Features of Patients with Influenza Virus Infection Examined in the Emergency Department of a University Hospital in North-western Japan

We aimed to determine if there were any changes in the clinical features of patients infected with influenza during an influenza epidemic in north-western Japan. We retrospectively obtained data on influenza-infected patients from an electronic database set up in the emergency department. Patients were examined in the Department of Emergency Medicine, Kanazawa Medical University in 2001, 2002 or 2003. The information collected included age, sex, time of visiting the emergency department, visiting method, grade of emergency, where they were when their symptoms started to develop, influenza-related complication(s) and outcome. The retrospective data collected for the 3 years analysed (2001-2003) were similar despite the influenza epidemic in the winter of 2002/2003. These results allow us to estimate the influenza-related total medical costs and total work burden for staff in the emergency department of a university hospital during any future influenza epidemics.