Laboratory Testing for Oral Herpes

Recommended Laboratory Tests

The European surveillance guidelines recommend Polymerase Chain Reaction (PCR) as the gold standard test with highest sensitivity (11-71% superior to viral culture) and specificity for detecting HSV in oral lesions 1
Viral Culture is a traditional method that can isolate HSV from vesicular or pustular lesions with 90% success rate (though lower for ulcerative or crusting lesions) 1, 2

The optimal sample for oral herpes testing is a swab from vesicular rash or mucous membranes of the oral cavity 2
The best results are obtained when samples are collected from fresh vesicles (90% isolation rate) rather than ulcerative (70%) or crusting lesions (27%) 5
For viral culture, samples should be refrigerated during transport to maintain viability 5
For PCR, less strict transportation conditions are acceptable 2

Viral culture requires specialized cell culture capabilities using cell lines such as MRC-5, Vero cells, baby hamster kidney, or rabbit kidney cells 6
Viral culture results are typically available in 24-72 hours but may take up to 5 days 5
PCR testing has a processing time of approximately 2 hours, significantly faster than viral culture 6
PCR testing has higher detection rates and allows detection and typing in a single reaction tube 6
Quality control is essential, and laboratories should use internal positive controls and negative controls with each DNA extraction and analysis 6

Cytological examinations like Tzanck smears have low sensitivity and specificity and should not be relied upon 1