[Elimination of mouse hepatitis virus infection in human malignant tumors transplanted into athymic (nude) mice (author's transl)].

Mouse hepatitis virus (MHV) infection occurred in athymic (nude) mice transplanted with human malignant tumors and 28 out of 38 tumor lines were contaminated with MHV. These 28 tumor lines were passaged in pathogen-free nude mice and 15 of these tumor lines (53.6%) became MHV-free. The MHV infection was eliminated in more than half of the tumor lines by passaging.