Researchers report that a strain of drug-resistant malaria is rapidly spreading across Southeast Asia, with fears that it could reach Africa.
Findings from a comprehensive genome study published in the journal Lancet Infectious Diseases reveal that a new strain of malaria parasites is spreading among Southeast Asian countries. There is fear that this new strain otherwise known as KEL1/PLA1 may lead to terrible consequences in places where malaria is endemic.
The strain observed by researchers from the Wellcome Sanger Institute, University of Oxford and Mahidol University, Bangkok is resistant to most common antimalarial drugs used in these countries.
It is thought that failure of first-line drugs for malaria treatment may have exacerbated the spread of the new strain.
Spreading and Dominant
Malaria results when Plasmodium parasites enter the body. This occurs through mosquito bites which carry these parasites.
There are treatments for successfully combating malaria, especially when they commence earlier enough. But there is problem of resistance to drugs by some of the parasites, making it difficult to completely get rid of the disease.
The new strain of malaria is believed to have evolved from Cambodia and spread from there between 2007 and 2013.
According to the researchers, KEL1/PLA1 has now spread to Laos, Vietnam and Thailand. It has also become the dominant strain in these places.
“The speed at which these resistant malaria parasites have spread in Southeast Asia is very worrying,” said Professor Olivo Miotto, a senior study author.
The scientists sequenced and analyzed the DNA of almost 1,700 malaria parasites between 2008 and 2018. These were obtained from the blood samples of people having malaria.
What they observed was that the prevalence of the new parasite strain has been increasing since 2013.
KEL1/PLA1 accounted for more than 50 percent of malaria cases in the countries that were studied, leaving out only Laos. Its incidence is as high as 80 percent, or greater, in Vietnam and northeastern Thailand.
The researchers are concerned that the new strain could make its way to Africa.
“This highly successful resistant parasite strain is capable of invading new territories and acquiring new genetic properties, raising the terrifying prospect that it could reach Africa,” Miotto said.
Most malaria cases and related deaths are believed to occur in Africa.
The disease resulted in 435,000 deaths worldwide in 2017, according to the World Health Organization (WHO). Of this total, about 403,000 were in Africa.
The only worrying thing is not that KEL1/PLA1 is fast spreading; it is also evolving. This is why it is becoming increasingly resistant to treatment.
A combination of two potent antimalarial medications, dihydroartemisinin and piperaquine, known as DHA-PPQ has been the preferred malaria treatment in most places in Asia over the past decade. The study shows that the new strain has evolved and become resistant to these powerful drugs.
This new study highlights the need for further research to better understand the extent of the problem. This should help to ascertain what drugs would help against the resistant parasites.
“With the spread and intensification of resistance, our findings highlight the urgent need to adopt alternative first-line treatments,” said Professor Tran Tinh Hien, one of the study authors.
A related study published in the same issue of The Lancet Infectious Disease suggests that treatment with DHA-PPQ contributed to spread of the drug-resistant strain.
Miotto said other drugs currently available might be helpful against the parasites. But the research suggests need for urgent action, according to him.
- Drug-resistant malaria ‘spreading aggressively’ across South East Asia, scientists say | The Independent (https://www.independent.co.uk/news/world/asia/malaria-warning-drug-resistant-mosquito-thailand-asia-cambodia-laos-vietnam-a9017316.html)
- Multidrug-resistant malaria spreading in Asia: Study reveals importance of genomic surveillance for malaria control strategies (https://www.sciencedaily.com/releases/2019/07/190723085947.htm)