Table 3. Incidence of nosocomial infections in 237 adults receiving mechanical ventilation.

Nosocomial infection	Frequency, n (%)	Incidence density	Culture-positivity rate
At least one nosocomial infection	147 (62%)	58.4 per 1,000 patient-days	—
Ventilator-associated pneumonia	144 (61%)	57.2 per 1,000 ventilator-days	108/144
Catheter-associated urinary tract infection	28 (12%)	11.1 per 1,000 catheter-days	26/28
Central line associated bloodstream infection †	12/116 (10%)	9.2 per 1,000 catheter-days	11/12*
Skin and soft tissue infection	5 (2%)	2.0 per 1,000 patient-days	5/5

*In one patient blood culture was sterile; but, the catheter tip culture yielded growth;

^†Denominator is the number of patients with a central venous catheter