Study Finds 7% of Farm Workers Exposed to H5N1-Infected Cattle Were Infected

A new study published in Morbidity and Mortality Weekly Report (MMWR) has found that 7% of farm workers “exposed to H5N1-infected dairy cattle” had “antibodies suggesting prior infection.” CIDRAP has the news.

These findings triggered “enhanced testing, prophylactic (preventive) treatment, and use of personal protective equipment (PPE) from the US Centers for Disease Control and Prevention (CDC).”

The study included “blood samples collected from June to August from 115 farm workers who had been exposed to sick cows in Colorado and Michigan. The samples were collected between 15 and 90 days after exposure.” Eight of the 115 samples were “positive for H5 avian influenza antibodies.” Four of the eight workers “said they remembered having symptoms,” and “none of the workers wore respiratory protection.” Only one of the workers reported “working with cows known to be infected.”

The CDC is now “expanding recommendations on who should be tested to include workers who are exposed to sick cows or poultry but aren't experiencing symptoms.” The agency also stepped up its “recommendation for oseltamivir (Tamiflu) prophylaxis to include any asymptomatic worker with high-risk exposure, especially those who didn't wear adequate PPE.”

A separate report published in MMWR also established that “PPE was usually available, but wasn’t always used” on farms where the virus was found in cows. PPE use “jumped 28% after the virus was found in cows.”