Age-specific seroprevalence to varicella-zoster virus: study in Swiss children and analysis of European data.
Up to date epidemiological data provide the rationale for potential varicella immunization strategies in Europe. The scope of this study was: (1) to generate new seroprevalence data by evaluating sera of 970 individuals aged 0-16 years for the presence of IgG against Varicella-zoster virus (VZV); and (2) to review existing seroprevalence data. Of 256 individuals >12 years of age, 96.1% (95% confidence interval [CI], 93.7-98.5) were seropositive. Swiss citizens > 12 years of age were less likely to be seronegative than foreign citizens (2.3 vs. 15.4%; odds ratio, 0.17; CI, 0.05-0.58). The age-specific seroprevalence curve demonstrated a peak at 7 years of age (84.9%; CI, 75.2-94.5) followed by lower rates at 8 and 9 years. A peak at 7-10 years of age was found in all previously reported seroprevalence curves (chi(2)-test for trend of pooled data, P = 0.09; Poisson analysis, P < 0.001). It is concluded that: (1) > 90% of individuals in Europe acquire immunity against VZV before adolescence; (2) there is no evidence for a recent upward shift of the age at primary varicella; and (3) there may be a north-to-south gradient of seroprevalence. The peak at 7-10 years may represent a transient loss of detectable antibody by some individuals.
Aebi
C
C
Department of Pediatrics, University of Bern, CH-3010 Inselspital, 3010, Bern, Switzerland. christoph.aebi@insel.ch
Fischer
K
K
Gorgievski
M
M
Matter
L
L
Mühlemann
K
K
D000293:Adolescent; D000367:Age Factors; D000914:Antibodies, Viral / Q000097:blood*; D002644:Chickenpox / Q000276:immunology*; D019433:Chickenpox Vaccine / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D005060:Europe; D005260:Female; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D007223:Infant; D008297:Male; D016036:Seroepidemiologic Studies; D013557:Switzerland
D000914:Antibodies, Viral; D019433:Chickenpox Vaccine