Publications of Faculty of Medicine:Comparative Study between Giemsa Stain, Shell Vial Culture and Immunofluorescence in Relation to PCR as a Gold Standard in Diagnosis of Herpetic Keratitis.: Abstract

Herpes Simplex virus type l(HSV 1) keratitis (HSK) is a threatening condition that requires prompt diagnosis and treatment. Diagnosis is usually based on clinical examination, however definitive diagnosis made by staining of corneal scrapings by Giemsa stain, viral culture and antigen detection. The aim of this study was to evaluate the efficacy of Giemsa stain, shell vial culture, and viral Ag detection by immunoflurescence assay (IFA) in diagnosis of HSK, and find an optimum combination of laboratory tests that would help to establish rapid diagnosis of suspected HSK. The study included70 patients clinically diagnosed as cases of HSK. Corneal scrapings were directly stained with Giemsa, and subjected to using shell vial assay followed by IFA and real time PCR for viral DNA detection: The specificity and predictive values of the three methods ranged between (94.7% to 97.4%. The sensitivity of shell vial culture and shell vial culture followed by IFA was 46.9% and 75% respectively; while their negative predictive values were higher than Giemsa stain. It is concluded that combination of shell vial culture and WA may help to improve diagnosis of herpetic keratitis.