Table 1.

Direct methods for HSV diagnosis

Method	Tissue sampled	Sensitivity	Specificity	Advantages	Disadvantages
Virus isolation by cell culture1	Skin/mucosal lesions (stage):				Specialized laboratories
	- vesicular content	>90%		Gold standard	Virus transport medium
	- ulcers	95%	~100%	Simplicity of sampling	Transport rapid, cooled, protected from light
	- scabs	70%		Virus typing	Results in 2/7 days
	- mucosa without lesions	30%		Resistance phenotype determination	Not suitable for CFS
		Unknown			Arrangement with laboratory necessary
	Biopsies
	Conjunctival smear/corneal
	Neonates
Cytologic diagnosis (Tzanck's smear)35	Skin/mucosal lesions	73–100%	100%	Easy, quick, reproducible and inexpensive	Optimal lesions are fresh, intact bisters of 1/3 days' duration
	Biopsies
	Conjunctival smear/corneal
IF (detection of infected cells)30	Smears, tissue sections, smears from base of vesicle	41–70%	>95%	Rapid (<4 h possible) Typing possible	Fresh vesicles
					Specialised laboratories
					Technically demanding
					Not standardized
Virus antigen detection by EIA o ELISA30	Smears from lesions, vesicular content with base of vesicle	41–80%	80%	Simplicity of sampling	Suitable only for fresh vesicles
				Does not require the integrity of the specimen
				Rapid (<4 h possible)
				Typing possible
				PCR:
				Most sensitive method
Virus DNA detection by PCR30 or Real-time PCR31	CSF	9798%	~100%	Result within 24–48 h	Only in specialised laboratories
	Aqueous or vitreous humour			Virus typing and resistance genotyping	Not standardised
				Method of choice for CSF	Not validated for all samples
					Risk of contamination (PCR)
				Real-time PCR:	High costs (real-time PCR)
	Skin lesions, vesicular content or mucosa without lesions			Rapid amplification
				Quantitative analysis
				Reduced risk of contamination
				Method of choice for skin lesions