Outbreak of Methicillin-resistant Staphylococcus aureus in a Hospital Center for Children's and Women's Health in a Swedish County.

The objective of this study was to investigate a sudden increase in methicillin-resistant Staphylococcus aureus (MRSA) cases primarily in one maternity ward at the Center for Children's and Women's Health at Linkoping University Hospital, Sweden. Approximately 300 individuals including patients, their family members, and healthcare workers were screened for MRSA. The antibiotic susceptibility was tested and isolates polymerase chain reaction (PCR)-positive for the mecA gene were spa typed. Isolates with the same antibiogram and spa type were further whole genome sequenced. Compliance to current cleaning and hygiene routines was also controlled, and environmental samples collected. The results showed that a total of 13 individuals were involved in the outbreak. It was caused by a t386 MRSA strain (ST-1, NCBI-accession AB505628) with additional resistance to erythromycin and clindamycin. All cases were epidemiologically connected to the index patient, who had recently emigrated from a high-endemic area for MRSA. With improved cleaning and better compliance to basic hygiene routines, no further cases were reported. This study demonstrates how rapid an MRSA strain can disseminate in a ward with susceptible patients and insufficient cleaning and hygiene. For a better control of MRSA, clinical cultures and screening samples need to be obtained early and more extensively than according to the current recommendations.