Malaria spit-test promises detection up to a week before symptoms appear
Despite advances in malaria treatments over the past few decades, the disease still kills around half a million people globally every year. Finding a better way to diagnose the illness, and subsequently treat it early, is a major goal for scientists. A team of researchers just revealed an innovative new salvia test that promises to quickly and cheaply screen for the presence of malaria parasites up to a week before any symptoms appear.
The only way to confidently diagnose malaria currently is through blood testing, which requires laboratory infrastructures, and well-trained clinicians literally examining the samples using microscopes to detect levels of the parasite. More recently scientists have developed what are called antigen-based "rapid diagnostic tests" (RDTs), which take a skin prick of blood and offer a diagnostic assessment within 20 minutes. While RDTs are hugely helpful in remote areas without access to more comprehensive laboratory services, they are not completely reliable and still require invasive blood sampling.
There have been several recent advances in the way of breath and odor-based markers being used to detect malarial infections. The science is incredibly promising, however, translating these discoveries into a cheap and effective diagnostic tool has proven a little more challenging. Picking up these air-based malaria-signaling compounds with elaborate gas chromatography-mass spectrometry devices is one thing, developing sensitive and cost-effective biosensors that can do the same in remote clinical environments is something else altogether.
"What if we can identify a child before they get sick because there's something in their saliva," says Rhoel Dinglasan, a researcher working on the project from the University of Florida. "If we get to them earlier, they can be cured well before they get the disease."
The new saliva-based malaria test homes in on a specific protein that is vital to the survival of a common malaria parasite called Plasmodium falciparum. The test can identify the presence of the parasite using this protein biomarker in less than 20 minutes after a person spits into a small test tube.
The test is called SMAART (Saliva-based Malaria Asymptomatic and Asexual Rapid Test) and it is being developed by a start-up founded in South Africa called ERADA. Benji Pretorius, ERADA's Managing Director, hopes the test can be rolled out into clinical use as soon as 2020.
"The introduction of SMAART is going to play a major part in achieving effective diagnostic testing and surveillance; as well as prevention and treatment of this disease, and therefore will be a major catalyst in meeting the WHO's 2030 target to reduce malaria incidence and mortality by 90 percent," says Pretorius.
The new research was published in the journal Science Translational Medicine.