"C. difficile Superbugs in Meat"
Clostridium difficile is one of our most urgent bacterial threats,
sickening a quarter million Americans every year,
and killing thousands to the cost of a billion dollars a year,
and it's on the rise.
Although uncomplicated cases have been traditionally managed with powerful antibiotics,
recent reports suggest that hypervirulent strains
are increasingly resistant to medical management.
So surgeons may need to come in and
remove our colon entirely to save our lives,
although the surgery itself is so risky
the operation alone may kill us half the time.
And there's been a rise in the percentage of cases
that end up under the knife, which could be a marker
of the emergence of these hypervirulent strains.
Historically, most cases appeared in hospitals,
but a landmark study published in the New England Journal of Medicine
found that only about a third of cases
could be linked to contact with an infected patient.
Another potential source is our food supply.
In the U.S., the frequency of contamination
of retail chicken with C. diff
has been documented to be up to 1 in 6 packages off store shelves,
and it didn't seem to matter which parts.
Pig-derived C. diff, however, has garnered
the greatest attention from public health personnel
because the same human strain that's increasingly emerging
in the community outside of hospitals is the major strain among pigs.
Since the turn of the century C. diff is increasingly being reported
as a major cause of intestinal infections in piglets.
C. diff is now one of the most common causes
of intestinal infections in baby piglets in the U.S.
Particular attention has been paid to pigs
because of high rates of C. diff shedding into their waste,
which can lead to the contamination of retail pork,
and the U.S. has the highest levels of C. diff meat contamination
so far tested anywhere in the world.
Carcass contamination by gut contents at slaughter probably contributes most
to the presence of C. diff in meat and meat products.
But why is the situation so much worse in the United States?
Well, slaughter techniques differ from country to country,
with those in the United States being what they call
more of a "quick and dirty" variety.
Colonization or contamination of pigs by superbugs
such as C. diff and MRSA at the farm production level
may be more important though than at the slaughterhouse level.
One of the reasons sows and their piglets
may have such high rates of C. diff
is because of cross-contamination of feces in the farrowing crate,
which are these kind of metal cages that mother pigs are kept in.
But can't you just follow food safety guidelines and cook the meat through?
Unfortunately, current food safety guidelines are ineffective
against this superbug because it forms these spores
that are resistant to heat.
To date, most food safety guidelines say cook at an internal temperature
as low as 63 Celsius, which is the official USDA recommendation for pork,
but recent studies show that these C. diff spores can survive
extended heating at 71, therefore the guidelines should be raised
to take this potentially killer infection into account.
See the problem is that sources of C. diff food contamination might include
not only fecal contamination on the meat, but transfer of spores from the gut
into the actual muscles of the animal, inside the meat.
Clostridia bacteria like C. diff comprise one of the main groups
of bacteria involved in natural carcass degradation,
so by colonizing muscle tissue before death,
C. diff can not only transmit to new hosts that eat the muscles, like us,
but gives them a head start on carcass break down.