Minnesota reports one H5N1 detection in dairy; statewide monthly milk testing continues

Minnesota officials confirmed one detection of highly pathogenic avian influenza (H5N1) in a dairy herd and said they will continue statewide monthly bulk-tank milk surveillance while moving to scale laboratory capacity and vaccine access.

The dairy detection, reported in March, was a low‑level positive on a follow‑up test, and state investigators said sequencing may not be possible because the sample cycle threshold values were high. “When you start to get to 35 and above, those are either waxing and waning or it's a new infection starter,” said Dr. Brian Hayes, executive director of the Minnesota Board of Animal Health, describing laboratory limits for sequencing and the implication for determining whether an infection is new or persistent.

Why it matters: The detection underscores a shift for animal health authorities from episodic outbreaks toward ongoing surveillance in multiple species. State and federal agencies are treating H5N1 as a multiyear, multi‑species challenge that affects commercial poultry, backyard flocks and dairy cattle and has human exposure implications.

What officials described - Milk testing program: Nikki Neazer, director of the…