(A) study on the air counts and airborne staphylococci in a general hospital
Staphylocoeei are ubiquitous and historically are known as one of the most important bacteria causing infectious disease in man. Following the introduction of atibiotics into clinical uses, the signification of staphylococcal infections occuring in hospitals and numorous studies have been conducted on this subject.
However, the state of staphylococcal infections may vary from country to country and from hospital to hospital depending upon the changes in biological properties and sensitivity to antibiotics, upon structure and manage system of each hospital and individual's usceptibility to infection and etc.
As a basic preliminary for the investigation of infections in a general hospital, the author carried out a series of experiment 1) to assess the extent of air contamination in hospital by total air counts and by isolation of airborne staphylococci, 2) to identify the staphylococci isolated from air and nasal cavities of hospital staffs and employees and 3) to obtain the antibiograms of coagulase positive staphylococci.
Results are summarized as follows;
1) The average number of air counts was 58 in the ward, 11 in the 3rd floor operating room, 7 in the 2nd floor operating room and 21 in the Basic Science Building per plate in 30 minutes exposure.
2) In ward, the obstetric and Gynecology Department was found to have fewer air counts compared with other department; and the utility room of each department had the highest number.
3) In the ward and operating room the air counts in the afternoon during which time air movement was extensive was 2 to 3 times higher than that in the early morning during which time air movement was minimum.
4) The rate of staphylococci isolation from the air counts was 87.5% in the operating room, 75.1% in the ward, and 48.4% in the Basic Science Building.
5) The ratio of coagulase positive staphylococci was slightly higher in the operating room (67.5%) as compared to the ward (52.5%). The average rate of mannitol fermenters among coagulase positive staphylococci was 59.3%
6) The rate of isolation of coagulase positive staphylococci from nasal cavities of 120 hospital staffs and employees was 33.3%. The carrier rate by vocation was as follows : 40% in nurse's aides and orderlies, 40% in operating room nurses, 35% in general ward nurses and 25% in doctors.
7) Antibiograms of airborne coagulase posotive staphylococci showed high resistance to Tetracycline (76.1%), and Ampicillin (59.0%), Penicillic-G (53.0%), and Cheoramphenicol (57.1%) in a decreased order of resistance. Resistance to Kanamycin was observed in 15.8%
8) The strains of coagulase positive staphylococci isolated from nose of the hospital staffs and emplcyees were also highly resistant to the antibiotics, 1.e.,92.9% resistant to Penicilin G, and Ampicillin, 73.8% to Streptomycin and 71.4% to Tetracycline, Chloramphenicol 21.4% and Kanamycin 11.9%.