The Real Epidemic: Bad News for Carnivores& OTC drug users

[Guest guest]

' The samples included ground beef, pork and turkey,

as well as a selection of beef, beef-pork and pork

sausages. Incredibly, one-quarter of the samples were

tainted with strains of Clostridium difficile....The

general population shouldn't be too concerned '

 

[ Let another couple thousand die...]

 

August 09, 2006

 

Remember SARS? C. difficile may be worse

 

It keeps mutating, acts fast -- and it's spreading.

Meet the No. 1 superbug in hospitals today

 

DAN HAWALESHKA

 

It was toward the end of a long day of scientific

detective work -- a sort of CSI for bacteria experts

-- when Glenn Songer, from the University of Arizona,

stepped up to the audience microphone.

 

The occasion, if not rare, was certainly unusual -- an

intensive one-day war council convened in May at the

Centers for Disease Control and Prevention in Atlanta,

Ga.

The panellists were North America's top experts on two

potentially deadly bacteria: Clostridium difficile and

Clostridium sordellii. C. difficile, in particular, is

now behaving in alarmingly and inexplicably new ways.

About 200 epidemiologists, microbiologists,

bacteriologists, physicians and public health

officials had gathered in the chill air of an overly

air-conditioned CDC auditorium to weigh options for

coping with what may be a silent epidemic in the

making.

 

And Songer was about to rattle them.

 

There are certainly dozens, perhaps hundreds of

strains of C. difficile, most notably a superbug known

as the epidemic strain.

This hypervirulent variety has killed thousands of

people -- often elderly patients in hospital -- across

North America over roughly the past five years,

particularly in Quebec.

There, C. diff. killed an estimated 2,000 patients in

2003-2004 alone. Typically, the victims have been on

antibiotics, which in addition to combatting

infection, also wipe out the good bacteria normally

found in the gastrointestinal tract.

In their absence, C. diff. has no competition and

thrives. The connection to recent exposure to

antibiotics is so pronounced it is considered a

virtual prerequisite for coming down with Clostridium

difficile. Until now.

 

Now, CDC officials are concerned by evidence

suggesting C. diff. is spreading out of U.S. hospitals

and into the community-at-large.

(We already know the bacterium has penetrated Quebec

communities, and the Public Health Agency of Canada is

tracking C. diff. in hospitals across the country and

is cognizant of the potential threat to cities, towns

and villages.)

 

The CDC first raised the alarm last December, noting

33 cases of atypical C. diff. infection had come to

its attention.

Twenty-three cases were community-acquired. The other

10 were women who were either pregnant or who had just

given birth. Both groups, the CDC noted, were

" previously thought to be at low risk. "

 

Uncharacteristically, one-quarter of these unusual

cases had not recently taken any antibiotics; half of

the community-associated patients were 18 years old or

younger; almost 40 per cent of the victims suffered a

relapse; one woman died.

Based on these and other findings, the CDC concluded

the disease could be changing, with new cases

distinguished by traits previously unseen in the

community, including young patient age, lack of

antimicrobial exposure and a high recurrence rate.

 

The audience of scientific sleuths in Atlanta had

heard much of this and more by the time Songer got up

to speak.

 

Songer said his lab had screened for the bacterium in

meat bought in Arizona grocery stores. (In addition to

striking humans, C. diff. also causes disease among

commercial farm animals.)

The samples included ground beef, pork and turkey, as

well as a selection of beef, beef-pork and pork

sausages.

Incredibly, one-quarter of the samples were tainted

with strains of Clostridium difficile. The workshop

participants, who had been quietly listening,

immediately broke into peals of nervous laughter

intermixed with groans of disbelief.

 

In an interview outside the auditorium afterward,

Songer cautioned there simply isn't enough data to say

much of anything right now.

" No conclusions can be drawn at this point from what

we've found, " Songer says.[sic]

" It just encourages us to look further, and hopefully

get a more definitive answer. " He said his fellow

researchers are still trying to identify the strains

of C. diff. implicated, and that " it would be very

surprising if it was the epidemic type -- I doubt that

very much. "

However, Scott Weese, a veterinarian at the University

of Guelph in Ontario, says his lab has already

observed the epidemic strain in live cattle, pigs, and

a dog. " You have to assume that if it's in the cattle

population, " Weese says, " it'll end up in the meat. "

 

Weese expects to soon publish a study that found C.

diff. in commercial beef bought in Ontario and Quebec

in percentages similar to Songer's findings in

Arizona. Because C. diff. spores have been known to

survive the cooking process, people will want to know

whether, for example, our hamburger meat could be

making us sick. But Weese says we still don't know if

the C. diff. bacterium is transmissible between people

and animals. " The general population shouldn't be too

concerned about it right now because we don't have

good evidence that it's a food-borne pathogen, " Weese

says. " That's something we need to look at, but

there's no reason to panic at this point. "

 

That said, Songer's lab results and the Atlanta

audience's nervousness underscore just how concerned

health authorities have become with community-acquired

Clostridium difficile.

It now appears to be an " emerging infection, " says

Dr. Paul Seligman, director of the U.S. Food and Drug

Administration's office of pharmacoepidemiology and

statistical science, and one of the event organizers.

" Clearly, " Seligman says, " we want to pay attention to

anything that moves from an environment we're familiar

with, such as hospitals, to a community setting --

particularly when you're talking about severe, rapidly

fatal illnesses. "

 

There are few good ways to die, and lying in a pair of

soiled diapers while waiting for the merciful end to

arrive certainly isn't one of them. But patients

fighting a severe Clostridium difficile infection

frequently suffer that indignity, enduring 10 to 20

bowel movements a day.

In addition to chronic diarrhea, the epidemic strain

can cause a ruthless inflammation of the colon called

colitis that sometimes necessitates surgical removal

of that part of the large intestine.

Sepsis, or blood poisoning, can also occur.

Patients endure horrible abdominal pain, perilously

low blood pressure and anemia that leaves them too

weak to crawl out of bed.

 

In 2002, an epidemic of C. difficile took hold of

hospitals in the Sherbrooke region in Quebec's Eastern

Townships, and in Montreal, 140 km to the northwest,

killing a staggering 2,000 Quebecers in the following

year. " Even those who survived spent many days in a

pitiful condition, " recalls Dr. Jacques Pépin, an

epidemiologist at the University of Sherbrooke, who

attended to many such patients. " I can tell you, it's

not a disease you would wish on anyone. "

 

C. difficile is spread through resilient spores found

in feces -- they can survive for months on a wide

variety of surfaces. The spores are ingested when

people put a hand down on a contaminated countertop or

sink, then absentmindedly touch their mouths or eat

food without first washing their hands with soap.

 

Once ingested, C. difficile can lie dormant

until a trigger, usually antibiotics,

disrupts the gut's normal bacterial flora.

It is estimated that between three and 10 per cent of

healthy North Americans are asymptomatic carriers of

the bacterium, while up to 40 per cent of hospitalized

patients are infected.

 

Physicians once considered C. diff. no more than a

clinical nuisance.

It caused a brief bit of diarrhea and had no impact

on mortality.

 

But the epidemic strain is an accomplished pathogen,

considered by many to be the No. 1 superbug in health

care facilities.

It is the most common cause of infectious diarrhea in

hospitals in the developed world. The risk of

contracting the disease is known to rise with

increasing length of hospital stay, age, and if a

person's immune system has been compromised.

 

As with all bacteria, the various strains of

Clostridium difficile mutate regularly.

In the past decade, massive overuse by hospitals of a

class of antibiotics known as fluoroquinolones

favoured the genetic selection of a tougher C. diff.

bacterium.

 

It is this fluoroquinolone-resistant, hypervirulent

variety that slammed Quebec.

Dubbed the epidemic strain, the bacterium has been

detected in British Columbia, Alberta, Saskatchewan,

Ontario, Nova Scotia and Newfoundland, as well as in

16 states, the United Kingdom and the Netherlands.

 

Hospitals are not supposed to make people sick, much

less the communities that surround them.

But creaking health care facilities with crowded

wards and inadequate access to sinks for handwashing

-- particularly in Quebec -- have turned these sites

into microbial incubators-cum-distribution hubs for

Clostridium difficile.

 

The superbug can spread among patients, who then

unwittingly carry the disease with them into the

community once they've been discharged. In Sherbrooke,

from 1991 to 2003, the rate of C. diff. infection in

the general population went from 35 per 100,000

inhabitants to 156 per 100,000.

 

Britain has also undergone an exponential rise in the

rates of C. diff. cases diagnosed in the community,

from less than one case per 100,000 persons in 1994 to

22 per 100,000 inhabitants in 2004.

 

Confounding scientists' ability to explain the

formidable hike is the fact antibiotic use within the

community actually decreased during the same period,

which suggests something else is going on to trigger

the disease.

But what? " Who knows? " says Michelle Alfa, a C.

difficile researcher at St. Boniface General Hospital

in Winnipeg. " Maybe there are other things out there

that cause an upset in people's gastrointestinal tract

that then allows C. diff. to do its merry thing. "

 

Dr. Sandra Dial, a researcher at McGill University in

Montreal, offers one possible explanation, one gaining

momentum and widely discussed at the CDC gathering in

Atlanta. Dial studied 1,233 patients drawn from a

British database who came down with C. diff. in their

communities between 1994 and 2004.

Of these, only 37 per cent had taken antibiotics in

the 90 days prior to being diagnosed with Clostridium

difficile.

 

Dial's study, published last December in the Journal

of the American Medical Association, found that

heartburn drugs, and medication used to treat

gastroesophageal reflux disease, increased a person's

chances of coming down with C. diff.-associated

diarrhea.

 

Dial reported that drugs known as proton pump

inhibitors, or PPIs -- including Nexium, Prevacid,

Prilosec and Protonix -- increased the risk almost

threefold.

So-called H2 receptor antagonists -- Pepcid and Zantac

are two -- doubled the risk.

 

People taking painkillers known as non-steroidal

anti-inflammatory drugs, or NSAIDs (but not Aspirin),

had a 30 per cent higher rate of C. difficile illness.

 

Dial speculates that C. diff. may have mutated to

take advantage of the decrease in stomach acid in

people who take these drugs.

" It has tremendous repercussions, as you can

imagine, " says Dr. Clifford McDonald, a CDC

epidemiologist, and one of the Atlanta meeting's

panellists. " PPIs are used widely. "

 

Predicting exactly what C. diff. is up to, says Dr.

Allison McGeer, director of infection control at

Toronto's Mount Sinai Hospital, is a little like

predicting when the next avian flu pandemic will

strike.

" We honestly don't know the extent to which this

strain is going to stay concentrated in hospitals, or

whether it's going to spread and cause similar

problems in the community and in younger people, " says

McGeer, adding that the public-health implications are

nevertheless plain to see.

" This is not a disease that is just in hospitals and

just affecting people who are going to die anyway, "

McGeer warns. " This is already a disease that has

caused a huge amount of public-health damage. This

disease poses significant risks to all of us, now. "

 

When the CDC first raised the alarm last December, it

was unable to determine with any certainty what strain

of C. diff. it was dealing with.

All the agency knows is the bug did things previously

unheard of in 33 people who ordinarily had no business

coming down with the disease. Of the atypical cases of

C. diff., the CDC singled out two as signposts:

 

¥ One was a 31-year-old woman who was 14 weeks

pregnant with twins. She sought medical attention at

her local emergency department after three weeks of

intermittent diarrhea, followed by three days of

cramping and watery, black stools four to five times

daily. She was admitted after her stool tested

positive for C. difficile toxin. She had taken

trimethoprim-sulfamethoxazole for a urinary tract

infection about three months before she was admitted.

Doctors prescribed the antibiotic metronidazole, one

of only two standard treatments for C. diff., and

discharged her the same day, but had to readmit her

less than 24 hours later.

She stayed for almost three weeks.

Treatment with the antibiotic vancomycin eased the

severe inflammation of her colon. She was discharged a

second time, but four days later was readmitted with

diarrhea and low blood pressure. She spontaneously

aborted her fetuses,

and later died despite aggressive treatment that

included the surgical removal of her colon.

" It's very disturbing when a pregnant woman in her

30s dies, " says Dr. André Weltman, a public-health

physician at the Pennsylvania Department of Health.

" That's not supposed to happen. "

 

The other U.S. case involved a 10-year-old girl who

went to a hospital suffering from intractable

diarrhea, projectile vomiting and abdominal pain.

It had been a year since she'd taken any antibiotics.

Her stool tested positive for C. difficile toxin. The

girl had fallen ill about two weeks earlier, a few

days after her younger brother had come down with a

fever and diarrhea. He got better on his own, but she

developed a fever as high as 102¡F.

Her symptoms worsened until she was having liquid

stools up to 14 times a day.

She was admitted to hospital and recovered after

doctors administered intravenous fluids, electrolytes

and metronidazole.

 

Thirty-three cases and a single death may not sound

like much, says John Dyke, a clinical microbiologist

with the Michigan Department of Community Health, but

to ignore them would be a grave mistake -- we could

easily be seeing only the tip of the epidemiological

iceberg.

 

In most states, Dyke notes, C. diff. is not a

reportable disease, and so we likely don't know the

true incidence in the population. Dyke says the

Atlanta meeting he attended will help draw attention

to the fact that we may have a disease, as he put it,

" smouldering in the population. "

 

Only two samples of the microbes were isolated from

the 33 patients. " Neither of them were the epidemic

strain, " says the CDC's McDonald. " That doesn't mean

the epidemic strain isn't playing a role, but we don't

know it yet. "

What is known, however, is both the epidemic strain

and the U.S. samples were eerily similar. " The two

isolates both produced a previously uncommon, extra

toxin -- a binary toxin -- that has been found in the

epidemic strain, " McDonald explains. " In addition,

each in its own way shared at least one other

significant genetic characteristic with the epidemic

strain. "

 

Pépin and his fellow researchers have looked for the

epidemic strain in C. diff. patients in the Sherbrooke

region who had no connection to a hospital, and have

found it in about one-third of all cases.

That is a rough, preliminary estimate, he cautions,

based on a small sample size, but there is no

disputing the fact that the nasty strain of C. diff.

has spread within the community.

 

" The opposite would have been very surprising because

in Quebec we've had literally, over two years,

something like 14,000 cases in hospitals, " says Pépin,

" and obviously these patients go back home, where

they're still shedding the bacteria in their stools,

and then it enters the chain of transmission in the

community. "

However, unlike a significant portion of the

community-associated cases singled out by the CDC,

Pépin has yet to observe the disease in individuals

with no antibiotic exposure.

 

Currently, only Quebec and Manitoba require health

care providers to report cases of C. difficile.

 

Ontario is considering doing likewise,[sic]

while the Public Health Agency of Canada will collect

data from 41 so-called sentinel hospitals from across

the country, starting this year.

 

The agency will look for the hypervirulent strain and

whether first-line antibiotics remain effective

against the bacterium. PHAC is also working to develop

a surveillance system to track cases of

community-acquired C. diff., says Denise Gravel,

acting manager of the PHAC's division of blood safety

surveillance and health care-acquired infections. " We

haven't been able to come up with a valid strategy for

the moment, " Gravel says. " But even if they are

acquired in the community, we are going to see them in

these hospitals, so we're not that concerned. "

 

It is entirely too easy for a physician to mistakenly

dismiss diarrhea as being caused by either a virus, or

food-borne bacteria, such as salmonella, shigella and

campylobacter.

That's why the CDC says clinicians need to consider

Clostridium difficile as a possible source of a

person's diarrhea, " even if the patients do not

necessarily have traditional risk factors such as

recent hospitalization or antimicrobial use. " The CDC

recommends that patients should seek medical attention

for diarrhea lasting longer than three days, or if

it's accompanied by blood or high fever.

 

Even with C. diff.'s apparent changing pathology, the

disease remains closely associated with antibiotic

use, says Dr. Thomas Louie, medical director of

infection prevention and control for the Calgary

Health Region. " We have seen patients in Calgary that

have not been on antibiotics and have C. diff., but

I'd have to review 100 to 500 cases to find one that

is like that, " Louie says. " The big picture is that C.

diff. is still, largely, antibiotic induced -- we're

talking 99 per cent. But I don't know about that one

per cent, " Louie concedes, " and why that happened to

that lady. " He's referring to the woman, pregnant with

twins, who died. Her death, coupled with the other

unusual cases flagged by the CDC, factor in Louie

calling for more proactive surveillance of C.

difficile. Louie hopes her death is an anomaly. " And

if it isn't, we have to take a good, hard look at

ourselves, at what we're doing in health care -- both

in the hospital, and in the community. "

 

Copyright by Rogers Media Inc.

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