“This is the first case of H5N1 bird flu in the U.S. that has been linked to exposure to a backyard flock,” said a Wednesday press release from the U.S. Centers for Disease Control and Prevention. It revealed that a patient in Louisiana has been hospitalized with a severe case of avian influenza A, also known as “bird flu.”
Data from the U.S. Department of Agriculture cited by the University of Maryland Extension indicates that 7% of all U.S. households own a small flock, with an average size of 49 birds. Throughout the country, there are more than 138,000 small backyard flocks.
Per the CDC, the Louisiana case was confirmed Dec. 13.
An investigation into the source of the infection in Louisiana is ongoing, but the CDC said that it has been determined that the patient was exposed to dead and sick birds in a backyard flock. Partial viral genome data virus that infected the patient indicates that the virus belongs to the D1.1 genotype that is related to other viruses recently detected in wild birds and poultry in the U.S. as well as and in recent human cases in British Columbia, Canada, and Washington state.
“This H5N1 bird flu genotype is different than the B3.13 genotype detected in dairy cows, sporadic human cases in multiple states, and some poultry outbreaks in the United States,” the CDC said. “Additional genomic sequencing and efforts to isolate virus from clinical specimens from the patient in Louisiana are underway at CDC.”
Audacy reported earlier this month that the USDA mandated that the entire national milk supply be tested for bird flu. The move came amid concerns about H5N1, which has spread to over 720 dairy herds across 15 states since March.
According to the CDC, sporadic cases of severe H5N1 bird flu illness are not unexpected and the virus has been linked to severe illness in humans – and even death – outside of the U.S. in the past. However, it added that no person-to-person spread of H5 bird flu has been detected.
Audacy reported in September that a Missouri resident tested positive for avian influenza without contacting an infected animal. In October, the CDC said that “none of the results,” of an extensive investigation into that case “support that human-to-human spread occurred.”
“This case does not change CDC’s overall assessment of the immediate risk to the public's health from H5N1 bird flu, which remains low,” said of the findings out of Louisiana.
In addition to being the first case linked to a backyard flock, the Louisiana case is also the first instance of severe illness linked to the virus in the U.S., said the CDC. It said that the case does underscore the risk of contracting bird flu through contact with backyard flocks.
“People with work or recreational exposures to infected animals are at higher risk of infection and should follow CDC’s recommended precautions when around animals that are infected or potentially infected with H5N1 avian influenza virus,” said the centers. “This means that backyard flock owners, hunters and other bird enthusiasts should also take precautions.”
These precautions include avoiding contact with sick and dead animals if possible and wearing personal protective materials when dealing with wild animals, sick animals or dead animals. To avoid contamination, the CDC also recommends not touching surfaces or materials contaminated with saliva, mucous, or animal feces from wild or domestic birds or other animals with confirmed or suspected avian influenza A virus infection.
This August, Audacy reported that avian influenza is one of the top potential pandemic concerns for public health officials in the U.S. It was first reported in 1996 and, though the U.S. Centers for Disease Control and Prevention said the current risk for human infection is low, there have been 61 human cases of H5 bird flu reported in the U.S. since April.