The Centers for Disease Control and Prevention (CDC) has confirmed the first case of severe bird flu in the United States. The federal health agency said Wednesday that the patient has been hospitalized in Louisiana. State health officials said the patient is over the age of 65 with underlying medical conditions. The patient is experiencing severe respiratory illness related to bird flu infection and is currently in critical condition, a spokesperson from the Louisiana Department of Health told ABC News. Genomic data showed the Louisiana patient was infected with a version of the virus recently found to be spreading in wild birds and poultry in the U.S., as well as found in some human cases in Canada and Washington state, according to the CDC. This is different than the version of the virus found to be spreading in dairy cows and some poultry populations in the U.S. The Louisiana patient was exposed to sick and dead birds in backyard flocks, although an investigation into the source of the illness is ongoing, the CDC said. This is the first case of human bird flu in the U.S. linked to exposure to backyard flock. Three influenza A (H5N1/bird flu) virus particles (rod-shaped). Note: Layout incorporates two CDC transmission electron micrographs that have been inverted, repositioned, and colorized by NIAID. Scale has been modified. CDC and NIAID There have been 61 reported human cases of bird flu reported in the U.S. since April, according to CDC data. Almost all confirmed cases have had direct contact with infected cattle or infected livestock. Prior to the case confirmed in the Louisiana patient, cases had been mild and patients had all recovered after receiving antiviral medication, according to the CDC and state health officials. One previous case in Missouri was hospitalized, but health officials pointed to other health conditions aside from bird flu infection involved in the patient’s admission to the hospital. Signs and symptoms of infection in humans often include sore throat, cough, fever, runny or stuffy nose, headache, muscle or body aches, fatigue and shortness of breath, the CDC says. Less common symptoms include nausea, vomiting, diarrhea and seizures. Infections can range from no symptoms or mild illness, such as flu-like symptoms, to more severe illness, such as pneumonia that could require hospitalizations, the CDC says. “The best way to prevent bird flu is to avoid exposure whenever possible. Infected birds shed avian influenza A viruses in their saliva, mucous and feces,” the CDC wrote Wednesday in a press release. “Other infected animals may shed avian influenza A viruses in respiratory secretions and other bodily fluids (e.g., in unpasteurized cow milk or ‘raw milk’).” The CDC said no person-to-person transmission has been detected and the risk to the general public is low. However, those who work with birds, poultry or cows — or have recreational exposure to them — are at higher risk and should take precautions recommended by the health agency. The U.S. Department of Agriculture issued a new federal order last week that raw milk samples nationwide will be collected and shared with the department in order to test for bird flu. The decision came after the bird flu virus was found in samples of raw milk from a California farm, which issued a recall of all of its raw milk products earlier this week. The farm was also placed under quarantine by state health officials. On Wednesday, California Gov. Gavin Newsom declared a state of emergency “to streamline and expedite the state’s response” to bird flu. There have been 33 cases of human bird flu confirmed in California this year, according to the CDC.