Fraser Health Authority confirmed the "cluster" of cases on Saturday, adding it likely started in Surrey, B.C., a suburb east of Vancouver. "The Health Department will evaluate the building's plumbing to look for evidence of Legionella bacteria in the building's water system", officials said.
New Hampshire averages about 32 cases of Legionnaires' disease each year.
The New Hampshire Department of Health and Human Services (DHHS) said Sunday that initial tests show the outbreak stemmed from "multiple sources" within the Sands Resort water system, including the hot tub area.
DHHS and the CDC will continue the investigation throughout the Labor Day weekend, including additional environmental testing and conducting interviews and re-interviews with the individuals who contracted the disease.
Legionnaires' disease symptoms are very similar to other types of pneumonia and can include cough, shortness of breath, fever, muscle aches, and headaches.
Fraser Health says most healthy people who come in contact with Legionella don't get sick, but people with weaker or compromised immune systems can be at risk. Symptoms will usually begin within 2 to 10 days after exposure to the bacteria. The Public Health Service of Canada points out it can not be transmitted between people.
Anyone who's at a higher risk and develops pneumonia-like symptoms should see a doctor.