NEW YORK Apr 6 (Reuters) Young children and older adults have shown decreasing rates of drug-resistant pneumococcal infections.
Investigators at the Centers for Disease Control and Prevention (CDC) attribute the falling rates to the introduction of the pneumococcal conjugate vaccine, which is recommended for individuals in those two age groups.
The Active Bacterial Core Surveillance of the Emerging Infections Program Network, headed in this phase of study by Dr. Cynthia G.
Whitney, tracked rates of antibiotic-resistant pneumococcal disease in the United States between 1996 and 2004.
Rates of penicillin-resistant strains peaked in 1999 at 6.3 cases per 100,000 and fell to 2.7 cases per 100,000 cases in 2004, for a decline of 57 percent. Rates of multiple drug-resistant pneumococcal infections peaked at 4.1 cases per 100,000 in 1999 to 1.7 cases per 100,000 in 2004, for a drop of 59 per cent.
Between 1999-2004, penicillin-resistant S. pneumonia strains fell 81 percent among children less than two years of age, and fell 49 percent among individuals aged 65 and older.
Rates of all resistant diseases caused by vaccine serotypes fell 87 percent.
However, there was an increase in resistance to serotype 19A-related disease, from 2.0 to 8.3 cases per 100,000 in children less than two years of age. This strain was not included in the conjugate vaccine.
''Physicians should be seeing fewer treatment failures due to resistant pneumococci in their patients,'' Whitney told Reuters Health. ''However, pneumococci have shown a remarkable ability to adapt and we need to continue to use antibiotics carefully if we want to preserve the benefits that the pneumococcal conjugate vaccine is having on resistance.'' Editorialist Dr Daniel M. Musher, of Baylor College of Medicine in Houston, Texas, points out that there are two effects of vaccination -- both the personal protection the vaccine confers and also herd immunity. He notes that the current research nicely documented protection of adults who had not been vaccinated.'' ''I think the current recommendations for children are fine. The real question, for which the research first needs to be done, is whether adults might eventually benefit more from the pediatric vaccine than from the present adult vaccine, which has limited efficacy,'' Musher said.
Musher said he's also concerned that ''some parents believe the profusion of nonsense that appears on the Internet suggesting that vaccines somehow harm children (websites with nonsense vastly outnumber the few rational, sensible, scientifically supported ones). Such parents state that they will 'delay' vaccinating their own kids, counting on herd effect. The herd effect is statistical.
The risk of infection is lowered, but the individual child remains fully susceptible.'' ''The United Kingdom, Ireland, Sweden and Germany have had major outbreaks of preventable infections such as pertussis and measles because of the prevalence of this kind of foolish attitude,'' Musher commented. ''In the pertussis outbreaks, among children who were hospitalized there were ICU admissions, seizures and deaths.'' ''Physicians should simply ask such parents if they are willing to have it be on their consciences if their toddler went unvaccinated and, as a result, contracted pneumococcal meningitis with lasting neurologic sequelae. Some pediatricians simply refuse to allow such parents to remain in their practices,'' Musher declared.
REUTERS MA RN0922