The Centers for Disease Control and Prevention confirmed on Friday that a child from Alameda County in the Bay Area tested positive for avian influenza (H5N1 bird flu). The child, who has been treated, is recovering at home. They had no known contact with an infected animal, but public health experts are investigating a possible exposure to wild birds. 

The California Department of Public Health is working with local public health officials and the CDC to investigate the cause of the initial positive test in the child. The positive test showed a low-level detection of the virus, indicating the child was not likely infectious to others. Repeat bird flu testing on the child four days later was negative, and additional testing shows the child was also positive for respiratory viruses that could be the cause of their cold and flu symptoms. 

CDC continues to closely monitor available data from influenza surveillance systems, particularly in states affected by outbreaks in animals, including California, where widespread outbreaks of H5N1 bird flu have been detected in wild birds and domestic poultry since 2022 and dairy herds since August 2024 in that state.

No person-to-person spread of the virus has been detected or is suspected. Due to mild respiratory symptoms, all close family members of the child were tested – and all are negative for bird flu and not suspected of having the virus at all. Family members were also confirmed to have the same, more common respiratory viruses as the child. They are also being treated with preventive medication. 

Out of an abundance of caution, other individuals who had contact with the child are being notified and offered preventive treatment and testing. Public health officials are aware that the child attended daycare with mild symptoms before the child's test was reported as a possible bird flu infection. Local public health officials have reached out to potentially exposed caregivers and families to conduct health checks for symptoms and offer connections to preventive treatment and testing if they develop symptoms. 

“It's natural for people to be concerned, and we want to reinforce for parents, caregivers and families that based on the information and data we have, we don't think the child was infectious – and no human-to-human spread of bird flu has been documented in any country for more than 15 years," said CDPH Director and State Public Health Officer Dr. Tomás Aragón. 

Human infections with bird flu viruses are rare, and no person-to-person spread has been detected in California or the United States. In the rare cases where bird flu has spread from one person to another, it has never spread beyond a few close contacts.  

People who have contact with infected dairy cows, poultry, or wildlife have a greater chance of getting bird flu, which can happen if the virus gets into a person's eyes, nose, mouth, or is inhaled. As a general precaution, whenever possible people should avoid direct contact with sick or dead wild birds, poultry, and other animals and observe them only from a distance. 

Including this most recent case, 55 human cases of H5 bird flu have now been reported in the United States during 2024, with 29 in California. To date, all have reported mild symptoms (primarily eye infections), and none have been hospitalized. Because bird flu viruses can change and gain the ability to spread more easily between people, public health officials have provided preventive measures and are monitoring animal and human infections carefully.  

CDPH has been closely monitoring the bird flu situation in both animals and humans since the state's first detection in poultry in 2022. To protect public health, and especially workers who may be exposed to infected animals, CDPH encourages those who work with infected dairy cows, raw milk, or infected poultry to use protective gear. Individuals who have symptoms or a significant exposure (such as raw milk splashing into the eye) should get tested quickly and treatment. In humans, bird flu symptoms include eye redness or discharge, cough, sore throat, runny or stuffy nose, diarrhea, vomiting, muscle or body aches, headaches, fatigue, trouble breathing, and fever. 

Public health experts also encourage farm workers to get a flu shot this year. While a seasonal flu shot doesn't stop bird flu, it protects against severe illness from seasonal flu and reduces the chance of human and bird flu viruses mixing and turning into new viruses that can spread more easily or be more severe. 

Pasteurized milk and dairy products are safe to consume.  Drinking raw milk or eating raw milk products could be dangerous. Reduce your risk by choosing pasteurized milk and dairy foods like cheese and yogurt. Pasteurization, the process of heating milk to specific temperatures for certain times, inactivates the bird flu virus and harmful germs that can be found in raw milk. 

For the latest information on the national bird flu response, visit: https://www.cdc.gov/bird-flu/