Table 2

Occurrence of nasal carriage, mean daily prevalence and carriage states for Staphylococcus aureus outcomes among 22 industrial hog operation workers based on 327 nasal swabs, North Carolina

Carriage states, N (%)
OutcomeEver carriage
N* (%)
Mean daily prevalence (% (range))PersistentIntermittentNon-carrier
S. aureus19 (86.4)65.3 (47.4–72.7)12 (54.5)7 (31.8)3 (13.6)
scn-negative S. aureus16 (72.7)50.6 (36.8–56.8)10 (45.5)6 (27.3)6 (27.3)
scn-positive S. aureus6 (27.3)14.7 (10.5–18.2)2 (9.1)4 (18.2)16 (72.7)
MRSA‡§1 (4.5)4.0 (0.0–4.5)1 (4.5)021 (95.5)
MDRSA§10 (45.5)32.7 (21.1–36.4)6 (27.3)4 (18.2)12 (54.5)
scn-negative MDRSA†9 (40.9)31.6 (21.1–36.4)6 (27.3)3 (13.6)13 (59.1)
scn-positive MDRSA1 (4.5)1.1 (0–2.3) 01 (4.5)21 (95.5)
  • *It was possible for participants to carry both scn-positive and scn-negative S. aureus and MDRSA during the study period; therefore, the sum of these subclassifications may not equal the total number of participants ever colonised by S. aureus and MDRSA.

  • scn-negative isolates were considered to be livestock associated.

  • ‡All MRSA isolates were scn-negative.

  • §MRSA and MDRSA are subsets of S. aureus.

  • MDRSA, multidrug-resistant S. aureus; MRSA, methicillin-resistant S. aureus.