
AsianScientist (Nov. 11, 2016) – A frontline malaria treatment is quickly losing power in Cambodia due to the rapid spread of drug-resistant parasites, according to a study published in The Lancet Infectious Diseases.
The presence of piperaquine-resistant malaria parasites in several Cambodian provinces was confirmed earlier this year by researchers from the US National Institutes of Health and their colleagues. Now, by comparing the complete genomes of 297 parasites isolated from Cambodian malaria patients to a reference malaria parasite genome, the team has identified two genetic markers that are strongly associated with the resistance to piperaquine.
Led by US National Institute of Allergy and Infectious Diseases (NIAID) scientist Dr. Rick Fairhurst and Dr. Roberto Amato of the Wellcome Trust Sanger Institute (WTSI), Cambridge, UK, the team also included researchers from the National Center for Parasitology, Entomology and Malaria Control in Phnom Penh, Cambodia, and from Mahidol University in Bangkok, Thailand.
The first genetic marker they identified, while associated with drug resistance, likely does not play a functional role in enabling parasites to resist piperaquine, according to the researchers. In contrast, the second resistance marker identified may play a functional role. That marker is an increased number of copies of the genes plasmepsin II and plasmepsin III in those parasites that resist piperaquine.
A simple finger pinprick blood test can show whether a malaria patient has parasites with the genetic markers. If so, the researchers say that an alternative drug combination, artesunate-mefloquine, should be used because the current frontline treatment combining fast-acting dihydroartemisinin with long-lasting piperaquine is likely to fail in this scenario.
The article can be found at: Amato et al. (2016) Genetic Markers Associated with Dihydroartemisinin-Piperaquine Failure in Plasmodium Falciparum Malaria in Cambodia: A Genotype-Phenotype Association Study.
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Source: National Institute of Allergy and Infectious Diseases; Photo: Pixabay.
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