Varicella susceptibility and transmission dynamics in Slovenia
1 Centre for Communicable Diseases, National Institute of Public Health of Republic of Slovenia, Trubarjeva 2, 1000 Ljubljana, Slovenia
2 Laboratory for virology, Centre for Communicable Diseases, National Institute of Public Health of Republic of Slovenia, Bohoričeva 15, 1000 Ljubljana, Slovenia
3 Rho Sigma Research & Statistics, Topniška 45, 1000 Ljubljana, Slovenia
BMC Public Health 2010, 10:360 doi:10.1186/1471-2458-10-360Published: 23 June 2010
A cross-sectional, age-stratified study was conducted to determine varicella-zoster seroprevalence and force of infection in Slovenia.
3689 serum samples were tested for VZV IgG antibodies with an enzyme immunoassay. Semiparametric and parametric modelling were used to estimate the force of infection.
Overall, 85.6% of serum samples were seropositive. Age-specific prevalence rose rapidly in preschool children and over 90% of 8 years old tested positive for VZV. However, 2.8% of serum samples among women of childbearing age were seronegative. Semiparametric modelling yielded force of infection estimates of 0.182 (95% CI 0.158-0.206), 0.367 (95% CI 0.285-0.448) and 0.008 (95% CI 0.0-0.032) for age groups 0.5- < 6, 6-11 and ≥12 years, respectively, and 0.175 (95% CI 0.147-0.202), 0.391 (95% CI 0.303-0.480) and 0.025 (95% CI 0.003-0.046) for age groups 0.5- < 5, 5-9 and ≥10 years, respectively.
Regardless of the age grouping used, the highest transmission occurred in children in their first years of school.