Ear infection superbug discovered to be resistant to all pediatric antibiotics

The 19A strain, for example, has developed resistance to every antibiotic approved by the FDA for use in children with ear infections (18 antibiotics). Having anticipated this problem, Wyeth began working on a vaccine that would also protect against the next six most common strains of S. pnemoniae, including 19A, almost as soon as it got approval for the original vaccine. Even if all goes well, however, the 13-strain vaccine is not expected before 2010.

In the current study, two pediatricians used tympanocentisis to identify S pneumoniae strains that caused ear infections in children between September 2003 and June 2005. All the children had received the Prevnar vaccine. Among 1815 children, aged 6 to 36 months, in whom otitis media was diagnosed, tympanocentesis was performed in 212, yielding 59 cases of S pneumoniae infection and 9 cases infected with a serotype 19A strain resistant to all FDA-approved antibiotics for use in children. Of those nine, four required surgery to implant ear tubes after several attempts to treat with antibiotics failed. Levofloxacin was used in the next five cases, resolving the infection without surgery. Pichichero has published on the effectiveness and safety of quinolones in children with hard-to-treat ear infections, and the American Academy of Pediatrics endorsed their limited use where the benefits outweigh the risks, he said. Some past animal studies caused concern that the drug class may cause damage to weight-bearing joint cartilage in children, although such a side effect has not been observed in humans.

As expected, analyses of the ear tap samples over the three years revealed that those strains included in the original Prevnar vaccine were effectively prevented. But the study also found that strains not included in the vaccine have become more numerous in their place. In addition, the study showed that the strains not included in Prevnar at first were nearly all sensitive to most antibiotics, but over three years became dramatically more resistant to penicillin (from 25 to 93 percent of cases) (P<.001) and other antibiotics.

“The solutions to this problem are clear,” said Janet Casey. M.D., co-author of the study, associate professor of Pediatrics at the Medical Center and a partner in Legacy Pediatrics. “Many more physicians need to learn and use the ear tap technique and how to test for the strains once the sample is collected. They also need to resist pleas by parents to treat colds with antibiotics for comfort’s sake alone.”