A High-Tech Approach to an Age-Old Disease
A novel approach to diagnosing malaria, which could significantly speed the time it takes to identify the infection in patients, has won the 2002 Invention of the Year Award from Johns Hopkins’ Applied Physics Laboratory (APL).
The technique is the brainchild of a team consisting of the School’s Nirbhay Kumar, PhD, and David Sullivan, MD, of the Johns Hopkins Malaria Research Institute, and colleagues from APL’s Research and Technology Development Center.
“One of the biggest needs in malaria is rapid diagnosis,” says Kumar, a professor in the W. Harry Feinstone Department of Molecular Microbiology and Immunology (MMI). The parasite infection affects between 300 and 500 million people each year and kills 1.5 to 2 million people—mostly children.
Currently, the most widely used tool for diagnosing malaria is microscopy—analyzing blood samples on glass slides to detect the presence of malaria parasites. This method requires 15 to 20 minutes to analyze a single sample; it can thus take up to 12 hours to diagnose just 50 people. In outbreaks there can be hundreds who need diagnosis immediately.
“We’re all using a 100-year-old diagnostic test,” says Sullivan, an MMI assistant professor. “I’ve heard plenty of stories of people lined up to see a doctor for diagnosis who don’t get diagnosed,” because of the time it takes to perform the tests. “It still happens in 2003,” he says. Treatment without proper diagnosis (as Kumar experienced) can lead to only partial recovery—and to drug resistance.
In looking for an alternative, the team decided to try running infected blood samples through a mass spectrometer, which performs analyses on a molecular level and can be used to detect biomarkers. Sure enough, they discovered that the presence of malaria produced a specific biomarker identified as HEME. Using mouse malaria models, they determined they could diagnose 20 samples (each less than a drop of blood) in 10 minutes.
The next step for the inventors? Using the technique to test infected human blood. At APL, scientists are working to build a smaller, cheaper, tougher mass spectrometer.
Kumar and Sullivan and their colleagues at APL are looking to the future cautiously but hopefully: “It’s current technology being applied to an age-old disease,” says Sullivan. “It’s been a long time coming.”