Authors

Discussion

Aim: The World Health Organization 2021–2030 roadmap on neglected tropical diseases has proposed that intensified control be implemented for cystic echinococcosis (caused by infection with the cestode Echinococcus granulosus sensu lato) in highly endemic areas of 17 countries by 2030. We aim to evaluate the effectiveness of different interventions in South America, which can be quantified with a transmission model for E. granulosus between sheep and dogs.

Methods: We developed a multi-host, individual-based transmission model that captures the parasite population dynamics processes across intermediate hosts (sheep)—which develop infective cysts; definitive hosts (dogs) that acquire the infection from ingestion of infected offal (and harbour adult worms), and the environment, contaminated with parasite eggs. Humans are accidental dead-end hosts that can develop cysts (hydatid disease). We simulated several interventions to assess their effectiveness in reducing CE prevalence in sheep and dogs.

Results: Local control of CE can be difficult using deworming drugs alone. However, the EG95 sheep vaccine could potentially be a game changer. Management practices play a large role in shaping transmission events and can have a substantial impact on human health.

Conclusions and Future work: Part of the challenge in controlling and eliminating CE is the costs of such a programme. As hydatid disease prevalence decreases in human communities, it becomes harder to justify the cost of elimination in the zoonotic reservoirs. We will conduct a cost-effectiveness analysis on each combination of interventions to evaluate their cost against the health benefits gained.