Learning Objectives for this Presentation:
By the end of the presentation participants will be able to recognize the impact of the 7-valent pneumococcal conjugate vaccine (PCV7) on nationwide hospitalizations for pneumococcal meningitis

Background:
In February 2000, PCV7 was licensed for young children in the US. Although hospitalizations rates for invasive pneumococcal disease have declined since 2000, trends in nationwide hospitalizations for pneumococcal meningitis are unknown.

Objectives:
Using the Nationwide Inpatient Sample (NIS), we assessed trends in hospitalization rates for pneumococcal meningitis from 1994 through 2003.

Methods:
Annual rates were calculated using census-derived population data as denominators and 1994 was used as reference for comparisons.

Results:
From 1994 through 2003, the NIS sampled 71,494,180 hospitalizations, representing a national estimate of 357,255,221 hospitalizations. Of these, 19,764 and 18,082 had a primary ICD-9 coded diagnosis of pneumococcal and streptococcal meningitis, respectively. Rates of pneumococcal meningitis hospitalizations remained stable between 1994 and 1999, and decreased after 2000. The largest decline was observed in children aged < 5 years. In children aged < 2 years, the rate was 67% lower in 1994 compared with 2003 (7.24 vs. 2.38 per 100,000; rate difference: -4.86; 95% CI: -4.80 to -4.93). In children aged 2 to 4 years, the rates decreased 56% from 0.73 to 0.32 per 100,000 (rate difference: -0.41; 95% CI: -0.39 to - 0.42). Among persons 65 years or older, the rates declined 23% from 1.17 to 0.90 per 100,000 (rate difference: -0.27; 95% CI: -0.25 to -0.29). In contrast, rates of streptococcal meningitis fluctuated over time and no trend was observed. Based on the rate difference of pneumococcal meningitis between 1994 and 2003, we estimated that 756 pneumococcal meningitis hospitalizations were prevented in people of all ages in 2003.

Conclusions:
These results indicate that both children and the elderly have benefited from the routine infant immunization with PCV7.