Efficacy of Common Laboratory Disinfectants on the Infectivity of <i>Cryptosporidium parvum</i> Oocysts in Cell Culture

Abstract

Nine liquid disinfectants were tested for their ability to reduce infectivity of Cryptosporidium parvum oocysts in cell culture. A 4-min exposure to 6% hydrogen peroxide and a 13-min exposure to ammonium hydroxide-amended windshield washer fluid reduced infectivity 1,000-fold. Other disinfectants tested (70% ethanol, 37% methanol, 6% sodium hypochlorite, 70% isopropanol, and three commercial disinfectants) did not reduce the infectivity after a 33-min exposure. The results indicate that hydrogen peroxide and windshield washer fluid or ammonium hydroxide disinfectant may be suitable laboratory disinfectants against C. parvum oocysts.