TABLE 4.

Epidemiologic classification and patient characteristics among 823 cases of invasive USA300 MRSA infections with unusuala resistance phenotype statuses, Active Bacterial Core surveillance, 2005 to 2008

Epidemiologic classification (patient characteristic)No. (%) of USA300 isolates with:P2 test)
No unusual resistance (n = 746)Unusual resistance (n = 71)
Health care-associated, community-onset infectionsb353 (47.3)50 (70.4)0.0002
    History of MRSA infection or colonization139 (18.6)28 (36.4)0.0001
    Hospitalization (prior year)314 (42.1)49 (63.6)0.0005
    Surgery (prior year)168 (22.5)28 (36.4)0.0039
    Dialysis (prior year)67 (9.0)9 (11.5)0.4577
    History of residence in a long-term care facility72 (9.7)15 (19.2)0.0088
Community-associated infections278 (37.3)11 (15.5)<0.0001
Hospital-onset infections95 (12.7)10 (14.1)0.3275
Classification undetermined20 (2.7)00.1432
  • a Likely plasmid-mediated resistance to clindamycin, mupirocin, gentamicin, trimethoprim-sulfamethoxazole, and/or doxycycline.

  • b Characteristics are not mutually exclusive.