Jun 27, 2007

The Challenges, and Opportunity, of Rapid Testing

by Laura Starita

Quick, accurate diagnosis is the holy grail of the medical world, a requirement for any doctor to fulfill his Hippocratic oath. Which is why a recent Economist piece about high false positive results from rapid HIV tests is so distressing. The article highlighted a case in Bukavu, DRC, where a medical team followed up with patients who were showing no signs of diminishing T-cell counts despite having received one or more positive HIV tests. Their investigation found that the rapid diagnostic tests the field staff was using was producing a false-positive rate of higher than 10-percent.

In HIV/AIDS circles a false positive is a preferable evil to a false negative (which denies a patient treatment and creates the possibility that he or she will unknowingly spread the virus), but they still aren’t good, especially given the high stigma associated with the disease. In addition, the number of false positives could dramatically increase over the next few years if the proponents of Provider-Initiated Counseling and Testing (PICT), where anyone who comes into a clinic for any reason is automatically tested unless they actively ask not to be, win in their push to move away from the current Voluntary Counseling and Testing (VCT) model, where a patient must actively consent to a test. The goal of PICT is admirable: increasing the number of people who know their status (some estimate that less than 10 percent of people living with HIV in sub-Saharan Africa know their status). This is vital to make prevention and treatment programs more effective. If people and providers cannot trust the test results, however, adoption of PICT could be wildly counter-productive, encouraging no change in behavior among people who have tested positive for the virus.

The story reveals a huge opportunity for health-related philanthropy—creating and delivering reliable, cheap rapid tests not only for HIV but for diseases like malaria, TB and hundreds of others. These tests would make all health delivery spending vastly more effective by ensuring that resources were properly allocated. Such tests would be a huge step forward for efforts to control and reduce HIV, malaria, pneumonia, TB and many other common diseases.

Economist: More Haste...