Clinical and socioeconomic impact of seasonal and pandemic influenza in adults and the elderly

Abstract

Influenza epidemics and pandemics carry a heavy socioeconomic burden. Hospitalization and treatment are more often necessary in high-risk patients, such as the elderly. However, the impact of influenza is not negligible even in adults, mainly because of lost productivity. The World Health Organization estimates that seasonal influenza causes 250,000-500,000 deaths worldwide each year; however, mortality may be very high in pandemic periods. Many estimates of the costs of seasonal influenza have been made in various socioeconomic contexts. For instance, among the adult population in Italy, a cost of €940.39 per case has been estimated. In the US, the average annual influenza burden in 18-49-y-old adults without underlying medical conditions is judged to include approximately 32,000 hospitalizations and 680 deaths. Estimating the influenza burden is a useful aid to determining the best influenza vaccination strategy and preventive and clinical treatments.

Epidemiology, ecology and gene pool of influenza A virus in Egypt: Will Egypt be the epicentre of the next influenza pandemic?

“…130 In the case of pandemics fatalities are estimated to be several millions of people. In the last century, 4 pandemics were documented: H1N1 in 1918, H2N2 in 1957, H3N2 in 1968 and H1N1 in 1977.…”

Costs associated with influenza-related hospitalization in the elderly

“…Thus, although morbidity is usually low in the elderly, influenza may occasionally have a severe and complicated clinical course. 10 A study in the elderly by Mullooly et al found an influenza-associated hospitalization rate of 560 per 100,000 persons in subjects with underlying medical conditions: the rate in healthy persons aged 65 y was one third lower. 11 Data from the Spanish Influenza Sentinel Surveillance System (SISS) show cumulative incidence rates in people aged 65 y were the lowest of all age groups in the community setting, but that hospitalization rates for severe laboratory-confirmed influenza (SLCI) were the highest, accounting for 59% of all SLCI cases hospitalized and 75% of deaths during 2 influenza seasons (2013-2014 and 2014-2015).…”

A dose-ranging study of MF59®-adjuvanted and non-adjuvanted A/H1N1 pandemic influenza vaccine in young to middle-aged and older adult populations to assess safety, immunogenicity, and antibody persistence one year after vaccination

“…7 Among healthy adults, influenza disease is responsible for high rates of outpatient hospital visits, work absenteeism, and general loss of productivity. 6,8 Higher hospitalization rates were recorded among older adults during the 2009 pandemic compared with previous influenza seasons, and the highest fatality rates among hospitalized patients were observed in those over 50 y of age. 9 Mass vaccination is currently the most effective and economic method of inhibiting viral transmission during the early stages of a pandemic, resulting in much reduced levels of disease and socioeconomic disruption.…”

“…[3][4][5] Influenza epidemics and pandemics result in substantial socioeconomic damage. 6 Mortality and morbidity rates are highest among vulnerable populations such as the elderly, who are especially likely to develop influenza-related complications. 7 Among healthy adults, influenza disease is responsible for high rates of outpatient hospital visits, work absenteeism, and general loss of productivity.…”