Aim: The aim of this study is to measure the seroprevalence of cytomegalovirus (CMV) infection in 3.5-year-old children, and identify the determinants of seropositivity.
Methods: A total of 1714 children were enrolled at birth. Approximately half were small for gestational age and half were appropriate for gestational age. Information on the children was collected at birth, 1 year and 3.5 years. At 3.5 years blood was collected and tested for CMV-specific immunoglobulin by an enzyme-linked immunosorbent assay in 530 children.
Results: The weighted seroprevalence of CMV was 32.8% (95% confidence interval (CI) 27.4-38.1%). The seroprevalence of CMV varied markedly by ethnicity (European: 26.5% (95% CI 20.9-32.2%); Maori: 68.0% (44.0-92.0%); Pacific: 74.5% (56.3-92.6%); Indian: 50.0% (20.2-79.8%); Chinese: 47.2% (10.8-83.5%); Other: 21.9% (0.0-52.7%); P < 0.001). Socio-economic factors, number of siblings, day care centres attendance, maternal smoking, breastfeeding and other factors examined were not related to CMV seropositivity.
Conclusions: The seroprevalence of CMV in New Zealand pre-school children is similar to that reported from other developed countries. The finding of marked ethnic differences is unexplained by socio-economic factors, or other factors that were examined.