Rapid detection of viruses in biopsy or autopsy specimens by the pseudoreplica method of electron microscopy

A rapid pseudoreplica method of electron microscopy (EM) was used to detect viruses in brain tissues obtained from 57 patients suspected of having herpes simplex encephalitis (HSE). Herpesvirus particles were demonstrated in 18 of the 20 (90%) specimens from which herpes simplex virus was isolated in tissue culture. The procedure takes less than 2 hours, as compared to the time (greater than or equal to 2 days) usually required for virus isolation or standard thin-section electron microscopy. Although the immunofluorescence test has comparable rapidity, it was found to be less sensitive and to yield occasionally false-positive reactions. Our findings indicate that, until a brain biopsy can be replaced by less invasive procedures, examination of brain tissue by the pseudoreplica method offers a rapid diagnosis of a herpesvirus encephalitis. Furthermore, the demonstration of viruses in brain, lung and liver specimens obtained by biopsy or at autopsy suggests that this electron-microscopic method would be advantageous for detecting viruses in tissue samples, particularly in the case of viruses which may not be readily demonstrable by conventional methods.