Community strains of methicillin-resistant Staphylococcus aureus as potential cause of healthcare-associated infections, Uruguay, 2002-2004

Abstract

Community-associated MRSA (CA-MRSA) strains have emerged in Uruguay. We reviewed Staphylococcus aureus isolates from a large healthcare facility in Montevideo (center A) and obtained information from 3 additional hospitals on patients infected with CA-MRSA. An infection was defined as healthcare-onset if the culture was obtained >48 hours after hospital admission. At center A, the proportion of S. aureus infections caused by CA-MRSA increased from 4% to 23% over 2 years; the proportion caused by healthcare-associated MRSA (HA-MRSA) decreased from 25% to 5%. Of 182 patients infected with CA-MRSA, 38 (21%) had healthcare-onset infections. Pulsed-field gel electrophoresis determined that 22 (92%) of 24 isolates were USA1100, a community strain. CA-MRSA has emerged in Uruguay and appears to have replaced HA-MRSA strains at 1 healthcare facility. In addition, CA-MRSA appears to cause healthcare-onset infections, a finding that emphasizes the need for infection control measures to prevent transmission within healthcare settings.

Figure 1

Number of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) infections by quarter and year, center A, August 2002–July 2004. N = 1,553.

Figure 2

Proportion of Staphylococcus aureus due to community-associated methicillin-resistant S. aureus (CA-MRSA) infections and healthcare-associated MRSA (HA-MRSA) infections by quarter and year, center A, August 2002–July 2004.

Figure 3

Patient age distribution of A) healthcare-related versus B) community-onset community-associated methicillin-resistant Staphylococcus aureus strain type infections, centers A–D, Uruguay, 2003–2004.