Nosocomial pneumonia in adult general medical and surgical patients at Christchurch Hospital.
OBJECTIVE
To determine the incidence, microbial cause, and outcome of nosocomial pneumonia in adult general medical and surgical patients at Christchurch Hospital.


METHODS
A one-year prospective study of consecutive patients developing nosocomial pneumonia in a university-affiliated hospital. Expanded diagnostic laboratory testing was undertaken to identify the microbial cause of pneumonia.


RESULTS
We recruited 126 patients, which represented an incidence of 6.1 per 1,000 admissions. Only 52 (41%) patients submitted sputum that satisfied the cytological screening criteria for testing. A microbial cause was identified in 47 cases (37%): the most common was Legionella spp. (sixteen cases), followed by Influenza A (six cases) and Staphylococcus aureus (four cases). We did not identify an environmental source of the Legionella species. Fourteen patients (11%) died as a consequence of pneumonia and nearly all of these had significant comorbidity. Renal impairment, alcohol excess, and severity of pneumonia were the most powerful predictors of a fatal outcome by univariate analysis.


CONCLUSIONS
In most patients we did not identify a microbial cause of pneumonia; when we did, Legionella species were the most common, although this micro-organism has a long incubation period so some subjects may have acquired it before admission. These results guide preventative efforts, diagnostic testing and selection of antimicrobial therapy for nosocomial pneumonia in our hospital.
Department of Infectious Diseases, Christchurch Hospital, Canterbury Health.
R J
RJ
Everts
D R
DR
Murdoch
S T
ST
Chambers
G I
GI
Town
S G
SG
Withington
I R
IR
Martin
M J
MJ
Epton
C
C
Frampton
A Y
AY
Chereshsky
M I
MI
Schousboe
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003428:Cross Infection / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D011014:Pneumonia / Q000453:epidemiology*; D011446:Prospective Studies