TORONTO - Food inspectors will step up their border and surveillance controls for cucumbers, lettuce and tomatoes from European countries affected by an E. coli outbreak, the Canadian Food Inspection Agency said Thursday.

The "super-toxic" bug has sickened at least 1,600 people, mainly in Germany, and killed at least 18 people, according to global health officials. It's a particularly nasty strain of E. coli that has caused kidney problems for about 500 of the patients. Women appear to be harder hit compared to past E. coli outbreaks in which kids and elderly people have tended to be more affected.

"Incoming shipments from the European Union will be identified and the CFIA will intensify sampling and testing these products for the presence of Shiga toxin-producing Escherichia coli, the E. coli strain linked to the outbreak in Europe," the agency said in an email response to questions.

"If any products are determined to be a health risk, the CFIA will work with importers and distributors to help ensure these products do not reach the Canadian marketplace."

Most patients in Europe who were interviewed said they ate lettuce, tomatoes or cucumbers, but the World Health Organization says numerous investigations are continuing and the cause of the outbreak is still unclear.

"WHO does not recommend any trade restrictions related to this outbreak," the international agency said.

The Canadian inspection agency said there's no indication that any contaminated produce has been shipped to Canada. Imports of fresh produce from European countries account for less than one per cent of total imports of produce from all countries, it said.

The Public Health Agency of Canada said no Canadians have been reported ill, and it is in constant communication with health colleagues in the European Community and at WHO.

"We are also being kept informed of the analysis of the type of E. coli that is currently the basis of the outbreak in Germany, this being a new strain of E. coli, something that we have seen before but certainly not seen in this context," said Mark Raizenne, director-general at the Centre for Food-borne, Environmental and Zoonotic Infectious Diseases.

"There's quite a bit of laboratory analysis in terms of genomic, genetic analysis that's being done to get all the details of this particular bacterium in hand."

A Canadian food scientist who has studied E. coli says travellers to Europe should be aware of the outbreak and take steps to remain healthy. The E. coli outbreak that killed seven people in Walkerton, Ont., in 2000 was blamed on O157:H7 in the community's water, but this European outbreak is thought to be attributed to an O104 strain, which falls into the category of non-O157 serotypes, scientists said.

There are no guarantees the new strain won't show up in this country at some point too, Prof. Keith Warriner of the University of Guelph said in an interview.

Two people who were sickened are now in the United States, and both had recently travelled to Hamburg, Germany, reports indicated.

"These are rapidly evolving pathogens and it could be that it's a hypervirulent strain. And it's in the U.S. right now, two cases, so to say that it won't come to Canada is very wishful thinking," Warriner said.

A vaccine for the new strain is currently not available.

Warriner suggested that visitors to Europe take the same sort of precautions they would take to avoid traveller's diarrhea.

"So avoid certain raw vegetables, for sure, avoid water that you're not sure of the origins of, wash hands and hand sanitizer are essential."

Raizenne also said the potential exists for the new bug to arrive in Canada.

"Bacteria don't respect borders," he said.

"It will really depend on the source of where it came from and its origin. And that's why public health officials and food inspection and people are really focusing a lot of effort to find what is the source. Because if we know that, that is where our point of control is going to be the best."

He also advised travellers to Germany to be aware that authorities there have told people to avoid tomatoes, cucumbers and lettuce.

"People who have been to northern Germany ... who are returning to Canada should be aware that if they become ill with symptoms of E. coli -- which includes cramping and nausea, sometimes vomiting, fever, and it's a persistent kind of illness -- that they should certainly ensure that they drink lots of fluids and then seek medical attention to determine the illness," Raizenne said.

The infection can also be transmitted person to person, so good personal hygiene and hand-washing are important, especially when food preparation is involved, he said.

Dr. Donald Low, an infectious diseases specialist at Mount Sinai Hospital in Toronto, said there's no question it's a big outbreak, and that travellers should pay attention.

"The risk is minimal. I wouldn't suggest that anybody change their travel because of something like this."

But he said travellers might want to pay attention to directives from local health authorities when deciding whether to consume raw vegetables.

"The unfortunate part is they haven't really been able to nail down what the vector is."

Prof. Rick Holley, a food microbiologist at the University of Manitoba, said it wouldn't be easy to detect these organisms through testing of produce. Methods for detecting four out of 200 non-O157 strains have been developed, he said, and they don't include this new one.

"It seems as though it has some very unusual characteristics ... gene combinations that predispose or give it the ability to be pathogenic in adult humans more so than similar organisms that have been identified in the past would seem to pick on kids and make them sick," he said.

"So the virulence of this organism is significant, the number of people that are ill is large," he said, noting that the average number of people who normally become ill in a single outbreak is about 200.