Table 1. Onchocerciasis modelling and policy impact.

Specific public health challenge	How modelling addressed the challenge
What is the minimal duration of the OCP necessary to mitigate the risk of recrudescence after cessation of interventions?	ONCHOSIM guided duration of vector control operations in the OCP and investigated the combined impact of vector and ivermectin treatment to reduce programme duration (1997) [5].
What is the feasibility of reaching elimination of onchocerciasis transmission based on ivermectin distribution as the sole intervention (i.e., in the absence of vector control)?	ONCHOSIM informed the Conceptual and Operational Framework of Onchocerciasis Elimination with Ivermectin Treatment launched by the APOC (2010) [8], and EPIONCHO and ONCHOSIM were fitted to data from proof-of-principle elimination studies in foci of Mali and Senegal (2017) [9].
Areas where onchocerciasis–loiasis are coendemic present challenges for ivermectin treatment because of the risk of SAEs in individuals with high Loa loa burden.	Environmental risk modelling helped to guide distribution of ivermectin by mapping risk for L. loa coendemicity in Cameroon (2007) [10].
	Geostatistical mapping, based on RAPLOA data in 11 countries, informed where extra precautionary methods or alternative strategies are needed to minimise SAE risk (2011) [11].
Annual ivermectin distribution may not be sufficient to achieve elimination in foci with high baseline (precontrol) endemicity.	EPIONCHO and ONCHOSIM supported the shift to 6-monthly ivermectin treatment in highly endemic foci in Africa (2014) [12, 13].
At the closure of the APOC in 2015, there was a need to delineate current and alternative/complementary intervention tools to reach elimination at the continental level.	EPIONCHO and ONCHOSIM supported deliberations and final APOC’s report on Strategic Options and Alternative Treatment Strategies for Accelerating Onchocerciasis Elimination in Africa (2015) [6].
Drug discovery and clinical trial design and analysis are essential toward optimising alternative treatment strategies based on the use of macrofilaricides (drugs that kill adult O. volvulus).	Modelling facilitated analysis of clinical trials and informed drug discovery and development by the A∙WOL Consortium (2015–2017) [14, 15].

Abbreviations: APOC, African Programme for Onchocerciasis Control; A∙WOL, Anti-Wolbachia; OCP, Onchocerciasis Control Programme in West Africa; RAPLOA, Rapid Assessment of Prevalence of Loiasis; SAE, severe adverse event