[A prospective study of septic episodes due to Staphylococcus aureus and the background of the patients]

From January 1983 to December 1991, 94 cases of Staphylococcus aureus septicemia were identified at Matsue Red Cross Hospital and were evaluated. Methicillin-resistant Staphylococci aureus counted 49%. Seventy two percent of the patients were 60 years or over in age. Intravascular catheters were the most common foci (33%), respiratory infections in 25% and so on. Administration of antibiotics before isolation of Staphylococcus aureus were thought to be the most significant factor in producing the methicillin-resistant septicemia, used in 41% of MSSA and 91.3% of MRSA cases. Especially, the trend of unproper usage of the 3rd generation cephems derivative antibiotics had a major role in producing multi-drug resistant bacteria. No significance was seen in the clinical background, underlying diseases, primary site of infection in between the two groups of methicillin resistant and sensitive cases. Mortality due to septicemia was 47.9% in the MSSA group of patients, while it was much higher in cases of MRSA (73.9%). In conclusion, as the administration of antibiotics even in non-infectious episodes is common in daily clinical activities in some out-patient clinics, the indications should be restricted, in order to prevent the further MRSA infections.