Abstract: Ninety nine cases among 1 195 aged hospitalized patients suffered form nosocomial in-fection(8.3%)with 7% mortality rates.The principal sites of infection were lower respira-tory tract,(54.1%),urinary tract(17.2%)and gastrointestimal tract(16.5%).235 rods were isolated.The most common species was the G(-)bacilli,Klebsiella,Pseudomonas and Enterobac.Accounting for 73.6% of all the rods.Many G(-)rods were resistant to com-monly used antibiotics.The aged patients were particularly susceptible to infection because of deficiency in their immunologic function,the occurrence of more than one underlying di-seases,administration of antibiotics,and relative long hospitalization etc.Nosocomial infec-tion in elderly is often attributable to members of the endogenous human microflora that happen to be the particularly resistant to antibiotics and presenting difficult management problems.Policies to control hospital infection in aged patients may consist of improvement of hygienie condition in hospital,strict sterization and disinfection,treating underlying dis-eases,improving patient's immune status whenever possible,and selecting appropriate antibi-otics.

Key words: aged patients, nosocomial infection, preventive measures