The last man standing is the most resistant: eliminating artemisinin-resistant malaria in Cambodia

Abstract

Background: Artemisinin combination therapy (ACT) is now the recommended first-line treatment for falciparum malaria throughout the world. Initiatives to eliminate malaria are critically dependent on its efficacy. There is recent worrying evidence that artemisinin resistance has arisen on the Thai-Cambodian border. Urgent containment interventions are planned and about to be executed. Mathematical modeling approaches to intervention design are now integrated into the field of malaria epidemiology and control. The use of such an approach to investigate the likely effectiveness of different containment measures with the ultimate aim of eliminating artemisininresistant malaria is described.

In vitro antiplasmodial effect of ethanolic extracts of coastal medicinal plants along Palk Strait against Plasmodium falciparum

“…Artemisinin, isolated from the well-known Chinese medicinal plant A. annua, is one of the best compounds used to treat multi-drug resistant strains of P. falciparum. However, artemisinin-resistant malaria parasites were recently detected in Cambodia [24] . The development and spread of drug resistant strains of the causative agent P. falciparum has limited the effectiveness of the currently used malarial drugs.…”

No Evidence of Delayed Parasite Clearance after Oral Artesunate Treatment of Uncomplicated Falciparum Malaria in Mali

“…First, artemisinins have only been widely used in Mali since 2004, compared with more than 30 years in Cambodia, and thus there has been relatively little drug pressure favoring resistance. 2,6 Second, because artemisinins are mainly available as co-formulated ACTs through subsidized programs, artemisinin monotherapy use in Mali is likely proportionally much lower than the 78% documented in western Cambodia in 2002. 22 Third, given the high intensity of falciparum malaria transmission in Mali, even in this pediatric population, host immunity and the large transmission reservoir of asymptomatic untreated individuals likely serve as powerful obstacles to the emergence of artemisinin resistance.…”

“…1,2 In recent years, Plasmodium falciparum resistance to artemisinins has developed and been confirmed along the Thai-Cambodian border. 3,4 In the absence of a molecular marker for artemisinin resistance, 5 and with no validated in vitro assay predictive of clinical measures of resistance, delayed parasite clearance has been identified as a useful indicator of artemisinin resistance.…”

Assessing the impact of next-generation rapid diagnostic tests on Plasmodium falciparum malaria elimination strategies

“…We used a deterministic model for the transmission of P. falciparum malaria similar to those previously described 32 with four infection classes: severe; clinical; asymptomatic and detectable by microscopy; and asymptomatic and undetectable by microscopy. Each infection class has a distribution of parasitaemia associated with it, which is used to estimate the sensitivity of various diagnostic tests.…”