Thought Bedbugs Were Bad? Try Bedbugs with MRSA
Thursday, May 12, 2011
The one bright side to having bedbugs - if you wanted to be
optimistic about it - has always been that at least the tormenting
critters didn't transmit disease. But now researchers in Vancouver
report that they've found bedbugs with
methicillin-resistant Staphylococcus aureus, or
The scientists studied five bedbugs, taken from three patients
treated at St. Paul's Hospital. All three patients were residents
of Vancouver's poor Downtown Eastside, where both bedbugs and MRSA
have been on the rise in recent years. The researchers wanted to
see if there was a connection.
So they crushed and analyzed the bugs and found three samples
with MRSA, the superbug that is resistant to most commonly used
antibiotics. The two other samples had
vancomycin-resistant Enterococcus faecium, or VRE, a
less dangerous antibiotic-resistant bacteria.
That's pretty much all they know at this point. It's not clear,
for example, whether the drug-resistant germs were transmitted from
people to bedbugs, or the other way around. The strain of MRSA the
scientists found was consistent with community-associated MRSA
found in other Downtown Eastside residents.
It's also not clear whether the bacteria existed on the bedbugs
or in them. That is, were the bedbugs carrying MRSA
on their backs, or were the bacteria living and growing inside
them? Either way, it's bad news: if bedbugs are capable of carrying
and transmitting MRSA the way a mosquito spreads malaria, it could
mean a whole new vector of human disease.
"To the best of my knowledge, we have not seen any research that
has proven bedbugs have been able to pass diseases to their human
hosts," says Gail Getty, a research entomologist at the University
of California, Berkeley, who specializes in urban pests. "Although
they do carry pathogens, there is no single scientific study that
has proven a transfer." (Past data show that the hepatitis B virus
can survive in bedbugs for six weeks after feeding, but there is no
evidence that the bugs are able to transmit disease.)
If, on the other hand, bedbugs simply carry MRSA the way
an airplane tray table does, it's less troubling but still
significant: bedbugs could still spread the germ from person to
person, especially in close-quartered living situations like
homeless shelters; the bacteria can survive on surfaces for hours
or even days under the right conditions.
"Even though this is a small study, it suggests that bedbugs may
be playing a role in the transmission of MRSA in inner-city
populations where bedbug infestations are a problem," said Marc
Romney, one of the study's authors and the medical director of
infection prevention and control at St. Paul's Hospital.
Since MRSA enters the bloodstream through open wounds or cuts,
it's technically possible that if an infected bedbug were to find
its way onto an infested person - with the telltale itchy welts and
broken skin from scratching - it could pass on the bacteria.
"I've been predicting this for years," says entomologist Dr.
Michael F. Potter, a professor at the University of Kentucky, in an
e-mail, "seeing how all it takes is a breakage of the skin for
If left untreated, MRSA can cause pneumonia or infections of the
skin, blood and joints. The bacteria, once confined to hospitals,
has been increasingly found in community settings like locker rooms
and gyms, and kills 19,000 Americans each year. Recently, the
FDA approved a quick diagnostic test that promises to help
infected patients receive treatment more quickly.
The peer-reviewed paper was published in the Centers for Disease
Control and Prevention's Emerging Diseases