Community-acquired methicillin-resistant Staphylococcus aureus, Finland.
Methicillin-resistant Staphylococcus aureus (MRSA) is no longer only hospital acquired. MRSA is defined as community acquired if the MRSA-positive specimen was obtained outside hospital settings or within 2 days of hospital admission, and if it was from a person who had not been hospitalized within 2 years before the date of MRSA isolation. To estimate the proportion of community-acquired MRSA, we analyzed previous hospitalizations for all MRSA-positive persons in Finland from 1997 to 1999 by using data from the National Hospital Discharge Register. Of 526 MRSA-positive persons, 21% had community-acquired MRSA. Three MRSA strains identified by phage typing, pulsed-field gel electrophoresis, and ribotyping were associated with community acquisition. None of the strains were multiresistant, and all showed an mec hypervariable region hybridization pattern A (HVR type A). None of the epidemic multiresistant hospital strains were prevalent in nonhospitalized persons. Our population-based data suggest that community-acquired MRSA may also arise de novo, through horizontal acquisition of the mecA gene.
Salmenlinna
Saara
S
Department of Microbiology, National Public Health Institute, Helsinki, Finland. saara.salmenlinna@ktl.fi
Lyytikäinen
Outi
O
Vuopio-Varkila
Jaana
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001434:Bacteriophage Typing; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000635:transmission; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D018562:Disease Transmission, Infectious; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D012189:Retrospective Studies; D021521:Ribotyping; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000635:transmission; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics
D004269:DNA, Bacterial