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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #415678

Research Project: Control Strategies to Prevent and Respond to Diseases Outbreaks Caused by Avian Influenza Viruses

Location: Exotic & Emerging Avian Viral Diseases Research

Title: Characterization of highly pathogenic avian influenza virus in retail dairy products in the United States

item Spackman, Erica
item GORAICHUK, IRYNA - Orise Fellow
item Jones, Deana
item COLONIUS, TRISTAN - Food And Drug Administration(FDA)
item MCCOIG, AMBER - Food And Drug Administration(FDA)
item Suarez, David

Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Bird flu infections were recently discovered in cows in the United States (US). Because virus could be detected in raw milk, a study was conducted to determine if the virus could be found in pasteurized dairy products in the US. Samples were collected from stores in 17 states and represented products that were produced or processed in 38 states. Viral genetic material was detected by PCR based methods in 20.2% of the samples tested. The PCR positive samples were all then tested for the presence of infectious virus. No infectious virus was found in any samples. This suggests that any virus that had been present was rendered non-infectious, likely due to the processes already in place, such as pasteurization.

Technical Abstract: In March 2024 Clade H5N1 highly pathogenic avian influenza virus (HPAIV) was detected in dairy cattle in the United States (US) and it was discovered that the virus could be detected in milk. Although infected cow milk is diverted from human consumption and current pasteurization requirements are expected to reduce or eliminate HPAIV from the milk supply, a study was conducted to characterize whether the virus could be detected by quantitative real-time RT-PCR in pasteurized retail dairy products and if detected, to determine whether the virus was viable. From April 18 to 22, 2024 a total of 297 samples of Grade A pasteurized retail milk products (23 product types) were collected from 17 US states and represented products from 132 processors in 38 states. Viral RNA was detected in 60 samples (20.2%) with titer equivalents of up to 5.4log10 50% egg infectious doses (EID50) per ml, with a mean and median of 3.0log10/ml and 2.9log10 /ml respectively. No infectious virus was detected in any of the qrRT-PCR positive samples in embryonating chicken eggs. Positive samples were confirmed to also be H5 positive by qBT-PCR. Further studies are needed to monitor the milk supply but these results provide evidence that infectious virus did not enter the US pasteurized milk supply.