Physicists use magnets and light to detect malaria
Baku, February 2 (AZERTAC). Researchers have discovered new method to determine malaria parasite in blood. This method is as good as the established methods but has potential to be significantly cheaper.
It is estimated that approximately 200 million people suffer malaria every year and 1 million people died. Since this disease can be easily cured so number of deaths is less. Adam Butykai at the Budapest University of Technology and Economics in Hungary were attempting to discover a cheaper method that could spot malaria parasites in the blood accurately.
Currently microscope is used to spot parasite present in the blood. This method is more trustworthy and can measure as low as 5-10 parasites per microlitre of blood and considered as important test for rapid and early diagnosis. The equipments used in this method make this test costly.
“The visual technique also allows medics to distinguish newly infected individuals from those who have had the disease in the past and have been treated but still have parasites in their blood. That’s an important feature since most people in areas where the disease is endemic will have been infected at some point. “
Certain other rapid methods are also being developed to spot parasite such as “new generation of rapid diagnostic tests “. In this method visual signals result due to interaction between malaria antigen and parasites on a test strip. Such methods are reliable and give quick results.
But they are effective enough to determine 100 parasites per microlitre of blood. This technique cannot differentiate between newly diagnosed patients of malaria and older patients. Certain genetic changes in parasites could also limit the use of this test.
A byproduct is produced due to breakdown of molecules of the blood pigments, hemoglobin when parasites attack on blood cells. This newly discovered test by Bulgarian team could determine this byproduct.
During this test tiny crystal of hemozoin results that contain iron and making hemozoin magnetic. Different studies have suggested that crystals line up when infected blood is placed in a magnetic field. “However, this effect is countered by the constant buffeting of thermal forces which tend to disorder the sample.”
“That gave Butykai and co an idea. Instead of a static field, these guys put their sample in a rotating field which causes the crystals to spin, like tiny magnetic spinning tops. Since their magnetic axis is along the length of the cylinder, they spin around this long axis, making the crystals stand up in the field like toy soldiers.”
“This alignment is much more stable against thermal forces and gives the blood unusual optical properties since it allows polarised light to travel more easily along one direction than in the perpendicular direction.”
“In addition, Butykai and co have found that the hemozoin soldiers interact more readily with some frequencies than others, producing a unique optical signature. It’s this that can be used to spot malaria parasites in blood, serum or plasma.”
“Butykai and co say the technique is currently sensitive down to 50 parasites per microlitre of blood. In blood plasma, however, it can detect the disease at levels below 1 parasite per microlitre.”
“The sensitivity achieved in our test measurements on hemozoin in blood plasma exceeds that of the most reliable diagnostic methods used presently,” they say.
“That’s impressive and has the potential to be optimised further by filtering the blood, for example. The test is also immune to genetic variations in the parasite, which can stymie antigen-based tests. The big question,of course, is whether the test can easily be developed into a cost effective device for use in developing countries.That’s a big ask. The light diagnostics should be straightforward to make but the required magnetic field is large-about 0.5 Tesla or so. That’s not so easy.”
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