Breakthrough test for elusive malaria strain

Professor Denise Doolan, the Deputy Director of JCU’s Australian Institute of Tropical Health and Medicine (AITHM), says the Plasmodium vivax strain of the disease has unique features that make it difficult to combat.

“This strain of the malaria-causing parasite, Plasmodium vivax, has a very specific characteristic that allows it to persist undetected for a long time in the human liver.

“This means that it can be undetectable in blood tests and people with this strain often have no symptoms even though they have the parasite. It can reactivate weeks or months after the initial infection, causing severe disease and death,” she said.

Professor Doolan said the international team, led by Professor Ivo Mueller at the Walter and Eliza Hall Institute in Melbourne, has now identified a panel of markers from the parasite genome that can serve as the basis of a diagnostic test.

This means scientists can find people who have the parasite hiding in their liver and treat the disease before symptoms become severe.

“The drugs for treating malaria have serious side-effects, so we can’t just apply them to a whole population in at-risk areas. It has to be a targeted approach,” she said.

Professor Doolan said scientists can now detect 80 per cent of people who had been infected with Plasmodium vivax within the past nine months.

“There is still a lot of work to be done, but this allows us to get a handle on a disease that 2.5 billion people are exposed to. “Mathematical models tell us we could reduce the spread of this disease by nearly 70 per cent using this new procedure,” she said.

Professor Doolan said elimination of malaria by 2030 is the goal in the Asia-Pacific region and the Americas.

She said the next step in the work was to develop an actual diagnostic test using these markers, and then use that test in the field to identify people who have been recently exposed to Plasmodium vivax and are at risk of disease so they can be treated.

“Despite some progress, global funding for malaria control has remained unchanged since 2010 and we urgently need tools like this to control the spread of the disease and improve global public health,” she said.