MX1 and bacterial urinary tract infection: Blood MxA levels were higher in virus-positive children with respiratory symptoms (median, 778 [interquartile range, 535–2538] μg/L) compared to either virus-negative (155 [94–301] μg/L, P < 0.001) or virus-positive (171 [112–331] μg/L, P = 0.006) children without respiratory symptoms at presentation with febrile UTI.