Up to 80% of the most common carriers of the disease are immune to the most common treatments, researchers find

This article is more than 1 year old

This article is more than 1 year old

Drug-resistant forms of malaria-causing parasites are spreading across south-east Asia leading to “alarmingly high” treatment failure rates of frontline medication, researchers have warned.

In twin studies published in the Lancet Infectious Diseases journal, they revealed that in parts of Thailand, Vietnam and Cambodia up to 80% of the most common malaria parasites were now resistant to the two most common antimalarial drugs.

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The Plasmodium falciparum parasites have also acquired resistance linked to the failure of treatment in half of cases to one of the newest and most potent frontline drug combinations, they said.

“These worrying findings indicate that the problem of multi-drug resistance in P falciparum has substantially worsened in south-east Asia since 2015,” said Olivo Miotto from the Wellcome Sanger Institute and University of Oxford, who co-led the study. “This highly successful resistant parasite strain is capable of invading new territories and acquiring new genetic properties.”

Roberto Amato, who worked with the team, said: “We discovered [it] had spread aggressively, replacing local malaria parasites, and had become the dominant strain in Vietnam, Laos and north-eastern Thailand.”

Miotto warned of the “terrifying prospect” of the parasite spreading to Africa, where most malaria cases occur.

A similar resistance to a long-time frontline malaria drug, chloroquine, contributed to millions of deaths across Africa in the 1980s.

Malaria kills more than 400,000 people a year, mostly children in Africa.

More than 200 million people are infected with the P falciparum parasite, which is responsible for nine out of 10 malaria deaths globally.

A drug combination known as DHA-PPQ was initially effective against the parasite, before doctors noticed signs of resistance in 2013.

The most recent study into DHA-PPQ failure rates showed they have now reached 53% in south-west Vietnam, and as high as 87% in north-eastern Thailand.



