Significant decline in lymphatic filariasis associated with nationwide scale-up of insecticide-treated nets in Zambia.



Nsakashalo-Senkwe, M, Mwase, E, Chizema-Kawesha, E, Mukonka, V, Songolo, P, Masaninga, F, Rebollo, MP, Thomas, B, Bockarie, MJ, Betts, H
et al (show 2 more authors) (2017) Significant decline in lymphatic filariasis associated with nationwide scale-up of insecticide-treated nets in Zambia. Parasite epidemiology and control, 2 (4). 7 - 14.

[img] Text
Significant decline in lymphatic filariasis associated with nationwide scale-up of insecticide-treated nets in Zambia.pdf - Published Version

Download (502kB) | Preview

Abstract

Lymphatic filariasis (LF) is a mosquito-borne disease, broadly endemic in Zambia, and is targeted for elimination by mass drug administration (MDA) of albendazole and diethylcarbamazine citrate (DEC) to at-risk populations. Anopheline mosquitoes are primary vectors of LF in Africa, and it is possible that the significant scale-up of malaria vector control over the past decade may have also impacted LF transmission, and contributed to a decrease in prevalence in Zambia. We therefore aimed to examine the putative association between decreasing LF prevalence and increasing coverage of insecticide-treated mosquito nets (ITNs) for malaria vector control, by comparing LF mapping data collected between 2003-2005 and 2009-2011 to LF sentinel site prevalence data collected between 2012 and 2014, before any anti-LF MDA was started. The coverage of ITNs for malaria was quantified and compared for each site in relation to the dynamics of LF. We found a significant decrease in LF prevalence from the years 2003-2005 (11.5% CI95 6.6; 16.4) to 2012-2014 (0.6% CI95 0.03; 1.1); at the same time, there was a significant scale-up of ITNs across the country from 0.2% (CI95 0.0; 0.3) to 76.1% (CI95 71.4; 80.7) respectively. The creation and comparison of two linear models demonstrated that the geographical and temporal variation in ITN coverage was a better predictor of LF prevalence than year alone. Whilst a causal relationship between LF prevalence and ITN coverage cannot be proved, we propose that the scale-up of ITNs has helped to control Anopheles mosquito populations, which have in turn impacted on LF transmission significantly before the scale-up of MDA. This putative synergy with vector control has helped to put Zambia on track to meet national and global goals of LF elimination by 2020.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 04 Jun 2019 10:00
Last Modified: 09 Jan 2021 03:32
DOI: 10.1016/j.parepi.2017.08.001
Open Access URL: https://doi.org/10.1016/j.parepi.2017.08.001
URI: https://livrepository.liverpool.ac.uk/id/eprint/3044374