Objective     To investigate the conversion of hospital acquired pneumonia (HAP)

distribution of its etiology and characteristics of its drug-resistance in order to provide evidence for its treatment.      Methods     Five hundred and twelve HAP patients fulfilling the diagnostic criteria for HAP admitted to 4 different medical institutions in Chongqing from January 2009 to December 2010 were enrolled in this study. Their gender

age

conversion after treatment

basic disease

distribution of etiology

and drug-resistant spectra were retrospectively studied.      Results     No significant difference was observed in gender of HAP patients admitted to the 4 different medical institutions in Chongqing. The average age of HAP patients in Chongqing First Social Welfare Institution was 78.6±7.3

which was higher than that of those in the other 3 medical institutions (P0.05). The total mortality of HAP patients was 23.4% in Chongqing. The analysis of basic diseases directly related with hospital stay showed that cerebral stroke and its sequel were the common reasons for HAP (24.4%)

followed by acute and chronic respiratory failure (17.2%)

cardiovascular disease (8.3%)

tumor (7.7%)，post-operation (7.1%)

chronic obstructive disease of lung (6.9%)

silicosis (5.9%)

diabetes mellitus (4.4%)

senile dementia (3.8%)

and dystrophy (2.4%). The main pathogens of HAP were Gram-negative bacteria (73.2%) especially Pseudomonas aeruginosa (27.2%)

followed by Gram-positive bacteria (22.9%) especially Staphylococcus aureus (13.0%)

and fungi (3.9%). The etiological pathogens of HAP found in Fukang Hospital of Chongqing First Social Welfare Institution were Streptococcus pneumoniae

Hemophilus influenza

Staphylococcus aureus

Escherichia coli and Staphylococcus epidermidis.      Conclusion     The mortality of HAP patients is rather high in Chongqing. Cerebral stroke and its sequel are the common reasons for HAP. The pathogenic spectra of HAP in Chongqing Social Welfare Institution are different from those in the other 3 medical institutions. The main pathogens of HAP are Pseudomonas aeruginosa

Acinetobacter baumanni

and Staphylococcus aureus with a severe drug resistance.