Rice University researchers have developed a rapid test for malaria that uses a laser pulse, eliminating the need to draw blood.
The test has not yet been tried on humans with the disease, but in experiments with blood samples and mice, it detected malaria when only one red blood cell in 1 million was infected, with no false positives, the inventor said.
The results were described in a study published online last week in Proceedings of the National Academy of Sciences.
In theory, said the inventor, Dmitri Lapotko, a physicist who studied laser weapons in his native Belarus, the technology can be used in a device powered by a car battery and is rugged enough to work in dusty villages. With a fiber-optic probe attached to a finger or ear lobe, the device could screen one person every 20 seconds for less than 50 cents each.
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If that happened, the new test could revolutionize malaria diagnosis. Current rapid tests require a finger prick, take 15 minutes and cost about $1. Those tests can also spoil in hot climates.
Malaria parasites feeding inside blood cells contain minute amounts of hemozoin, iron crystals left over from the digestion of hemoglobin. A laser burst of a fraction of a second heats the crystals until they create a bubble, which pops.
The acoustic signature of that pop, which lasts one ten-millionth of a second, can be detected “in the same way a destroyer detects a submarine,” Lapotko said.
The technology has been found to be safe in healthy humans, he said, and a clinical trial on humans with malaria symptoms is to begin in a few weeks.