Abstract

Serosurveillance is an important component of any comprehensive surveillance system for vaccine preventable diseases. Disease notification data are necessary to detect outbreaks and can provide timely epidemiological profiles of a disease. However, the incidence of a disease is often under-estimated by notifications, especially when a proportion of cases are asymptomatic. If this proportion changes with age, or if cases are clinically misdiagnosed, then notification data may present biased information.