Noninvasive Technology Accurately Detects Malaria Through the Skin

The noninvasive technology accurately detects low levels of malaria infection in seconds with a laser scanner.

The new diagnostic technology uses a low-powered laser that creates tiny vapor nanobubbles inside malaria-infected cells. The bursting bubbles have a unique acoustic signature that allows for a very sensitive diagnosis.

The vapor nanobubble technology requires no dyes or diagnostic chemicals, and there is no need to draw blood. The new technology uses a low-powered laser that creates tiny vapor nanobubbles inside malaria-infected cells. The bursting bubbles have a unique acoustic signature that allows for an extremely sensitive diagnosis.

“Ours is the first through-the-skin method that’s been shown to rapidly and accurately detect malaria in seconds without the use of blood sampling or reagents,” said lead investigator Dmitri Lapotko, a Rice University (Houston, TX, USA) scientist who invented the vapor nanobubble technology. The diagnosis and screening will be supported by a low-cost, battery-powered portable device that can be operated by nonmedical personnel. One device should be able to screen up to 200,000 people per year, with the cost of diagnosis estimated to be below 50 cents, he said.

The preclinical study published in the January 2014 Proceedings of the National Academy of Sciences of the United States of America (PNAS) shows that Rice’s technology detected even a single malaria-infected cell among a million normal cells with zero false-positive readings.

Inexpensive rapid diagnostic tests exist, but they lack sensitivity and reliability. The gold standard for diagnosing malaria is a “blood smear” test, which requires a sample of the patient’s blood, a trained laboratory technician, chemical reagents, and high-quality microscope. These are often unavailable in low-resource hospitals and clinics in the developing world.

“The vapor nanobubble technology for malaria detection is distinct from all previous diagnostic approaches,” said study coauthor Dr. David Sullivan, a malaria clinician and researcher at Malaria Research Institute at Johns Hopkins University. “The vapor nanobubble transdermal detection method adds a new dimension to malaria diagnostics, and it has the potential to support rapid, high-throughput and highly sensitive diagnosis and screening by nonmedical personnel under field conditions.”

The transdermal diagnostic method takes advantage of the optical properties and nanosize of hemozoin, a nanoparticle produced by a malaria parasite inside red blood cell. Hemozoin crystals are not found in normal red blood cells.

Lapotko, a faculty fellow in biochemistry and cell biology and in physics and astronomy at Rice University, and lead coauthor Ekaterina Lukianova-Hleb found that hemozoin absorbs the energy from a short laser pulse and creates a transient vapor nanobubble. This short-lived vapor nanobubble emerges around the hemozoin nanoparticle and it is detected both acoustically and optically. In the study, the researchers found that acoustic detection of nanobubbles made it possible to detect malaria with extraordinary sensitivity.

The first trials of the technology in humans are expected to begin in Houston in early 2014.

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