CXCL9 and infection: During the 1st week, the concentration of CXCL9 was higher in secondary infections than that in primary infections (710.20 ± 1435.59 versus 238.61 ± 265.29), while CCL17 was lower in secondary infections than that in primary infections (151.09 ± 155.53 versus 303.26 ± 490.43).