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Ex vivo drug sensitivity profiles of Plasmodium falciparum field isolates from Cambodia and Thailand, 2005 to 2010, determined by a histidine-rich protein-2 assay.

Tyner SD, Lon C, Se Y, Bethell D, Socheat D, Noedl H, Sea D, Satimai W, Schaecher K, Rutvisuttinunt W, Fukuda MM, Chaorattanakawee S, Yingyuen K, Sundrakes S, Chaichana P, Saingam P, Buathong N, Sriwichai S, Chann S, Timmermans A, Saunders DL, Walsh DS - Malar. J. (2012)

Bottom Line: In northern Cambodia, from 2009-2010, GM IC50 values for most drugs approximated the highest western Cambodia GM IC50 values in 2009 or 2010.Western Cambodia is associated with sustained reductions in anti-malarial drug susceptibility, including the artemisinins, with possible emergence, or spread, to northern Cambodia.This potential public health crisis supports continued in vitro drug IC50 monitoring of P. falciparum isolates at key locations in the region.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology and Medicine, US Army Medical Corps, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.

ABSTRACT

Background: In vitro drug susceptibility assay of Plasmodium falciparum field isolates processed "immediate ex vivo" (IEV), without culture adaption, and tested using histidine-rich protein-2 (HRP-2) detection as an assay, is an expedient way to track drug resistance.

Methods: From 2005 to 2010, a HRP-2 in vitro assay assessed 451 P. falciparum field isolates obtained from subjects with malaria in western and northern Cambodia, and eastern Thailand, processed IEV, for 50% inhibitory concentrations (IC50) against seven anti-malarial drugs, including artesunate (AS), dihydroartemisinin (DHA), and piperaquine.

Results: In western Cambodia, from 2006 to 2010, geometric mean (GM) IC50 values for chloroquine, mefloquine, quinine, AS, DHA, and lumefantrine increased. In northern Cambodia, from 2009-2010, GM IC50 values for most drugs approximated the highest western Cambodia GM IC50 values in 2009 or 2010.

Conclusions: Western Cambodia is associated with sustained reductions in anti-malarial drug susceptibility, including the artemisinins, with possible emergence, or spread, to northern Cambodia. This potential public health crisis supports continued in vitro drug IC50 monitoring of P. falciparum isolates at key locations in the region.

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Map depicting provinces in Cambodia and Thailand (shaded) whereP. falciparumisolates were obtained.
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Figure 1: Map depicting provinces in Cambodia and Thailand (shaded) whereP. falciparumisolates were obtained.

Mentions: All studies were approved by 1 or more ethical review boards which included Cambodian National Ethics Committee for Health Research (NECHR), Ethical Review Committee for Research in Human Subjects, Thailand Ministry of Public Health (MoPH), Walter Reed Army Institute of Research (WRAIR) Institutional Review Board and World Health Organization (WHO) Ethical Review Committee (protocol numbers: WRAIR 973, WRAIR 1327, WRAIR 1296, WRAIR 1396, WRAIR 1576, and WRAIR 1737). All protocols complied with International Conference on Harmonization Good Clinical Practice (ICH-GCP) guidelines. Enrollment centers were located in western and northern Cambodia (Pailin, Battambang, Oddar Meanchey and Preah Vihear Provinces (Figure 1), and Trat, eastern Thailand. All sites were considered low transmission, malaria endemic regions at the time of sample collection [8,9].


Ex vivo drug sensitivity profiles of Plasmodium falciparum field isolates from Cambodia and Thailand, 2005 to 2010, determined by a histidine-rich protein-2 assay.

Tyner SD, Lon C, Se Y, Bethell D, Socheat D, Noedl H, Sea D, Satimai W, Schaecher K, Rutvisuttinunt W, Fukuda MM, Chaorattanakawee S, Yingyuen K, Sundrakes S, Chaichana P, Saingam P, Buathong N, Sriwichai S, Chann S, Timmermans A, Saunders DL, Walsh DS - Malar. J. (2012)

Map depicting provinces in Cambodia and Thailand (shaded) whereP. falciparumisolates were obtained.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3403988&req=5

Figure 1: Map depicting provinces in Cambodia and Thailand (shaded) whereP. falciparumisolates were obtained.
Mentions: All studies were approved by 1 or more ethical review boards which included Cambodian National Ethics Committee for Health Research (NECHR), Ethical Review Committee for Research in Human Subjects, Thailand Ministry of Public Health (MoPH), Walter Reed Army Institute of Research (WRAIR) Institutional Review Board and World Health Organization (WHO) Ethical Review Committee (protocol numbers: WRAIR 973, WRAIR 1327, WRAIR 1296, WRAIR 1396, WRAIR 1576, and WRAIR 1737). All protocols complied with International Conference on Harmonization Good Clinical Practice (ICH-GCP) guidelines. Enrollment centers were located in western and northern Cambodia (Pailin, Battambang, Oddar Meanchey and Preah Vihear Provinces (Figure 1), and Trat, eastern Thailand. All sites were considered low transmission, malaria endemic regions at the time of sample collection [8,9].

Bottom Line: In northern Cambodia, from 2009-2010, GM IC50 values for most drugs approximated the highest western Cambodia GM IC50 values in 2009 or 2010.Western Cambodia is associated with sustained reductions in anti-malarial drug susceptibility, including the artemisinins, with possible emergence, or spread, to northern Cambodia.This potential public health crisis supports continued in vitro drug IC50 monitoring of P. falciparum isolates at key locations in the region.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Immunology and Medicine, US Army Medical Corps, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.

ABSTRACT

Background: In vitro drug susceptibility assay of Plasmodium falciparum field isolates processed "immediate ex vivo" (IEV), without culture adaption, and tested using histidine-rich protein-2 (HRP-2) detection as an assay, is an expedient way to track drug resistance.

Methods: From 2005 to 2010, a HRP-2 in vitro assay assessed 451 P. falciparum field isolates obtained from subjects with malaria in western and northern Cambodia, and eastern Thailand, processed IEV, for 50% inhibitory concentrations (IC50) against seven anti-malarial drugs, including artesunate (AS), dihydroartemisinin (DHA), and piperaquine.

Results: In western Cambodia, from 2006 to 2010, geometric mean (GM) IC50 values for chloroquine, mefloquine, quinine, AS, DHA, and lumefantrine increased. In northern Cambodia, from 2009-2010, GM IC50 values for most drugs approximated the highest western Cambodia GM IC50 values in 2009 or 2010.

Conclusions: Western Cambodia is associated with sustained reductions in anti-malarial drug susceptibility, including the artemisinins, with possible emergence, or spread, to northern Cambodia. This potential public health crisis supports continued in vitro drug IC50 monitoring of P. falciparum isolates at key locations in the region.

Show MeSH
Related in: MedlinePlus