Diagnosis of herpes simplex virus-1 keratitis: comparison of Giemsa stain, immunofluorescence assay and polymerase chain reaction.
OBJECTIVE
To evaluate three different diagnostic tests against the gold standard of viral isolation, in the diagnosis of HSV-1 keratitis.


METHODS
Corneal scrapings from 170 patients with clinically suspected HSV keratitis were tested by; 1) Giemsa staining procedure for the presence of multinucleated giant cells and lymphocytes, 2) immunofluorescence assay for HSV-1 antigen, 3) polymerase chain reaction (PCR) for HSV-1 DNA and 4) virus isolation by shell vial culture in SIRC (Rabbit corneal epithelial cell line). The results of the former three tests were compared among 14 cases that were culture positive and 156 cases that were culture negative for HSV-1.


RESULTS
The sensitivity of PCR was 100%, while IFA and Giemsa had sensitivities of 85.7% and 57.1% respectively. The specificity of PCR, IFA and Giemsa were found to be 67.9%, 85.3% and 85.9% respectively.


CONCLUSIONS
In the present study, a combination of PCR and immunofluorescence assay appears to be the most suitable choice of tests for diagnosis of HSV-1 keratitis, while detection of MNGC by Giemsa staining procedure may give us a presumptive diagnosis of suspected viral infection.
Subhan
Shaheen
S
Jhaveri Microbiology Center, Prof. Brien Holden Eye Research Center, Hyderabad Eye Research Foundation, L.V. Prasad Eye Institute, L.V. Prasad Marg, Banjara Hills, Hyderabad 500-034, India.
Jose
Roby James
RJ
Duggirala
Aparna
A
Hari
R
R
Krishna
Pravin
P
Reddy
Sesha
S
Sharma
Savitri
S
D001399:Azure Stains; D004396:Coloring Agents; D005455:Fluorescent Antibody Technique / Q000592:standards*; D018259:Herpesvirus 1, Human; D006801:Humans; D016849:Keratitis, Herpetic / Q000175:diagnosis*; D016133:Polymerase Chain Reaction / Q000592:standards*; D012680:Sensitivity and Specificity
D001399:Azure Stains; D004396:Coloring Agents