What does the COVID-19 pandemic mean for the next decade of onchocerciasis control and elimination?

Abstract

BACKGROUND:

Mass drug administration (MDA) of ivermectin for onchocerciasis has been disrupted by the coronavirus disease 2019 (COVID-19) pandemic. Mathematical modelling can help predict how missed/delayed MDA will affect short-term epidemiological trends and elimination prospects by 2030.

METHODS:

Two onchocerciasis transmission models (EPIONCHO-IBM and ONCHOSIM) are used to simulate microfilarial prevalence trends, elimination probabilities and age profiles of Onchocerca volvulus microfilarial prevalence and intensity for different treatment histories and transmission settings, assuming no interruption, a 1-y (2020) interruption or a 2-y (2020-2021) interruption. Biannual MDA or increased coverage upon MDA resumption are investigated as remedial strategies.

RESULTS:

Programmes with shorter MDA histories and settings with high pre-intervention endemicity will be the most affected. Biannual MDA is more effective than increasing coverage for mitigating COVID-19's impact on MDA. Programmes that had already switched to biannual MDA should be minimally affected. In high-transmission settings with short treatment history, a 2-y interruption could lead to increased microfilarial load in children (EPIONCHO-IBM) and adults (ONCHOSIM).

CONCLUSIONS:

Programmes with shorter (annual MDA) treatment histories should be prioritised for remedial biannual MDA. Increases in microfilarial load could have short- and long-term morbidity and mortality repercussions. These results can guide decision-making to mitigate the impact of COVID-19 on onchocerciasis elimination.

• Authors: Jonathan I D Hamley, David J Blok, Martin Walker, Philip Milton, Adrian D Hopkins, Louise C Hamill, Philip Downs, Sake J de Vlas, Wilma A Stolk, Maria-Gloria Basáñez
• Journal: Transactions of the Royal Society of Tropical Medicine and Hygiene (Trans R Soc Trop Med Hyg) Vol. 115 Issue 3 Pg. 269-280 (03 06 2021) ISSN: 1878-3503 [Electronic] England
• PMID: 33515042 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2021. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

Chemical References

• Filaricides
• Ivermectin

Topics

• COVID-19 (epidemiology)
• Communicable Disease Control (organization & administration)
• Disease Eradication
• Filaricides (therapeutic use)
• Humans
• Ivermectin (therapeutic use)
• Mass Drug Administration
• Models, Theoretical
• Neglected Diseases (epidemiology, prevention & control)
• Onchocerciasis (epidemiology, prevention & control)
• Pandemics
• Prevalence
• SARS-CoV-2