CHERRY HILL, N.J. ? A mysterious illness killed one woman attending a weekend convention and sent seven others to hospitals, but health officials said Sunday they didn’t think anyone else who didn’t already have symptoms would get sick.

The woman, who died early Sunday at Kennedy Memorial Hospitals-Cherry Hill, had a viral, flu-like illness for about two days before becoming seriously ill Saturday night, said Dr. David V. Condoluci, chief of infectious diseases for Kennedy Health System.

Joanne Hemstreet, 45, of Kingston, Mass., was attending a national sales convention at the Cherry Hill Hilton with about 500 other employees of Cendant Mortgage.

“We do not know the exact cause of her demise,” Condoluci said at a news conference outside the hospital in this Philadelphia suburb. “This looks like possibly a case of pneumococcal pneumonia,” worsened by a subsequent, aggressive bacterial infection.

Health officials had worried the outbreak was caused by meningococcus, anthrax or Legionnaires’ disease, but Condoluci said none of those appeared to be involved.

Results of an autopsy on Hemstreet and preliminary test results on the seven people admitted to the hospital should be available today.

None of those admitted was in critical condition. They were given antibiotics and admitted for further treatment and observation as a precaution.

About 80 other people who might have had contact with Hemstreet had gone to the hospital’s emergency room for evaluation, hospital spokeswoman Nicole Pensiero said.

Condoluci said investigators from the state and Camden County health departments were at the hotel Sunday, interviewing convention guests.

The hotel was quarantined for several hours early in the day but the restriction was lifted before noon.

The illnesses brought back memories of an outbreak of Legionnaires’ disease at a convention 25 years ago.

Legionnaires’ disease, caused by a bacterium that grows in water and can be spread through air conditioning ducts, takes its name from a July 1976 outbreak that killed 29 people at the Pennsylvania American Legion convention at a hotel in Philadelphia. It also causes pneumonia-like symptoms.