[IgG antibody level in saliva from rabbits infected with Trichinella spiralis]

Twenty-eight Japanese big ear rabbits were randomly divided into control group and experimental group. Twenty rabbits in experimental group were each infected with 3000 larvae of Trichinella spiralis. Serum and saliva samples were collected at pre-infection and every week after infection, and were examined for IgG antibody by indirect ELISA using T. spiralis muscle larvae excretory-secretory antigen (MLESA). At 1, 2, 3, 4, 5 and 6 weeks afer infection, the positive rate in saliva samples was 10%, 15%, 40%, 65%, 85%, and 95%, respectively; and that of serum samples was 35%, 50%, 80%, 90%, 100%, and 100%, respectively. The positive rate was significantly different between saliva and serum samples at 1, 2 and 3 weeks post-infection (chi2 = 3.58, 5.23, 6.67, P < 0.05), but no significant difference at 4, 5, and 6 weeks post-infection (chi = 0.12, 1.03, 1.03, P > 0.05). The results indicate that the indirect ELISA using MLESA to detect IgG antibody in saliva may be helpful for clinical diagnosis of trichinellosis.