Genotype of Varicella Zoster Virus Isolated from Korean Elderly Patients with Herpes Zoster

ABSTRACT

BACKGROUND: Herpes zoster develops via reactivation of the latent varicella zoster virus (VZV) in neuronal ganglia as host immunity declines. In Korea, seroprevalence of VZV is very high and population at risk for herpes zoster is increasing. The goal of this study is to evaluate the infection rate of the VZV and the lifetime prevalence of herpes zoster, and to determine the genotype of VZV. MATERIALS AND METHODS: Serum IgG antibody titer was measured in 399 patients. Lifetime prevalence of herpes zoster was evaluated through a survey of 2,054 participants. VZV was isolated by cell culture technique using MRC-5 cells. To determine the genotype of VZV, ORF 22, 38, 54, 62 were amplified by PCR, and after digestion of the PCR products with enzymes pstI, bglI, and smaI, restriction-fragment-length-polymorphism (RFLP) was analysed. The amplified ORF 22 PCR product was sequenced and checked for single nucleotide polymorphisms. RESULTS: The overall seroprevalence of VZV IgG in adults was 93.9% (375/399). The overall lifetime prevalence of herpes zoster was 13.7% (282/2,054). Of the patients with herpes zoster, 17.7% (50/282) of patients experienced postherpetic neuralgia for more than one month. All 22 VZV isolates were of J genotype; 21 (95.4%) isolates were all pstI+ bglI+ smaI-, and 1 (4.5%) isolate was pstI- bglI+ smaI- (pOka) genotype. CONCLUSIONS: The seroprevalece of VZV IgG antibody was 93.9% in adults. The lifetime prevalence of herpes zoster was 13.7%. The genotype of VZV isolated from adults over 60 years old were all of J genotype.