Salmonella's Main Drug Hits Resistant Strain
Outbreak in two Oregon nursing homes first person-to-person transmissions
WEDNESDAY, May 30, 2001 (HealthDayNews) -- The first U.S. outbreak of infection caused by drug-resistant bacteria, unheard of in this country until recently, could become more commonplace, government officials warn.
A 1998 infection in two nursing homes and a hospital in Portland, Oregon was caused by fluoroquinolone-resistant salmonella, the government research shows. Imported from the Philippines, the infection spread from person to person -- an unusual way for the salmonella to spread. It usually infects someone by way of raw eggs, poultry, dairy products and other foods. Salmonella causes a variety of typhoid-like symptoms in humans, including fever and vomiting, and can be deadly if the immune system is weak.
Hospitals and long-term care facilities should cut down on using the antibiotic fluoroquinolone, the drug of choice for severe salmonella poisoning in adults.
"It is the first outbreak ever to occur in the United States," says study co-author Dr. Frederick Angulo, a medical epidemiologist with the National Center for Infectious Diseases in Atlanta, Ga.
"What was additionally remarkable about this outbreak was that it was spread from person-to-person, which has not been described since the 1960s for salmonella."
The infection started in a patient in the Philippines who was transported to the United States and hospitalized. Then other patients got the infection in the hospital and then spread the disease to patients in the two nursing homes, Angulo says. It normally takes a lot of salmonella to infect someone, but because the bug was resistant to the most widely used drug to fight it, it didn't take much to make someone sick. "The wide use of fluoroquinolones was advantageous to the spread of this type of salmonella."
Fluoroquinolones are a group of broad-spectrum antibiotics derived from nalidixic acid, which itself is used to treat a variety of serious urinary and respiratory tract infections in people and in animals.
Eventually 11 patients came down with the resistant salmonella, Angulo says. "Some patients died from the infection who were nursing home residents, but whether the salmonella was the sole cause is hard to discern."
Angulo says that fluoroquinolones are also used to prevent infections in chickens and "is causing salmonella to move towards resistance, but we have not had a case in the U.S. transmitted from chickens."
He adds, "But we are concerned that we are on the threshold of that, and that is why we support the U.S. Food and Drug Administration's action concerning the use of fluoroquinolones in chickens that was announced six months ago."
The FDA in October proposed a ban on two fluoroquinolone-class antibiotics fed to chickens to prevent disease.
The nursing home outbreak was described in a recent issue of The New England Journal of Medicine.
"This [resistance]is an increasing problem in the United States," says Jacqueline Vance, director of clinical affairs for the American Medical Directors Association. "And one other problem is that the majority of guidelines on dealing with antibiotic-resistant infections have been developed for acute hospital care, and not for long-term care."
"Say [if] someone has an antibiotic-resistant organism in their bladder, it has colonized, caused infection and has cleared up, but the organism remains in the body," Vance explains. "In acute care, you would have to culture the organism, isolate the patient and then treat it. But if you have an 85-year-old Alzheimer's patient who is also incontinent, you couldn't follow acute-care guidelines to isolate the patient. That patient might have to be isolated for the rest of their days, and that's just not appropriate."
The solution, although multi-faceted, is "relatively simple," Vance says.
"We must look at how we are prescribing antibiotics. We know there is an over-prescription even for minor problems like the flu or a cold, which [are] viral based, and antibiotics are not even going to work [to cure them]."
Also, she adds, "We must be much more stringent that our health care professionals follow standard precautions, specifically hand washing between patients."
"It is proven that hand washing is the single most effective method of preventing the spread of these infections," she notes.
What To Do
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