Streptococcus Pneumoniae Serotypes in Utah Adults at the End of the PCV7 Era

While heptavalent pneumococcal conjugate vaccine (PCV) has decreased vaccine type invasive pneumococcal disease (IPD) nationwide, rapid serotype replacement and increasing parapneumonic empyema, has been reported in Utah children. The effect of pediatric vaccination on adults in this population is unknown. We identified 117 adults with IPD from the Intermountain Healthcare Central Laboratory between November 2009 and October 2010. We serotyped 61 (52%) stored isolates. We compared the serotype distribution of adult IPD isolates with that of pediatric isolates collected in 2009-2010. PCV7 serotypes were rare in adults (3%) and children (3%). Emerging 13-valent PCV serotypes 3, 7F, and 19A caused the majority of IPD in adults (63%) and children (56%). Fifty-one (84%) adult isolates were serotypes included in 23-valent polysaccharide vaccine and 66% in PCV13. Adult and pediatric IPD serotypes are closely associated in Utah. PCV13 vaccination in Utah children is likely to significantly impact IPD in Utah adults.