Background: Congenital rubella syndrome, which is associated with severe malformations, can result from infants exposed in utero to maternal rubella infection. Health care workers and school-based educators are targeted for immunization, but evidence is scarce on rubella seronegativity in daycare centre educators who appear to be a high-risk occupational group. The purpose of the study was to generate new evidence on the magnitude of rubella seronegativity and associated risk factors in daycare centre educators.
Methods: Sera and questionnaires were collected between October and December 2001 from 481 female educators working in 81 daycare centres in Montréal, Québec. Rubella IgG serology was performed using ELISA.
Results: An overall seronegativity of 10.2% was found. The positive predictive value of previous rubella vaccination with seropositivity was high (92.1%). Ninety-one percent of the women were of childbearing age (= 49 years). Only 1.3% (n = 6) were currently pregnant, none of whom were seronegative. Significant predictors of seronegativity for educator- and daycare-level variables included lack of previous rubella vaccination (OR = 3.60; 95% CI: 1.43, 9.01), not having own children (OR = 3.76; 95% CI: 1.67, 8.55), age per 5-year increment (OR = 0.81; 95% CI: 0.66, 0.99), and increased number of colds in educators in the daycare centre in the last two weeks (OR = 1.15; 95% CI: 1.01, 1.31).
Interpretation: The high proportion of seronegativity, in addition to the potential increased transmission in daycare centres emphasize the need for a review of the rubella vaccination recommendations and health promotion interventions targeted to this occupational group.