California’s dairy industry is facing a rapid spread of H5N1 bird flu, with infected cow herds doubling over the weekend. According to a recent report from Ars Technica, the number of confirmed cases jumped from 17 to 34 between Thursday and Monday.

This surge places California second among affected states, trailing only Colorado’s 64 infected herds. The outbreak, which began in March, has now impacted 232 herds across 14 states.

California officials stated that the new cases were “not unexpected” due to connections with initially affected premises. They emphasized early detection as crucial for implementing enhanced biosecurity measures.

The spread of H5N1 bird flu to dairy cows is particularly concerning and unusual, as the virus primarily affects birds. This unexpected crossover to mammals highlights the evolving risks posed by the virus.

Karen Ross, California Department of Food and Agriculture Secretary, assured dairy farmers, saying, “Our extensive experience with [highly pathogenic avian influenza] in poultry has given us ample preparation and expertise to address this incident.”

Meanwhile, public health experts are concerned about a puzzling H5 bird flu case in Missouri. The infected individual had no known animal exposure, unlike previous cases involving farmworkers. This marks the 14th human infection amid the dairy cow outbreak this year.

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The Centers for Disease Control and Prevention is investigating potential transmission routes, including possible infections in a household member and healthcare workers who interacted with the Missouri patient.

While there’s no evidence of human-to-human transmission yet, experts worry that insufficient testing may be masking unseen spread. As the virus infects new mammalian species, it gains opportunities to adapt to humans, raising concerns about its pandemic potential.

Read more at Ars Technica