USA now seen dozens number of avian flu cases in humans this yearAll light—until now.
Centers for Disease Control and Prevention Wednesday confirmation that a patient in Louisiana was hospitalized with a severe case of bird flu caused by the H5N1 virus. This marks the first case of severe illness linked to the virus in the US.
The virus has devastated poultry and wild bird populations across the country and has infected more than 800 dairy herds in 16 states. Infected animals transmitted the virus to people who came into contact with them. Since April, the United States has seen a total of 61 cases of bird flu were reported in humans in eight states. Of those, 37 were exposed to sick or infected dairy cows, while 21 were exposed to poultry farms and culling operations. In those cases, people developed conjunctivitis and mild respiratory symptoms and recovered completely.
A severe case is important because bird flu has previously been linked to severe illness in other countries, including outbreaks that resulted in deaths in up to 50% of cases. From 2003 to 2023, of the 878 people who tested positive for the virus, 458 deaths have been reported.
An investigation by the Louisiana Department of Health and CDC determined that the hospitalized patient, a resident of southwest Louisiana, was exposed to sick and dead birds in a backyard flock. This is the first case of H5N1 bird flu in the US linked to contact with backyard poultry. instead of a commercial farm.
“While the investigation into the source of this infection in Louisiana is ongoing, it is believed that the patient reported by Louisiana was exposed to poultry,” said Demet Daskalakis, director of the CDC's National Immunization Center. sick or dying on their premises.” and Respiratory Diseases, during a press conference on Wednesday. No other details were available about the source of exposure or the patient's condition.
One person with bird flu in Missouri was hospitalized in late August, but CDC officials said it was due to underlying medical conditions. The patient had no respiratory symptoms and was not seriously ill from the infection. “In the Missouri case, we really don't have the same type of data that proves it was related to their flu infection,” Daskalakis said.
There are genetic similarities between the virus from the patient in Louisiana and the virus from a teenager in Canada hospitalized with H5N1. Scientists have classified the virus in Louisiana as type D1.1, the same type found in the Canadian patient and another case in Washington state. This variant has also been detected in wild birds and poultry in the US.
This type is different from type B3.13, which has been detected in dairy cattle, some outbreaks in poultry, and in sporadic cases in humans in many states. CDC scientists are conducting additional genome sequencing of the Louisiana patient's virus sample. Genome sequencing can identify potential changes associated with the virus that signal an increased likelihood of infecting humans or transmitting from person to person.
To date, human-to-human transmission of H5N1 avian influenza has not been detected. The CDC says the immediate risk to public health remains low, but people who come into contact with infected animals for work or recreation are at increased risk of contracting the virus. “This means backyard flock owners, hunters and other bird enthusiasts should also take precautions,” the agency said in a statement.