Nosocomial infection and antibiotic utilization in geriatric patients: a pilot prospective surveillance program in skilled nursing facilities.

Prospective surveillance of nosocomial infection was conducted at seven skilled proprietary nursing facilities in Orange County, Calif., USA. The average incidence of facility-acquired infection was 5.2 infections/1,000 patient days. The most common source of infection was urinary tract (47%), followed by respiratory tract (26%) and skin (14%). The four most common pathogens isolated were Proteus spp. (20%), Escherichia coli (17%), Staphylococcus aureus (13%) and Pseudomonas spp. (11%). Trimethoprim-sulfamethoxazole (20%) was the most frequently used antibiotic among all prescriptions, followed by ampicillin (16%) and ciprofloxacin (14%). Among all residents surveyed, 33% received at least one course of antibiotics during the study. Of special significance was the fact that 4 (22%) of the 18 strains of Pseudomonas were gentamicin resistant as were 12 of 80 (15%) of the strains of Enterobacteriaceae. Furthermore, 9 of 29 (31%) strains of Pseudomonas tested were found resistant to norfloxacin as were 15 of 129 (12%) strains of enterobacteriaceae. Susceptibility patterns of the isolated pathogens were similar to those of the acute care hospital. This study indicates that infection continues to be a major problem in the skilled nursing facility and that antibiotic-resistant pathogens will be a challenge for the future.