An experimental blood test can quickly and accurately diagnose malaria from other infections, so treatment of the mosquito-borne illness can be started promptly.
The symptoms of malaria, which strikes an estimated 200 million people around the globe every year, are non-specific. That means the fever, aches, pains and chills in the early stages could be mistaken for any number of infections.
Identifying and treating malaria promptly not only increases a patient’s chances of survival, but also helps prevent the disease from spreading to more people.
The blood test, developed by researchers at Stanford University in California, looks for patterns of immune system activation to determine whether a person is infected with the malaria parasite, and not a bacterium or virus. It is reportedly 96 percent accurate.
Purvesh Khatri, a professor of medicine at Stanford, helped develop the biomarker test, which looks at which genes are switched on or off, depending on the infection.
A simple blood test measuring these immune markers could be helpful in resource-poor settings, according to Khatri.
“So a test like ours is useful,” he said, “You could take a blood test that would not require an expert technician, and they are more sensitive than the rapid diagnostic test than we have now.”
Khatri notes the current test is not very accurate because it looks for a molecule, called an antigen, that activates an immune response in a malaria infection.
“And the problem with those are there are not enough antigen,” said Khatri. “So treatment then [could] be inappropriate and then it could awhile before malaria is diagnosed.”
Khatri and his team drew upon data from 40 studies involving more than 3,000 blood samples from patients with various infections. Some were known to have malaria. But there were also other tropical illnesses observed in the studies, including dengue, typhoid and leishmaniasis.
From those blood studies, investigators analyzed the activation of 2,100 different genes, looking at which genes switched on and off with parasitic, viral and bacterial infections.
They found a group of seven genes that were expressed in malaria compared to healthy people and those with other infectious illnesses.
To confirm their discovery, the researchers whittled the samples down to 900, in which they were able to discern the pattern of gene activation unique to malaria with near 100 percent accuracy.
While the experimental blood test is accurate in diagnosing malaria, Khatri says it might also detect other parasitic diseases that researchers have not yet studied.
But he said the blood test could be reliably used in cases where malaria is strongly suspected and confirmation of the disease is needed.
Khatri presented his findings at a meeting of the European Congress of Clinical Microbiology and Infectious Diseases before World Malaria Day this week.