Inactivation of Murine Norovirus in Breast Milk by Heat Treatment

Abstract

  Human norovirus (HuNoV) may pose significant health risks to infants if the virus contaminates infant feed, and HuNoV infections are very important to prevent through infant feed such as breast milk. However, little is known about the appropriate condition to inactivate HuNoV, due to the lack of a routine cell culture system for HuNoV. The present study used a murine norovirus which is culturable and genetically close to HuNoV as a surrogate for HuNoV, and investigated its inactivation characteristics in breast milk. MNV inoculated in breast milk was rapidly inactivated and reached more than 99.9% (3 log₁₀) inactivation after 1 min treatment at 65°C. Our results suggest that heat treatment of more than 65°C and 1 min can adequately inactivate HuNoV in breast milk.