title: Pneumococcal peritonitis: Still with us and likely to increase in importance.
abstract: BACKGROUND
  Pneumococcal peritonitis is uncommon and poorly understood.
  
  
  METHODS
  As part of a five-year study (2000 to 2004) of invasive pneumococcal disease (IPD) in Alberta, all cases of peritonitis due to Streptococcus pneumoniae were reviewed and compared with all other cases of IPD.
  
  
  RESULTS
  Twenty-three of 1768 (1.3%) IPD patients were found to have peritonitis. Patients with peritonitis were more likely to have cirrhosis, hepatitis C, alcoholism and HIV/AIDS, than the remainder of the patients with IPD. The all-cause mortality did not differ between the two groups. Peritonitis was classified as primary in nine (39%) patients, secondary in 12 (52%) patients, and genitourinary in females, specifically, in two (9%) patients. Pneumococcal serotypes causing peritonitis were under-represented in current vaccines - 17% among peritonitis patients versus 53% for the remainder of IPD patients for the 7-valent pneumococcal conjugate vaccine, and 56% versus 86% for the 23-valent pneumococcal polysaccharide vaccine.
  
  
  CONCLUSIONS
  Peritonitis represents a small subset of patients with IPD, but one that is likely to grow in importance given the increase in the number of patients with hepatitis C and HIV, and the reduced coverage of peritonitis serotypes in currently available vaccines.
authors.affiliation: University College Dublin, Dublin, Ireland;
authors.forename: Darcy C
authors.initials: DC
authors.lastname: Waisman
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Tyrrell
authors.forename: James D
authors.initials: JD
authors.lastname: Kellner
authors.forename: Sipi
authors.initials: S
authors.lastname: Garg
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Marrie