Mass drug administration for the control and elimination of Plasmodium vivax malaria: an ecological study from Jiangsu province, China

Recent progress in malaria control has caused renewed interest in mass drug administration (MDA) as a potential elimination strategy but the evidence base is limited. China has extensive experience with MDA, but it is not well documented.
Methods

An ecological study was conducted to describe the use of MDA for the control and elimination of Plasmodium vivax in Jiangsu Province and explore the association between MDA and malaria incidence. Two periods were focused on: 1973 to 1983 when malaria burden was high and MDA administered to highly endemic counties province-wide, and 2000 to 2009, when malaria burden was low and a focal approach was used in two counties. All available data about the strategies implemented, MDA coverage, co-interventions, incidence, and adverse events were collected and described. Joinpoint analysis was used to describe trends in incidence and the relationship between MDA coverage and incidence was explored in negative binomial regression models.
Results

From 1973 to 1983, MDA with pyrimethamine and primaquine was used on a large scale, with up to 30 million people in target counties covered in a peak year (50% of the total population). Joinpoint analyses identified declines in annual incidence, -56.7% (95% CI -75.5 to -23.7%) from 1973–1976 and -12.4% (95% CI -24.7 to 2.0%) from 1976–1983. Population average negative binomial models identified a relationship between higher total population MDA coverage and lower monthly incidence from 1973–1976, IRR 0.98 (95% CI 0.97 to 1.00), while co-interventions, rainfall and GDP were not associated. From 2000–2009, incidence in two counties declined (annual change -43.7 to -14.0%) during a time when focal MDA using chloroquine and primaquine was targeted to villages and/or individuals residing near passively detected index cases (median 0.04% of total population). Although safety data were not collected systematically, there were rare reports of serious but non-fatal events.
Conclusions

In Jiangsu Province, China, large-scale MDA was implemented and associated with declines in high P. vivax malaria transmission; a more recent focal approach may have contributed to interruption of transmission. MDA should be considered a potential key strategy for malaria control and elimination.

AUTHORS: Michelle S Hsiang, Jimee Hwang, Amy R Tao, Yaobao Liu, Adam Bennett, George Dennis Shanks, Jun Cao, Stephen Patrick Kachur, Richard GA Feachem, Roly D Gosling and Qi Gao

Source: Malaria Journal 2013, 12:383 doi:10.1186/1475-2875-12-383
http://www.malariajournal.com/content/12/1/383/abstract
Published: 1 November 2013

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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QUESTION

Why is there no mention here of all the work being done on biolarvicides – the low cost solution for malaria control?

ANSWER

Actually, we had a question a while ago about the ECOWAS program in West Africa, which centers around the use of biolarvicides. A link to that question, and the answer, is provided here: http://www.malaria.com/questions/ecowas-malaria.

The most common form of biolarvicides are those using various microbes, notably Bacillus species, which target mosquito larvae but are harmless to other non-target organisms. A recent study in the Gambia showed very high success rates in killing Anopheles gambiae larvae, when a microbial larvicide using Bacillus thuringiensis varisraelensis strain AM65-52 was applied weekly. Some practitioners are concerned about the amount of effort and man-power a weekly application of larvicide might require, plus the training necessary for correct identification of habitat, but the study in the Gambia seemed to show good compliance once personnel were suitable trained. A link to the study, which is freely available via the Malaria Journal, is available here: http://www.malariajournal.com/content/6/1/76.

 

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In which year did malaria spread in Limpopo?

ANSWER

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