Anthony Fauci, the former top infectious disease expert in the United States, is recovering from an infection with West Nile virus, a spokesman said.

The 83-year-old was briefly hospitalized but is now home and is expected to make a full recovery.

In a message to X on Saturday, Jonathan LaPook, chief medical reporter for CBS News, wrote that he had spoken to Dr. Fauci, who said the infection was likely caused by a mosquito bite he received in his backyard.

“Dr. Fauci was hospitalized approximately 10 days ago after developing fever, chills and severe fatigue … he left the hospital three days ago and is now recovering at home,” he said.

As White House medical advisor, Dr. Fauci has been the face of the U.S. government during the COVID-19 pandemic, a role that has made him both a trusted voice to millions and a target of partisan ire.

He left the government in 2022, but in June he was back before Congress to testify as part of the Republicans’ years-long investigation into the origins of COVID-19 and the U.S. response to the disease.

Last year he was appointed professor at Georgetown University.

What is West Nile?

West Nile virus is usually spread through the bite of an infected mosquito.

According to the Centers for Disease Control and Prevention (CDC), most people experience no symptoms, but about one in five may experience fever, headache, body aches, vomiting, diarrhea or skin rash.

About one in 150 infected people develops a serious, sometimes fatal, illness.

There are currently no vaccines that can prevent the virus, and no medicines to treat it.

As of August 20, the CDC, the United States’ national health agency, has recorded 216 cases in 33 states this year.

The West Nile region is considered the main source of mosquito-borne diseases in the country, which are most prevalent from June to November, the mosquito season in the Northern Hemisphere.

West Nile virus is not contagious, but can affect anyone bitten by an infected mosquito. It is best to avoid being bitten by mosquitoes.

The CDC recommends protective measures such as using insect repellent, wearing long-sleeved shirts and pants, and taking steps to control mosquitoes indoors and outdoors.

People with weakened immune systems, those over 60, or those with existing medical conditions may be susceptible to serious illness, but deaths are rare.

West Nile is found in many parts of the world, including North America, Europe, Africa, the Middle East, and Asia.

One strain called West Nile virus/Kunjin is found in parts of Australia, particularly the Northern Territory and northern Western Australia, and is a nationally notifiable disease. No other subtypes are known.

ABC/AP