A Colorado inmate has become the first human in the United States to test positive for the H5N1 strain of bird flu, amid the worst virus outbreak in seven years and the culling of millions of poultry in dozens of ‘states.
The unnamed prisoner contracted the infection while on an away assignment at a Montrose County farm where workers were euthanizing an infected herd, the Colorado Department of Public Health and Environment said.
The federal Centers for Disease Control and Prevention (CDC) said the health risk to the general public remains low.
“The patient reported fatigue for a few days as the only symptom and has since recovered,” the agency said, adding that the man, who was under 40, had been treated with the antiviral drug oseltamivir.
The Colorado case “does not change the human health risk assessment,” the CDC said.
“[The agency] tracked the health of more than 2,500 people exposed to birds infected with the H5N1 virus and this is the only case that has been found to date. Others involved in the culling operation in Colorado have tested negative for H5 virus infection, but are being retested out of an abundance of caution.”
The only other known human case of the currently predominant bird flu strain occurred in the UK in December last year, the CDC noted, although nearly 900 cases have been reported worldwide from earlier H5N1 viruses since 2003.
The US Department of Agriculture has tracked the spread of bird flu to 30 states and affecting more than 35 million birds, according to its latest figures.
The Guardian reported on Thursday that more than 22 million birds have been killed in an attempt to contain the outbreak, the majority in Iowa, America’s biggest egg producer. That figure did not include a commercial egg farm in Knox, Nebraska, where 2.1 million birds were reportedly affected Wednesday.
At an egg factory in Rembrandt, Iowa, about 250 workers were laid off after roasting 5.3 million chickens alive, the largest slaughter of any factory farm nationwide, in circumstances some laid off workers and animal rights groups have called it inhumane.
The Storm Lake Times revealed Rembrandt’s birds were culled using a system known as Ventilation Shutdown Plus (VSD+) in which air is closed off at the barns and pumped in until temperature exceeds 104 F (40 C).
“They cooked these birds alive,” said one of the workers involved.
Earlier in the week, an H3N8 strain of bird flu was detected in humans for the first time in Henan province in China.
The infected four-year-old boy had been in contact with chickens and crows raised in his home, according to information from China’s National Health Commission.
Avian influenza, or bird flu, is a highly contagious viral disease. The first human cases were reported in the 1990s.
Some strains have been transmitted to humans, but these are currently very rare and usually only occur after very close contact with infected birds or animals.