Learning Objectives for this Presentation:
By the end of the presentation, participants will be able to:
- Describe coverage rates for pneumococcal seven-valent conjugate vaccine (PCV7) in Arizona in 2002 and 2005.
- Describe the serotype distribution change in invasive Streptococcus pneumoniae (ISP) in Arizona from 2002 to 2005 and compare it to national ISP serotype distribution.

Background:
ISP is a reportble disease in Arizona and submission of ISP isolates to the Arizona State Laboratory for serotyping has been required since 2000. PCV7 was licensed in the United States and made available to Arizonans in 2000. In 2002, the PCV7 coverage rate for the 19-35 month age group was only 28%; however, the coverage increased to 82% in 2005.

Objectives:
1. Compare the serotype distribution of ISP in Arizona in 2002 to 2005.
2. Compare the ISP serotype distribution caused by non-PCV7 serotypes in Arizona to the US serotype distribution in 2002.

Methods:
Arizona ISP serotype data from 2002 and 2005 from the National Electronic Telecommunications System for Surveillance were compared to national data reported through the Active Bacterial Core Surveillance System using chi-square analysis.

Results:
The proportion of serotyped ISP disease in Arizona due to non-PCV7 serotypes increased from 73% (N=327) in 2002 to 98% (N=164) in 2005 (p<0.001). In contrast, national data indicate that the proportion of serotyped ISP disease with non-PCV7 serotypes in the US was 49.5% (N=2,726) in 2002. This proportion is significantly lower than that seen in Arizona in the same year (p<0.001).

Conclusions:
As expected, the proportion of ISP non-PCV7 serotypes in Arizona increased significantly between 2002 and 2005, indicating that PCV7 vaccination was effective. However, the baseline proportion of non-PCV7 ISP serotypes in Arizona was significantly higher than the national proportion in 2002, suggesting less opportunity to decrease overall cases of ISP in Arizona.