Research suggests that 25% of the MRSA infections in the hospital happen in patients who have been admitted newly to the hospital. The research was published in the latest issue of BMJ online.
The bacterium can infect many sites; one serious form of infection is that in which blood stream infection occurs (bacteremia). A UK national surveillance scheme counts MRSA bacteremia by hospital trust, but it has not yet addressed whether cases of MRSA bacteremia are arriving in hospitals from the community.
Researchers at the University of Oxford analyzed methicillin resistant Staphylococcus aureus (MRSA) and methicillin sensitive Staphylococcus aureus (MSSA) bacteremia in patients on arrival in two Oxfordshire hospitals over a seven-year period (1997 to 2003).
At one hospital, patients admitted from the community accounted for 49% of total MSSA cases and 25% of total MRSA cases. The proportion of methicillin resistance among patients admitted with Staphylococcus aureus bacteremia, rose from 14% in 1997 and 1998 to 26% in 2003.
Most patients (at least 91%) admitted with MRSA bacteremia had previously been in hospital, half had never had MRSA detected before, and 70% were admitted to emergency medical and surgical services. A similar pattern was observed in the other hospital.
Despite some study limitations, the authors conclude that, of the cases of MRSA bacteremia detected in hospital, a quarter occurs in patients who have just arrived from the community, and that this proportion is increasing. These patients tend to be older and have been in hospital before. The researchers had called for additional research to be undertaken into the best way to recognize these patients.