Health officials are trying to track down the source of seven E. coli cases that sprang up around Nova Scotia at Christmas time.

The Department of Health and Wellness said seven people were infected with E. coli O157 — a potentially deadly strain — between Dec. 23 and Dec. 26.

There were three cases in the Halifax region, two in Antigonish and one each in Truro and Stellarton. Two people were hospitalized, including one suffering from kidney failure.

E. coli O157 is the same strain that killed seven people in Walkerton, Ont., in 2000. (CBC)

Dr. Robert Strang, the province's chief public health officer, said Nova Scotians shouldn't be alarmed.

"Since the initial cases were reported, it has been more than a week since we've seen a new case," he said in a statement Friday.

There are five reported cases of the same E. coli strain in New Brunswick. That has officials looking for any links.

Strang said it's possible that the source is a food item sold in both Maritime provinces.

E. coli O157 is the same strain that killed seven people in Walkerton, Ont., in 2000.

It also led to the biggest beef recall in Canadian history last fall. The Canadian Food Inspection Agency recalled more than 1,500 beef products that were packed at XL Foods, a meat processing plant in Brooks, Alta.

This particular strain of E. coli secretes a powerful toxin that can destroy red blood cells, leading to severe illness, high blood pressure and kidney damage.

Symptoms of E. coli O157 resemble gastro-intestinal illness, such as severe cramps, bloody diarrhea, abdominal pain and vomiting.

There are cases of E. coli every year in Nova Scotia. Since 2008, the number of reported cases in a year has ranged from five to 17.