Health officials have narrowed their search for the source of an E. coli outbreak in Nova Scotia and New Brunswick to about a dozen possible sources.
“When you look at the geographic spread, the time frame of exposure and the food histories, from the outset our hypothesis — and it’s a fairly solid one — is that we’re looking at some kind of manufactured food product or a food that’s been processed in some way that’s been widely distributed,” said Dr. Robert Strang, Nova Scotia’s chief public health officer.
“Right now we’re looking at exposures more through restaurants rather than a food that’s been distributed through groceries.”
He said officials were able to focus in on a smaller number of food products over the weekend and are looking at produce of some sort.
“We are following up with individuals who were sick and the food distribution chain to rules things in or out more conclusively,” he said. It is probably raw produce that may have been cut up and included in a dish.
He said he doesn’t want to speculate publicly on what the product is but “we have made some progress and we’re hoping over the next few days that we’ll be able to have something concrete.”
He said, though, that sometimes outbreaks happen and the exact source can’t be positively identified.
Three cases were confirmed over the weekend, bringing the number across Nova Scotia to 10 since the first case was reported on the weekend of Dec. 29. Five have been in the Capital Health area, two in the Guysborough Antigonish Strait health authority, and one each in the Pictou, Cumberland and Colchester-East Hants health authorities.
All 10 have been seen by doctors and are recovering or already have recovered, Strang told reporters Monday afternoon. They range in age from 18 to 83, and two were still in hospital Monday.
The incubation period for E. coli is one to 10 days, so new cases may be reported far apart but originate around the same time, Strang said. All the people affected in Nova Scotia and five cases in New Brunswick have had common food exposure during the time period of the outbreak.
He said specimens taken locally are being sent to a national lab in Winnipeg, which can identify the exact sub-strain or subtype of E. coli, and that can help find a common source if they are similar.
“It helps us out in our investigation, especially if we’re able to test some food. It’s kind of like detective work. You have to do various types of testing and investigation and put the pieces together to come up with some answers.”
Strang said it can be a bit harder to identify sources of contamination when produce is sent to a central facility and mixed with the same type of food from other areas and then shipped out.
“It certainly makes it a more complicated in terms of the potential sources and where you have to go,” he said. “One of the things we have on our side now is that a lot of the food companies have computer systems so we’re working actively with some of them, and their information and information systems are helping us.”
He said washing and peeling raw vegetables and fruits before eating, properly cooking meat, and washing hands, cutting boards and other surfaces that come in contact with raw meat are important to prevent and reduce the spread of E. coli.
Symptoms include bloody diarrhea, abdominal cramps and vomiting. Usually there is little or no fever, and in some cases there is no blood in the diarrhea. In some cases, there are no symptoms at all.