CDC Calls for Wider Bird Flu Testing After More Farmworker Infections Found

Health officials from the Centers for Disease Control and Prevention (CDC) on Thursday called for more testing of people on farms who have contracted bird flu.

The federal agency updated its recommendations for wider testing after a new study revealed more farmworkers had signs of infection, even though they reportedly did not display symptoms of illness.

In the study conducted from June to August, blood tests for 115 farmworkers in Michigan and Colorado showed that 7 percent of the workers appeared to have been infected with Type A H5N1 influenza—a flu virus subtype that causes bird flu—but only half said they recalled experiencing symptoms.

Dr. Nirav Shah, principal director of the CDC, said people in close contact with infected animals should get tested and seek treatment even if they feel fine.

“The purpose of these actions is to keep workers safe, to limit the transmission of H5 to humans and to reduce the possibility of the virus changing,” Shah said to reporters.

Angela Rasmussen, virus expert at the University of Saskatchewan in Canada, used the new study to criticize the current response to the bird flu outbreak.

“It shows yet again that we are not responding effectively to the H5N1 cattle outbreak in humans or animals and if we continue to let this virus spread and jump from species to species, our luck will eventually run out,” Rasmussen told the Associated Press.

How Many Reported Cases Of Bird Flu?

There have been 46 confirmed human cases of bird flu during the 2024 outbreak as of Thursday, according to the CDC. Nearly all of those infected were exposed to either cattle or poultry. Only one case in Missouri had an unknown source.

The new CDC study suggests that the virus has infected more humans than previously reported. As of this week, bird flu has been detected in 10,528 wild birds, roughly 105.2 million poultry and 443 dairy herds.

How Is Bird Flu Spread and What Are the Symptoms?

Bird flu viruses may spread from infected birds to other animals and humans. While bird flu infections among humans are rare, the virus can spread if it gets into a person’s eyes, nose or mouth, or is inhaled.

Bird flu symptoms can range from mild to severe. Mild symptoms may include eye redness or flu-like upper respiratory symptoms.

Here are severe symptoms that infected people may experience:

• Pneumonia requiring hospitalization
• Fever (temperature of 100ºF or greater) or feeling feverish
• Cough
• Sore throat
• Runny or stuff nose
• Muscle or body aches
• Headaches
• Fatigue
• Shortness of breath or difficulty breathing.

The CDC also lists less common symptoms: diarrhea, nausea, vomiting or seizures.

How to Stop the Spread of Bird Flu

The CDC advises people to wear protective equipment when interacting with infected or potentially infected animals. Protective gear includes fluid-resistant coveralls and, if necessary, a waterproof apron; a National Institute for Occupational Safety and Health-approved particulate respirator; safety goggles or face shield, if necessary; rubber boots or rubber boot covers; head or hair cover; and gloves.

People should also monitor their health for 10 days after their most recent exposure to the virus, according to the CDC.

The agency recommends avoiding close, long or unprotected exposures to sick or dead animals as well as unprotected exposures to animal poop, bedding, unpasteurized milk or materials that have been touched by, or were close to, animals with suspected or confirmed bird flu.