A Colorado man has become the first human in the U.S. to test positive for the H5N1 strain of bird flu, amid the worst outbreak of the virus in seven years and a cull of millions of poultry in dozens of states.
The unnamed patient, an inmate in Colorado, contracted the infection during a work release assignment at a farm in Montrose county where workers were euthanizing an infected flock, the Colorado Department of Public Health and Environment said in a statement.
The federal Centers for Disease Control and Prevention (CDC) said the health risk to the general public remained low.
“The patient reported fatigue for a few days as their only symptom and has since recovered,” the agency said, adding that the man, who was younger than 40, was isolated and being treated with the antiviral drug oseltamivir, reports The Guardian.
Monitoring for the H5N1 virus is ongoing
The CDC has been monitoring for illness among people exposed to H5N1 virus-infected birds since these outbreaks were detected in U.S. wild birds and poultry in late 2021 and into 2022.
In February, the avian flu was first detected in a commercial turkey flock in Dubois County, Indiana, according to the US Department of Agriculture. This was the first case of infection in the US since 2020.
Since that initial outbreak, the disease has been confirmed in commercial and backyard flocks across at least two dozen states and in wild birds across more than 34 states, according to the federal agency.
Earlier this month, Digital Journal reported that the spread of avian flu led zoo officials across the country to move their birds indoors temporarily as a safety precaution.
CDC has tracked the health of more than 2,500 people with exposures to H5N1 virus-infected birds and this is the only case that has been found to date. Other people involved in the culling operation in Colorado have tested negative for H5 virus infection.
Cases of the H5 avian flu virus globally
The Colorado case is only the second human case associated with this specific group of H5 viruses that are currently predominant, and the first case in the United States.
The first case internationally occurred in December 2021 in the United Kingdom in a person who did not have any symptoms and who raised birds that became infected with the H5N1 virus.
More than 880 human infections with earlier H5N1 viruses have been reported since 2003 worldwide, however, the predominant H5N1 viruses now circulating among birds globally are different from earlier H5N1 viruses.
Readers may be wondering about the finding last Tuesday of the first human case of the H3N8 bird flu virus in a young boy in China. The H3N8 variant is common in horses and dogs and has even been found in seals. No human cases of H3N8 have been reported up to this time, according to Reuters.
However, the most recognized strain of avian influenza is the HPAI strain, H5N1. the HP designation means the strain is highly pathogenic. This strain was first isolated from a goose in China in 1996.
Human infections were first reported in 1997 in Hong Kong. Since 2003, more than 700 human cases of Asian HPAI H5N1 have been reported – primarily from 15 countries in Asia, Africa, the Pacific, Europe, and the Middle East, though over 60 countries have been affected.
