CLINICAL STUDIES ON URINARY TRACT INFECTIONS CAUSED BY SERRATIA MARCESCENS

II. Epidemiological Studies on Onset of Serratia marcescens Urinary Tract Infections in the Urological Ward

Abstract

From January 1975 through December 1981, 109 UTI in-patients were found to harbor S. marcescens at the Department of Urology, Sapporo Medical College Hospital. We performed epidemiological studies by means of O-serotyping and partial biotyping, and bacteriological studies on the environment of the urological ward.
The results are as follows:
1) The largest number of UTI patients with S. macrescens in one year was 35 (12.2%), in 1980. Recently, the number of patients infected at the time of admission has been increasing gradually.
2) Annual changes in the O-serotypes can be seen. Sometimes there was an outbreak of apparent nosocomial infections by strains of the same O-serotype. On the other hand, in 1979 and 1980. there were nosocomial infections thought to be caused strains imported from other wards or hospitals.
3) According to the epidemiological survey, in 1977, 1979 and 1980, there were nosocomial infections due to cross-infections in our ward and indwelling catheters were identified as an important inducer of those infections.
4) From January 1978 to March 1979, we performed a bacteriological study on the environment in the ward, and isolated GNR from 2.4% of the specimens. Three strains of S. marcescens were isolated from the floor of the sickroom and mops, and enviornmental pollution by infected urine was speculated upon as the main cause. Cross-infection via the environment is thus quite possible.
5) Sanitation countermeasures were undertaken based on the above findings. In 1981, these efforts bore fruit: the number of UTI patietts with S. marcescens in our in-patients decreases, with only one patient considered to have acquired the infection in our hospital.