An inmate in Colorado has grow to be the primary human within the US to check optimistic for the H5N1 pressure of chicken flu, amid the worst outbreak of the virus in seven years and a cull of hundreds of thousands of poultry in dozens of states.

The unnamed prisoner contracted the an infection throughout a piece launch task at a farm in Montrose county the place staff have been euthanising an contaminated flock, the Colorado division of public well being and atmosphere mentioned.

The federal Facilities for Illness Management and Prevention (CDC) mentioned the well being danger to most people remained low.

“The affected person reported fatigue for a number of days as their solely symptom and has since recovered,” the company mentioned, including that the person, who was youthful than 40, was handled with the antiviral drug oseltamivir.

The Colorado case “doesn’t change the human well being danger evaluation”, the CDC mentioned.

“[The agency] has tracked the well being of greater than 2,500 folks with exposures to H5N1 virus-infected birds and that is the one case that has been discovered so far. Different folks concerned within the culling operation in Colorado have examined damaging for H5 virus an infection, however they’re being retested out of an abundance of warning.”

The one different recognized human case of the pressure of chicken flu at present predominant was within the UK in December final 12 months, the CDC famous, though nearly 900 instances have been reported worldwide from earlier H5N1 viruses since 2003.

The US agriculture division has been monitoring the unfold of avian influenza throughout 30 states and affecting greater than 35 million birds, in line with its newest figures.

The Guardian reported on Thursday that greater than 22 million birds have been killed in an try to include the outbreak, the bulk in Iowa, the largest US producer of eggs. That determine didn’t embody a industrial egg farm in Knox, Nebraska the place 2.1 million poultry have been reported affected on Wednesday.

At one egg manufacturing facility in Rembrandt, Iowa, about 250 workers have been fired after roasting alive 5.3 million chickens, the most important cull at any manufacturing facility farm within the nation, in circumstances some fired staff and animal rights teams say have been inhumane.

The Storm Lake Occasions revealed that birds at Rembrandt have been culled utilizing a system generally known as air flow shutdown plus (VSD+) wherein air is closed off to the barns and warmth pumped in till the temperature rises above 104F (40C).

“They cooked these birds alive,” mentioned one of many staff concerned.

Earlier within the week, an H3N8 pressure of chicken flu was detected in people for the primary time in Henan province in China.

The four-year-old boy contaminated had been involved with chickens and crows raised at his house, in line with stories from China’s Nationwide Well being Fee.

Avian influenza, or chicken flu, is a extremely contagious viral illness. The primary stories of human instances got here within the Nineties.

Some strains have been handed to people however it’s at present very uncommon and normally happens solely after very shut contact with contaminated birds or animals.