An outbreak of ventilator-associated pneumonia in Merida, Yucatan.

Objective,To determine the main epidemiological, clinical, and microbiologi c characteristics of an outbreak. of ventilator-associated pneumonia at an intensive care unit in Yucatan. Material and methods. A I I-month prospecti ve and observational study was designed to determine incidence, mortality, potential reservoirs, etiologic agents and antibiotic susceptibility patter ns. Results, The incidence of ventilator-associated pneumonia was 74%. The crude mortality rare was 88% compared to a 19.5% expected-mortality rate. G ram-negative bacteria were isolated from 98% of the cultures, of which 46% were susceptible to third generation cephalosporins, 59% to fourth generati on cephalosporins, 70% to ciprofloxacin and 100% to imipenem. Klebsiella pn eumoniae and Pseudomonas aeruginosa were isolated from some of the ventilat or circuits and the sink. Conclusions. The high incidence of pneumonia and associated mortality in our intensive care unit may be attributed to the ab sence of infection control measures and the high prevalence of multiresista nt organisms which is related to antibiotic abuse.