RT Journal Article
SR Electronic
T1 Why onchocerciasis transmission persists after 15 annual ivermectin mass drug administrations in South-West Cameroon
JF BMJ Global Health
JO BMJ Global Health
FD BMJ Publishing Group Ltd
SP e003248
DO 10.1136/bmjgh-2020-003248
VO 6
IS 1
A1 Armelle Forrer
A1 Samuel Wanji
A1 Elisabeth Dibando Obie
A1 Theobald Mue Nji
A1 Louise Hamill
A1 Kim Ozano
A1 Helen Piotrowski
A1 Laura Dean
A1 Abdel J Njouendou
A1 Relindis Ekanya
A1 Winston Patrick Chounna Ndongmo
A1 Ebua Gallus Fung
A1 Dum-Buo Nnamdi
A1 Raphael A Abong
A1 Amuam Andrew Beng
A1 Mathias Esum Eyong
A1 Bertrand L Ndzeshang
A1 Desmond Akumtoh Nkimbeng
A1 Samuel Teghen
A1 Anicetus Suireng
A1 Ernerstine Ebot Ashu
A1 Emmanuel Kah
A1 Michele M Murdoch
A1 Rachael Thomson
A1 Sally Theobald
A1 Peter Enyong
A1 Joseph D Turner
A1 Mark J Taylor
YR 2021
UL http://gh.bmj.com/content/6/1/e003248.abstract
AB Introduction Onchocerciasis is targeted for elimination mainly with annual community-directed treatment with ivermectin (CDTI). High infection levels have been reported in South-West Cameroon, despite ≥15 years of CDTI. The aim of this study was to assess factors associated with continued onchocerciasis transmission and skin disease.Methods A large-scale cross-sectional study was conducted in 2017 in 20 communities in a loiasis-risk area in South-West Cameroon. A mixed-methods approach was used. Associations between infection levels, skin disease and adherence to CDTI were assessed using mixed regression modelling. Different community members’ perception and acceptability of the CDTI strategy was explored using semi-structured interviews.Results Onchocerciasis prevalence was 44.4% among 9456 participants. 17.5% of adults were systematic non-adherers and 5.9% participated in ≥75% of CDTI rounds. Skin disease affected 1/10 participants, including children. Increasing self-reported adherence to CDTI was associated with lower infection levels in participants aged ≥15 years but not in children. Adherence to CDTI was positively influenced by perceived health benefits, and negatively influenced by fear of adverse events linked with economic loss. Concern of lethal adverse events was a common reason for systematic non-adherence.Conclusion CDTI alone is unlikely to achieve elimination in those high transmission areas where low participation is commonly associated with the fear of adverse events, despite the current quasi absence of high-risk levels of loiasis. Such persisting historical memories and fear of ivermectin might impact adherence to CDTI also in areas with historical presence but current absence of loiasis. Because such issues are unlikely to be tackled by CDTI adaptive measures, alternative strategies are needed for onchocerciasis elimination where negative perception of ivermectin is an entrenched barrier to community participation in programmes.