Infectivity of hepatitis C virus in plasma after drying and storing at room temperature.

OBJECTIVE: To determine effect of environmental exposure on the survival and infectivity of hepatitis C virus (HCV).

METHODS: Three aliquots of chimpanzee plasma containing HCV and proven infectious HCV inoculum were dried and stored at room temperature, 1 aliquot for 16 hours, 1 for 4 days, and 1 for 7 days. A chimpanzee (CH247) was sequentially inoculated intravenously with each of these experimental inocula, beginning with the material stored for 7 days. Each inoculation was separated by at least 18 weeks of follow-up to monitor for infection. The concentration of HCV RNA was measured and quasi species were sequenced for each experimental inoculum and in serum samples from CH247.

RESULTS: Evidence of HCV infection developed in CH247 only after inoculation with the material stored for 16 hours. No infection occurred after inoculation with the material stored for 7 days or 4 days. Compared with the original infectious chimpanzee plasma, the concentration of HCV RNA was 1 log lower in all 3 experimental inocula. The same predominant sequences were found in similar proportions in the original chimpanzee plasma and in the experimental inocula, as well as in serum samples from CH247.

CONCLUSION: HCV in plasma can survive drying and environmental exposure to room temperature for at least 16 hours, which supports the results of recent epidemiologic investigations that implicated blood-contaminated inanimate surfaces, objects, and/or devices as reservoirs for patient-to-patient transmission of HCV. Healthcare professionals in all settings should review their aseptic techniques and infection control practices to ensure that they are being performed in a manner that prevents cross-contamination from such reservoirs.