Incidence and recall of influenza in a cohort of Glasgow healthcare workers during the 1993-4 epidemic: results of serum testing and questionnaire

The United States Centers for Disease Control and Prevention advocate annual influenza immunisation for all healthcare workers in contact with vulnerable patients.1 The health departments in the United Kingdom, however, advise immunising only people with risk factors.2 Little evidence exists to support or refute a policy of immunisation for such healthcare workers, and, although influenza outbreaks have been documented, epidemiological data concerning influenza in healthcare workers are lacking. We aimed principally to determine the incidence of influenza in a cohort of healthcare workers. As prevention of cross infection is one of the main arguments in favour of immunisation of healthcare workers, we also estimated the proportion of asymptomatic infection by linking recall of illness with serological results. The study population consisted of all 970 healthcare workers at four acute hospitals in Glasgow who had serum stored for a routine post-vaccination test for antibody to hepatitis B between 1 February and 26 …