Evaluating whether the ivermectin mass drug administration stoppage threshold for onchocerciasis can be safely adjusted

This study, benefiting from the technical support of Sightsavers in Benin, is part of a multi-country study (Benin, Ghana and Tanzania) supported by African Field Epidemiological Network (AFENET) in partnership with neglected tropical diseases (NTDs) departments of ministries of health and US Centers for Disease Control and Prevention.

The study questions whether the World Health Organization’s (WHO) 2016 serological threshold of 0.1% for stopping mass drug administration (MDA) for onchocerciasis is too stringent.

The primary aim is to assess whether an Ov-16 enzyme-linked immunosorbent assay (ELISA) seroprevalence of ≤%2 can be safely used as a threshold for stopping MDA without risk of recrudescence when the prevalence of O-150 polymerase chain reaction (PCR) positivity (Poolscreen) is <1/1000 (<0.1%) in parous blackflies or <1/2000 (0.05%) in all blackflies.

• Determine the seroprevalence of anti-Ov-16 antibodies by ELISA in children aged five to nine years at baseline and end of the study
• Conduct annual serological assessments to establish any recrudescence in the study area after the cessation of MDA during the period between the initial and end-of-study assessments
• Determine the initial infection rate of blackflies by O-150  (PCR) in pools of blackflies already collected by the national NTDs control programme in the study area to ensure that it is acceptable to stop MDA
• Conduct annual entomological assessments to establish any recrudescence in the study area after the cessation of MDA using the new serological threshold in children

The results will contribute to the evidence for keeping/updating the currently recognised serological threshold for stopping MDA.

• Quantitative

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