The H5N1 virus has been identified in raw milk purchased at a retail outlet in California and, in a separate case, the Centers for Disease Control and Prevention (CDC) has confirmed the first reported H5 virus in a child in the U.S.
The County of Santa Clara Public Health Department has been testing raw milk from local retail stores as part of the county's monitoring program for H5N1. On November 21, the county's Public Health Laboratory identified H5 in samples of raw milk produced by Raw Farms LLC, purchased at a retail outlet. The county immediately notified the California Department of Public Health. The raw milk was voluntarily recalled by the company and the state has advised the public to not consume the contaminated raw milk.
The County of Santa Clara Public Health Department is monitoring a multi-state outbreak of H5N1 bird flu in dairy cows in the United States. This is the first time that H5N1 bird flu has been found in cows, and transmission from cows to humans has been reported. H5N1 bird flu was first detected among cows in California in August. H5N1 bird flu was first detected among humans in California in October.
To date, there have been no reported cases of H5N1 bird flu in cows or humans in Santa Clara County.
Child infected with H5N1
Separately, the CDC has confirmed a human infection with H5N1 in a child in California. This is the first reported H5N1 virus infection in a child in the United States. Consistent with previously identified human cases in the United States, the child reportedly experienced mild symptoms and received flu antivirals. There were low levels of viral material detected in the initial specimen collected, and follow-up testing of the child several days later was negative for the virus, but was positive for other common respiratory viruses. The child is recovering from the illness. An investigation by the California Department of Public Health (CDPH) into the child's possible H5N1 exposure source is ongoing.
During CDPH's investigation, all household members reported having symptoms, and specimens were collected from those people. All test results from members of the household were negative for H5 bird flu, and some family members were positive for the same common respiratory viruses as the child. Contact tracing continues, but there is no evidence of person-to-person spread of H5N1 bird flu from this child to others. To date, there has been no person-to-person spread identified associated with any of the H5N1 bird flu cases reported in the United States.
This case was detected through influenza testing and reported to CDPH through influenza surveillance. This is the second U.S. case identified through national surveillance. CDC continues to closely monitor available data from influenza surveillance systems, particularly in states affected by outbreaks in animals, including California.
CDC's risk assessment for the general public is low. However, people with exposure to infected or potentially infected animals, such as birds, dairy cattle, or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at higher risk of infection. CDC recommends avoiding unprotected exposures to sick or dead animals, including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cows).
