[Epidemiology of nosocomial infections in a second level hospital]

To determine the incidence, specific rates, areas of greatest risk and causal agents of nosocomial infections at the Hospital General de Durango, of the Secretaría de Salud, Mexico.

Prospective study of nosocomial infection vigilance during one year including all patients discharged during this period.

An overall rate of 9 infections per 100 discharged patients was found, the higher specific rates were in the areas of intensive pediatric care and births and the lowest were in the surgery, pediatric and gynecology and obstetrics departments. Infections were most frequent in urinary tract and surgical wounds as well as pneumonia among adults; among children, the most frequent were bacteremias and an epidemic outbreak with predominating Serratia marscecens was observed. Most patients presented one only infectious process and E coli, Klebsiello and Enterobacter sp. were the most frequently isolated microorganisms.

The nosocomial infection rate observed in this study is higher than the average in Mexico for similar institutions. The most affected areas were those of critical patients and new births with urinary tract and surgical wound infections, and pneumonia, and the most frequent causal agents were enteric Gram-negative bacilli. These findings suggest guide lines for the design of a nosocomial infection control program, adjusted to the particular features of each institution.