Authors: Martha Powell, Future Science Group
New research has warned a highly drug-resistance ‘super’ malaria from western Cambodia has spread to southern Vietnam, leading to alarming rates of the first-line treatment, dihydroartemisinin–piperaquine.
In a letter, published recently in the Lancet Infectious Diseases, researchers have reported the spread of a multidrug-resistant strain – the C580Y Plasmodium falciparum lineage, suggesting this may pose a serious threat to malaria control and eradication efforts. Arjen Dondorp, from the Oxford Tropical Medicine Research Unit in Mahidol, Thailand, commented: “A single mutant strain of very drug-resistant malaria has now spread from western Cambodia to north-eastern Thailand, southern Laos and into southern Vietnam and caused a large increase in treatment failure of patients with malaria.
“This could result in an important increase in malaria transmission in these countries and severely jeopardise their malaria elimination efforts. We hope this evidence will be used to reemphasise the urgency of malaria elimination in the Mekong sub-region before falciparum malaria becomes close to untreatable.”
Resistance to malarial drug artemisinin has previously been observed and associated with mutations in the PfKelch gene. However, in recent developments, a single dominant artemisinin-resistant P. falciparum C580Y mutant lineage arose in western Cambodia and went on to outcompete other resistant parasites, acquiring resistance to a second drug – piperaquine. This forced policy change in Cambodia, with a switch in its first-line treatment from dihydroartemisinin–piperaquine back to artesunate-mefloquine.
This latest update reports the lineage has now spread to South Vietnam and is responsible for alarming failure rates in treatment there.
Senior author, Nicholas White (Oxford Tropical Medicine Research Unit), explained: “We are losing a dangerous race. The spread of this malaria ‘superbug’ has caused an alarming rise in treatment failures forcing changes in drug policy and leaving few options for the future. We need to tackle this public health emergency urgently.”
Michael Chew from the Wellcome Trust’s Infection and Immunobiology team (London, UK), concluded: “The spread of this malaria ‘superbug’ strain, resistant to the most effective drug we have, is alarming and has major implications for public health globally. Around 700,000 people a year die from drug-resistant infections, including malaria. If nothing is done, this could increase to millions of people every year by 2050. Efforts to help track resistance to drugs are vital for improving diagnosis, treatment, and control of drug resistant infections.”
Sources: Imwong M, Hien TT, Thuy-Nhien NT, Dondorp AM, White NJ. Spread of a single multidrug resistant malaria parasite lineage (PfPailin) to Vietnam. Lancet Inf. Dis. doi:10.1016/S1473-3099(17)30524-8 (2017) (Epub ahead of print); http://www.ox.ac.uk/news/2017-09-21-superbug%E2%80%99s-spread-vietnam-threatens-malaria-control