WASHINGTON/WEST PALM BEACH, Fla. (Reuters) - U.S. Senator Ted Cruz said on Sunday he will quarantine himself at his Texas home this week “out of an abundance of caution” after brief contact 10 days ago at a gathering of conservatives with someone who has since tested positive for coronavirus.

Cruz was among the U.S. conservative politicians and activists who gathered just outside Washington last month for the annual Conservative Political Action Conference (CPAC), which met this year under the theme “America vs. Socialism.”

Separately, the conference organizer, American Conservative Union Chairman Matt Schlapp, said he had “incidental” contact with the attendee who tested positive, but that he felt “healthy as a horse” and had not heard of anyone else falling ill.

President Donald Trump and Vice President Mike Pence also attended the gathering in late February, but Schlapp told Fox News Channel’s “Fox & Friends Weekend” that neither had contact with the person infected by the virus.

More than half of the 50 U.S. states have reported cases, including the first cases in Virginia and Connecticut on Sunday. As the outbreak spreads, daily life has been disrupted, with some concerts and conferences canceled and some universities telling students to stay home and take classes online.

The coronavirus outbreak, which originated in China last year and causes the sometimes deadly respiratory illness COVID-19, has killed more than 3,600 globally.

Cruz, a Texas Republican, said that while at the conference he had a less than one-minute interaction, consisting of a handshake and brief conversation, with the unidentified individual who has since tested positive for coronavirus.

“I’m not experiencing any symptoms, and I feel fine and healthy. Given that the interaction was 10 days ago, that the average incubation period is 5-6 days, that the interaction was for less than a minute, and that I have no current symptoms, the medical authorities have advised me that the odds of transmission from the other individual to me were extremely low,” Cruz said in a statement.

“Nevertheless, out of an abundance of caution ... I have decided to remain at my home in Texas this week, until a full 14 days have passed since the CPAC interaction,” he added, saying physicians have advised him that people he has dealt with since CPAC “should not be concerned about potential transmission.”

A top U.S. health official, Anthony Fauci, said Americans, especially those who are vulnerable, may need to stop attending big gatherings as the coronavirus spreads.

In addition to Trump and Pence, participants at the conference included incoming White House chief of staff Mark Meadows, Trump’s son-in-law Jared Kushner, and Representative Jim Jordan, one of Trump’s biggest congressional allies.

Schlapp shook hands with Trump before the president spoke on the conference’s last day. However, the infected attendee was not attending that day, Schlapp wrote on Twitter.

The incubation period for the coronavirus is anywhere between two to 14 days and the conference ended on Feb. 29.

In a statement, CPAC said the Maryland Department of Health has screened thousands of employees from a conference centre and a hotel where the event was held and that no one had reported any unusual illness.

The health department encouraged the workers to take their temperature twice a day and be alert for any unusual symptoms, something the organizer encouraged its attendees to do as well.

In an interview with Reuters, Schlapp said the patient who tested positive and is quarantined, “seemed to have a big step forward to health last night and feels even better today.”