Efficacy of chloroquine in the treatment of Plasmodium vivax malaria in Turkey

Abstract In most regions of the world, chloroquine (CQ) has been the standard treatment for Plasmodium vivax malaria for more than 40 years. Recently, however, CQ-resistant P. vivax has been reported from Oceania, several parts of Asia, and South America. The therapeutic efficacy of CQ in the treatment of acute, P. vivax malaria has now been assessed in two areas of the Turkish province of Şanlıurfa: the towns of Karacadag and Sekerli. On admission and on days 2, 3, 7, 14, 21, and 28, all 112 patients investigated were examined clinically and blood samples were collected and smeared. Treatment consisted of 10 mg CQ/kg on day 0, the same dose on day 1, and 5 mg CQ/mg on day 2, each dose being supervised. Worryingly, 14.7% of the patients from Karacadag and 10.3% of those from Sekerli showed apparent treatment failure between days 3 and 28. In Şanlıurfa province, in south–eastern Turkey, there therefore seems to be a high risk of therapeutic failure in patients given CQ to cure P. vivax malaria, probably because of CQ resistance.