Two-centre study comparing DNA preparation and PCR amplification protocols for herpes simplex virus detection in cerebrospinal fluids of patients with suspected herpes simplex encephalitis.

In a two-centre study, the routine DNA preparation and PCR amplification protocols were compared for herpes simplex virus (HSV) detection in cerebrospinal fluids (CSFs) of 43 patients with suspected herpes simplex encephalitis (HSE). The combined clinical, radiological and laboratory results indicated HSE in 6/43 (14%) patients. Discrepant PCR results between the two centres were obtained in 8 (18%) cases consisting of 5 false-positive and 3 false-negative results. Seven out of 8 (88%) discrepant results were associated with the method of CSF preparation using protease K digestion followed by heat inactivation. In contrast, CSF digestion with proteinase K followed by DNA purification on silica spin columns was better yielding discrepant PCR results in only 1 of 78 analyses (1.3%). The results point to the need for standardization and inter-laboratory quality control for routine clinical work.