Scaling-down mass ivermectin treatment for onchocerciasis elimination: modelling the impact of the geographical unit for decision making
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
BACKGROUND: Due to spatial heterogeneity in onchocerciasis transmission, the duration of ivermectin mass drug administration (MDA) required for eliminating onchocerciasis will vary within endemic areas and the occurrence of transmission 'hotspots' is inevitable. The geographical scale at which stop-MDA decisions are made will be a key driver in how rapidly national programmes can scale down active intervention upon achieving the epidemiological targets for elimination. METHODS: We use two onchocerciasis models (EPIONCHO-IBM and ONCHOSIM) to predict the likelihood of achieving elimination by 2030 in Africa, accounting for variation in pre-intervention endemicity levels and histories of ivermectin treatment. We explore how decision-making at contrasting geographical scales (community vs. larger scale 'project') changes projections on populations still requiring MDA or transitioning to post-treatment surveillance. RESULTS: The total population considered grows from 118 million people in 2020 to 136 million in 2030. If stop-MDA decisions are made at project level, the number of people requiring treatment declines from 69-118 million in 2020 to 59-118 million in 2030. If stop-MDA decisions are made at community level, the numbers decline from 23-81 million in 2020 to 15-63 million in 2030. The lower estimates in these predictions intervals are based on ONCHOSIM, the upper limits on EPIONCHO-IBM. DISCUSSION/CONCLUSIONS: The geographical scale at which stop-MDA decisions are made strongly determines how rapidly national onchocerciasis programmes can scale down MDA programmes. Stopping in portions of project areas or transmission zones would free up human and economic resources.
Date Issued
2021-06-15
Date Acceptance
2021-04-01
Citation
Clinical Infectious Diseases, 2021, 72 (Suppl. 3), pp.S165-S171
ISSN
1058-4838
Publisher
Oxford University Press
Start Page
S165
End Page
S171
Journal / Book Title
Clinical Infectious Diseases
Volume
72
Issue
Suppl. 3
Copyright Statement
© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/33909070
PII: 6256998
Subjects
Onchocerciasis
elimination
ivermectin
mass drug administration
mathematical modelling
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2021-06-14