Resistant Strep Sounds a Warning
An outbreak of strep throat resistant to a common antibiotic could be considered a wake-up call that some drugs may fail when they’re needed.
In monitoring 100 children at a Pittsburgh school last year, Dr. Judith M. Martin found 46 children with strains resistant to erythromycin, one of the most frequently used drugs for strep. Although some children never became ill, others had to be treated with different antibiotics.
Martin, who reported her findings in last week’s New England Journal of Medicine, said weekly throat swabs showed continued resistance this year among children in the same school.
There have been many reports of other bacteria that didn’t respond to certain antibiotics, but “this is really the first time this is recorded to this degree in the United States with group A streptococcus,†said Martin, a pediatric infectious-disease specialist at Children’s Hospital of Pittsburgh. “People have looked for it but never found it.â€
Strep A bacteria are responsible for sore throats, high temperatures, rheumatic fever and sometimes life-threatening infections that are difficult to control.
Martin’s discovery has major implications for the way doctors think about and prescribe antibiotics in this country.
Increasingly, physicians have been criticized for too often acceding to patient requests for antibiotics at the first sign of sore throats or ear infections. To make matters worse, they sometimes prescribe a drug related to erythromycin, called azithromycin (Zithromax), which requires just six pills in five days, instead of the front-line amoxicillin or penicillin. Those drugs require three pills a day for 10 days.
Now that Martin has found a pocket of some resistance to erythromycin, that means the entire group of antibiotics called macrolides--erythromycin, azithromycin and clarithromycin (Biaxin)--might fail to win the battle against infection with strep A.
Not only should doctors be more prudent when deciding whether to prescribe antibiotics, Martin said, they should use amoxicillin or penicillin except with patients allergic to either of them. Strep A has not been shown to resist either of those workhorse drugs.
She also recommends that public health officials support broader surveillance with strep-throat cultures to identify other groups of resistance cases around the country.
Already, Dr. Stanford Shulman, chief of infectious disease at Children’s Memorial Hospital in Chicago, is studying 1,000 children with strep throat at 13 locations, including Southern California. Although the information is still incomplete, “there appears to be at least some increase in this resistance compared to previous years,†Shulman said.
“If indeed the Pittsburgh experience is reflective of other places, we won’t be able to assume that the macrolides will be effective,†he added.
In the Pittsburgh case, Martin said, the researchers notified local pediatricians, who responded by changing their prescribing habits and using less of the macrolides.
Doctors know from experiences in Finland and Japan, which had high rates of macrolide use, that resistance went down when they prescribed less of those drugs.
“Both are good examples of how you can make a difference,†Martin said.
