Published online by Cambridge University Press: 15 May 2009
The twenty-four young women and one man treated in an ultra-clean isolation ward should have had a low incidence of staphylococcal infection on grounds of age, sex and clean environment alone. However, they apparently acquired new strains of Staph. aureus at the rate of 4·7/100 patient weeks (3·9 multiple resistant strains/100 patient weeks) from the sixth week after admission onwards.
Environmental factors contributing to infection included introduction of resistant strains by the patients on admission, contact between patients in the unit, and failure to eliminate nasal carriage in staff and patients.
Host susceptibility was increased by malignancy, and by antibiotic and cytotoxic therapy. The nasal carriage rate of Staph. aureus was significantly greater for patients with repeated episodes of leucopenia induced by cytotoxic drugs.