Streptococcus pneumoniae. Resistant to one or more commonly used antibiotics. Seven sero-types (6A, 6B, 9V, 14, 19A, 19F, and 23F) accounted for most DRSP before the introduction of 7-valent pneumococcal conjugate vaccine (PCV7, Prevnar®, Wyeth) in the U.S. in 2000). Most antibiotic resistance today is found in serotype 19A, which is included in the new 13-valent pneumococcal conjugate vaccine (PCV13, Prevnar13®, Pfizer) introduced in the U.S. in February 2010.

Persons who attend or work at child-care centers and persons who recently used antimicrobial agents are at increased risk for infection with DRSP. In general, children at increased risk of pneumococcal infections include those with anatomic or functional asplenia (including sickle cell disease), patients taking immunosuppressive drugs, those with congenital and acquired immune deficiency (including HIV infections), children with cochlear implants, and those with chronic renal disease. Some American Indian, Alaska Native and African American children may also be at increased risk.  Adults over age 65, those with long-term health problems or a condition that lowers the body’s resistance to infection, 19-64 year old who smoke or have asthma, and residents of nursing homes or long-term care facilities are at increased risk for pneumococcal disease.  Among those with pneumococcal infections, those who recently used antibiotics are more likely to have a resistant infection than those who have not. 

Campaigns for more judicious use of antibiotics and use of the conjugate vaccine may slow or reverse emerging drug resistance. Prevention of infections could improve through expanded use of 23-valent polysaccharide vaccine and the conjugate vaccine. Among children 5 years of age or younger, the new conjugate vaccine elicits protection against ~97% of invasive pneumococcal isolates that are not susceptible to penicillin.