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Breath Test Developed for Malaria

Distinctive chemicals can be detected in the breath of patients infected with malaria, opening the way for a simple diagnostic test.

When researchers at the CSIRO, QIMR Berghofer Medical Research Institute and the Australian National University looked at the breath of volunteers who had been given a controlled malaria infection as part of existing studies to develop new treatments, they found that the levels of some chemicals that are normally almost undetectable increased markedly in the breath of the volunteers.

“What is exciting is that the increase in these chemicals was present at very early stages of infection, when many other methods would have been unable to detect the parasite in the body of people infected with malaria,” said Dr Stephen Trowell of CSIRO. “In addition to its potentially better sensitivity, human breath offers an attractive alternative to blood tests for diagnosing malaria.”

The study, published in the Journal of Infectious Diseases, identified four sulfur-containing compounds whose levels varied across the time course of the malaria infection. “The sulfur-containing chemicals had not previously been associated with any disease, and their concentrations changed in a consistent pattern over the course of the malaria infection,” said Prof James McCarthy of QIMR Berghofer. “Their levels were correlated with the severity of the infection and effectively disappeared after they were cured.”

Malaria continues to place a huge health and economic burden on many of the poorest people in the world, with almost 200 million cases and over half a million deaths due to this disease in 2013.

As malaria diagnosis is mostly based on the use of powerful microscopes to look for parasites in blood, there is an urgent need for more sensitive and convenient tests to detect early and hidden cases.

“Now we are collaborating with researchers in regions where malaria is endemic to test whether the same chemicals can be found in the breath of patients,” Trowell said. “We are also working with colleagues to develop very specific, sensitive and cheap biosensors that could be used in the clinic and the field to test breath for malaria.”