Disturbing new evidence that common bacteria are becoming more and more resistant to antibiotics, making infections ever harder to defeat, was reported Wednesday by a research team in Atlanta.
A 10-month study of samples from 431 adults and children with streptococcus pneumoniae infections found that one-fourth of them had drug-resistant strains, according to researchers at the U.S. Centers for Disease Control and Prevention and Emory University, both in Atlanta.
The high percentage “was a shock,” said CDC epidemiologist Dr. Martin Cetron.
A second shock, Cetron said, was that almost as many drug-resistant infections were found among adults (24 percent) as among children (27 percent). Typically, it has been children who developed the ear infections or potentially deadly meningitis that the bacteria can cause. The prevalence among adults means that much more attention must be given to vaccinating vulnerable people - the elderly, those with damaged immune systems and diabetics, for instance - against the bacteria, Cetron said.
Drug-resistant bacteria also were more prevalent among white suburban children than among black children in the city. The researchers said this suggests that ready access to medical care - combined with doctors’ aggressive, even reckless, prescription of penicillin, sulfa drugs, erythromycin and cefotaxime - contributed to the emergence of drug-resistant bacteria.
The findings also suggest that daycare centers are prime incubators of antibiotic-resistant infections.
The article on the findings, to be published in today’s issue of the New England Journal of Medicine, was co-authored by Cetron, Dr. Monica Farley and colleagues at Emory, and others.
A second report in the same issue, from researchers in Spain, was somewhat more reassuring. The Barcelona team found no increase in the death rate from drug-resistant Streptococcus pneumoniae, since higher-than-usual doses of penicillin, or other antibiotics such as cephalosporin, were effective.
Still, the Barcelona researchers have also observed an “alarming” rise in pneumonia bugs resistant to the drug cephalosporin, a second line of defense after penicillin.
Dr. Carol Dukes, an infectious diseases specialist at Duke University Medical Center in Durham, N.C., observed that “it’s not a panic thing, but it is a warning flag. It means we need to pay attention, or we’re going to get into trouble here.”
Cetron said in an interview that elsewhere in the United States, “the scope and magnitude of resistance are not really known.” But the study results demonstrate “a pressing need to know how much drug-resistant pneumoniae are out there.”
Cetron, at the CDC, is worried because Streptococcus pneumoniae ranks “among the most common bacterial pathogens in the world”; it can readily be detected in about half of the people tested, even if they are not ill. It has long been controllable with penicillin, but 15 or 20 years ago drug-resistant strains began to be reported in South Africa, Europe and less frequently in the United States.
Medical records show that in the United States alone, Streptococcus pneumonia is the leading cause of bacterial meninigitis, about 3,000 cases a year. It also causes 50,000 cases of bacteremia, 500,000 pneumonia cases, and about 7 million ear infections, otitis media.