Encephalitis in Newborn Hamsters after Intracerebral Injection of Attenuated Human Measles Virus

Abstract

ACUTE encephalitis following measles infection in humans usually develops within a few days of the exanthema and can be fatal within 24 h. The presence of intracerebral infective measles virus in one such fatal human case may have been demonstrated by Shaffer et al.¹ who inoculated a brain emulsion into two macaques and noted development of clinical measles. Animals also develop acute measles encephalitis. Suckling mice, rats and hamsters of varying ages have shown acute symptoms after intracerebral inoculation of neurotropic strains of measles virus^2–4. The mouse model has been carefully studied⁵ using a mouse-adapted strain of measles virus and monitoring the virus by infectious assays and electron microscopy. The onset of symptons of encephalitis corresponded both to the development of a minimal level of infective virus within the brain and to the presence of observable nucleocapsids within the dying cell. The experimental study described here was undertaken to determine the effect of attenuated measles virus in newborn hamsters after intracerebral inoculation.