FIG. 1.
Course of acute, self-limited WHV infection in adult woodchucks following experimental WHV infection. (A) Woodchuck F3538. (B) Woodchuck F3539. (C) Woodchuck F3524. (D) Woodchuck M3540. (E) Woodchuck F3391. (F) Woodchuck M3553. All woodchucks were infected with 1 × 107 WID50 of the WHV7P1 inoculum at week zero. The kinetics of WHV DNA, free WHsAg, and SDH in serum are presented in the graphs. Bars below the graphs indicate the appearance and duration of CICs, anti-WHc, and free anti-WHs in serum. Serum WHV DNA was quantitated by a real-time PCR-based assay with cutoff values of 1 × 103 WHVge/ml for woodchucks F3524, F3538, and M3540 and 1 × 102 WHVge/ml for woodchucks F3391, F3539, and M3553, as indicated by the dotted line. Free WHsAg was quantitated by electroimmunodiffusion with a detection limit of 2 μg/ml. SDH was quantitated using a Hitachi autoanalyzer. The baseline value for SDH observed in healthy adult WHV-negative woodchucks is 40 IU/liter. CICs were detected qualitatively by PEG precipitation followed by Western blotting. Anti-WHc and anti-WHs were measured qualitatively by ELISA with an assay cutoff value of ≥0.05 ODU. ○, serum WHV DNA (WHVge/ml); ▪, serum WHsAg (μg/ml); •, serum SDH activity (IU/liter).