The Centers for Disease Control and Prevention (CDC) has confirmed the first case of severe bird flu in the United States.

The federal health department said Wednesday that the patient was hospitalized in Louisiana. No identifying information about the patient was provided.

Genomic data showed the Louisiana patient was infected with a version of the virus that was recently found to be spreading in wild birds and poultry in the United States and in some cases in people in Canada and Washington state, according to the CDC.

This is different from the version of the virus that has been shown to spread among dairy cows and some poultry populations in the United States

The Louisiana patient had come into contact with sick and dead birds in backyard flocks, although an investigation into the cause of the illness is ongoing, the CDC said. This is the first case of human avian influenza in the United States linked to exposure to backyard flocks.

According to CDC data, 61 human cases of bird flu have been reported in the United States since April.

Almost all confirmed cases had direct contact with infected cattle or infected livestock. Before the case was confirmed in the Louisiana patient, the cases had been mild and all patients had recovered after taking antiviral medications, according to the CDC and state health officials. A previous case in Missouri was hospitalized, but health officials indicated health problems other than an avian flu infection when the patient was admitted 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, according to the CDC. Less common symptoms include nausea, vomiting, diarrhea and seizures.

Infections can range from no symptoms or mild illnesses such as flu-like symptoms to more severe illnesses such as pneumonia that could require hospitalization, the CDC said.

“The best way to prevent bird flu is to avoid contact if possible. Infected birds shed avian influenza A viruses through their saliva, mucus and feces,” the CDC wrote in a news release Wednesday. “Other infected animals can shed avian influenza A viruses through respiratory secretions and other body fluids (e.g. in unpasteurized cow’s 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 are exposed to them recreationally – are at higher risk and should take precautions recommended by the health authority.

The U.S. Department of Agriculture last week issued a new federal regulation requiring raw milk samples to be collected nationwide and provided to the department to test for avian influenza.

The decision came after the bird flu virus was found in raw milk samples from a California farm that issued a recall of all of its raw milk products earlier this week. The farm has also been quarantined by state health officials.

ABC News’ Youri Benadjaoud contributed to this report.