Fig 1.
Carriagea of MRSA, MSSA and S. aureusb in household members of pig farmers (a) and mean cross-sectional nasal MRSA, MSSA and S. aureusb prevalences per sampling moment (b).
a A persistent carrier was a person with all nasal cultures positive, non-carriers had no positive cultures, intermittent carriers were the remaining persons. b Since MRSA and MSSA could co-exist in one sample, and S. aureus carriage could be a combination of MRSA and/or MSSA, the numbers do not add up. For example, a person carried MRSA on four out of six sampling moments, and MSSA on the remaining two sampling moments. This person was an intermittent MRSA carrier, an intermittent MSSA carrier, but a persistent S. aureus carrier.
Fig 2.
Linear regression model and 95% confidence bands between log-transformed colony forming units of methicillin-resistant Staphylococcus aureus in nasal (A) and oropharyngeal (B) swabs from start of study (x-axis) and persistence of MRSA nasal carriage during one year (y-axis) in household members who were MRSA-positive at start of the study.
Prevalence ratio (PR) per log CFU = 1.23, 95% confidence interval 0.95–1.60, p = 0.11 for nasal samples. PR = 0.78, 95% CI 0.33–1.88, p = 0.58 for oropharyngeal samples.
Table 1.
Determinants of MRSA nasal carriage in household members of pig farmers after multivariate analysis.
Table 2.
Effect of exclusive MSSA nasal carriage on MRSA carriage in the next sampling moment.
Table 3.
Environmental samples positive for MRSA.