Experience with multiplex nested PCR and fluorescent antibody tests in the diagnosis of acute central nervous system infections with herpes simplex virus type 1 and 2

The specific diagnosis of herpes simplex virus type 1 and 2 infections has an extreme importance in acute infections of central nervous system due to both availability of specific antiviral therapy and the possible serious consequences of the disease. Aims: Evaluation of the relevance and interpretation of the results of PCR and the specific antibody testing. Methods: Home made multiplex nested herpes simplex virus PCR and immunofluorescent IgM, IgA, IgG antibody tests were carried out in a total of 474 cerebrospinal fluid and 555 serum samples of 396 patients with acute infection of the central nervous system between 1. January, 2003 and 31. December, 2009. Results: The herpes simplex virus etiology was verified in 21% of 396 patients (82 patients, mean 12 cases per year): 26 were diagnosed by both methods (32%), 41 by PCR only (50%), 15 by the detection of intrathecal antibody production only (18%) (p<0.0001). HSV type1 or 2 DNA remained detectable in 35% of the samples drawn after the 30th day of the disease. These patients were all younger than two years of age. Conclusions: 1. PCR increased the ratio of verified herpes simplex virus etiology in acute central nervous infections. 2. Testing the specific antibody response cannot be ceased even in the availability of PCR. 3. Herpes simplex virus type 1 or 2 DNA might persist in central nervous system in spite of the specific antiviral therapy especially in the infants. 4. Herpes simplex virus PCR can be repeated if an early sample is negative or if it is suspected false positive. 5. There is a need for cooperation between clinicians and virologists in the appropriate interpretation of the results and in finding etiology.