The evidence of annual occurrence of varicella zoster virus (VZV) in temper climate of Czech Republic
Abstract
Study objectives: Varicella is a highly infectious disease, which is, however, preventable and an effective vaccine is available. Samples from a cohort of ambulatory and hospitalized patients (Faculty Hospital Hradec Králové) were analyzed as part of our molecular genetic study of varicella-zoster virus during years 2009 - 2016.
Materials and methods: Altogether, 463 persons with varicella were younger than 18 years and 160 persons (25,7 %) were older. A total of 18 patients (2,9 %) were immunocompromised.
Fifty patients reported the second incidence and 1 patient even third incidence of varicella. Results: Patients reported with varicella during the entire calendar year with two peaks in incidence - in winter (January, February) and late spring (May and June).
This is contrary to the previous reports in literature, which describe this disease being seasonal in the temperate climate countries with a peak during winter months. While chickenpox is typically childhood disease in our country, we also report a detailed analysis of 160 adults.
Genotypic analysis confirmed our previous findings and showed a higher prevalence of the European VZV wild type strains 2 (E2 - 65,6 %) compared to European VZV wild type strains 1 (E1 - 33,7 %). Conclusion: During the past eight years we have analyzed samples from a uniquely large cohort of patients treated on both the inpatient and outpatient bases in the Faculty Hospital Hradec Kralove.
The size of the cohort, presence of patients from varying age groups and the availability of the clinical data, which can be correlated with the laboratory findings, all contribute to the validity of the results and bring additional questions for future studies.