A new serology study by the CDC and state health departments found that 7% of farm workers exposed to H5N1-infected dairy cattle had antibodies, indicating potential prior infection. In response, the CDC is enhancing recommendations for testing, prophylactic Tamiflu use, and personal protective equipment (PPE) use among workers exposed to infected livestock.
The study analyzed blood samples from 115 workers in Colorado and Michigan collected 15 to 90 days post-exposure. Eight samples tested positive for H5 avian flu antibodies. Four individuals recalled symptoms, such as conjunctivitis, and none used respiratory protection, with less than half wearing eye protection.
The CDC also reported three new H5 cases, raising the U.S. total to 46. Recommendations now include testing asymptomatic workers exposed to sick animals and providing Tamiflu for those with high-risk exposure. The CDC is also emphasizing PPE use for high-risk farm tasks, noting that PPE usage, especially eye protection, increased after H5N1 detection on outbreak farms.
For more information, refer to the CDC’s findings in the Morbidity and Mortality Weekly Report (MMWR) here.
