Rice University researchers tested an experimental laser device that can diagnose malaria in a few seconds. The ultra-rapid diagnostic may offer substantial cost savings in global efforts to combat malaria .
The study has been published in the July issue of Emerging Infectious Diseases.
The laser was able to correctly identify which person, among the total group of six, who were infected with Plasmodium falciparum, a parasite that causes malaria. Further, the device was able to detect the parasite in dead mosquitoes, according to a New Scientist report.
The laser works by pulsing energy into a vein of a person who is suspected to have malaria. The test can be done on the wrist or earlobe.
The laser’s wavelength is harmless to human tissue, but is absorbed by waste crystals produced by the malaria parasite as it feeds on human blood.
The waste crystals absorb the energy, warm the surrounding blood plasma, making it bubble. An oscilloscope then detects malaria by sensing the bubbles as they are popping.
The diagnosis process only takes 20 seconds.
“It’s the first true non-invasive diagnostic,” says Dmitri Lapotko of Rice University in Houston, Texas, whose team tested the device, which was able to identify which person had malaria in a group of six. The device also was able to identify the malaria parasite in dead mosquitos.
Malaria is one of the leading causes of death in the world, killing 584,000 people in 2013. The World Health Organization (WHO) reports that progress has been made. In the last decade, effective strategies of vector control, rapid diagnostics, and combination therapies have reduced malaria mortality by 47% worldwide and 58% in Africa.
SEARCH FOR COST-EFFECTIVE DIAGNOSTICS
While existing tests for malaria are already quick, taking 15 to 20 minutes, they could be simpler and less expensive. Current rapid diagnostics require blood to be taken and tested by trained health workers.
Blood has to be taken, the test has to be conducted by trained personnel to get reliable results, and extra chemical reagents must be used.
Chemical reagents used in diagnostic tests come at a significant cost. The Foundation for Innovative New Diagnostics (FIND), a nonprofit established by the WHO, estimates that reagents cost $100 million USD per year.
The experimental diagnostic is non-invasive would simplify diagnosis, not needed reagents or blood handling procedures. FIND’s chief scientific officer Mark Perkins said, “The pursuit of technologies that avoid these pitfalls, especially when as innovative as this one, is welcome,” according to the New Scientist.
Lapotko estimates that a single testing unit would cost around $15,000, which could test 200,000 people. The per-person cost could be brought down from 50 cents to 8 cents per person.
THE ROAD AHEAD: FIELD TRIALS
The team is preparing for trials in Africa and to see how the device fares in real-world field conditions. It is not yet known whether the diagnostic will work in people with lower levels of parasites in their blood.
Further, the probe is less reliable with people with darker skin, a major problem because children in African account for the major of malaria deaths. Lapotko’s team is confident that they will be able to fix this pitfall with a wavelength adjustment.
Reference
Lukianova-Hleb E, Bezek S, Szigeti R, Khodarev A, Kelley T, Hurrell A, et al. Transdermal diagnosis of malaria using vapor nanobubbles. Emerg Infect Dis. 2015 Jul 3. http://dx.doi.org/10.3201/eid2107.150089