TBP and infection: In contrast, infection history was significantly different in TBP (Pearson chi-square = 4.47, p = 0.04, positivity rate in the arriving period was 33.3% and in the wintering period was 55.7%), but not in MBP (Pearson chi-square = 0.08, p = 0.77, infection history in the arriving period was 85.4% and in the wintering period was 81.8%) (Table 3).