Los Angeles County health officials said Monday that 170 people had fallen ill after a four-day conference that culminated in a fundraiser at the Playboy Mansion, but that the outbreak is not believed to have spread beyond the conference.

The possible outbreak of legionellosis, or Pontiac fever, affected people connected with the DOMAINfest Global Conference held at the Fairmont Miramar Hotel & Bungalows in Santa Monica on Feb. 1-3, “with symptoms mostly consisting of fever, chills, general discomfort (malaise) and some cough,” according to a statement by the county Department of Public Health on Monday. More than 700 people from 30 countries attended the conference.

The department was notified last Friday of a “suspected respiratory infection outbreak” among those associated with the conference, and officials were still identifying and contacting possible victims Monday, the statement said.

“The department is investigating several locations associated with this conference, including the Playboy Mansion in Holmby Hills,” the statement said. “At this time, Public Health has not determined that the source of exposure is limited to a specific location. The department is working to conclusively identify the source of exposure and the likely cause of illness for this suspected outbreak.”

The state Department of Public Health, the Centers for Disease Control and Prevention and surrounding county health departments are providing assistance “as a number of conference attendees live outside of Los Angeles County,” the statement said. “Public Health has no information suggesting that this suspected outbreak extends beyond those individuals associated with this conference.”

The conference was for technology professionals in the domain name industry.

A spokeswoman for Playboy did not return phone calls Monday.

Staff from the Centers for Disease Control and Preventionwho are based at the health department were assisting with the investigation, but CDC headquarters in Atlanta has not been enlisted, said CDC spokeswoman Alison Patti. It was not clear how soon investigators could determine whether the illness is Pontiac fever, a milder form of Legionnaires’ disease caused by a bacterium that grows in warm water and can take root in hot tubs or air-conditioning systems, according to the CDC.

Pontiac fever is not contagious, and most symptoms eventually disappear in two to five days, according to the CDC. Legionnaires’ disease is a type of pneumonia that usually responds to antibiotics, although 5% to 30% of cases prove fatal, according to the CDC.

A statement the department sent to conference attendees on Friday noted that some at the conference had developed pneumonia.

Seven patients became sick and two died in a Legionnaires’ outbreak at Good Samaritan Hospital in 2002. Nationally, Legionnaires’ affects 8,000 to 18,000 people annually.

Testing for the bacterium can be done within a week, but the challenge is to identify victims who have left the area.

“It is a lengthy process; there are a lot of people involved that we need to talk to,” said Sarah Kissell, a department spokeswoman.

Fairmont Miramar Hotel & Bungalows staff issued a statement Monday saying they had not “received any reports of illness with the same symptoms from any employees or other hotel guests and patrons” not involved with the conference.

Ron Jackson, of Tampa, Fla., attended the conference with his wife, who got sick. He said he knows of one attendee diagnosed with legionellosis after returning home to Sweden. Jackson said he has compiled a sick list of 97 people. He said all were conference attendees, but added that he was concerned about models hired for the Playboy event. One model contacted him to say she had been sick, he said.

David Castello, of Palm Springs, became ill after attending the conference. He still felt weak Monday and planned to see his doctor Tuesday for chest X-rays and treatment before he leaves for a conference in Uruguay.

“I’d like to know what took away a week of my life,” he said. “They just need to find out where and when it started. Now it’s like a big mystery — everyone wants to know.”

molly.hennessy-fiske@latimes.com