Replication of clinical measles virus strains in hispid cotton rats

An alternative model to nonhuman primates to study measles virus (MV) patho genesis, to evaluate potential MV vaccines, or to screen for potential anti virals effective against this virus is highly desirable. The laboratory-ada pted Edmonston strain of MV has been reported to replicate in the lungs of hispid cotton rats following intranasal inoculation, immunosuppress infecte d animals, and disseminate widely from the lungs, making these animals a ca ndidate model. However, clinical MV strains have generally not been found t o grow in these animals, limiting the utility and acceptance of this model. In the present studies we demonstrate reproducible replication of several clinical MV strains in hispid cotton rats. As with the Edmonston strain, le ukocytes appear to be the primary target cells of these viruses following i ntranasal inoculation, and extrapulmonary dissemination is common. It is al so demonstrated that prior MV infection or immunization of test animals wit h MV vaccine prevents pulmonary tract infection. These findings should make the MV-cotton rat model more acceptable.