Modelling strategies to break transmission of lymphatic filariasis - aggregation, adherence and vector competence greatly alter elimination

Title: Modelling strategies to break transmission of lymphatic filariasis - aggregation, adherence and vector competence greatly alter elimination
Authors: Irvine, MA
Reimer, LJ
Njenga, SM
Gunawardena, S
Kelly-Hope, L
Bockarie, M
Hollingsworth, TD
Item Type: Journal Article
Abstract: Background With ambitious targets to eliminate lymphatic filariasis over the coming years, there is a need to identify optimal strategies to achieve them in areas with different baseline prevalence and stages of control. Modelling can assist in identifying what data should be collected and what strategies are best for which scenarios. Methods We develop a new individual-based, stochastic mathematical model of the transmission of lymphatic filariasis. We validate the model by fitting to a first time point and predicting future timepoints from surveillance data in Kenya and Sri Lanka, which have different vectors and different stages of the control programme. We then simulate different treatment scenarios in low, medium and high transmission settings, comparing once yearly mass drug administration (MDA) with more frequent MDA and higher coverage. We investigate the potential impact that vector control, systematic non-compliance and different levels of aggregation have on the dynamics of transmission and control. Results In all settings, increasing coverage from 65 to 80 % has a similar impact on control to treating twice a year at 65 % coverage, for fewer drug treatments being distributed. Vector control has a large impact, even at moderate levels. The extent of aggregation of parasite loads amongst a small portion of the population, which has been estimated to be highly variable in different settings, can undermine the success of a programme, particularly if high risk sub-communities are not accessing interventions. Conclusion Even moderate levels of vector control have a large impact both on the reduction in prevalence and the maintenance of gains made during MDA, even when parasite loads are highly aggregated, and use of vector control is at moderate levels. For the same prevalence, differences in aggregation and adherence can result in very different dynamics. The novel analysis of a small amount of surveillance data and resulting simulations highlight the need for more individual level data to be analysed to effectively tailor programmes in the drive for elimination.
Issue Date: 22-Oct-2015
Date of Acceptance: 6-Oct-2015
ISSN: 1756-3305
Publisher: BioMed Central
Journal / Book Title: Parasites & Vectors
Volume: 8
Copyright Statement: This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.
Keywords: Science & Technology
Life Sciences & Biomedicine
Disease Transmission, Infectious
Elephantiasis, Filarial
Insect Control
Models, Theoretical
Sri Lanka
Mycology & Parasitology
1108 Medical Microbiology
1117 Public Health And Health Services
Publication Status: Published
Article Number: 547
Appears in Collections:Epidemiology, Public Health and Primary Care

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Creative Commonsx