Rapid hepatitis C testing identified infections in high-risk population

Rapid testing for hepatitis C virus (HCV) at agencies for people with drug dependence identified many previously unrecognized infections, a recent study found.

The division of public health in Wisconsin conducted a pilot program from October 2012 to October 2013, in which rapid HCV testing was offered at 4 agencies that typically offer HCV and HIV testing, syringe exchange, counseling, and other harm reduction services. Results were published in the April 11 Morbidity and Mortality Weekly Report.

In total, 1,255 people received the rapid HCV test, and 20% of the results were positive. Of those positive tests, 72% had not been previously reported. A blood specimen was collected from 78% (192 patients) of the patients with positive rapid tests for further testing (the other 54 participants either refused venipuncture or a vein could not be accessed). Almost all (190) of the blood specimens were also tested for HCV antibody using enzyme immunoassays, and no false-positive results from the rapid HCV test were found. Most (183) of the blood samples were also tested using reverse transcription–polymerase chain reaction, which indicated active infection in 70% of the HCV cases.

The pilot project also found that 53% of participants said they had not been tested previously for HCV and another 10% didn't remember being tested. The majority of participants reported having injected drugs within the past 6 months, and the average number of persons with whom they reported injecting drugs was 5.4 (range, 0 to 100). Two-thirds of the study participants also reported having shared drug injection equipment, and 42% had shared equipment within 6 months of testing.

The results show that rapid tests could be a powerful tool for screening for HCV, conveying prevention information, and initiating treatment, the study authors concluded. The finding that patients frequently shared equipment is concerning, especially considering that these patients were participating in a syringe-exchange service. It indicates the importance of prevention messages that emphasize the risk of HCV transmission from any sharing of injection equipment, not just syringes, the authors said.