The American Israel Public Affairs Committee (Aipac) sent out a warning to the thousands of pro-Israel activists who attended its annual conference this week, that they might have come into contact with coronavirus.

The letter, which was also posted on Twitter, read that Aipac organisers “have been made aware of a group of Policy Conference attendees from New York was potentially in contact prior to the conference with an individual who contracted coronavirus.”

“To our knowledge, no one who attended the conference has tested positive for coronavirus at this time,” the letter, signed by Aipac President Betsy Korn and Aipac Chairman Dr Mort Fridman, continued.

It stated that a group from New York had been added to a self-quarantine list, and that Aipac was liaising with health authorities.

Haaretz reported that the at-risk group represented a New York synagogue where one congregant has been confirmed as a carrier of the virus, and that they could have come into contact with the coronavirus patient during services.

Aipac’s annual conference ran from February 28 to March 3 in Washington D.C. and was attended by some 18,000 people.

Organisers had taken precautions against the possible spread of the virus, which has 159 known cases in the United States, by adding hand sanitation dispensers and laying-on cleaners to disinfect highly trafficked areas.

Aipac claims two thirds of members of Congress attended the event. Congressional medical staff informed members that “no particular action” was “necessary at this time” in an email.

Congressional staff were informed that exposure at Aipac “would be considered an indirect exposure”, while Aipac also clarified that the District of Columbia’s Health Department “considers this a low-risk exposure”.

Speakers at the conference included the Chief Rabbi Ephraim Mirvis, former Labour MP Ian Austin, as well US Secretary of State Mike Pompeo, Vice President Mike Pence and key players in Congress.

The Israeli Health Ministry circulated new guidelines that instructed Israelis to avoid attending “international conferences abroad”, and stating attendees would “be charged with home isolation for 14 days.”

The regulations do not name Aipac, but the new guidelines were circulated on Tuesday, the day Aipac’s conference.

This coronavirus outbreak has killed over 3,200 people, mainly in China, and has infected some 95,000 people worldwide.

It was first reported in Wuhan, in central China, in December.