Edmonton Journal from Edmonton, Alberta, Canada • 52

F6 The Edmonton Journal, Sunday, June 29, 1997 For more about the stories on the Science pages and links to related web sites httpywww.ednriontonjournal.com World of Science SHARON OOSTHOEK South am Newspapers Hamilton ou can't smell it, taste it or see it In fact the tinv parasite that launched fsl I J' -K li If a nasty North American outbreak of diarrhea and vomiting last spring continues to elude the best minds in disease control. The cyclospora parasite is thought to have used Guatemalan raspberries to hitch-hike its way into the intestines of at least 195 Canadians and 1,270 Americans and probably many more. They missed days, even weeks of work. For some, the disease hung on for a month or more, only to return later. And while epidemiologists with the Centres for Disease Control in Atlanta are pretty sure the raspberries are the culprits, a year later they've yet to find a single cyclospora parasite on a berry.

Canadian-grown fruit has never been implicated in any of the illnesses. Already this year, CDC labs have confirmed 140 new cyclospora cases and officials suspect another 370. In Canada, there is one confirmed cluster in the Ontario municipality of York a family of nine in which five relatives came down with the parasite. Health officials suspect half a dozen more unrelated cases in Ontario and Quebec. "There's going to be many, many more," predicts Dr.

Michael Osterholm, the state epidemiologist for the Minnesota Department of Health and an expert in food-borne illness. In a population of about 300 million in Canada and the U.S., a couple thousand confirmed cyclospora victims is not a large number, especially when the illness, as uncomfortable as it may be, has yet to kill. But it points to an alarming trend in food contamination. "This is a good example of how a widely distributed product can lead to an outbreak in widely different geographic parts of North America, or in any part of the world," says CDC epidemiologist Dr. Bill MacKenzie.

"There was a time when consumers would buy a i i -1 ii neau ui cauuage ana that was it Now they want everything," says Southam NewspapersHamilton Spectator complains (to a public health unit) and maybe they think twice about going out to investigate." The estimated number of food-borne illnesses in Canada runs as high as one million a year. Of course, the vast majority of fruit and vegetables arrive in Canada without incident But as recent outbreaks public," says Douglas Powell, an assistant professor in food sciences at the University of Guelph. "In the meantime, people have to make decisions. There's more and more pressure to go public early. You can't wait People are getting sick." Even thoroughly washing produce offers no guarantee of avoiding pathogens.

Minnesota health department Condon. Twenty years ago, the vast majority of the fresh produce available at the average Canadian grocery store was home-grown. At the time, we imported $250 million worth of fruits and vegetables. Last year, we imported $1.5 billion worth of produce. Dr.

Ewen Todd, chief of Health Canada's con-taminated food section, says it's hard to nail down whether the rate of food-borne ill- ness is actually increasing or if we're g' just more aware of such illnesses. fr there may be less reporting going on in Canada and the rest of the world because of health Experts say such outbreaks are increasing and can be expected to worsen as the world moves toward a global food economy. Produce grown in Canada is considered among the safest in the world, but that cannot be resources being cut Someone of food-borne illness show, we must be more vigilant in protecting our food supply. "The fact we had any cases at all was cause for concern. It was a flag," says Jeff Wilson, Health Canada's chief of food-borne intestinal diseases.

And the question for which no one seems to have an answer is staff intentionally seeded produce with bacteria and parasites and then repeatedly and vigorously washed the produce. The pathogens remained. "Consumers have a false sense of security. They think washing it will make a difference. It won't do anything," Osterholm says.

Those unlucky enough to swallow the parasite are usually pre- "It's scratching the surface. What else is happening in developing countries with exotic agents that we're missing?" Dr. Michael Osterholm said for some developing countries. Raspberries contaminated in the fields of a Guatemalan grower can land on the shelves of your local grocer the next day. "It's scratching the surface," says Osterholm.

"What else is happening in Much remains unknown about o- developing countries with exotic agents that we're missing? Or even right here (at home). We never even heard of cyclospora until recently." this: How can public health officials manage risk for contami- nated food coming from so many sources? When the cyclospora outbreak began last spring, they suspected California strawberries. They warned consumers to thoroughly wash the berries before eating them and even cautioned people with weak immune systems to avoid the berries altogether. A few weeks later, the blame was switched to Guatemalan raspberries. But by then, the damage was done.

The California Strawberry Commission estimates the scare cost its member farmers up to $40 million in lost sales. For health officials, it's not an easy call. "There are no good scientific models that state if this is true, and this is true, then you go YA cyclospora cayetanensis, which causes symptoms ranging from diarrhea and vomiting to fatigue and loss of appetite. Some of what we do know: If you lined up 1 ,000 of the tiny organisms, the column would stretch less than a centimetre. It's thought to lie dormant in soil, water, food or fecal matter, waiting for a host to wander by.

That host is probably human but no one is sure. It takes about a week after ingesting the parasite for symptoms to show up. Once in your intestinal tract, the parasite's protective cell wall breaks open, spilling its spores. Those spores enter the lining of the small intestine and multiply thousands of times. Scientists suspect multiplication damages cells of the small intestine, causing the diarrhea scribed sulphur-based antibiotics, but there are no alternatives for people allergic to sulfa drugs.

Osterholm believes the only workable solution is irradiation exposing food to radiation that kills pathogens without affecting taste. While states such as Florida and Indiana make limited use of irradiation, many consumers worry about the procedure's safety. In Canada, there's next to no commercial food irradiation. Legally, it's allowed only for onions, potatoes, wheat, wheat flour and spices. Practically, it's too much of a hard sell.

But Osterholm sees no way around it "We know we can't guarantee the safety of this (food). We're stretching the limit, clearly." Hamilton Spectator This year's outbreak is linked not only to Guatemalan raspberries but also to raspberries from Chile. And it's not an isolated occurrence. In April, more than 2,200 Michigan kids were inoculated against hepatitis A after 163 cases of the illness were linked to a shipment of Mexican-grown frozen strawberries. The suspect berries were used in school lunch programs.

George Condon, editor ofThe Canadian Grocer, says part of the problem is that the produce section of most stores has more than doubled in size in the past 25 years. And many of those fruits and vegetables are imported. Co The sliort, violent life of a Icndopout The tornados that sweep inland plains grow out of atmospheric "supercells." Coastal areas get a different type non-supercell tornadoes, also called landspouts because of their similarity to ocean waterspouts. A Si'percell tornado cr Ian- 1 V1 41 with children and pushchairs, or elderly people. Researchers at Belgium's national research centre have developed lights that create and monitor a "detection zone" between the two sides of the street.

When pedestrians are within the zone, the normal cycle of the traffic light is overridden. The illuminated pedestrian figure stays green and the traffic light stays red until any pedestrians have moved out of the zone. Trials in several locations in Europe, including Britain, are planned for next year. DNA fingerprints' used to catch crooks Police have begun tracking criminals using DNA "fingerprints" left on virtually anything the suspect touches, Australian scientists say. DNA "fingerprints" have long been found in hair, blood and semen.

But Roland van Oorschot and Maxwell Jones of Australia's Victoria Forensic Science Centre said they have also found genetic material in fingerprints themselves. "We show that an individual's genetic profile can now also be generated from swabs taken from objects touched by hands, providing a new tool for crime scene investigations," they say in a letter in the science journal Nature. DNA was even transferred after a handshake, they said. "Our methods have already been used at our lab to provide evidence in attempted murder, rape, armed robbery, extortion and drug-trafficking cases," the scientists wrote. Russians building a 'saucer' plane Russia is putting $12 million into a flying saucer that will be built at a factory near Saratov, according to the news agency ITAR-TASS.

Aleksandr Yermishin, the aircraft plant's director, has said several tests of the futuristic craft, Ekip, have been done but there have been no flights yet. A particular feature of its aerodynamic wing gives the aircraft extra lift. Conventional aircraft can take a pay load of 25 per cent of its weight, but thanks to the aerodynamics of the saucer, Ekip can lift up to 40 per cent of its weight. The machine has four engines, a ceiling of up to 10,000 metres and a speed of up to 700 km-h. It is fitted with devices that enable it to carry three tonnes of water for firefight-ing.

Yermishin said the forestry protection service was interested in the flying saucer. When finished, the aircraft may be used to cany up to 2,000 passengers on medium-range routes. The first test flight is scheduled for 1999. Pedestrian safety gets a green light Clever traffic lights that do not change colour if a pedestrian is halfway across the road are to be introduced next year in an attempt to improve road safety. The lights will use a video camera and image analysis software to determine if someone is crossing the road.

Traffic lights are at present set to allow enough time for the average person to cross, but not for parents ECOLINE, Out.iOW-, VT Seed Rain or a cold front creates an outflow, or mass of dense air colder than the surrounding air 2 Creation Relatively weak shearing winds moving along the edge of the outflow produce large circulating disturbances by Catherine Farley y' ST. Cumulonimbus Caring for Our Land 1m! 0 II 0 A TV program showed a wolverine driving three much larger wolves away from Hs kilL How is this possible? Pound for pound, a wolverine is simply stronger than many Switching to green cleaners Pure soap biodegrades safely and completely, and is non-toxic. It Is the key Ingredient 3 Development Vortexes of circulating winds intensify as they are stretched up toward the cloud base ot green domes cleaners. Washing: Add 13 cup of washing soda to water as the machine is filling. Add clothes.

Add 112 cups soap. If water is hard, add 14 cup of soap or 14 cup of vinegar during FT first rinse. For heavily soiled items, I 5 Demise Vortex degrades as the new cold pool tilts the spout, creating a brief rope stage. Dust and other debris sucked into the spout a cause the fS base to darken of Hs adversaries and can kill animals much larger than Itself. Wolves are probably aware of this, says The Macmfflan Dlus-trated Animal Encyclopedia For example, a wolverine's Jaws am so strong It can crush a frozen caribou's large bones, part of its adaptation to life in a wintry climate.

It can also use Hs relatively large flat feet like snow-shoes to pursue hoofed animals over soft, deep snow. The wolverine is the largest member of the weasel, or Mustelidae, family. It can weigh up to 25 kg. fjie-suori in weimi waier wuri i cup washing soda for 30 minutes. Softening: Add 14 cup white vinegar to rinse water.

4 Maturity Vortex winds become strongest when rain creates new cold pools around the spout's base Silif'iii lli'Uilitt' Whitening: Add 12 cup of washing soda to each load to whiten Oo whites and brighten colors. 42f When making the switch, wash Hems once with 13 cup washing soda to remove detergent residues. Source: Greenpeace Sun-Sentinel, Knight-Ridder TribuneR. SCOTT HORNER.