Abstract
Medical staffs who worked on the surgical ward (E3 isolation rate of methicillin-resistant S. aureus (MRSA) among S. aureus was 78%), ICU (69%) and the medical ward (W2, 7.0%) were screened for S. aureus nasal carriage. MRSA carrier was not demonstrated among the staffs of ICU on which isolation rate of MRSA from patients revealed high percentage, and there was no carriage on W2 ward either. On E3 ward a MRSA carriage rate was 12.5%. In the study of the strains which were isolated from the patients between 1989 and 1990 on E3 ward, 98% of MRSA was coagulase type II, and these could be classified into 3 types by enterotoxin (ET) production, ETC producing strains (ET type C, 24%), ETB producing strains (ET type B, 22%) and ET A and C coproducing strains (ET type AC, 52%). The carrier of ET type AC which was prevalent in 1990 on E3 ward was not found, although ET type C and ET type B MRSA carrier existed. Considering these results and the fact that no carrier was found in the ICU staffs, MRSA carriage of medical staffs was not the main cause of nosocomial infection, and cross infection between patients was supposed to be another serious factor.
