STREAM 3: MINIMIZING IMPACT

Overview

Influenza is a highly contagious respiratory disease thought to spread by droplet, contact and airborne routes. Respiratory droplets are currently thought to be the main mode of transmission. There is also some suggestion that influenza may spread through airborne aerosols that are expelled through coughing or sneezing or aerosol generating procedures such as bronchoscopy or intubation. The disease, characteristically a febrile illness with respiratory symptoms, ranges in severity from mild to debilitating and can lead to lethal primary fulminant pneumonia, particularly in persons with underlying pulmonary or cardiopulmonary pathologies. Adults are most infectious from 1 day before symptom onset up to 5 and even 7 days afterwards. Rates of infections are highest among young children who shed virus longer and are a potential source of infection for older age cohorts . Rates of serious illness, complications and death are highest in persons aged 65 years and older, and in persons with chronic cardiac or respiratory conditions. Hospitalizations are common in young children. The great majority of influenza-related deaths can be attributed to secondary bacterial pneumonia caused by common respiratory pathogens such as pneumococci, group A streptococci and staphylococci .