Gonzales-Gustavson Eloy, Pizzitutti Francesco, Bonnet Gabrielle, Muro Claudio, Gamboa Ricardo, Bustos Javier A, Gabriël Sarah, Pan William K, Garcia Héctor H, ÓNeal Seth
Universidad Nacional Mayor de San Marcos.
Universidad San Francisco de Quito.
Res Sq. 2025 Apr 23:rs.3.rs-6496988. doi: 10.21203/rs.3.rs-6496988/v1.
is a zoonotic parasite causing significant health and economic burdens, with complex transmission dynamics requiring improved control strategies.
This study investigates the effect of infection and reinfection on cyst development in pigs and evaluates how acquired immunity constrains parasite burden. A total of 116 pigs were purchased from commercial farms in northern Peru and housed in pathogen-free facilities under controlled conditions. Of these, 110 pigs were allocated to 18 experimental groups to (1) evaluate the impact of infection and reinfection with varying doses of eggs and (2) generate a model to predict the number of live cysts produced, given the dose and age at infection. Gravid proglottids collected from human cases of taeniasis were used to prepare egg pools, ensuring viability consistency. Infections were administered orally using gelatin capsules via esophageal catheterization, followed by necropsy 10 weeks after the final infection event to quantify cysts. A negative binomial regression model was used to analyze cyst burden dependence on infection dose, past infection, age, and other factors.
No statistically significant differences in cyst counts were observed between pigs infected once and those that were reinfected, regardless of the initial dose (as low as 100 eggs) or reinfection dose (up to 20,000 eggs). This finding highlights that infection results in strong acquired immunity, effectively blocking subsequent infections. A quantitative dose-response model suggests that the relationship between egg dose and the number of viable cysts is best described by a power relationship. Combining data from single-infection and reinfected pigs into a unified model improved prediction precision. Finally, incorporating age at infection results in a model of the number of viable cysts in pigs depending on dose and age that combines acquired and innate immunity effects, i.e. changes in susceptibility with age.
Initial exposure to eggs induces strong acquired immunity in pigs, effectively preventing reinfection. Our quantitative dose-response model predicting live cyst counts based on egg dose and pig age offers valuable insights for integrating immunity processes into models of transmission.
是一种人畜共患寄生虫，会造成重大的健康和经济负担，其传播动态复杂，需要改进控制策略。
本研究调查了感染和再感染对猪体内囊肿发育的影响，并评估获得性免疫如何限制寄生虫负担。从秘鲁北部的商业农场购买了116头猪，并在可控条件下饲养在无病原体设施中。其中，110头猪被分配到18个实验组，以（1）评估不同剂量的虫卵感染和再感染的影响，以及（2）建立一个模型，根据感染时的剂量和年龄预测产生的活囊肿数量。从人体带绦虫病例中收集的孕节用于制备虫卵库，确保活力一致性。通过食管插管使用明胶胶囊口服给药，在最后一次感染事件10周后进行尸检以量化囊肿。使用负二项回归模型分析囊肿负担对感染剂量、既往感染、年龄和其他因素的依赖性。
无论初始剂量（低至100个虫卵）或再感染剂量（高达20000个虫卵）如何，单次感染的猪和再感染的猪之间在囊肿计数上均未观察到统计学上的显著差异。这一发现突出表明，感染会产生强大的获得性免疫，有效阻断后续感染。定量剂量反应模型表明，虫卵剂量与活囊肿数量之间的关系最好用幂关系来描述。将单次感染和再感染猪的数据合并到一个统一模型中提高了预测精度。最后，纳入感染时的年龄，得到了一个根据剂量和年龄预测猪体内活囊肿数量的模型，该模型结合了获得性免疫和先天性免疫效应，即易感性随年龄的变化。
初次接触虫卵可在猪体内诱导强大的获得性免疫，有效预防再感染。我们基于虫卵剂量和猪年龄预测活囊肿计数的定量剂量反应模型为将免疫过程整合到传播模型中提供了有价值的见解。
