|Red blood cells from a patient infected with Plasmodium falciparum--Courtesy of MIT|
Malaria parasites produce waste products as they spread in the blood. Those parasitic discharges may give scientists an ideal diagnostic biomarker to help spot the infection and determine how serious it is, researchers from the Massachusetts Institute of Technology and colleagues in Singapore have found.
Their study is published in the latest issue of Nature Medicine.
The new test relies on magnetic resonance relaxometry (MRR, similar to magnetic resonance imaging, or MRI) to detect hemozoin, a waste product generated by the Plasmodium parasite--the cause of malaria.
It turns out to be a very common biomarker for malaria. Here's how it's created: the Plasmodium parasite feeds on hemoglobin in red blood cells as the infection grows, which leads to the release of iron. The malaria parasite, in turn, converts this to hemozoin, which is a paramagenetic crystallite, MIT explained in its announcement of the news.
The team, from the Singapore-MIT Alliance for Research and Technology (SMART), came up with their prototype device (the MRR) to help spot this substance. It fits on a table, and plans are in the mix to develop a smaller version about as big as an electronic tablet computer. According to MIT, hemozoin can disrupt the normal magnetic spins of hydrogen atoms, and an outside magnetic device such as the MRR can identify the disruption and how bad it is, relying on a relatively small blood sample from a finger prick. (It's also cheaper than an MRI.)
More research is needed, of course. But the scientists involved are bullish about their discovery and MRR invention. They argue that it would be a boost over the current diagnostic standard--a test involving a blood smear across a glass slide, special dye and a search of the sample for Plasmodium under a microscope. They note that the test can accurately count the number of parasites in the blood but there's also plenty of room for human error.
"There is real potential to make this [new diagnostic tool] into a field-deployable system, especially since you don't need any kind of labels or dye," Jongyoon Han, a senior author of the team's research paper and a professor of electrical engineering and biological engineering at MIT, said in a statement included in the school's research announcement. "It's based on a naturally occurring biomarker that does not require any biochemical processing of samples."
That inexpensive diagnostic approach could help control the disease in the developing world. Globally, 219 million clinical cases of malaria were documented in 2010, according to World Health Organization statistics cited previously by the CDC, and most were in sub-Saharan Africa and South Asia.
Scientists are trying to tackle malaria's persistence in a number of ways. A group of researchers from Thailand, for example, have developed a blood test to screen for patients who have drug-resistant malaria, allowing clinicians to adjust treatment sooner and improve outcomes.
- here's the MIT release
- check out the journal abstract