COVER

THE RENEGADE BUGS

September 9 1996
COVER

THE RENEGADE BUGS

September 9 1996

THE RENEGADE BUGS

COVER

One of the oldest life-forms on Earth, bacteria are everywhere.

They thrive inside people—and as many as 100,000 of them can inhabit a square inch of human skin. Most are harmless to humans, some are beneficial in helping, among other things, to break down nutrients—but others can be deadly. Among the increasingly drug-resistant bacteria that can menace human health:

« MRSA (methiciltin-resistant staphylo1 coccus aureus) Often found in hospilt; tais, particularly among intensive-care I and elderly patients. The bug can g cause a wide range of potentially lifel threatening problems, including infec-

tions, blood poisoning, pneumonia meningitis, toxic shock and food poisoning. Resistant most antibiotics, including ci 11 in, a semi-synthetic form of cillin, and related drugs. But is still usually treatable by the so called drug of last resort, van comycin. According to the U.S. Cen ters for Disease Control and Preven tion in Atlanta, 38 per cent of staph aureus specimens examined ir large American hospitals in 1991 were drug-resistant. In Canada, a series of hospital outbreaks show that MRSA is a growing problem.

VRI (vancomycin-resistant enterococcus) The enterococci bacteria usually live harmlessly in the human gastrointestinal tract and do not pose a threat to healthy people. But when the bacteria enter the blood-

stream—through a cut or a surgical wound—-they can cause fatal infections. In its drug-resistant form, the enterococcus bug can shrug off virtually every widely used antibiotic, including vancomycin. When that happens, doctors can try a handful of newer or experimental drugs. According to the CDC, nearly eight per cent of enterococcus samples from U.S. hospitals analyzed in 1993 were vancomycin-resistant. VRE is probably gaining ground in Canada as well, but no statistics are available.

STREPTOCOCCUS PNEUMONIAE

Often called “pneumococcus” for short, this bug is a frequent cause of ear infections in children and meningitis and pneumonia in adults. In the United States, more than 30 per cent of pneumococci cases are now resistant to penicillin, and doctors estimate

that more than 10 per cent of Canadian cases are penicillinresistant. When physicians encounter the resistant form of the bug, they have to resort to more expensive drugs such as | cefaclor and ceftriaxone. §

GROUP A STREPTOCOCCUS These bacteria can cause strep throat, pneumonia, boils, scar let fever, the kind of toxic shock that killed Muppeteer Jim Hen son, and the flesh-devouring disease, necrotizing fasciitis. In Canada, strep Illnesses can

still be effectively treated with antibiotics. But some signs of drug-resistant group A strep have appeared in Japan, Eu rope and the United States.