Many healthcare workers in hospital EDs are colonized with methicillin-resistant Staphylococcus aureus (MRSA), two studies have found. Although colonization is often transient, it's an important mechanism for transmitting MRSA from patient to patient, researchers say.

In one study, researchers collected nasal swabs from 105 ED staff members. Sixteen (15%) tested positive for MRSA: 12 nurses, 2 physicians, and 2 technicians. Researchers say this rate of MRSA colonization is similar to rates seen in other studies of non-ED healthcare workers, but the rate is much higher than in the general population.

In the second study, researchers measured the prevalence of S. aureus and MRSA in 255 ED staff members. Of those, 32% were positive for S. aureus and MRSA colonization was 4%. Colonization was limited to nurses, nursing assistants, and radiology and respiratory technicians.

The relationship between nasal colonization of healthcare workers and transmission to patients is uncertain. Researchers say they now need to determine if members of the ED staff who tested positive represent transient or persistent colonization. Then they want to determine the rate of unprotected contacts between ED staff and patients.

Sources: Bisaga A, Paquette K, Sabatini L, Lovell EO. A prevalence study of methicillin-resistant Staphylococcus aureus colonization in emergency department health care workers. Ann Emerg Med. 2008;52(5):525-528;

Suffoletto BP, Cannon EH, Ilkhanipour K, Yealy DM. Prevalence of Staphylococcus aureus nasal colonization in emergency department personnel. Ann Emerg Med. 2008;52(5):529-533; Jernigan JA. Methicillin-resistant Staphylococcus aureus colonization among health care personnel in the emergency department: what does it tell us? Ann Emerg Med. 2008;52(5):534-536.