CDC expands bird flu testing recommendation of dairy farm workers

Driving the news: The Centers for Disease Control and Prevention released a study on Thursday that analyzed blood serum collected from farm workers in Colorado and Michigan between June and August.

• Field staff collected anonymous serum specimens and conducted interviews with 115 workers at dairy farms that had herds with laboratory-confirmed bird flu cases in both states.
• The testing indicated 7% of participating dairy workers had evidence of recent infection with the virus.
• Half of those with antibodies to the virus did not report illness. It is possible they had only very mild symptoms.

Between the lines: All of the workers who had antibodies to the virus reported cleaning the milking parlor, compared with 38% of workers without antibodies to the virus.

• The finding suggests the higher-risk job is due to a high viral load of H5N1 in the milk of infected cows and could be important to understanding where to focus efforts to protect workers.

What to watch: The study found dairy workers weren't adhering to personal protective equipment (PPE) guidelines, suggesting a need to simplify messaging to farm workers and to focus on the highest risk activities.