Jonathan I D Hamley1,2, David J Blok3, Martin Walker1,4, Philip Milton1,2, Adrian D Hopkins5, Louise C Hamill6, Philip Downs6, Sake J de Vlas3, Wilma A Stolk3, Maria-Gloria Basáñez1,2. 1. London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's campus), Imperial College London, Norfolk Place, London W2 1PG, UK. 2. MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St Mary's campus), Imperial College London, Norfolk Place, London W2 1PG, UK. 3. Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. 4. London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield AL9 7TA, UK. 5. Neglected and Disabling Diseases of Poverty Consultant, Kent, UK. 6. Sightsavers, 35 Perrymount Road, Haywards Heath, RH16 3BW, UK.
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.
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: Anna Borlase; Epke A Le Rutte; Soledad Castaño; David J Blok; Jaspreet Toor; Federica Giardina; Emma L Davis Journal: Lancet Glob Health Date: 2022-11 Impact factor: 38.927
Authors: Laura Willen; Philip Milton; Jonathan I D Hamley; Martin Walker; Mike Y Osei-Atweneboana; Petr Volf; Maria-Gloria Basáñez; Orin Courtenay Journal: PLoS Negl Trop Dis Date: 2022-01-12
Authors: Jessica Clark; Wilma A Stolk; María-Gloria Basáñez; Luc E Coffeng; Zulma M Cucunubá; Matthew A Dixon; Louise Dyson; Katie Hampson; Michael Marks; Graham F Medley; Timothy M Pollington; Joaquin M Prada; Kat S Rock; Henrik Salje; Jaspreet Toor; T Déirdre Hollingsworth Journal: Gates Open Res Date: 2022-02-02
Authors: Sarah Gwyn; Ado Abubakar; Oluwaseun Akinmulero; Eric Bergeron; Ugboaja Nkechi Blessing; Jasmine Chaitram; Melissa M Coughlin; Ayuba B Dawurung; Felicia Nwatu Dickson; Mudiaga Esiekpe; Erasogie Evbuomwan; Stacie M Greby; Nnaemeka C Iriemenam; Markus H Kainulainen; Thomas Andrew Naanpoen; Loveth Napoloen; Ifeanyichukwu Odoh; McPaul Okoye; Temitope Olaleye; Amy J Schuh; S Michele Owen; Awala Samuel; Diana L Martin Journal: Am J Trop Med Hyg Date: 2022-06-27 Impact factor: 3.707
Authors: T Déirdre Hollingsworth; Pauline Mwinzi; Andreia Vasconcelos; Sake J de Vlas Journal: Trans R Soc Trop Med Hyg Date: 2021-03-06 Impact factor: 2.184