After various evaluations of endemicity it was found that Mali qualified to conduct pre-stop ivermectin treatment surveys according to World Health Organization (WHO) guidelines. Thus, between the end of 2019 and the beginning of 2020, a large-scale serological survey of children 5–9 years was conducted in all health districts of Mali suspected of being endemic for onchocerciasis.
The results of this investigation showed the seroprevalence thresholds measured by the OV16 rapid diagnostic test in the laboratory were below the WHO defined 2% level for success in all operational transmission zones, except for an operational transmission zone in the Kayes region, namely the KA05 zone, where there was 2.60% seropositivity to OV16.