Public Health Policy Pillars for the Sustainable Elimination of Zoonotic Schistosomiasis

Abstract

Schistosomiasis is a parasitic disease acquired through contact with contaminated freshwater. The definitive hosts are terrestrial mammals, including humans, with some Schistosoma species crossing the animal-human boundary through zoonotic transmission. An estimated 12 million people live at risk of zoonotic schistosomiasis caused by Schistosoma japonicum and Schistosoma mekongi, largely in the World Health Organization’s Western Pacific Region and in Indonesia. Mathematical models have played a vital role in our understanding of the biology, transmission, and impact of intervention strategies, however, these have mostly focused on non-zoonotic Schistosoma species. Whilst these non-zoonotic-based models capture some aspects of zoonotic schistosomiasis transmission dynamics, the commonly-used frameworks are yet to adequately capture the complex epi-ecology of multi-host zoonotic transmission. However, overcoming these knowledge gaps goes beyond transmission dynamics modelling. To improve model utility and enhance zoonotic schistosomiasis control programmes, we highlight three pillars that we believe are vital to sustainable interventions at the implementation (community) and policy-level, and discuss the pillars in the context of a One-Health approach, recognising the interconnection between humans, animals and their shared environment. These pillars are: (1) human and animal epi-ecological understanding; (2) economic considerations (such as treatment costs and animal losses); and (3) sociological understanding, including inter- and intra-human and animal interactions. These pillars must be built on a strong foundation of trust, support and commitment of stakeholders and involved institutions.

Quantifying Spillover Risk with an Integrated Bat-Rabies Dynamic Modeling Framework

“…Te behavior efects on intervention need to be accounted for in the model if we want more realistic predictions. Furthermore, the intervention strategies efective to reach programmatic goals need to be evaluated in economic manner as the government and farmers' fnancial sources are limited [48]. For example, anemia from bat bites may reduce livestock productivity [7], hence making a difference in bat culling compared to bat vaccination.…”

Metalloenzyme Inhibitors against Zoonotic Infections: Focus on Leishmania and Schistosoma

“…This results in approximately 24,000 fatalities and at least 2.5 million disability-adjusted life years (DALYs) annually. 9,10 This parasitic infection is caused by Schistosoma haematobium, S. japonicum, and S. mansoni, and the only available treatment is the anthelmintic drug praziquantel (1, Figure 1). 11,12 The lack of alternative treatments, together with the schistosomial biphasic sensitivity to 1 over its life cycle, emphasizes parasite resistance as a major cause of concern, considering the different susceptibility to the drug during juvenile and adult infections.…”

“…Nevertheless, the heaviest burden is borne by sub-Saharan Africa (SSA), where 90% of human schistosomial infections are concentrated. This results in approximately 24,000 fatalities and at least 2.5 million disability-adjusted life years (DALYs) annually. , This parasitic infection is caused by Schistosoma haematobium , S. japonicum , and S. mansoni , and the only available treatment is the anthelmintic drug praziquantel ( 1 , Figure ). , The lack of alternative treatments, together with the schistosomial biphasic sensitivity to 1 over its life cycle, emphasizes parasite resistance as a major cause of concern, considering the different susceptibility to the drug during juvenile and adult infections. − Although the human medicines committee (CHMP) of the European Medicines Agency (EMA) has recently expressed a positive opinion about the use of 1 for the treatment of schistosomiasis in children (from 3 months to 6 years old), the discovery of an alternative treatment would be urgently needed to manage early or persistent infections.…”

Reaching the World Health Organization elimination targets for schistosomiasis: the importance of a One Health perspective

“…Approximately 12 million people have been estimated to be at risk of zoonotic schistosomiasis in Asia [ 90 ]. Such estimates are yet to be produced for Africa.…”

“…Improved understanding of the eco-epidemiology of schistosomiasis at the human–animal interface and the economic and sociological factors affecting the feasibility and effectiveness of control interventions has been recently proposed as policy pillars for the sustainable elimination of zoonotic schistosomiasis [ 90 ]. Zoonotic S. japonicum clade and S. haematobium clade schistosomes, as well as species that cause animal schistosomiasis, ought to be considered when setting animal health and veterinary public health goals to accompany existing public health elimination goals [ 3 ].…”