Physicists use magnets and light to detect malaria

Hungarian researchers announced the discovery this week of a new technique for spotting malaria parasites in blood that is both efficient and cost effective.

Adam Butykai, a physicist with the Budapest University of Technology and Economics in Hungary, and a team of researchers examined a malaria parasite byproduct called hemozoin. The iron content of the tiny cylindrical crystal makes the substance magnetic, Technology Review reports.

When infected blood is placed in a magnetic field, the crystals of hemozoin line up, but the constant buffering of thermal forces usually disorders the sample. Butykai and his team tried placing a blood sample in a rotating field, which caused the crystals to spin around their long axes and stand up like toy soldiers.

Current techniques for detecting malaria include physically spotting the parasites in a drop of blood, a reliable but expensive method, and using rapid diagnostic tests. The quick tests are cheap and quick but can only detect levels of above 100 parasites per microliter of blood.

Butykai said that while the hemozoin detection system is currently down to a sensitivity of 50 parasites per microliter in blood, it can detect the disease at levels below one parasite per microliter in blood plasma.

"The sensitivity achieved in our test measurements on hemozoin in blood plasma exceeds that of the most reliable diagnostic methods used presently," the researchers said, according to Technology Review.

A challenge for the diagnostic method, is the required generation of the required 0.5 Tesla magnetic field, which could hold the test back from cost effectiveness. If lab-on-a-chip type devices continue to progress as they have in the past few years, a cheap and effective version of the device could emerge, Technology Review reports.