Scientists have found a new use for an anti-tank Javelin missile detector: to identify malaria parasites in blood.
Originally developed for Javelin heat-seeking missiles, a special imaging device known as a focal plane array (FPA) gives highly detailed information on a sample area in minutes.
The technique is based on Fourier transform infrared spectroscopy, which provides information on how molecules vibrate. Scientists say the novel idea, published in the journal Analyst, could set a new gold standard for malaria testing.
Missiles and parasites
The heat-seeking detector, which is coupled to an infrared imaging microscope, allowed the team to detect the earliest stages of the malaria parasite in a single red blood cell.
The infrared signature from the fatty acids of the parasites enabled the scientists to detect the parasite at an earlier stage, and crucially determine the number of parasites in a blood smear.
Lead researcher Bayden Wood, an associate professor at Monash University, says to reduce mortality and prevent the overuse of antimalarial drugs, a test that can catch malaria at its early stages is critical.
“Our test detects malaria at its very early stages, so that doctors can stop the disease in its tracks before it takes hold and kills. We believe this sets the gold standard for malaria testing,” Wood says.
“There are some excellent tests that diagnose malaria. However, the sensitivity is limited and the best methods require hours of input from skilled microscopists, and that’s a problem in developing countries where malaria is most prevalent,” he adds.
Four-minute count down
As well as being highly sensitive, the new test has a number of advantages—it gives an automatic diagnosis within four minutes, doesn’t require a specialist technician and can detect the parasite in a single blood cell.
The disease, which is caused by the malaria parasite, kills 1.2 million people every year. Existing tests look for the parasite in a blood sample. However the parasites can be difficult to detect in the early stages of infection. As a result the disease is often spotted only when the parasites have developed and multiplied in the body.
Professor Leann Tilley from the University of Melbourne says the test could make an impact in large-scale screening of malaria parasite carriers who do not present the classic fever-type symptoms associated with the disease.
“In many countries only people who display signs of malaria are treated. But the problem with this approach is that some people don’t have typical flu-like symptoms associated with malaria, and this means a reservoir of parasites persists that can reemerge and spread very quickly within a community,” she says.
“Our test works because it can detect the malaria parasite at the very early stages and can reliably detect it in an automated manner in a single red blood cell. No other test can do that,” Tilley adds.
Source: Monash University