International Travel and the Spread of Extended-spectrum Beta-lactamase-producing Escherichia Coli

For analyses surrounding the risks for acquisition comparisons between those who acquire ESBLs and those who do not, will be made using Stata version 9.0 (Stata Corp, College Station, TX). Differences in proportions among categorical data will be assessed using Fisher's exact test for pair-wise comparisons. Student T-test or Mann-Whitney U tests will be used for comparing means and medians. For all statistical comparisons a p-value \<0.05 will be deemed to represent statistical significance.