Infectious Diseases Research

[graags12]

Influenza epidemics generally affect elderly persons disproportionately, with the elder population presenting with the highest rates of morbidity and mortality. Another important risk factor is excess hospitalization. Patients with chronic diseases that require hospitalization have greater risk of acquiring influenza. Rates of hospitalization for acute cardiopulmonary events and mortality were higher during the influenza season and the presence of other comorbidities increased the risk of hospitalization and death. Studies assessing the Influenza vaccine demonstrated a decrease in hospitalizations for cardiac disease and cerebrovascular disease among a large cohort of patients 65 years and older compared to members who were not vaccinated. However, influenza vaccine optimization is challenging as the influenza strain rapidly mutates as it moves from continent to continent.

 

Although death rates from influenza are usually disproportionately higher among elderly individuals and infants during influenza epidemics, a shift in the age distribution is seen during pandemics. During the 1918 influenza pandemic, high rates of mortality occurred in young adults between the ages of 20 and 40 years, in addition to affecting the older populations. The 2009 pandemic showed a similar trend, with high rates of morbidity and mortality among children and young adults. 

source:seasonal influenza