Bird Flu Cases Undercounted, Experts Warn

A new study by the Centers for Disease Control and Prevention (CDC) has found that bird flu is silently spreading from animals to veterinarians, contradicting earlier reports of no human infections among veterinary workers. The CDC published a study in September 2024, which involved recruiting 150 veterinarians from 46 states and testing their blood for H5N1 antibodies.

The results showed that three veterinarians (2%) had evidence of past infection, despite none recalling symptoms. This discovery raises concerns that the official tally of human bird flu infections is likely an undercount. Dr. Gregory Gray, an infectious disease researcher, said that the virus can spread through occupational exposure without causing noticeable symptoms.

Similar findings were reported in previous studies, including one published last year which found two dairy farmworkers with evidence of past infection. The CDC has acknowledged that these cases are likely underreported and urged caution around animals. While the risk to the general public remains low, officials continue to remind veterinarians and others who handle poultry to take precautions.

“It’s a different story if the virus mutates or changes its behavior,” said Dr. Jacqueline Nolting, an Ohio State University researcher. Experts emphasize that natural immunity is possible, but increased vigilance around animals is necessary to prevent further spread.

Source: https://www.pbs.org/newshour/health/cdc-finds-evidence-that-bird-flu-spread-silently-to-veterinarians-suggesting-undercount-of-cases