RESUMEN
INTRODUCTION: The objective was to alert Danish hospital physicians to the risk of nosocomial spread of penicillin-resistant Streptococcus pneumoniae (PRP). MATERIALS AND METHODS: The study was conducted in the County of Northern Jutland during the 3-year period 1996-1998. Data on isolates of PRP were retrieved retrospectively from a computerised laboratory information system, and additional information was obtained from patients' charts and notes by infection control nurses. RESULTS: Four incidents of likely nosocomial spread of PRP, serotype 9V, were identified in departments of medicine or pulmonary diseases. Clusters included two to four patients. The eleven patients were 53 to 92 years of age, and all but one had severe underlying pulmonary disease or a malignant disorder. During the same period, we found that among pneumococcal bacteraemias of definite origin 8.9% (95% confidence limits 5.9-12.9%) was nosocomial. CONCLUSION: The risk of nosocomial spread of pneumococci, including PRP, should be acknowledged. A policy of isolation should be implemented for patients with PRP; isolation precautions should also be considered for patients with a previous isolate of PRP if readmitted, as such patients may become chronic carriers.