There are four main types of flu viruses with multiple. Some people, such as older adults, young children, and people with certain health conditions, are at higher risk for flu complications. The season occurs during the cold half of the year in each hemisphere. More information about clinical risk groups and vaccination can be found in the influenza green book chapter 19 and nice national institute for health and care excellence guidance. Vaccines for the prevention of seasonal influenza in patients. In the northern hemisphere, cases of influenza occur in greater numbers during the winter months, usually peaking from december to march, with a 5% to 20% attack rate in the general population. Note the flu information page below can be slow to load, please be patient, it is loading the latest information. For seasonal influenza, mortality is usually well below 0. Influenza type a causes moderate to severe illness and affects all age groups. Influenza a occurs more frequently and is more virulent. Although there is not universal consensus regarding where the virus originated, it spread worldwide during 19181919. Influenza medicago announces positive results in animal trials for its vaccine candidate against covid19. Influenza types a and b are responsible for most cases of clinical illness in.
Immunisation against infectious disease the green book, 2014. Influenza is an acute respiratory illness caused by rna viruses of the family orthomyxoviridae influenza viruses. It is totally different from avian influenza and influenza pandemic. Overall influenza associated mortality has been estimated to. Impact of influenza vaccination on seasonal mortality in. Abstract this article follows up on two older articles by rga associates. The model allowed us to examine the effects of varying influenza exposure risk, antiviral efficacy, antiviral cost, and the probability of different influenza outcomes such as hospitalization, preterm delivery, and mortality. Influenza immunisation information including updates for public health professionals. A, in the unadjusted findings, the black circles show the 3year moving averages of the excess mortality rates, and the green line shows influenza vaccination coverage. Estimates of global seasonal influenzaassociated respiratory mortality.
With news circulating that influenza kills more people, the world health organisation. Public health england gateway number 2018805 pdf, 8kb, 27 pages this file may not be suitable for users of assistive technology. High excess mortality impact was also seen in children under the age of four years. Influenza, influenzaassociated mortality, and novel. In almost all countries, the season was dominated by influenza ah3n2 viruses.
Influenza april 2019 19 influenza the disease influenza is an acute viral infection of the respiratory tract. Vol 391 march 31, 2018 1285 estimates of global seasonal influenzaassociated respiratory mortality. Epidemiological factors associated with increased odds for influenza included weeks when. No elevated risk was found for cancer, infections, neurodevelopmental problems, chronic diseases, or all cause morbidity or mortality in the children of vaccinated mothers. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. The french data were obtained from the sentinel system, created in 1984. Take the 20192020 seasonal influenza vaccination training.
Excess mortality associated with influenza epidemics in. Mortality attributable to seasonal and pandemic influenza. The mortality rate associated with the 2009 h1n1 pandemic in 200910 was comparable to that of seasonal influenza during the seasonal years 19. Every winter, the uk experiences a seasonal influenza epidemic that affects the morbidity and mortality of thousands of its citizens and puts increased pressure on nhs resources. Prevention and control of seasonal influenza with vaccines recommendations of the advisory committee on immunization practices united states, 201617 influenza season. Cdc influenza surveillance data confirms severity of flu. The exact burden of influenza is difficult to quantify because laboratory tests are rarely conducted on a routine basis. Influenza causes significant loss of workdays, human suffering, and mortality. Previous global influenza mortality estimates were calculated more than 10 years ago and detailed information about the methods used are not available. Seasonal influenza an overview sciencedirect topics.
Elderly people, children under 6 months old, pregnant women, and people with chronic conditions or immunosuppression are at increased risk of complications. Influenza, commonly referred to as the flu, is a severe respiratory illness that is easily spread and can lead to severe complications, even death. Since these estimates were made available by who the number of countries with capacity to calculate national estimates for seasonal influenza associated excess mortality has increased. Further information on influenza infection is included in the green book influenza chapter and on nhs. The 1918 influenza pandemic was the most severe pandemic in recent history. Seasonal and pandemic influenza are well documented in producing a significant burden of morbidity and mortality on human health. For information on the use of influenza vaccines in egg allergic individuals please see the green book influenza. Death rates estimated by the cdc range from about 12,000 during 20112012 to 56,000 during 201220.
It is caused by influenza virus and is easily transmitted, predominantly via the droplet and contact routes and by indirect spread from respiratory secretions on hands etc. Inactivated influenza vaccine information for healthcare practitioners. Mortality is only the most severe manifestation of influenza impact, and similar techniques can be used to estimate excess morbidity due to influenza epidemics. The cdc presents seasonal influenza morbidity and mortality not as raw numbers, but as calculated estimates based on submitted international.
Impact of influenza vaccination on seasonal mortality in the. In diabetic patients of workingage 1864 years, influenza vaccination prevented allcause hospitalization with a pooled ve of 58% 95% ci, 681% and hospitalization due to influenza or pneumonia ve 43%. Influenza is a highly infectious, viral infection of the respiratory tract. Investigating obesity as a risk factor for influenza. Influenza a in this season was predominating so it caused 60% of the deaths, but both types of influenza a and both types of influenza b can cause mortality. The mdhhs seasonal influenza web page has information on influenza activity, influenza vaccination, and resources for specific groups including health professionals and clinical laboratories. Visit the 20192020 seasonal influenza resource center. Estimates of global seasonal influenzaassociated respiratory. Serious outcomes can include hospitalization or death.
How deadly is covid19 compared to the seasonal flu. The severity of seasonal influenza depends on the virus, host factors, and other factors, e. Comparative age distribution of influenza morbidity and. Overall influenzaassociated mortality has been estimated to. The net result is a resounding lack of evidence of harm from flu vaccination in pregnancy. Flu is responsible for between 200 and 500 deaths each year in ireland. Influenza is an acute viral infection of the respiratory tract. Influenza is usually self limiting in healthy individuals, with recovery in 37 days. Apr 11, 2016 influenza activity started in week 502014 and lasted until week 202015, as in the previous season. Seasonal influenza is a common respiratory tract infection caused by human seasonal influenza viruses.
Mortality associated with influenza and respiratory syncytial virus in. Based on national center for health statistics nchs mortality surveillance data available on may 14, 2020, 8. Heterogeneity in estimates of the impact of influenza on. Seasonal influenza epidemics have a substantial mortality and morbidity impact on human health globally.
This percentage is above the epidemic threshold of 6. Influenza vaccination and 1year risk of myocardial infarction, stroke, heart failure, pneumonia, and mortality among intensive care unit survivors aged 65 years or older. Influenza activity can sometimes be predicted and even tracked geographically. Jun 30, 2017 large variation in estimates was observed among studies. Influenza and the winter increase in mortality in the. Coronavirus is five times deadlier than the seasonal flu. As reported in this and other studies, 2,3 approximately 90%. Influenza is an acute respiratory viral infection which typically occurs in the winter months in temperate areas.
Inactivated influenza vaccine information for healthcare. In contrast, avian influenza ai is caused by those influenza viruses that mainly affect birds and. In the united states, it was first identified in military personnel in spring 1918. Annual national flu programme letter 2019 to 2020 nhs england. The most recent data for the mortality death rates from influenza rate death rate for the united states in 2016 indicates that mortality from influenza varies from year to year. Modelling the population effectiveness of the national. Public health england phe reports that morbidity and mortality attributed to flu is a major cause of harm to individuals, especially vulnerable people, and a key factor in nhs winter pressures. This guideline will also be used to develop the nice quality standard for flu. Mortality attributable to seasonal and pandemic influenza, australia, 2003 to 2009, using a novel time series smoothing approach article pdf available in plos one 86. Patients with reduced immune function due to disease or pharmacotherapy are vulnerable to severe or complicated influenza infection, and national immunisation guidelines commonly recommend this population are vaccinated to protect against such outcomes. For the latest influenza surveillance data, click the image below. The annual crude influenza associated allcause mortality rate for all ages, subdivided by period, ranged from 0 to 178 per 100,000 persons in seasonal periods. History of 1918 flu pandemic pandemic influenza flu cdc. During the pandemic, there were fewer than 500 laboratory confirmed deaths from influenza ah1n1v in the.
Seasonality of mortality, by kyle nobbe, published in the january 2017 edition of reflections, 1 and seasonal flu and the impact on mortality, by dr. Immunisation against infectious diseases the green book and updates. High excess mortality impact was also seen in children. Aug 27, 2010 during 19762007, annual estimates of influenza associated deaths from respiratory and circulatory causes ranged from 3,349 in 198687 to 48,614 in 200304, and the annual rate of influenza associated death for all ages ranged from 1. Morbidity and mortality attributed to flu is a key factor in hsc winter pressures and a. New evidence emerged following the 2009 h1n1 influenza pandemic that obesity was an independent risk factor for hospitalization, intensive care unit admission and death in laboratory. The influenza chapter of the green book recommends both intradermal and. Seasonal influenza is a preventable infectious disease with mostly respiratory symptoms. A new study from harvard university found that the death rate on the diamond princess ship was 0. The us centers for disease control and prevention cdc documented that seasonal influenza was responsible for 34,40057,300 deaths during the 20182019 season. In the 20172018 season, deaths reached a new high of about. Influenza a and influenza b are responsible for most clinical illness.
Not recommended for use as part of seasonal influenza vaccination. Healthcare practitioners should refer to the green book influenza chapter for. Several studies have shown a relatively high mortality rate among young people infected by the 2009 pandemic influenza a h1n1 virus. Influenza chapter 19 influenza april 2019 table 19. The purpose of the influenza vaccination programme is to protect those most at risk of developing severe disease or complications or from dying if they develop the infection. Compared with the previous season, nine eueea countries reported higher peak ili rates in primary care. Why flu vaccination is important for health care workers hse. These symptoms typically begin two days after exposure to the virus and most last less than a week. Budd said influenza a h3n2 is the predominant strain of the virus this season, which is often linked with higher mortality and hospitalization rates among older adults and young children, though. It was caused by an h1n1 virus with genes of avian origin.
Seasonal influenza annual epidemiological report for 2014. The mdhhs seasonal influenza web page has information on influenza activity, influenza vaccination, and resources for specific groups including health. The latter is a nationwide network of general practitioners who report, in real time, the number of medical visits. Influenza is highly infectious with a usual incubation period of one to three days. The average annual number of influenzaassociated deaths during influenza ah3n2 prominent seasons was 7,722 for pneumonia and influenza causes and 28,909 for respiratory and circulatory causes, compared with 2,856 deaths for pneumonia and influenza causes and 10,648 deaths for respiratory and circulatory causes in seasons in which it was not. Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus. Influenza vaccination for immunocompromised patients. The severity of seasonal influenza depends on the virus, host. Estimates of deaths associated with seasonal influenza. Number of fatal flu cases % mortality rate per 100,000 population ageadjusted relative risk in a risk group. In 2000, the policy was extended to include all people aged.
Influenza flu is a respiratory illness caused by influenza viruses. Influenza immunisation has been recommended in the uk since the late 1960s, with the aim of directly protecting those in clinical risk groups who are at a higher risk of influenza associated morbidity and mortality. The current recommendations for seasonal influenza vaccine in the influenza chapter of the green book. Inactivated influenza vaccine information for healthcare practioners. Influenza or flu leads to the hospitalization of more than 200,000 people yearly and results in 36,000 deaths from flu or flurelated complications in the united states 15, striking both the elderly and infant populations particularly hard 24. We believe this further increases the likelihood that the singular cause of excess winter seasonal mortality is, in fact, influenza. Clinical practice guidelines by the infectious diseases. Seasonal influenza results in yearly epidemics of varying severity, with sporadic cases or outbreaks occurring outside of typical season patterns. Seasonal influenza vaccination programme 201819 business. Antiviral medications for pregnant women for pandemic and. Influenza august 2018 19 influenza the disease influenza is an acute viral infection of the respiratory tract. For deaths with underlying pneumonia and influenza causes during 19762007 in the united states, the models estimated an annual.
Because of probably vaccinations and the treatment like we have tamiflu and medications, the mortality is not that high with the seasonal flu probably 0. Influenza types a and b are responsible for most cases of clinical illness in the uk. In hong kong, seasonal influenza is usually more common in periods from january to marchapril and from july to august. Excess mortality was 36 fold higher during seasons dominated by the ah3n2 subtype than seasons dominated by ah1n1b. You also see that the age of the children is variable. For a variety of pandemic influenza scenarios attack rate 20% or. Furthermore, exacerbations of underlying disease, e.
These clinical practice guidelines are an update of the guidelines published by the infectious diseases society of america idsa in 2009, prior to the 2009 h1n1 influenza pandemic. Variations in influenzaassociated mortality by age group also should be noted. Green book 3 and in the annual flu letter for 2018192. Several studies have suggested that respiratory pathogens other than influenza viruses, especially respiratory syncytial virus, contribute to. Flu season is an annually recurring time period characterized by the prevalence of outbreaks of influenza flu. Influenza was associated with a seasonal average of 24. Pdf mortality burden from seasonal influenza and 2009. While the beginning of major flu activity in each season varies by location, in any. Since these estimates were made available by who the number of countries with capacity to calculate national estimates for seasonal influenzaassociated excess mortality has increased. Uk with an overall estimated case fatality ratio of. Mortality is highest in infants and elderly persons. We chose influenzalike illness ili as the sole indicator of morbidity. Here we compared the age distributions of morbidity and mortality during two seasonal influenza epidemics h1n1 and h3n2 in france and the united states with those of the 2009 h1n1 pandemic waves in the same countries.
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