Four New Bird Flu Cases Confirmed in US

The Centers for Disease Control and Prevention (CDC) confirmed four new cases of bird flu in Colorado on Sunday. All of the infected people work at a poultry farm in the northeast of the state. The positive results bring the total number of cases in the United States to nine since the current outbreak of the H5N1 virus in humans was discovered in 2022. Eight of the nine cases have been reported this year.

The workers who tested positive this weekend were slaughtering infected poultry at a Colorado poultry plant when they began showing mild symptoms, including pink eye and general respiratory symptoms such as fever, chills, cough, sore throat and runny nose. None of the people were hospitalized, according to the state Department of Public Health and Environment. A fifth worker tested positive at a state lab on Saturday, July 13, and is awaiting confirmation from the CDC.

The bird flu virus has been spreading among mammals — from dogs, cats, skunks, bears, even seals and porpoises — in dozens of countries, including the United States, since 2020. Earlier this year, the H5N1 virus was detected in cattle in the United States and is now circulating in cattle in several states.

Given these new cases, federal health officials still believe the threat to the public is low because the virus is not transmissible between people. “CDC’s current risk assessment for the general public remains low. As we learn more, we will continue to evaluate the situation and provide updates. These preliminary results further highlight the risk of exposure to infected animals. Otherwise, there is no indication of an unexpected increase in flu activity in Colorado or other states affected by outbreaks of H5 avian influenza in cows and poultry,” they said in a statement.

However, the CDC emphasizes that human infections “are of concern because of their potential to cause serious illness” in addition to “their pandemic potential.” “If these viruses were to change and become easily transmitted from person to person, it could trigger a pandemic, although to date we have not observed genetic changes in the virus that make it more likely to spread between people,” they add.

The country’s first human case of bird flu was reported in 2022: Like the four cases confirmed Sunday, a Colorado poultry worker at the time had direct contact with infected birds that were being slaughtered for the purpose. Since that first positive result, four more human cases have been reported, but due to contact with infected dairy cows: another in Colorado, two in Michigan, and one in Texas. So far, all of the people who have tested positive have had mild symptoms.

As of Friday, the H5N1 virus had been confirmed in 152 dairy cows in 14 states, according to the Department of Agriculture. Additionally, more than 99 million birds have been infected with H5N1 or other types of bird flu in 48 states since January 2022, according to CDC reports.