title: Comparison of the sensitivity of a 24 h-shell vial assay, and conventional tube culture, in the isolation of Herpes simplex virus - 1 from corneal scrapings.
abstract: BACKGROUND: Herpes simplex keratitis is a sight threatening ocular infection. A rapid and specific diagnosis is essential for the institution of specific antiviral therapy and to avoid complications that can arise from misdiagnosis and inappropriate treatment. Though a variety of techniques are available, isolation of Herpes simplex virus 1 (HSV-1) in culture provides the most reliable and specific method, and is considered as the gold standard in laboratory diagnosis of herpes simplex keratitis. We report a comparative study of the sensitivity of a 24 h-shell vial assay and conventional tube culture in the isolation of HSV-1 from corneal scrapings. METHODS: A total of 74 corneal scrapings obtained from 74 patients with a clinical suspicion of herpes simplex keratitis submitted for the isolation of HSV-1, were simultaneously inoculated into shell vial and tube cultures employing the vero cell line. Shell vial and tube cultures were terminated at 24 h and fifth day respectively. Isolation of HSV-1 was confirmed employing an indirect immunofluorescence assay. RESULTS: HSV-1 was isolated from 24/74 (32.4%) specimens employing both the methods. Sensitivity of both the techniques were found to be similar (20/24, 83.3%) (P = 1.0). CONCLUSION: A 24 h-shell vial assay is a rapid alternative technique in comparison to the time consuming conventional tube cultures for the isolation of HSV-1, especially from corneal scrapings for the laboratory diagnosis of herpes simplex keratitis.
authors.affiliation: Jhaveri Microbiology Center, Hyderabad Eye Research Foundation, L, V, Prasad Eye Institute, L, V, Prasad Marg, Banjara Hills, Hyderabad - 500 034, A, P, India. sreedhar@lvpeye.stph.net
authors.forename: Sreedharan
authors.initials: S
authors.lastname: Athmanathan
authors.forename: Sesha
authors.initials: S
authors.lastname: Bandlapally
authors.forename: Gullapalli N
authors.initials: GN
authors.lastname: Rao