Pneumonia vaccine has not increased dangerous methicillin-resistant Staphylococcus aureus in children
Research Activities, February 2010, No. 354
Past studies have shown that children whose noses harbor colonies of the bacteria that cause pneumonia (Streptococcus pneumonia) tend to have few colonies of Staphylococcus aureus bacteria that in some forms can be resistant to antibiotics and an increasing public health problem. The widespread pneumonia vaccination effort for children that began in 2000 has not greatly upset the bacteria balance or increased colonization with methicillin-resistant Staphylococcus aureus (MRSA) in children age 6 and younger, a new study finds.
That's good news, since MRSA infection is typically resistant to most antibiotics and kills 1 in 20 hospitalized patients with the infection, according to recent data from the Agency for Healthcare Research and Quality (AHRQ). In this study, Boston researcher Grace M. Lee, M.D., M.P.H., and colleagues swabbed the nostrils of 1,968 children in 16 primary care practices in Massachusetts from 2003 to 2004 and 2006 to 2007. During the study periods, colonies of pneumonia strains susceptible to the vaccine decreased from 3.4 percent to 1 percent, respectively, while other pneumonia strains not susceptible to the vaccine rose from 19.4 percent to 29.1 percent. At the same time, colonization with S. aureus remained between 14 and 15 percent, and colonization with MRSA remained stable at less than 1 percent.
Children younger than 5 and children who recently received antibiotics were less likely to host colonies of S. aureus, regardless of the antibiotic they took. Many antibiotics, including trimethoprim/sulfamethoxazole, tetracycline, mupirocin, vancomycin, and linezolid, were able to vanquish S. aureus isolates. However, erythromycin and clindamycin were not as powerful against S. aureus in the 2006-2007 samples. This study was funded in part by the Agency for Healthcare Research and Quality (HS13908).
See "Epidemiology and risk factors for Staphylococcus aureus colonization in children in the post-PCV7 era," by Dr. Lee, Susan S. Huang, M.D., M.P.H., Sheryl L. Rifas-Shiman, M.P.H., and others in the July 11, 2009, BMC Infectious Diseases 9, pp. 1-10.