In vivo susceptibility of Plasmodium falciparum to artesunate in Binh Phuoc Province, Vietnam

• Published in: Malaria Journal
• Main Authors: Hien Tran, Thuy-Nhien Nguyen, Phu Nguyen, Boni Maciej F, Thanh Ngo, Nha-Ca Nguyen, Thai Le, Thai Cao, Van Toi Pham, Thuan Phung, Long Le, Dong Le, Merson Laura, Dolecek Christiane, Stepniewska Kasia, Ringwald Pascal, White Nicholas J, Farrar Jeremy, Wolbers Marcel
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2012
• Subjects: Plasmodium falciparum; Artesunate; Parasite clearance half-life; Parasite reduction ratio; Parasite clearance of >72 hours; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/1475-2875-11-355; https://doaj.org/article/3c7ecf9343324e6092a07e122a2cd4e1

Abstract Background By 2009, there were worrying signs from western Cambodia that parasitological responses to artesunate-containing treatment regimens for uncomplicated Plasmodium falciparum malaria were slower than elsewhere which suggested the emergence of artemisinin resistance. Vietnam shares a long land border with Cambodia with a large number of migrants crossing it on a daily basis. Therefore, there is an urgent need to investigate whether there is any evidence of a change in the parasitological response to the artemisinin derivatives in Vietnam. Methods From August 2010 to May 2011, a randomized controlled clinical trial in uncomplicated falciparum malaria was conducted to compare two doses of artesunate (AS) (2mg/kg/day versus 4 mg/kg/day for three days) followed by dihydroartemisinin-piperaquine (DHA-PPQ) and a control arm of DHA-PPQ. The goal was characterization of the current efficacy of artesunate in southern Vietnam. The primary endpoint of this study was the parasite clearance half-life; secondary endpoints included the parasite reduction ratios at 24 and 48 hours and the parasite clearance time. Results 166 patients were recruited into the study. The median parasite clearance half-lives were 3.54 (AS 2mg/kg), 2.72 (AS 4mg/kg), and 2.98 hours (DHA-PPQ) (p=0.19). The median parasite-reduction ratio at 24 hours was 48 in the AS 2mg/kg group compared with 212 and 113 in the other two groups, respectively (p=0.02). The proportions of patients with a parasite clearance time of >72 hours for AS 2mg/kg, AS 4mg/kg and DHA-PPQ were 27%, 27%, and 22%, respectively. Early treatment failure occurred in two (4%) and late clinical failure occurred in one (2%) of the 55 patients in the AS 2mg/kg group, as compared with none in the other two study arms. The PCR-corrected adequate clinical and parasitological response (APCR) rates in the three groups were 94%, 100%, and 100% (p=0.04). Conclusions This study demonstrated faster P . falciparum parasite clearance in southern Vietnam than in western Cambodia but ...