667. Streptococcus pneumoniae serotypes in Utah adults with invasive pneumococcal disease at the end of the PCV7 era
Session: Poster Abstract Session: Pneumococcal Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background:

The incidence of invasive pneumococcal disease (IPD) decreased in both US children and adults following licensure of the heptavalent pneumococcal conjugate vaccine (PCV7) in 2000.  However, IPD in Utah children has differed from CDC surveillance sites with earlier emergence of non-vaccine serotypes and increase in parapneumonic empyema (PE) after PCV7 introduction. It is unknown whether changes in IPD serotype distribution and clinical syndromes seen in Utah children have occurred in Utah adults.

Methods:

We collected all S. pneumoniae isolates from sterile site cultures in adults >18 years submitted to the Intermountain Central Laboratory and in all children < 18 from Primary Children’s Medical Center (Salt Lake City, UT) from 2009 -2010. Isolates were serotyped using the capsular swelling method. We queried the Intermountain Healthcare Electronic Medical Record for demographic, clinical, radiographic, and microbiologic data.  We compared serotype distribution and clinical IPD syndromes in Utah adults to Utah children with IPD in 2009 and 2010.

Results:

We identified 117 adults and 91 children with culture-confirmed IPD.  In adults, 98 (84%) had bacteremic pneumonia compared with 21 (23%) children (p < 0.0001) and 9 adults (8%) had PE compared with 19 (21%) of children (p=0.27).  59 adults (50%) and 91 children (100%) had stored isolates for serotyping. There were more meningitis cases (p = 0.05) among adult patients with serotyped compared with non-serotyped isolates; these cohorts were otherwise similar. PCV7 serotypes were rare in adults (3%) and absent in children.  Emerging PCV13 serotypes 3, 7F, and 19A caused the majority of IPD in both adults (63%) and children (56%). 84% of isolates in adults are included in 23-valent pneumococcal polysaccharide vaccine and 66% in the 13-valent PCV.

Conclusion:

In Utah, adults with IPD were more likely than children with IPD to have bacteremic pneumonia. Rates of PE in adults and children were similar. Ten years after the introduction of PCV7, PCV7 serotypes have nearly disappeared.  Emerging serotypes in adults are similar to emerging serotypes in children and are included in PCV13.  Continued epidemiologic data on adults and children from a wide variety of sites is crucial to inform adult vaccine policy.


Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Brian Kendall, MD1, Kristin Dascomb, MD, PhD2, Rajesh Mehta, RPh, MS3, Edward Mason, PhD4, Krow Ampofo, MD1, David Pombo, MD5, Andrew Pavia, MD, FIDSA1 and Carrie L. Byington, MD1, (1)University of Utah, Salt Lake City, UT, (2)Intermountain Medical Center, Murray, UT, (3)Intermountain Health Care, Murray, UT, (4)Baylor College of Medicine, Houston, TX, (5)LDS Hospital, Salt Lake City, UT

Disclosures:

B. Kendall, None

K. Dascomb, None

R. Mehta, None

E. Mason, None

K. Ampofo, None

D. Pombo, None

A. Pavia, None

C. L. Byington, Wyeth/Pfizer: Grant Investigator, Research grant

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.