Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus. 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. In almost all countries, the season was dominated by influenza ah3n2 viruses. Seasonal influenza is a common respiratory tract infection caused by human seasonal influenza viruses. Green book 3 and in the annual flu letter for 2018192. Heterogeneity in estimates of the impact of influenza on. 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. Seasonal influenza vaccination programme 201819 business. 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. Several studies have suggested that respiratory pathogens other than influenza viruses, especially respiratory syncytial virus, contribute to.
Seasonal influenza an overview sciencedirect topics. The mortality rate associated with the 2009 h1n1 pandemic in 200910 was comparable to that of seasonal influenza during the seasonal years 19. Prevention and control of seasonal influenza with vaccines recommendations of the advisory committee on immunization practices united states, 201617 influenza season. History of 1918 flu pandemic pandemic influenza flu cdc. Influenza flu is a respiratory illness caused by influenza viruses. The latter is a nationwide network of general practitioners who report, in real time, the number of medical visits. Annual national flu programme letter 2019 to 2020 nhs england. During the pandemic, there were fewer than 500 laboratory confirmed deaths from influenza ah1n1v in the. High excess mortality impact was also seen in children. The french data were obtained from the sentinel system, created in 1984. Compared with the previous season, nine eueea countries reported higher peak ili rates in primary care. Modelling the population effectiveness of the national. A new study from harvard university found that the death rate on the diamond princess ship was 0. The michigan department of health and human services mdhhs seasonal influenza is a contagious respiratory illness caused by influenza viruses.
Influenza was associated with a seasonal average of 24. High excess mortality impact was also seen in children under the age of four years. The 1918 influenza pandemic was the most severe pandemic in recent history. It was caused by an h1n1 virus with genes of avian origin. Seasonal influenza annual epidemiological report for 2014. Influenza is an acute respiratory illness caused by rna viruses of the family orthomyxoviridae influenza viruses.
Estimates of global seasonal influenzaassociated respiratory mortality. It is totally different from avian influenza and influenza pandemic. The us centers for disease control and prevention cdc documented that seasonal influenza was responsible for 34,40057,300 deaths during the 20182019 season. Vaccines for the prevention of seasonal influenza in patients. 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. Some people, such as older adults, young children, and people with certain health conditions, are at higher risk for flu complications. The severity of seasonal influenza depends on the virus, host. 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.
Influenza types a and b are responsible for most cases of clinical illness in. The season occurs during the cold half of the year in each hemisphere. 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. Uk with an overall estimated case fatality ratio of. Not recommended for use as part of seasonal influenza vaccination. Vol 391 march 31, 2018 1285 estimates of global seasonal influenzaassociated respiratory mortality. These symptoms typically begin two days after exposure to the virus and most last less than a week. Inactivated influenza vaccine information for healthcare. Serious outcomes can include hospitalization or death. Excess mortality was 36 fold higher during seasons dominated by the ah3n2 subtype than seasons dominated by ah1n1b. 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. We believe this further increases the likelihood that the singular cause of excess winter seasonal mortality is, in fact, influenza. Several studies have shown a relatively high mortality rate among young people infected by the 2009 pandemic influenza a h1n1 virus. Inactivated influenza vaccine information for healthcare practitioners.
Influenza a occurs more frequently and is more virulent. 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. Antiviral medications for pregnant women for pandemic and. This document addresses new information regarding diagnostic testing, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal influenza. In hong kong, seasonal influenza is usually more common in periods from january to marchapril and from july to august. 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. Seasonal influenza epidemics have a substantial mortality and morbidity impact on human health globally. Mortality associated with influenza and respiratory syncytial virus in. Previous global influenza mortality estimates were calculated more than 10 years ago and detailed information about the methods used are not available.
Coronavirus is five times deadlier than the seasonal flu. Influenza activity can sometimes be predicted and even tracked geographically. 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. 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. 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.
Flu is responsible for between 200 and 500 deaths each year in ireland. Influenza types a and b are responsible for most cases of clinical illness in the uk. Influenza and the winter increase in mortality in the. Impact of influenza vaccination on seasonal mortality in. Estimates of deaths associated with seasonal influenza. Take the 20192020 seasonal influenza vaccination training. Overall influenzaassociated mortality has been estimated to. How deadly is covid19 compared to the seasonal flu. Comparative age distribution of influenza morbidity and. Influenza is highly infectious with a usual incubation period of one to three days. The influenza chapter in the green book contains more details of the clinical and. The mdhhs seasonal influenza web page has information on influenza activity, influenza vaccination, and resources for specific groups including health professionals and clinical laboratories.
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. Public health england gateway number 2018805 pdf, 8kb, 27 pages this file may not be suitable for users of assistive technology. 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. Number of fatal flu cases % mortality rate per 100,000 population ageadjusted relative risk in a risk group. This percentage is above the epidemic threshold of 6. The exact burden of influenza is difficult to quantify because laboratory tests are rarely conducted on a routine basis. Variations in influenzaassociated mortality by age group also should be noted. Impact of influenza vaccination on seasonal mortality in the. Mortality is only the most severe manifestation of influenza impact, and similar techniques can be used to estimate excess morbidity due to influenza epidemics. Influenza chapter 19 influenza april 2019 table 19.
For a variety of pandemic influenza scenarios attack rate 20% or. Note the flu information page below can be slow to load, please be patient, it is loading the latest information. You also see that the age of the children is variable. The net result is a resounding lack of evidence of harm from flu vaccination in pregnancy. 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. The severity of seasonal influenza depends on the virus, host factors, and other factors, e. The cdc presents seasonal influenza morbidity and mortality not as raw numbers, but as calculated estimates based on submitted international. Elderly people, children under 6 months old, pregnant women, and people with chronic conditions or immunosuppression are at increased risk of complications. Epidemiological factors associated with increased odds for influenza included weeks when. Pdf mortality burden from seasonal influenza and 2009. Inactivated influenza vaccine information for healthcare practioners. Seasonal and pandemic influenza are well documented in producing a significant burden of morbidity and mortality on human health.
Influenza is an acute viral infection of the respiratory tract that spreads easily from person to person. Influenza, commonly referred to as the flu, is a severe respiratory illness that is easily spread and can lead to severe complications, even death. 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. Influenza medicago announces positive results in animal trials for its vaccine candidate against covid19. 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. Visit the 20192020 seasonal influenza resource center. Further information on influenza infection is included in the green book influenza chapter and on nhs. 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. Influenza type a causes moderate to severe illness and affects all age groups. Seasonal influenza is a preventable infectious disease with mostly respiratory symptoms. While the beginning of major flu activity in each season varies by location, in any. Cdc influenza surveillance data confirms severity of flu. In the united states, it was first identified in military personnel in spring 1918.
Morbidity and mortality attributed to flu is a key factor in hsc winter pressures and a. 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%. 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. 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. Jun 21, 2011 influenza was associated with a seasonal average of 24. Influenza is an acute viral infection of the respiratory tract. 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. Influenza april 2019 19 influenza the disease influenza is an acute viral infection of the respiratory tract.
Abstract this article follows up on two older articles by rga associates. Based on national center for health statistics nchs mortality surveillance data available on may 14, 2020, 8. Influenza a and influenza b are responsible for most clinical illness. 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. Excess mortality associated with influenza epidemics in. Immunisation against infectious diseases the green book and updates. No elevated risk was found for cancer, infections, neurodevelopmental problems, chronic diseases, or all cause morbidity or mortality in the children of vaccinated mothers. With news circulating that influenza kills more people, the world health organisation. Healthcare practitioners should refer to the green book influenza chapter for. Influenza is an acute respiratory viral infection which typically occurs in the winter months in temperate areas. This guideline will also be used to develop the nice quality standard for flu. Flu season is an annually recurring time period characterized by the prevalence of outbreaks of influenza flu. Mortality attributable to seasonal and pandemic influenza.
Seasonal influenza results in yearly epidemics of varying severity, with sporadic cases or outbreaks occurring outside of typical season patterns. Influenza vaccination and 1year risk of myocardial infarction, stroke, heart failure, pneumonia, and mortality among intensive care unit survivors aged 65 years or older. We chose influenzalike illness ili as the sole indicator of morbidity. For deaths with underlying pneumonia and influenza causes during 19762007 in the united states, the models estimated an annual. The current recommendations for seasonal influenza vaccine in the influenza chapter of the green book. As reported in this and other studies, 2,3 approximately 90%.
Jun 30, 2017 large variation in estimates was observed among studies. In contrast, avian influenza ai is caused by those influenza viruses that mainly affect birds and. Mortality is highest in infants and elderly persons. Investigating obesity as a risk factor for influenza. The dates of the us seasonal epidemics and the age distribution of ili were extracted from published studies 8. Influenza immunisation information including updates for public health professionals. Influenza vaccination for immunocompromised patients.
Furthermore, exacerbations of underlying disease, e. The mdhhs seasonal influenza web page has information on influenza activity, influenza vaccination, and resources for specific groups including health. In 2000, the policy was extended to include all people aged. Influenza is usually self limiting in healthy individuals, with recovery in 37 days. Immunisation against infectious disease the green book, 2014. 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. Overall influenza associated mortality has been estimated to. There are four main types of flu viruses with multiple. For information on the use of influenza vaccines in egg allergic individuals please see the green book influenza. Influenza, influenzaassociated mortality, and novel. Clinical practice guidelines by the infectious diseases.
Although there is not universal consensus regarding where the virus originated, it spread worldwide during 19181919. For seasonal influenza, mortality is usually well below 0. For the latest influenza surveillance data, click the image below. 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. Apr 11, 2016 influenza activity started in week 502014 and lasted until week 202015, as in the previous season. Influenza causes significant loss of workdays, human suffering, and mortality. Estimates of global seasonal influenzaassociated respiratory. Influenza is a highly infectious, viral infection of the respiratory tract. Why flu vaccination is important for health care workers hse. In the 20172018 season, deaths reached a new high of about. 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. Influenza august 2018 19 influenza the disease influenza is an acute viral infection of the respiratory tract.
890 929 959 208 219 264 1085 351 432 708 465 247 1310 225 1071 1308 1251 690 1262 468 450 618 150 260 531 824 782 353 498 261 1030