Health and agriculture officials in the United States are taking urgent measures to address the escalating bird flu outbreak affecting dairy cows. The virus, identified as Type A H5N1, has been detected in nearly three dozen dairy herds across eight states, with traces found in grocery store milk. The U.S. Department of Agriculture reports that the virus is spreading among cows, including those without visible symptoms, and between cows and birds.
A new federal order mandates that hundreds of thousands of lactating dairy cows must test negative for the virus before interstate movement is permitted, starting Monday.
Unusual Aspects of the Outbreak
This strain of highly pathogenic avian influenza has historically circulated in wild birds but has recently been found in various mammals globally, including farmed minks, aquatic mammals, and now dairy cows in the U.S. The discovery of the virus in cows earlier this year has raised concerns among experts about the potential for human transmission due to the virus's ability to adapt to new species.
Tracking the Outbreak
Scientists confirmed the presence of the virus in cows in March after reports of ill animals on dairy farms. The virus has likely been spreading since late last year, primarily through contact with contaminated objects on farms. Efforts to track the outbreak include increased surveillance and testing in cows and farm workers to assess the extent of the problem.
Risk to Humans and Future Concerns
While the risk to the general public from consuming pasteurized milk is low, experts advise against consuming raw milk. Additional precautions for dairy farm workers, such as wearing masks and practicing good hygiene, are recommended. Currently, one person has tested positive for a mild eye infection related to the outbreak, with others being monitored for symptoms.
Experts emphasize the need for proactive screening and surveillance to detect and address such outbreaks promptly to prevent potential threats in the future.
