CDC Can’t Confirm Suspected Bird Flu Case Tied to Raw Milk

CDC could not confirm what was suspected to have been the first H5N1 bird flu case linked to raw milk consumption.

The patient, a child in Marin County, California, experienced fever and vomiting after drinking raw milk, as reported last week. The child initially tested positive for influenza A, with the local lab unable to find evidence of person-to person transmission between the child and her family members.

The State Laboratory and the CDC conducted additional testing, “but due to low levels of viral RNA, they were unable to confirm whether the influenza A virus present was H5N1 (avian influenza) or seasonal influenza,” according to the Marin County public health department.

“The sample was negative for all flu targets,” Kevin Griffis, director of the CDC’s office of communications, told STAT on Thursday.

A Marin County public health officer suggested that the amount of virus in the initial test sample had been already low and may have degraded to an undetectable level by the time it got to the CDC lab.

The child, who has now recovered from the mystery illness, remains classified as a suspected case of avian influenza under National Notifiable Diseases Surveillance System criteria.

Public health officials nationwide remain concerned that the continued spread of H5N1 could increase the chances of it mutating to spread more easily in humans.

The raw milk consumed by the California patient had been produced by Raw Milk, a company that has products under quarantine due to H5N1-positive test results.

Since March, 59 people in the U.S. have been infected with bird flu, according to the CDC, mostly workers at poultry and dairy farms who became mildly ill after close contact with infected animals. California alone accounts for 34 confirmed cases.

Given its disproportionate number of confirmed cases, California is one of six states that will initiate mandatory testing of raw milk for bird flu starting this week, under a recent federal order by the U.S. Department of Agriculture.

Some experts believe that there may be more bird flu going around undetected, as H5N1 infections could be easily missed in people.

Healthcare providers are advised to consider H5N1 virus in persons with fever, gastrointestinal symptoms, respiratory symptoms, or conjunctivitis who have had recent consumption of raw milk products or exposure to animals suspected or confirmed to have avian influenza.