A huge trove of aggregated data on malaria parasites from around the globe is unlocking genetic secrets on the organism’s evolution and could assist in the mounting battle against drug resistance, experts say.
Scientists analysed genetic variations of 7,000 Plasmodium falciparum parasites from 28 countries, and curated the data to make it accessible to other researchers, including those without expertise in genetics.
The open access dataset, analysed in a study that is currently undergoing peer review in the journal Wellcome Open Research, represents the world’s largest resource of genomic data on malaria parasite evolution and drug resistance, according to the Wellcome Sanger Institute, Cambridge, UK.
Richard Pearson, co-author and data scientist at the Wellcome Sanger Institute, told SciDev.Net the data could help in the search for new drugs and vaccines, and the development of surveillance tools needed to control and eliminate malaria.
The Plasmodium falciparum parasite, which is transmitted to people via mosquito bites, is the deadliest malaria parasite globally and the most prevalent species in Africa, where it accounted for almost 100 per cent of malaria cases in 2018, according to World Health Organization (WHO) estimates.
Malaria is preventable and curable, yet remains a major global health problem, with an estimated 229 million cases and 409,000 deaths in 2019, according to the WHO.
The WHO African region is disproportionately affected, accounting for 94 per cent of malaria cases and deaths in 2019, though people in South-East Asia, the Eastern Mediterranean, Western Pacific, and the Americas are also at risk.
Resistance of the parasite to antimalarial medicines has been a recurring problem since the 1950s. Pearson, also of the University of Oxford’s Big Data Institute, said the curated data could help build understanding of the genetics of this resistance.
“Malaria parasites are constantly evolving, for example, in ways that can make them resistant to the different drugs used to treat malaria,” he said. “Understanding which genes are changing, and where in the world this is happening, can help with control programmes.”
Other genetic changes in the parasite can cause the failure of diagnostic tests, resulting in patients not receiving the correct treatment, said Pearson.
“We’re in a constant arms race with the parasite,” he added. “We try new things, new drugs and so on, but the parasite, as with all life, keeps evolving to find a way round them. We’re trying to keep a step ahead.”
The data was produced by MalariaGEN, a global network of groups who are leading separate studies into the biology and epidemiology of malaria while working together to build data resources aimed at controlling the disease.
Researchers conducting 49 studies at 73 locations in Africa, Asia, South America and Oceania together contributed 7,113 samples of P. falciparum for the aggregated analysis and scientists at the Wellcome Sanger Institute sequenced each sample, looking at more than three million changes in the parasite’s DNA.
“Going forwards, as the dataset grows, the longer-term goal is to help inform the decision making of national malaria control programmes, to enable them to answer questions like, ‘Which drugs should we be using in which places?’ based on near real-time, high-quality data.”
According to the WHO, stronger malaria surveillance systems are urgently needed to tackle the disease in endemic regions.
Daniel Neafsey, assistant professor of immunology and infectious diseases at the Harvard T.H. Chan School of Public Health, USA told SciDev.Net: “This dataset is the latest and largest agglomeration of Plasmodium falciparum malaria parasite genomic data in the world.
“A lot of the value comes from the consistent, homogeneous and very high-quality way in which the data are analysed. This can really help, for example, with sifting the importance of different mutations that signal drug resistance for ongoing drug-resistance surveillance.
“As we continue to build understanding about how variation among malaria parasites contributes to vaccine efficacy, I think this will be a really valuable resource for making sure vaccine development proceeds at a faster pace.”
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