PURPOSE: To determine the frequency of nosocomial invasive pneumococcal disease (IPD) and to compare these with community-acquired infections.
METHODS: Analysis of IPD cases reported to a national laboratory-based surveillance system in South Africa during 2005. Nosocomial IPD was defined as a positive culture or latex agglutination for Streptococcus pneumoniae from a normally sterile site, with the pneumococcus isolated >48 hours after admission. Antimicrobial susceptibility testing was according to CLSI guidelines.
RESULTS: 4052 episodes of IPD were reported; 2285 (56%) cases had documented admission and specimen collection dates. Nosocomial IPD was identified in 67/2285 cases (3%); 34 lower respiratory tract infections, 18 meningitis, 12 bacteremias, 3 unknown. There was a trend towards less cerebrospinal fluid (CSF) isolates in nosocomial infections (13/67 (19%) vs. 671/2218 (30%); p=0.056). Both penicillin non-susceptible isolates (25/59 (42%) vs. 599/1926 (31%); p=0.060) and erythromycin resistant isolates (13/59 (22%) vs. 259/1926 (13%); p= 0.058) tended to be more common in nosocomial infections. An excess of nosocomial cases were reported from the Western Cape (19/67 (28%) versus 286/2218 (13%) community-acquired infections; p<0.001).
CONCLUSION: 3% of IPD in South Africa during 2005 could be classified as nosocomial. These infections tended to be less commonly meningitis and more commonly associated with resistance to penicillin and erythromycin. Proportionately more nosocomial infections were reported from the Western Cape province in 2005.
CLINICAL IMPLICATIONS: Nosocomial IPD is relatively common in South Africa and further studies are being undertaken to investigate important risk factors for and mortality from such infections.
DISCLOSURE: Charles Feldman, Grant monies (from sources other than industry) This surveillance study is supported by grants from the National Institute for Communicable Diseases, South Africa and the Centers for Disease Control and Prevention, Altanta, USA.