Dataset Information

Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study.

ABSTRACT:

Background

The Shoklo Malaria Research Unit has been working on the Thai-Myanmar border for 25 y providing early diagnosis and treatment (EDT) of malaria. Transmission of Plasmodium falciparum has declined, but resistance to artesunate has emerged. We expanded malaria activities through EDT and evaluated the impact over a 12-y period.

Methods and findings

Between 1 October 1999 and 30 September 2011, the Shoklo Malaria Research Unit increased the number of cross-border (Myanmar side) health facilities from two to 11 and recorded the number of malaria consultations. Changes in malaria incidence were estimated from a cohort of pregnant women, and prevalence from cross-sectional surveys. In vivo and in vitro antimalarial drug efficacy were monitored. Over this period, the number of malaria cases detected increased initially, but then declined rapidly. In children under 5 y, the percentage of consultations due to malaria declined from 78% (95% CI 76-80) (1,048/1,344 consultations) to 7% (95% CI 6.2-7.1) (767/11,542 consultations), p<0.001. The ratio of P. falciparum/P. vivax declined from 1.4 (95% CI 1.3-1.4) to 0.7 (95% CI 0.7-0.8). The case fatality rate was low (39/75,126; 0.05% [95% CI 0.04-0.07]). The incidence of malaria declined from 1.1 to 0.1 episodes per pregnant women-year. The cumulative proportion of P. falciparum decreased significantly from 24.3% (95% CI 21.0-28.0) (143/588 pregnant women) to 3.4% (95% CI 2.8-4.3) (76/2,207 pregnant women), p<0.001. The in vivo efficacy of mefloquine-artesunate declined steadily, with a sharp drop in 2011 (day-42 PCR-adjusted cure rate 42% [95% CI 20-62]). The proportion of patients still slide positive for malaria at day 3 rose from 0% in 2000 to reach 28% (95% CI 13-45) (8/29 patients) in 2011.

Conclusions

Despite the emergence of resistance to artesunate in P. falciparum, the strategy of EDT with artemisinin-based combination treatments has been associated with a reduction in malaria in the migrant population living on the Thai-Myanmar border. Although limited by its observational nature, this study provides useful data on malaria burden in a strategically crucial geographical area. Alternative fixed combination treatments are needed urgently to replace the failing first-line regimen of mefloquine and artesunate. Please see later in the article for the Editors' Summary.

SUBMITTER: Carrara VI

PROVIDER: S-EPMC3589269 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study.

Carrara Verena I VI Lwin Khin Maung KM Phyo Aung Pyae AP Ashley Elizabeth E Wiladphaingern Jacher J Sriprawat Kanlaya K Rijken Marcus M Boel Machteld M McGready Rose R Proux Stephane S Chu Cindy C Singhasivanon Pratap P White Nicholas N Nosten François F

PLoS medicine 20130305 3

<h4>Background</h4>The Shoklo Malaria Research Unit has been working on the Thai-Myanmar border for 25 y providing early diagnosis and treatment (EDT) of malaria. Transmission of Plasmodium falciparum has declined, but resistance to artesunate has emerged. We expanded malaria activities through EDT and evaluated the impact over a 12-y period.<h4>Methods and findings</h4>Between 1 October 1999 and 30 September 2011, the Shoklo Malaria Research Unit increased the number of cross-border (Myanmar si ...[more]

PMID: 23472056

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Dataset Information

Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study.

Background

Methods and findings

Conclusions

Publications

Malaria burden and artemisinin resistance in the mobile and migrant population on the Thai-Myanmar border, 1999-2011: an observational study.

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