AsianScientist (Jun. 28, 2016) – To provide an accurate view of the global spread of artemisinin resistance, an international research group led by the Pasteur Institute in Phnom Penh (Cambodia) has drawn up a world map of current resistance.
Practically all currently available treatments for malaria are based in some form or other on a derivative of artemisinin, found in the leaves and flowers of annual mugwort (Artemisia annua).
As recent as ten years ago, many malaria researchers did not consider the possibility of resistance developing to artemisinins, because of their new modes of action and because they are administered in combination with other drugs.
Led by Associate Professor Harald Noedl and Associate Professor Michael Ramharter from the Medical University of Vienna, the research team examined a total of 14,000 samples from Gabon, Bangladesh and Ethiopia.
Their findings, published in the New England Journal of Medicine, provide unambiguous evidence that artemisinin resistance is exclusively concentrated in Southeast Asia.
“Currently, artemisinin resistance is exclusively concentrated in Southeast Asia; African regions are not yet affected,” the researchers said of their findings.
For years now, the greatest threat when it comes to malaria has been that a resistant pathogen develops in Africa and then spreads.
“The descendants of these parasites are like clones. If one becomes resistant, they may spread and be transmitted further,” said Ramharter.
In Southeast Asia, resistance is presumably due to the fact that there are far fewer cases of malaria so that selection pressure is greater.
“It is much easier for one resistant parasite in 100 to survive and pass on the resistant gene than it is for one in several thousand,” noted Ramharter.
The scientists hope that the new map of artemisinin resistance will make it possible to identify any shifts more quickly and optimize control of one of mankind’s most deadly diseases.
The article can be found at: Menard et al. (2016) A Worldwide Map of Plasmodium falciparum K13-Propeller Polymorphisms.
Source: Medical University of Vienna; Photo: Thomas Wanhoff/Flickr/CC.
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