Monitoring of clinical efficacy and in vitro sensitivity of Plasmodium vivax to chloroquine in area along Thai Myanmar border during 2009-2010

Malaria Journal

Research

Kanchana Rungsihirunrat¹  Ronnatrai Ruengweerayut²  Wanna Chacharoenkul³  Kesara Na-Bangchang³  Poonuch Muhamad³ 

[1] College of Public Health, Chulalongkorn University, Thailand;Mae-Sot General Hospital, Mae-Sot, Tak Province, Thailand;Pharmacology and Toxicology Unit, Graduate Program in Biomedical Sciences, Thammasat University, Thailand;

关键词: Malaria;    Chloroquine;    Artesunate;    Vivax Malaria;    Vivax Infection;   

DOI  :  10.1186/1475-2875-10-44

 received in 2010-10-07, accepted in 2011-02-16,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundIn Thailand, the proportion of Plasmodium vivax infection has become equal to Plasmodium falciparum. Reports of a trend of gradual decline of in vitro sensitivity of P. vivax to chloroquine in some areas of the country, together with accumulating evidences of chloroquine resistance P. vivax in other parts of the world, emphasize the need for closely and continuously monitoring clinical efficacy in conjunction with in vitro sensitivity of P. vivax isolates.MethodsThe study was conducted at Mae Tao clinic for migrant workers, Tak Province during March 2008 - August 2009. A total of 130 patients (17 Thais and 113 Burmeses; 64 males and 66 females) with mono-infection of P. vivax malaria, aged between 15-60 years and weighing more than 40 kg, were included in the study. Patients received treatment with chloroquine (2,000 mg chloroquine phosphate over three days) and the anti-relapse drug primaquine (15 mg for 14 days). In vitro sensitivity of P. vivax isolates was evaluated by schizont maturation inhibition assay.ResultsAll patients showed satisfactory response to treatment. The cure rate was virtually 100% within the follow-up period of 42 days. Neither recurrence of P. vivax parasitaemia nor appearance of P. falciparum occurred during the investigation period. In vitro data showed a stable sensitivity of chloroquine in this area since 2006. Geometric mean and median (95% CI) values of IC50 for chloroquine were 100.1 and 134.7 (1.1-264.9) nM, respectively.ConclusionIn vivo results suggest that the standard regimen of chloroquine was still very effective for the treatment of blood infections with P. vivax in the Thai-Myanmar border area. In vitro sensitivity data however, raise the possibility of potential advent of resistance in the future. Regular monitoring of the chloroquine sensitivity of P. vivax is essential to facilitate the early recognition of treatment failures and to expedite the formulation of appropriate changes to the drug policy.

【 授权许可】

Unknown   
© Muhamad et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.