[Estimation with bacteriology of the evolution of nosocomial infections between 1989 and 1991 in an university hospital].

The bacteriological laboratory data base was studied with an original software (Bacterio) and an appropriate method ("doubles" and early samples are not taken in account) to estimate the nosocomial infections. The incidence rates for 100 hospitalizations at the University hospital of Nancy are 9.2, 8.2 et 8.2 for respectively 1989, 90 et 91. These values are corrected while taking into account a method's sensibility of 65%. The 1000 days of hospitalization's rates allow a better comparison between the medical departments. For the whole hospital, the results are respectively of 7.9, 7.2 and 7.5%. Even if the many bias described cannot always been checked, the method gives some evolutivity indicators which are very useful for the hygienists.