Viremia and serum antibodies in Syrian hamster after inapparent infection with European tick-borne encephalitis virus.

1.) Adult Syrian hamsters (Cricetus auratus) are relatively insusceptible to the lethal affect of the ETBE virus after peripheral inoculation. After subcutaneous infection with 10(3) i. cer. mouse LD50 of the virus they manifest 25 per cent mortality. 2) In subcutaneously infected hamsters the virus is demonstrable in the CNS of only 20 per cent of the animals. CF- and VN-antibodies can be found in the blood from the 10th day; CF--antibodies culminate on the 20th-30th day receding relatively quickly, whereas VN-antibodies peak after the 28th day, dropping only partly and persisting. 3) The dynamics of CF- and VN-antibodies and a high number of clinically inapparent hamster infections resemble the situation in humans infected with ETBE under natural conditions.