Efficacy of disinfectants to inactivate H1N1 influenza A virus isolated from pigs

The aim of this study was to access the efficacy of four disinfectants to inactivate influenza A [H1N1]0 hour and 72 hours after disinfectant dilution. A pandemic H1N1 influenza virus isolated from a pig with respiratory disease was used to obtain inoculums containing 6.4log(10) EID50/mL; 5.4log(10) EID50/mL; 4.4log(10) EID50/mL and 3.4log(10) EID50/mL Suspension test was composed of 4004 of viral inoculum, 100 mu L of organic load and 500 mu L of each individually diluted disinfectant and incubated for ten minutes of contact time. After a neutralizing step, each mixture was filtered on a 0.22 mu m membrane and 0.2mL was inoculated in six 9-day-old embryo chicken egg through allantoic route. The allantoic fluid from eggs was harvest for RT-PCR and hemagglutination test. The experiment was repeated 72 hours after disinfectant dilution. On the first assessment with fresh disinfectant, influenza virus was inactivated by oxidizing compost disinfectant and phenolic disinfectant in all virus concentrations, the quaternary ammonium compound (QAC) and glutaraldehyde association inactivated the virus up to a concentration of 5.4log(10) EID50/mL. QAC disinfectant did not eliminate virus viability. Seventy-two hours after disinfectants were diluted, oxidizing compost disinfectant and QAC and glutaraldehyde association disinfectant demonstrated the same result as the evaluation with fresh disinfectant solution. Phenolic disinfectant inactivated viral inoculum up to a concentration of 5.4log(10) EID50/mL. QAC had no effect on inactivating 3.4log(10) EID50/mL of influenza virus. In conclusion, three of the four disinfectants tested were effective to inactivate pandemic H1N1 influenza virus in the presence of organic load. Test result performed 72hours after disinfectant dilution suggest a decrease in the effectiveness of one disinfectant.