Widespread, restricted low-level measles virus infection of brain in a case of subacute sclerosing panencephalitis.

In situ reverse transcriptase-polymerase chain reaction amplification with labeled-probe hybridization (in situ RT-PCR/LPH) was used to detect measles virus RNA within formalin-fixed, paraffin-embedded brain tissue sections from a patient who died with subacute sclerosing panencephalitis (SSPE). Many more infected neurons and oligodendrocytes were detected by in situ RT-PCR/LPH than by immunohistochemistry or by in situ hybridization alone. In addition, infection of vascular endothelial cells was demonstrated only by in situ RT-PCR/LPH. The observation that many cells contained only a few copies of viral RNA without detectable antigen is consistent with a persistent viral infection of the central nervous system. In situ RT-PCR/LPH, combining the sensitivity of PCR with the tissue localization of in situ hybridization, should prove useful in further studies to detect nucleic acids in situ in the central nervous system.