In a recent development, Colorado health officials have identified three presumptive cases of H5 bird flu virus infection among poultry workers, as reported by the Centers for Disease Control and Prevention (CDC) on Friday. These individuals, who were involved in culling infected animals at a poultry facility experiencing an H5N1 bird flu outbreak, exhibited mild symptoms including conjunctivitis and common respiratory infection signs. None required hospitalization.


State epidemiologists believe the infections likely occurred through direct contact with infected poultry. The CDC, responding to the situation, is dispatching a team to Colorado to assist with the investigation. Despite these cases, the agency maintains that the risk to the general public remains low.


The CDC emphasizes the significance of human H5N1 infections due to their potential for causing severe disease and the possibility of sparking a pandemic if the virus were to mutate and become easily transmissible between humans.


These cases are part of a broader H5N1 bird flu outbreak that has been spreading globally, affecting wild birds, poultry, various mammal species, and recently causing an outbreak in U.S. dairy cows. The CDC notes that there are no indications of unexpected increases in flu activity in Colorado or other states affected by H5 bird flu outbreaks in cows and poultry.


Preliminary testing by Colorado officials suggests the three individuals were infected with a novel influenza type, presumed to be bird flu. Samples have been sent to the CDC for confirmatory testing. If confirmed, these would represent the fourth, fifth, and sixth cases of bird flu in Colorado and bring the total U.S. cases to nine since March.


Prior to these cases, the CDC reported one human H5N1 case after poultry exposure since 2022, and four cases in humans after exposure to dairy cows, all occurring this year.


The CDC is awaiting the results of their investigation to determine if any changes to current guidance are necessary. Additionally, analysis of virus sequences from this outbreak will be crucial in reassessing the risk level.


The agency's recommendations regarding H5N1 remain unchanged. They advise people to avoid close, prolonged, or unprotected exposure to sick or dead animals, including wild birds, poultry, and other domesticated animals. This caution extends to animal feces, litter, unpasteurized or raw milk, and materials that may have been in contact with animals suspected or confirmed to have bird flu.


As this situation develops, health officials continue to monitor the spread of H5N1 closely, balancing the need for vigilance with efforts to maintain public calm and provide accurate information.