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The 1918 Influenza A Pandemic
Published in Patricia G. Melloy, Viruses and Society, 2023
The influenza virus is transmitted from person to person through respiratory droplets dispersed with sneezing or coughing by the infected individual. Symptoms of influenza can vary, but classic symptoms include headache, chills, fever, pain, sneezing, runny nose, and “nonproductive” cough, among others. However, not everyone with influenza viral infection will show these symptoms (Couch 1996; Krammer et al. 2018). The symptoms last from one to five days before the body can fight off the infection. Full recovery from influenza may take weeks even without major complications, resulting in reduced productivity in school for children and work for adults (Krammer et al. 2018).
Immunization
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Michael F. Para, Susan L. Koletar, Carter L. Diggs
Timing of vaccination in relation to anticipated exposure is important in disease control by immunization. To have optimal efficacy, vaccines must be administered far enough in advance of potential exposure to permit immunity to be induced. In general, it takes one to three weeks for full development of the immune response following vaccination. Further, the induced immunity and resulting protection may wane with the passage of time, requiring the administration of “booster” immunizations to maintain adequate protection. Knowledge of epidemiologic factors is thus crucial in deciding appropriate timing of vaccine administration. Immunization against influenza is most efficacious if the vaccine is administered in late autumn or early winter just prior to the influenza “season.” Similarly, the schedule for routine childhood immunizations against measles, diphtheria, whooping cough and scarlet fever for example is based on the prevalence of those diseases in childhood. Immunization is usually done before enrollment in school where concentration of children in classrooms favors infection.
A brief history of pandemics
Published in Edward M. Rafalski, Ross M. Mullner, Healthcare Analytics, 2022
History’s second most deadly pandemic after the Black Death was caused by an avian influenza virus that emerged in 1918 and spread around the globe, carried initially on troop ships engaged in World War I [6]. Influenza viruses also caused the pandemics of 1889, 1957, 1968, 2009, and likely others in history prior to the discovery of viruses. Influenza is spread by respiratory droplets (Table 2.1), but depending on the host and environmental conditions, it can also spread via aerosol or fomites. Smallpox, caused by the variola virus, is spread in a similar manner and has been causing epidemics since prehistoric times. In modern history, smallpox caused many regional epidemics at the level of a city or country. One example was the introduction into the island nation of Japan in 735; smallpox spread rapidly and is estimated to have killed up to one-third of the population [7]. Recurrences were common until 1206, occurring 5–32 years apart. Smallpox was also the centerpiece of what is known in history as the “Columbian Exchange” where the ships of Spanish explorers including Columbus carried syphilis from Central America back to Europe in 1494 and seeded smallpox and other diseases in Mexico in 1520 [8]. Syphilis spread rapidly through Europe following invasions during the Italian Wars, killing an estimated 50,000 persons [1]. Smallpox is thought to have killed half the population of Mexico City in the first year after introduction, and it may have wiped out as much as 95% of the indigenous populations of South and Central America in subsequent decades.
Effectiveness of on-site influenza vaccination strategy in Italian healthcare workers: a systematic review and statistical analysis
Published in Expert Review of Vaccines, 2023
Francesco Paolo Bianchi, Pasquale Stefanizzi, Eustachio Cuscianna, Antonio Di Lorenzo, Andrea Martinelli, Silvio Tafuri
Vaccination is an effective measure of individual and collective protection from disease and is especially important for healthcare workers (HCWs). It protects both HCWs from occupational infectious diseases and patients from the risk of infection in the nosocomial environment. High vaccination coverage (VC) among HCWs also prevents absenteeism and guarantees the quality of health care services offered [1]. Among the recommended vaccinations, the influenza vaccine should be administered once a year, shortly before the flu season. In fact, HCWs are constantly in contact with a number of people (family members, other HCWs, patients, ward visitors) and are at a greater risk of exposure to influenza viruses than the general population; moreover, if infected (ill o incubating) they are potential contagion spreaders [2].
Efficacy and safety of baloxavir marboxil versus neuraminidase inhibitors in the treatment of influenza virus infection in high-risk and uncomplicated patients – a Bayesian network meta-analysis
Published in Current Medical Research and Opinion, 2021
Vanessa Taieb, Hidetoshi Ikeoka, Piotr Wojciechowski, Katarzyna Jablonska, Samuel Aballea, Mark Hill, Nobuo Hirotsu
Influenza is an acute viral infection of the respiratory tract, which occurs seasonally. It is a frequent cause of mild to severe illness, but it can also lead to death. The symptoms of influenza are often similar to those caused by other respiratory viruses circulating in temperate climates, including some or all of the following: fever or feeling feverish/chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue (tiredness)1. Therefore, epidemiologists often use the term “influenza-like illness” (ILI) to refer to them2. The World Health Organization (WHO) defines ILI as an acute respiratory infection with a measured fever of ≥38 °C and cough; with an onset within the last 10 days3; however, other definitions are also used in the literature.
Cost-effectiveness of the cell-based quadrivalent versus the standard egg-based quadrivalent influenza vaccine in Germany
Published in Journal of Medical Economics, 2021
Rui Cai, Laetitia Gerlier, Martin Eichner, Markus Schwehm, Sankarasubramanian Rajaram, Joaquin Mould-Quevedo, Mark Lamotte
There are two main types of influenza viruses that commonly cause seasonal influenza: Types A and B. Influenza A viruses are further classified into subtypes H1N1 and H3N2. Influenza B viruses are broken down into lineages B/Yamagata and B/Victoria1. The most common symptoms of influenza are chills, fever, sore throat, muscle pains, headache (often severe), coughing, weakness/fatigue, and general discomfort1. Annually, an estimated three to five million influenza-related hospitalizations and about 250,000–500,000 influenza-related deaths are reported globally1. In Germany, 3.8 million general practitioner (GP) visits and 18,000 hospitalizations were reported in the 2018–2019 season due to influenza2. Influenza can occasionally lead to pneumonia, and several rare but severe complications such as myocarditis, myocardial infarction, stroke, and gastrointestinal bleeding3. All age groups can be affected by influenza; however, elderly people (>65 years of age), young children (<2 years of age), and patients with comorbidities such as chronic lung, heart, and renal diseases, and immunodeficiency are more prone to develop complications and are considered as high risk groups4. In Germany, quadrivalent influenza vaccine (QIV) is recommended for all people aged ≥60 years and for high risk groups5.