H5N1 in raw milk is a "seven out of ten" pandemic worry, says CSU virologist Angela Bosco

Add to Google Preferred Sources A Colorado State University virologist who tests North American wildlife against emerging pathogens is most concerned about one virus. Angela Bosco-Laflor rates H5N1 bird flu a 7 out of 10 on her personal pandemic-risk scale, pointing to viral loads of 10¹¹–10¹² PFU per milliliter in raw dairy cow milk — concentrations comparable to the highest ever recorded in any infection — and to new genotypes with "scary" traits like improved mammal-to-mammal transmission. Speaking on the This Week in Virology podcast with colleagues Rebecca Kading and Mark Stenglein, she argues the most dangerous factor isn't exotic wildlife but untracked, everyday pathways: raw cat food, dead birds in backyards, and a dairy industry that still cannot explain how the virus moves between cows. The report covers the full threat landscape — Usutu virus's impact on American robins, SARS-CoV-2's retreat into wildlife, rabbit hemorrhagic disease from failed biocontrol, and Rift Valley fever's quiet spread in East Africa — and concludes that pandemic preparedness depends less on prediction than on funding unglamorous, curiosity-driven science. The scientists' practical guidance: don't feed cats raw meat, bury dead birds safely, and expect the next surprise to come from a completely unexpected host. Key Elements Angela Bosco-Laflor H5N1 Rift Valley fever Rebecca Kading Mark Stenglein Usutu virus RHDV2 SARS-CoV-2 Colorado State University Culex tarsalis This Week in Virology Vincent Racaniello Ifakara Health Institute Imagine a glass of raw milk carrying a viral load higher than nearly any infection ever measured in a mammal. That is the reality Colorado State University virologists are confronting with H5N1, and it is why one of them rates the virus a 7 out of 10 on her personal pandemic-worry scale. "I don't want to be a panic button about it," Angela Bosco-Laflor said on the This Week in Virology podcast, "but the way it's moving through different species and the way there's new genotypes emerging that have some really scary characteristics like increased mammalian to mammalian transmission, we just need to keep this one really forefront."