Bacterial outbreak kills four in Ontario
This story has just broken during the past two days or so and may not
yet have been picked up by the US media. The story below appeared in
the Toronto Globe and Mail this morning. During the day another person
died and 10 were reported to be in critical condition.
At the moment, many people are pointing fingers at the managers of the
town's water supply and blaming them for not using enough chlorine and
not notifying residents when the problem became apparent. This would
be the proximate cause.
Officials are reported to be looking for the source of the
contamination. I expect they will find that the source is cattle
manure that was flushed into the watershed following heavy rains in
the region, and contaminated one of the wells the town uses for
water. Much of southern Ontario is ripe for such a problem.
There is extensive production of corn in the region and much bare land
during this time of year. Many farmers have been out spreading manure
during the past month on fields with subsurface drains and extensive
ditches that funnel surface and subsurface water down the watershed
into streams and rivers. The agricultural landscapes we have are not
very good at holding onto water. During the period when we got these
rains (May 12th) I saw quiet little streams turned into raging
torrents by the flood of water coming off the corn fields in my
Many municipalities use these rivers as a source of water, and I
suspect there will be more of this in the future.
Bacterial outbreak kills four in Ontario
The Globe and Mail;
With reports from Gay Abbate, Caroline Alphonso,;
Susan Bourette, John Saunders,
Canadian Press Thursday, May 25, 2000
Walkerton, Ont. -- What may be Canada's worst modern outbreak of
bacterial infection from contaminated water has killed a toddler, an
adult and an elderly woman and left hundreds with bloody diarrhea and
in some cases kidney failure.
More are expected to die in Walkerton, a western Ontario farm town of
4,800, and nearby towns. Nearly 20 people were in hospital last night,
some gravely ill, and there were unconfirmed reports that another
elderly person had died.
Three children were in intensive care -- two in critical condition on
kidney-dialysis machines -- at the Children's Hospital of Western
Ontario in London, to the south.
"There's never been anything like this in Canada before of this
magnitude, never," said Murray McQuigge, the local medical officer of
The germ involved is Escherichia coli O157:H7, a deadly strain of the
most common bug in the human gut, E. coli. Most E. coli is harmless,
but O157:H7 is a cause of what is popularly called hamburger disease,
a sometimes lethal food contamination, as well as severe illnesses
associated with bad water. It often originates in cattle intestines.
Dr. McQuigge said he believes that the first human exposure occurred
between May 12 and May 15. On May 12, parts of the Walkerton area were
flooded after a heavy rainstorm.
Most of those affected began to show symptoms, which include fever,
severe cramping, bloody diarrhea and vomiting, late last week. Among
them were people who passed through Walkerton, including some who ate
in the town's restaurants on Mother's Day, May 14.
All schools and daycare centres in Walkerton are closed for the rest
of the week as officials try to pinpoint the source of the
contamination. Early indications point to a town well.
Walkerton has seven wells to provide water to its residents, but only
three were in use at the time of the outbreak. Two of those are nearly
300 feet deep and are several kilometres west of town. One, on the
south side of town, is only 65 feet deep and is adjacent to a farm.
Dr. McQuigge said it is not unusual to see up to a dozen E. coli
cases, usually involving food contamination, in a small community over
a year, but it is unheard of in Canada to have an outbreak of at least
200 cases as a result of drinking-water contamination. "There's been
nothing to begin approaching this."
Public-health officials were alerted to the outbreak by a pediatrician
in nearby Owen Sound who had two cases of bloody diarrhea referred to
him from the South Bruce Grey Health Centre in Walkerton.
Initially, chlorine tests by Walkerton public-utilities workers
suggested that the water supply was safe.
But, given the number of people who became ill, Dr. McQuigge issued a
bulletin this past Sunday warning residents to boil drinking water. An
Ontario Health Ministry analysis of Walkerton's water supply, made
public on Tuesday, showed E. coli contamination.
The incubation period for E. coli O157:H7 is from two to eight days.
Parents of all young children in the area are being urged to take them
for blood tests every two days.
Those who become ill may shed bacteria through their stools for up to
three weeks. Hand-washing after using the toilet is essential to
curtail the spread of the disease.
Seven to 10 per cent of victims may develop kidney complications.
"This is especially a concern in the very young and the elderly," Dr.
People should not take antibiotics or antidiarrheal medication to
fight the bacteria because those who do are more likely to have kidney
trouble, he said.
Doctors are largely powerless against the bacteria. All they can do
for their patients is prevent dehydration and wait for the illness to
run its course.
"Once you've got it, there is nothing we can do to alter the course of
it," said Allison McGeer, a microbiologist at Mount Sinai Hospital in
The symptoms start with diarrhea and abdominal cramps, and the
diarrhea turns a bloody red in a couple of days, she said. For most
people, symptoms fade in about four days. Others are admitted to the
hospital with a potentially fatal kidney ailment called
The bacteria are particularly harmful to young children because "of
the immaturity of their immune systems," Dr. McGeer said.
In Walkerton, even those not yet ill fear they will be stricken. Greg
McLean and Jane Slosser and their children, seven-month-old Lucas, and
Abigael, 3, have been lucky so far.
"We're afraid we've been exposed to it and might have it and we don't
know what's going to happen," said Mr. McLean, a Grade 8 teacher at
Mother Teresa Catholic School.
The couple are upset that town officials provided insufficient warning
and schools were kept open on Tuesday. Dozens of children were
obviously sick in class, including several in kindergarten who soiled
their pants with diarrhea, they said.
Doctors in the town are so swamped that a call has gone out for help.
Douglas Matsell of the Children's Hospital of Western Ontario, who is
treating the hardest-hit children, said one Walkerton doctor saw 75
patients with bloody diarrhea in a day. As a result, an appeal has
been made to London hospitals for staff to go to Walkerton during the
Dr. Matsell said that about 80 childen have bloody diarrhea. He
expects that 10 to 15 will develop kidney problems and about half will
The children being treated at the London hospital range in age from 1?
to 15 years and all were perfectly healthy before they came into
contact with the bacteria. He said he expects more cases as people who
continued to drink contaminated water over the weekend begin to show
Walkerton is part of the larger municipality of Brockton, whose mayor,
David Thomson, was shaken by news of the deaths.
"It is very distressful," he said. "We're very sympathetic and would
like to offer our condolences to those people who have suffered loss
as well as those people who are ill. We are doing everything in our
power to rectify this problem."
He said the town did everything it could short of going door to door
to advise people to boil drinking water. "It happened before anyone
was aware of the seriousness of the problem. You know, people were
sick before it was known there was a problem."
He advised people not to use tap water "until we're certain that it is
potable and it is excellent water. If it takes a week it will be a
week, if it takes two weeks it will be two weeks."
Former mayor Jim Bolden said that he believes that the relatively
shallow well could be the source of the contamination because it would
be exposed to farm runoff after heavy downpours.
Mr. Bolden got out of bed only yesterday after being hit hard by the
bacteria. "I've never been sick like this before, never in a hundred
years, and I don't ever want to go through it again," he said.
At the local Tim Horton Donuts shop, owner Sue Harrison said the
epidemic is a disaster. "I think it's very scary for anyone to think
their water is unsafe."
For Ms. Harrison, a 52-year-old grandmother, it has hit especially
close to home. All three of her grandchildren, aged 1 to 7, have been
ill. The middle child, Liam, 2?, has been the sickest and must have
his blood tested every two days to check for signs of kidney damage.
At the doughnut shop, business is off because "people are too scared
to go, are sick themselves or are looking after sick children," Ms.
Steve Burns, an engineer advising the municipality, said that the
source of the contamination may remain a mystery.
"I would hope that within two or three days we will have looked at all
of the likely candidate sources and we will eliminate them as we go
along," he said. "There's no guarantee here that we will ever find the
exact source of the contamination."
Possible sources include the aquifer from which the town water is
drawn, wells and wellheads, construction activity and elevated
water-storage basins, he said. He also said data will be checked to
see whether town water employees were using sufficient chlorine.
So far, the investigation has yielded no evidence that recent flooding
fouled the water, he said. "That's just one of the possibilities."
Meanwhile, the water system has been flushed once with high doses of
chlorine and another flush is underway. The town has begun
distributing bulk and bottled water at the community centre.
Ontario Environment Minister Dan Newman said ministry officials began
their investigation of the contamination on the weekend, but they
still had few answers for Walkerton's residents yesterday.
"I don't think we ought to be pointing fingers at anyone or anything
at this time," Mr. Newman told reporters. "Our focus must be on on the
people of Walkerton, that they have a safe supply of drinking water."
He said the ministry is working to ensure that there is proper
chlorination in adjacent communities.
May 12: Storm hits Southern Ontario and runoff, believed to have been
contaminated with E. coli, is suspected to have entered the water
May 12-15: Residents first exposed to E. coli, probably through
May 17: First symptoms begin to surface. Patients complain of bloody
diarrhea, vomiting, cramps and fever.
May 20: Two cases of bloody diarrhea are reported to public-health
officials by area pediatrician. The hospital sees more than 20 cases
and receives dozens of telephone calls about similar symptoms.
May 21: Public-health officials receive the first positive E. coli
test and issue a warning advising residents to boil water, despite
assurances from the Brockton Public Utilities Commission that the
water supply was safe.
May 23: Officials report 160 people sought hospital treatment, another
500 called hospitals complaining of similar symptoms over the past few
days. The town's water samples test positive for contamination. Dr.
Murray McQuigge, medical officer of health with the Bruce-Grey-Owen
Sound Health Unit, declares the E. coli outbreak Canada's worst.A
toddler dies from complications of E. coli.
May 24: An elderly woman and another adult die from complications of
E. coli. At least three children were in critical condition, 20 others
were being treated in hospital. CP, Staff
HOW E.COLI AFFECTS THE BODY
In North America, the most common strain of E. coli is known as E.
coli 0157:H7. This strain appears in the intestines of healthy cattle.
HOW DOES THE DISEASE SPREAD?
Outbreaks are normally caused by eating undercooked ground beef or
drinking unpasteurized milk. It is believed that the recent outbreak
in Walkerton, Ont., occurred after storm runoff carried feces into the
local water supply.
Severe and sudden abdominal cramps with watery diarrhea that typically
becomes bloody within a couple of days. Body temperature is usually
normal but can reach 38.8 degrees Celsius (102 degrees Fahrenheit).
Diarrhea lasts about one to eight days. Anemia caused by the breakdown
of red blood cells. Kidney failure, strokes, or other complications or
nerve or brain damage. These usually occur in the second week of
illness. Death may occur. Children and the elderly are the most
susceptible. E. coli: Bacteria infects gut, where it produces toxins,
which enter the bloodstream. Infection: Toxins destroy red blood
cells, causing sudden, potentially fatal, kidney failure.
Source: The Merck Manual of Medical Information
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