Inactivation of hepatitis B virus in plasma by hospital in-use chemical disinfectants assessed by a modified HepG2 cell culture.

Because of the difficulties of the chimpanzee model and the genetic differences using the duck model, we developed a cell culture method to measure human hepatitis B virus (HBV) inactivation in vitro. Pooled HBV-infected human plasma that had been exposed to a disinfectant was left in contact for three days with a cell culture of the human hepatoma cell line, HepG2, with 4% polyethyleneglycol and 3 mM sodium butyrate. The mean log10 of the viral titre of unexposed plasma was 4.87 infectious units per mL. Our results showed that 1% glutaraldehyde, sodium hypochlorite at 4700 ppm free chlorine and an iodophor-detergent disinfectant containing 3.6% povidone-iodine reduced viral titres by factors exceeding 10(3)-10(4). However, sodium hypochlorite at 1000 ppm free chlorine had minimal activity and povidone-iodine at 9, 5 and 3.6% had no measurable activity (less than 10-fold reduction). This is the first study using a cell culture model to assess disinfectant activity against HBV. It demonstrates more rapidly than the chimpanzee model that glutaraldehyde and sodium hypochlorite, using standard concentrations and exposure times compatible with clinical practice, were highly active against HBV. However, unexpectedly for an enveloped virus, we found no antiviral activity for iodine in the absence of detergent.