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Showing posts with the label pasteurization

#Thermal #inactivation spectrum of #influenza A #H5N1 virus in raw #milk

Abstract The spillover of highly pathogenic avian influenza (HPAI) H5N1 virus to dairy cows and shedding of high amounts of infectious virus in milk raised public health concerns. Here, we evaluated the decay and thermal stability spectrum of HPAI H5N1 virus in raw milk. For the decay studies , HPAI H5N1 positive raw milk was incubated at different temperatures and viral titers and the thermal death time D-values were estimated. We then heat treated HPAI H5N1 virus positive milk following different thermal conditions including pasteurization and thermization conditions. Efficient inactivation of the virus was observed in all tested conditions, except for thermization at 50C 10 min . Utilizing a submerged coil system with temperature ramp up times that resemble commercial pasteurizers, we showed that the virus was rapidly inactivated by pasteurization and most thermization conditions . These results provide important insights on the food safety measures utilized in the dairy industry. S...

#Pasteurisation temperatures effectively inactivate #influenza A viruses in #milk

Abstract In late 2023 an H5N1 lineage of high pathogenicity avian influenza virus (HPAIV) began circulating in American dairy cattle.  Concerningly, high titres of virus were detected in cows’ milk , raising the concern that milk could be a route of human infection . Cows’ milk is typically pasteurised to render it safe for human consumption, but the effectiveness of pasteurisation on influenza viruses in milk was uncertain . To assess this, here we evaluate heat inactivation in milk for a panel of different influenza viruses. This includes human and avian influenza A viruses (IAVs), an influenza D virus that naturally infects cattle, and recombinant IAVs carrying contemporary avian or bovine H5N1 glycoproteins . At pasteurisation temperatures of 63 °C and 72 °C , we find that viral infectivity is rapidly lost and becomes undetectable before the times recommended for pasteurisation ( 30 minutes and 15 seconds, respectively ). We then show that an H5N1 HPAIV in milk is effectively i...