—Dr. Kepes's point, in essence, relates to the neuropathologic criteria for the involvement of the brain with a virus. The reason for calling the inclusions lyssa and Negri bodies and the justification for entertaining the possibilities of rabies is presented in the article. These inclusion bodies were PAS positive. However, the usefulness of PAS staining in differentiating the exact viral nature of such inclusions needs immunofluorescent and electron microscopic corroboration. This was not recorded in the only reference available to me in this regard.1
A short survey of the literature indicates that, in many instances, the evidence for diagnosing "rabies" was limited to the presence of Negri bodies with little or no encephalitis in sight.2 Dr. Kepes seems to suggest that the absence of inflammatory response, as in the reported case, is a sufficient ground for excluding the possibility of pathologic involvement of the brain by a virus.