One Health approach. Within this context, dynamic models of transmission can have an important role to play in improving our understanding of disease transmission and can serve as effective tools to aid in the development of control strategies.
In this study, we develop a modified dynamic compartmental model for the zoonotic transmission of toxocariasis from dogs and cats. We further incorporate stochasticity into the model to account for existing uncertainties related to the proportion of seroprevalent individuals who exhibit symptoms of the infection.
We initially use the model to estimate region-specific transmission rates from dogs and cats to humans by iterative model fitting to existing estimates of seroprevalence across a selection of countries. We then examined the performance of the model in estimating the number of human exposures and symptomatic cases of toxocariasis and found a good level of concordance between the model predictions and estimates from previous work. Finally, we use the model to estimate the potential disease burden and economic impact across a range of countries, with the potential for more realistic estimates in countries that may have underestimates for seroprevalence.
We described the first zoonotic transmission model of toxocariasis, which can serve as a foundational tool for testing public veterinary health interventions to reduce the burden of toxocariasis. This model represents an important first step to improving One Health control for this disease.
弓首蛔虫病是一种由犬科和猫科动物的蛔虫线虫引起的被忽视的人畜共患病。它是一个全球性问题，影响着高收入、低收入和中等收入国家的人群。此前估计，每年因弓首蛔虫病导致的伤残调整生命年损失超过90,000个，经济影响每年达25亿美元。弓首蛔虫病的传播取决于人类与终末动物宿主之间的相互作用和接触，这是由长期存在的寄生虫卵对环境的污染介导的。这可能使控制措施复杂化，需要采用“同一健康”方法。在此背景下，传播动态模型在增进我们对疾病传播的理解方面可发挥重要作用，并可作为协助制定控制策略的有效工具。
在本研究中，我们开发了一种用于犬猫弓首蛔虫病人畜共患传播的改良动态 compartmental 模型。我们还将随机性纳入模型，以考虑与表现出感染症状的血清阳性个体比例相关的现有不确定性。
我们最初通过对选定国家现有血清流行率估计值进行迭代模型拟合，使用该模型估计犬猫向人类的特定区域传播率。然后，我们检查了该模型在估计人类接触弓首蛔虫病和有症状病例数量方面的性能，发现模型预测与先前工作的估计之间具有良好的一致性。最后，我们使用该模型估计一系列国家的潜在疾病负担和经济影响，对于血清流行率可能被低估的国家，有可能进行更现实的估计。
我们描述了首个弓首蛔虫病人畜共患传播模型，它可作为测试公共兽医卫生干预措施以减轻弓首蛔虫病负担的基础工具。该模型是改善该病“同一健康”控制的重要第一步。
