"Urinary Tract Infections from Eating Chicken"
Only about 1 in 4 people have heard of Campylobacter,
compared to 90% familiar with Salmonella.
Although the incidence of these two gastrointestinal infections
is amazingly high, infecting more than a million Americans every year,
it is outranked by the incidence of a bug even fewer people have likely heard of:
ExPEC--extraintestinal (meaning outside of the intestines,
like as in causing bladder infections) pathogenic (meaning disease-causing)
E. coli, resulting in millions of infections annually.
Multiple lines of evidence indicate poultry may be
a major food animal reservoir for bacteria that cause
urinary tract infections in people, as I explored about five years ago.
This is based not only on studies showing these kinds of E. coli from
commercial chicken meat and eggs can cause blood infections, brain infections,
and urinary tract infections in mouse models,
studies on women with multidrug resistant urinary tract infections
do report significantly more frequent retail chicken consumption.
Similarly, elderly chicken eaters were significantly more likely
to have Cipro-resistant bladder infections compared to those eating no chicken at all.
Pork was also associated with increased risk, but not beef.
There have been few observed associations between beef cattle or retail beef
and human ExPEC infections, suggesting that beef cattle are not a reservoir
for human bladder infections, whereas in chickens,
of the up to 90% of chicken carcasses harboring E. coli,
about 1 in 5 isolates tested had the potential to cause urinary tract infections.
What about eggs?
We know retail chicken meat is contaminated with ExPEC isolates
that resemble the strains that cause human infections,
but what about retail chicken eggs?
Instead of 1 in 5 being ExPEC in chicken meat,
it was more like just 1 in 20 among eggs, closer to down around pork or beef levels.
Researchers are so sure that chicken is the primary reservoir
that when they find the same kind of strain in a vegetarian,
they interpret that as people saying they're vegetarian
but actually eating some chicken,
or evidence of human- to-human transmission,
or even shopping-cart- to-human transmission.
Remember how most people fail to sanitize their hands
after picking up a package of poultry in the grocery store?
And so then, even a shopper who's not purchasing poultry could still be exposed
to poultry contamination pushing the same cart after them.
It's difficult to estimate how much ExPEC exchange can be attributed
to person-to-person contact after a chicken consumer's rectum has been colonized.
Researchers went swabbing around public restrooms to try to quantify the risk—
a thousand samples from 56 public restrooms in 33 establishments.
They found lots of evidence of E. coli in general,
particularly in public park restrooms and fast food joints—
more than gas stations, which surprised me—
but this was really surprising: women's rooms were worse than men's!
But only about 1% of the samples they took were positive for ExPEC bacteria,
though they were recovered from non-toilet associated sites
that were not visibly contaminated, so one might touch it with bare hands
after like turning the faucet off after you've washed your hands.
So the risk may not be fully eliminated by careful hand washing
or avoidance of fecal-appearing debris,
though that's probably a good idea to avoid anyway.
And using hand sanitizers after exiting the restroom,
not to mention in the meat aisle after touching a package of poultry,
may offer additional protection.
What proportion of the 7 million bladder infections every year
in the U.S. are due to chicken meat?
Like if no more chicken were consumed, how many E. coli UTIs would be prevented?
How much would the prevalence decline?
It's hard to tell because of the time lag between the acquisition
and asymptomatic colonization of the intestine with an ExPEC organism
and the development of an infection.
So you eat some contaminated chicken today, and the UTI-causing
ExPEC bacteria may hang out in your colon for months before
making an appearance, making its way into your bladder and triggering an infection.
The reason we know it can take that long is by studying
the intestinal population dynamics of UTI-causing E. coli between partners.
Increased rectum-to-rectum transfers might be explained by the high levels
of E. coli present in the urine of an infected woman,
which could then be transferred over depending on certain intimate practices.
Bottom-line, there is compelling evidence that retail meat,
particularly poultry, serves as an important reservoir
for human exposure to antibiotic-resistant E. coli
that is causing UTIs— urinary tract infections.
Thus, instead of just UTIs, maybe we should call them foodborne UTIs
or FUTIs or maybe pronounced F.U.T.I's.
Sure, we could decrease the burden of these foodborne bladder infections
by developing some sort of ExPEC vaccine,
or we could just cut down our contact with fresh or frozen poultry.
No harm, no fowl.