Emerging artemisinin resistance in the border areas of Thailand

Abstract

Emergence of artemisinin resistance has been confirmed in Cambodia and the border areas of Thailand, the well-known hotspots of multidrug resistance Plasmodium falciparum. It appears to be spreading to the western border of Thailand along the Thai-Myanmar border, and will probably spread to other endemic areas of the world in the near future. This raises a serious concern on the long-term efficacy of artemisinin-based combination therapies, as these combination therapies currently constitute the last effective and most tolerable treatment for multidrug-resistant Plasmodium falciparum. Attempts have been made by a diverse array of stakeholders to prevent the emergence of new foci of artemisinin resistance, as well as to limit the spread of resistance to the original foci. The success in achieving this goal depends on effective integration of containment and surveillance programs with other malaria control measures, with support from both basic and operational research.

Artesunate versus Chloroquine Infection–Treatment–Vaccination Defines Stage-Specific Immune Responses Associated with Prolonged Sterile Protection against Both Pre-erythrocytic and Erythrocytic Plasmodium yoelii Infection

“…Although sterile protection can be achieved by immunization with a low number of bites of malaria-infected mosquitoes under CQ coverage, widespread resistance to this drug limits the applicability of the CQ-ITV approach in malaria control. Artemisinin-based combination therapies are currently the treatment of choice for uncomplicated P. falciparum and P. vivax malaria in adults and children in all endemic areas (33), although there have been several reports of drug resistance in the same geographic area where CQ resistance originated in the 1950s, where artemisinin and its derivatives have been used as a monotherapy for more than three decades at subtherapeutic doses (34,35). Like CQ, AS prevents BS infection by blocking the ability of the parasite to complete the intraerythrocytic cycle.…”

Identification of Three Novel Ring Expansion Metabolites of KAE609, a New Spiroindolone Agent for the Treatment of Malaria, in Rats, Dogs, and Humans

“…Drug resistance to widely used artemisinin-based therapies (Carter et al, 2015;Hott et al, 2015) has become an imminent issue since drugresistance strains were identified in Bangladesh, Cambodia, Thailand, Vietnam, Myanmar and Laos (Haque et al, 2013;Na-Bangchang and Karbwang, 2013;Witkowski et al, 2013). Growing global efforts are focusing on finding new cures to combat malaria drug resistance.…”

Pre-erythrocytic Stage of Malaria Infection and the Molecular Targets Available for Interventions

“…Continuous emergence and spread of resistance to newly developed antimalarials (Cohen et al, 2010;Na-Bangchang and Karbwang, 2013;Price et al, 2014;WWARN, 2015) as well as vector resistance to insecticides (Dhiman and Veer, 2014;Strode et al, 2014) are key challenges against existing malaria control measures and highlights the urgent need for an effective vaccine. Despite several preclinical and clinical trials with the aim of developing an effective malaria vaccines (Moreno and Joyner, 2015), the most advanced malaria vaccine candidate in phase 3 trial, RTS,S/AS01, has only shown 31% and 50% efficacy in infants and children respectively (Foquet et al, 2014).…”