Detection of herpes simplex and varicella zoster viruses in clinical specimens using direct immunofluorescence and cell culture assays

Patients (33 in tote) with a clinical diagnosis of herpes infections (simpl ex, zoster or chickenpox) were investigated for the presence of herpes simp lex virus (HSV) and varicella tester virus (VZV) in skin samples, using dir ect immunofluorescence and cell culture assays. Five patients with nonherpe tic vesiculobullous disorders were included as negative controls. Of the 33 patients, nineteen (57.6%) were positive for HSV or VN acid fourteen (42.4 %) were negative. Five controls were all negative for HSV or VZV. Of the ni neteen positive patients, HSV was isolated from eight (42.1%) patients, by both direct immunofluorescence and cell culture assays. VZV was isolated fr om eleven (57.9%) patients, eleven (100%) by direct immunofluorescence assa y, and six (54.5%) by cell culture assays. HSV was isolated from one patien t clinically diagnosed as chickenpox (VZV), but otherwise the positive labo ratory results were concordant with the clinical diagnosis. For epidemiolog ical studies, atypical cases and immunocompromised patients the clinical di agnosis should be confirmed in the laboratory.