Pathogenicity of Trichomonas vaginalis: cytopathologic and histopathologic changes of the cervical epithelium.

Virulence of 52 Trichomonas vaginalis isolates was estimated by the subcutaneous mouse assay. A positive linear relationship was found between the mean volumes of subcutaneous abscesses caused by the parasites in mice and severity of cervical epithelial abnormalities observed in the patients from whom these strains had been isolated. This relationship implies that virulence of the human urogenital trichomonad, as measured by the mouse assay, may be related to some factors associated with dysplastic changes in the cervical epithelium. No relationships appeared to exist between the results of the mouse assay and inflammation of the vagina and cervix as evaluated clinically or pathologically, although these data were not analyzed statistically; likewise, no relationships were found between the mouse assay and nonprotozoal microorganisms identified in donors of the trichomonad strains.