Diagnosis of herpes simplex virus-1 keratitis using Giemsa stain, immunofluorescence assay, and polymerase chain reaction assay on corneal scrapings

Abstract

Aims: To evaluate three tests used routinely for the diagnosis of herpes simplex virus (HSV) keratitis. Methods: Corneal scrapings from 28 patients with clinically typical dendritic corneal ulcer suggestive of HSV keratitis, and 30 patients with clinically non-viral corneal ulcers, were tested by (i) Giemsa stain for multinucleated giant cells, (ii) immunofluorescence assay (IFA) for HSV-1 antigen, and (iii) polymerase chain reaction (PCR) for HSV-1 DNA, by investigators masked to clinical diagnosis. The control subjects were also investigated by smears and cultures for bacteria, fungus, and Acanthamoeba. Results: The specificity and positive predictive values of all three tests for the diagnosis of HSV keratitis were between 95-100%. The sensitivity of IFA and PCR was 78.6% and 81.2%, respectively, and the difference was not significant; however, their sensitivity and negative predictive value were significantly higher than Giemsa stain. Conclusions: While a combination of IFA and PCR constitute the choice of tests in clinically suspected cases of HSV keratitis, multinucleated giant cells in Giemsa stain can preempt testing by IFA and PCR in otherwise atypical cases of HSV keratitis.

Microbiota Evaluation of Patients With a Boston Type I Keratoprosthesis Treated With Topical 0.5% Moxifloxacin and 5% Povidone–Iodine

“…PCR is a sensitive technique that is able to detect single copies of pathogen DNA in complex mixtures. It has been applied in the diagnosis of many ocular conditions, including viral infections, 24 protozoal keratitis, 25 fungal keratitis, 26 and infectious endophthalmitis. 27 However, in the majority of these studies, the molecular test used broad-spectrum microbial PCR, comparing with culture, and was performed using standard, validated, 16S (bacterial) and 18S (fungal) primer sets.…”

Detecção do vírus herpes simples por reação em cadeia da polimerase em pacientes com ceratite herpética típica ou atípica

“…A sensibilidade da PCR foi de 70% e especificidade de 71,4% e a imunofluorescência apresentou sensibilidade de 80% com valor preditivo negativo de 81,8%. A sensibilidade da PCR, nas ceratites herpéticas epiteliais do tipo dendrítica com infiltrado subepitelial, realizada no estudo de Farhatullah et al (27) foi de 81,2%. Em outro estudo, o resultado da sensibilidade da PCR para detectar a CH epitelial típica foi de 77,0% (28) .…”

Current Concepts in the Management of Herpes Simplex Anterior Segment Eye Disease

“…In view of virus culture having a very low positivity in corneal scraping and the need for a well-equipped virology laboratory, a combination of PCR and IFA tests is optimum to achieve a reliable diagnosis of HSV keratitis, and the presence of MNGCs in routine Giemsa-stained corneal scrapings may provide a useful clue in unsuspected cases [53,54].…”