MONCTON -- The outbreak of legionnaires' disease in greater Moncton that was declared over in September may not be over after all.

Sixteen people in Moncton fell ill with the pneumonia-like disease this past summer. That number has now jumped to 20.

"Since declaring the outbreak over on Sept. 10, we've had four additional cases reported to public health," said Dr. Yves Leger, the regional medical health officer.

Claudette Lirette was one of the 16 patients who contracted legionnaires' disease from a cooling tower in the west end of Moncton.

When she found out there were four new cases, she couldn't help but wonder if the new patients got sick from the same source.

"I thought that these people are related to the same case that we are," Lirette said.

Leger says the four new cases are not related to the original outbreak.

The latest patients were diagnosed between Sept. 30 and Oct. 21.

"We do an extensive 14-day travel history to see where cases have been, their travel patterns, and we map all that information on maps and compare that between different cases," Leger said.

Leger says these are considered sporadic cases, unrelated, and without a common source.

One of the four people was from out of town and spent minimal time in the Moncton area.

"Out of those other three, we were able to get one specimen collected for culture, which was sent to the health laboratories in Quebec, and typing was done on that specimen," Leger said.

Results indicated that case was not a match to the cooling tower where legionella was originally found.

That site has not been identified by Public Health -- something that triggered frustration among the original 16 who contracted legionnaires'.

Some of those patients held a meeting recently to consider taking legal action.

"We're going to try to go for the class-action lawsuit and we filled out all the papers," Lirette said.

Leger says Public Health stands by its decision not to disclose the location of the cooling tower and that a site linking to the new cases has yet to be found.

As for the four new cases, Leger says they are doing well and there were no fatalities, though some could take months to recover.

He also said he has no reason to believe there is any ongoing source of legionnaires' in the community.