DENVER — Three poultry workers at a commercial egg-laying facility in Weld County affected by an outbreak of highly pathogenic avian influenza have tested presumptive positive for bird flu, state health officials said Friday, underscoring the need to get a virus that has already killed more than 6 million birds and which is now infecting dairy cattle across the state under control.
The three additional cases — which have yet to be confirmed by the U.S. Centers for Disease Control and Prevention (CDC) — would mean Colorado isn’t just leading the nation in the number of bird flu outbreaks among dairy cattle, but more importantly, in the number of people infected by the H5N1 virus.
If confirmed by the CDC, the three additional cases would mean Colorado has now detected five cases of H5N1 among poultry and dairy workers since the outbreak of highly pathogenic avian influenza was first detected in the state in March of 2022.
In a statement early Friday evening, a spokesperson with the Colorado Department of Public Health and Environment (CDPHE) said the workers were culling poultry at a farm in northeast Colorado and exhibited mild symptoms, including conjunctivitis, or pink eye, as well as “common respiratory infection symptoms.” The statement from the CDPHE did not expand on what those respiratory symptoms were and did not say whether antiviral treatment had been given to the workers who tested presumptive positive for the virus. Denver7 was not able to reach anyone from the department by phone or email Friday evening to answer those questions.
None of the individuals were hospitalized, the spokesperson said in the statement.
"These preliminary results again underscore the risk of exposure to infected animals," a CDC spokesperson said in a statement. "There are no signs of unexpected increases in flu activity otherwise in Colorado, or in other states affected by H5 bird flu outbreaks in cows and poultry."
The statement continued, "Human infections with this novel influenza virus (and others) are concerning because of the potential to cause severe disease. The other reason these types of human infections are concerning is because of their pandemic potential. If these viruses were to change to spread easily from person-to-person, it could trigger a pandemic."
CDPHE first learned about symptomatic workers at the poultry farm on Thursday and tested seven individuals. On Friday, the CDPHE returned with a larger team to the site and tested 48 additional symptomatic workers, a spokesperson said in an email to Denver7 Friday evening. "The test results from samples collected today (July 12) are still pending," the spokesperson added, saying those samples will be tested this weekend.
“State epidemiologists suspect the poultry workers’ cases are a result of working directly with infected poultry. The investigation is ongoing with support from CDC,” according to the statement from the CDPHE.
These potential cases are connected to the bird flu outbreak at a Weld County egg-laying operation where 1.8 million chickens had to be culled, according the CDPHE.
As a result of outbreak at the Weld County egg-laying operation, a quarantine order is now in place in parts of Weld County in order to limit the movement of birds in and out of the area, and commercial or backyard poultry owners in the quarantine area were being asked to report the status of their flock through this online form.
The CDC is sending a team to Colorado to support their investigation, the CDC spokesperson said, which will include "looking into compliance with the recommended use of personal protective equipment."
How can I protect myself against bird flu?
State health officials maintain that the risk of catching bird flu for the general public is low, though people who come into contact with sick poultry or cattle are at greater risk of becoming infected with the virus.
So far, no human-to-human transmission of bird flu has been detected, according to the CDC.
The nation's top public health agency recommends that farm workers who come into contact with cattle suspected or confirmed to be infected with H5N1 wear disposable fluid-resistant coveralls, disposable gloves, boots or boot covers, vented safety goggles or a face shield, as well as an N95 respirator.
The general public should avoid contact with sick birds or other animals to reduce their chances of becoming infected with bird flu, state epidemiologist Dr. Rachel Herlihy has said in the past. If you must handle sick or dead birds or animals, be sure to wear gloves, a high-quality mask such as a KN95 or N95 respirator, and eye protection. After handling the animal, double bag it and throw it away in your municipal trash can before thoroughly washing your hands with soap and warm water. If soap and water are not available, use an alcohol-based hand rub, the CDC recommends.
People should also avoid unprotected exposures to animal poop, bedding (litter), unpasteurized milk, or materials that have been touched by, or close to, birds or other animals with suspected or confirmed H5N1 infection, CDC officials said.
The CDPHE is advising anyone who works with dairy cows or poultry who may have flu-like symptoms, to call the state health department at 303-692-2700 (after normal business hours: 303-370-9395). Officials said the department can help those potentially exposed get a flu test and medicine if needed.
Can I catch bird flu from drinking milk or eating meat?
FDA officials have said the likelihood that eggs will contain H5N1 is low “due to the safeguards in place, which include testing of flocks and federal inspection programs,” that call for the disposal of eggs and meat from infected poultry. Proper egg storage and preparation “further reduce the risk,” they said.
Though the agency “does not know at this time if the HPAI H5N1 virus can be transmitted to humans through consumption of raw milk and products made from raw milk from infected cows,” scientists are advising people to avoid raw milk and dairy products made from raw milk, as it does not go through the process of pasteurization, which inactivates harmful viruses and bacteria.
Though Colorado isn't testing swine and beef cattle for bird flu, ground beef appears to be safe for consumption after USDA researchers found no live virus in retail meat samples from states with ongoing outbreaks. The agency said it was confident that the meat supply was safe after at least three different safety studies found no viral particles in beef cattle, including one in which the meat was cooked to varying degrees of preparedness.
As of July 4, the CDPHE was monitoring more than 500 dairy workers for possible exposure to bird flu. Nearly 70 people in Colorado have been tested for possible exposure to H5N1 after coming in contact with infected birds or cattle since March, the CDPHE spokesperson said.
