Evidence of the non-infectivity of herpes simplex viral particles in Trichomonas vaginalis.

Fan et al., employing an indirect immunofluorescent antibody (IFA) technique, reported the presence of herpes simplex virus type 2 (HSV-2) in Trichomonas vaginalis. However, using the same method, we found that the protozoa showed autofluorescence immediately after acetone fixation. In order to demonstrate the non-infectivity of HSV-2 in T. vaginalis, several other methods were performed in this study. Trichomonads were experimentally incubated together with HSV-2 and examined after immunofluorescent staining procedures. Organisms without any contact with HSV-2 were used as control. Results obtained from both vital stained and methanol-fixed organisms failed to show any fluorescence. Data from DNA fluorochrome staining, immunoblot, electron microscopy and viral titer assay were in accordance with the results of the IFA method. No obvious difference between the freshly isolated and the long term-cultured organisms could be detected by these methods. All strains of T. vaginalis investigated by this study failed to show the presence of intracellular HSV-2.