Antibiotic misuse causing frightening new bugs
RTw 22.08.97 20:23
Copyright 1997 Reuters Ltd. All rights reserved.
The following news report may not be republished or
redistributed, in whole or in part, without the prior written
consent of Reuters Ltd.
By Maggie Fox, Health Correspondent
WASHINGTON, Aug 22 (Reuter) - Frightening new strains of
bacteria, parasites and even fungi are turning up in hospitals
thanks to medicine's over-reliance on antibiotics, doctors said
on Friday.
News that a Michigan man is infected with an especially tough
strain of bacteria has brought to the United States a specter
that has haunted the rest of the world for several years -- that
of mutated microbes that drugs cannot kill.
The new case involves a staphylococcus bacteria -- a common and
usually harmless bug -- that has become resistant to the
antibiotic vancomycin.
What is so frightening is that vancomycin is often a last-resort
drug used when other antibiotics fail.
Doctors are quick to point out these new strains normally infect
people who have been in hospitals for a long time, have been
treated with a battery of drugs and who have badly suppressed
immune systems.
But they say people's attitudes toward drugs will ensure their
spread.
"Patients should not request, nor health care workers
provide, antibiotics without a clear indication for them,"
David Johnson, chief executive of Michigan's Community Public
Health, said.
"When antibiotics are prescribed, the full course should be
taken as directed."
The problem is that patients demand prescriptions for infections
caused by viruses that do not respond to drugs, or for bacterial
infections that will clear up on their own -- or they stop taking
the drug once they start feeling better.
The result is that microbes are exposed to just enough drugs to
damage, but not kill all of them. Natural selection ensures that
the bacteria that have a genetic resistance to the antibiotic
live, and pass on these resistant genes to the next generation.
A thousand generations later -- and this can be just a few weeks
in the fast-moving world of microbes -- a "superbug"
has evolved. The tenacious bugs are not completely new to the
United States.
Last year, a study at Chicago's Cook County Hospital found 40
percent of severely ill patients infected with
vancomycin-resistant enterococci, a strain of gut bacteria.
The Centers for Disease Control (CDC) describe a bug that causes
2.5 million cases of pneumonia, seven million ear infections and
3,000 cases of meningitis every year.
"It is only susceptible to one antibiotic and if we lose the
capacity to fight this strain then you have a very serious health
problem," Mitchell Cohen of the CDC told a conference in
London last year.
Doctors in Europe have been fighting multidrug-resistant
Stapholycoccus aureus (MRSA) for years, and have reported a
resistant strain of a common fungus, aspergillus, can invade the
chests of hospital patients, filling them with a green and deadly
slime.
Parasites such as the organism that causes malaria, spread by
mosquitoes, have also developed several resistant forms.
U.S. officials sought to calm fears about the new
vancomycin-resistant bug on Friday.
"I want to make it perfectly clear that this is not a
widespread situation. We have no reason to believe there is any
danger to the general public," James Haveman, director of
the Michigan Department of Community Health, said.
Johnson said the bacteria was not completely unkillable.
"This isolate is not fully resistant to vancomycin, and it
is susceptible to other commonly available antibiotics," he
said. REUTER