Advance of resistant malaria 'poses serious global threat'

Researchers who found resistant malaria in samples from Myanmar say it is moving at an alarming pace across Asia. They call for a more vigorous international effort to stop it crossing to neighboring India and turning into a serious global threat.

Malaria samples collected in and around Myanmar contained evidence of resistance to the frontline drug artemisinin.

In The Lancet Infectious Diseases, the team reports how samples collected in and around Myanmar contained evidence of resistance to the frontline drug artemisinin.

The researchers, at the Wellcome Trust in the UK, warn that if the resistant parasite spreads into neighboring India, it would pose a serious threat to the global control and eradication of malaria.

The warning is a reminder of what happened 50 years ago when malaria resistant to the drug chloroquine emerged in Asia, spread from Myanmar to India and then to the rest of the world, claiming millions of lives in its wake.

The new research shows that history is repeating itself with parasites resistant to artemisinin drugs, the mainstay of modern malaria treatment, now widespread in Myanmar.

We are facing the imminent threat of resistance spreading into India, with thousands of lives at risk.

Resistant malaria found 25 km from the Indian border

For the study, the researchers at Oxford University in the UK, tested nearly a thousand malaria parasite samples collected at 55 malaria treatment centers across Myanmar and its border regions.

The research team found 39% of samples carried genetic evidence of resistance to artemisinin. They also confirmed resistant parasites were present in samples taken from centers located only 25 km from the Indian border.

The authors note how the discovery of the K13 genetic marker in the malaria parasite Plasmodium falciparum "has transformed approaches to the monitoring of artemisinin resistance, allowing introduction of molecular surveillance in remote areas through analysis of DNA."

The rapid collection of samples, even from remote locations, coupled with the ability to test immediately for K13, gives the team a unique opportunity generate near "real-time" information on the spread of resistance. 

With artemisinins, we are in the unusual position of having molecular markers for resistance before resistance has spread globally. The more we understand about the current situation in the border regions, the better prepared we are to adapt and implement strategies to overcome the spread of further drug resistance.

'Real-time' mapping of resistant malaria spread anticipates likely routes

The research team has produced maps of the region that show the predicted extent of artemisinin resistance based on the rate of K13 mutations in the samples collected from the various sites.

The maps suggest in large areas of East and North of Myanmar - including areas close to the border with India - more than 10% of malaria parasite is of the resistant type.

Having near real-time information on malaria drug resistance helps predict the routes it is likely to take so threatened countries can prepare their national and regional treatment strategies.

With such information, they can review their medicine dosing - especially for vulnerable groups such as children and pregnant women - and thereby preserve the lifespan of life-saving drugs.

A team of clinical experst at the Worldwide Antimalarial Resistance Network (WWARN), says the study "highlights that the pace at which artemisinin resistance is spreading or emerging is alarming." 

"We need a more vigorous international effort to address this issue in border regions."

Meanwhile, we have recently learned how scientists are developing a geographical information system (GIS) to fight parasitic diseases like malaria using satellite data combined with health data. The idea is that decision makers can use the GIS to quickly locate the high-risk areas and see if they have enough resources there.

References:

1.  Spread of artemisinin-resistant Plasmodium falciparum in Myanmar: a cross-sectional survey of the K13 molecular marker, Kyaw M. Tun, et al., The Lancet Infectious Diseases, doi:10.1016/S1473-3099 (15)70032-0, published online 19 February 2015, abstract.
2.  Wellcome Trust news release, accessed 19 February 2015 via EurekAlert.