CXCL8 and infection: The mRNA of IL-4 on the 24th day after infection, IL-8 on the 24th and 40th days, and IL-12p40 on the 40th day were significantly up-regulated; IL-6 mRNA was up-regulated during the test period, while IL-10 mRNA was significantly down-regulated on the 3rd and 31st days after infection.