The mortality rate from influenza in the United States is by far highest among those aged 65 years and older. During the 2022-2023 flu season the mortality rate from influenza for this age group was around 26.6 per 100,000 population.

The burden of influenza The impact of influenza in the U.S. varies from season to season, but in the 2022-2023 flu season there were an estimated 31 million cases. These cases resulted in around 360,000 hospitalizations. Although most people recover from influenza without requiring medical treatment, the disease can be deadly for young children, the elderly, and those with weakened immune systems or chronic illnesses. During the 2022-2023 flu season, around 21,000 people in the U.S. lost their lives due to influenza.

Impact of vaccinations The most effective way to prevent influenza is to receive a yearly vaccination at the beginning of flu season. Flu vaccines are safe and can greatly reduce the burden of the disease. During the 2022-2023 flu season vaccinations prevented around 2,479 deaths among those aged 65 years and older. Although flu vaccines are usually cheap and easily accessible, every year a large share of the population in the U.S. still does not get vaccinated. For example, during the 2021-2022 flu season only about 37 percent of those aged 18 to 49 years received a flu vaccination.

During the 2022-2023 flu season in the United States, around 21,401 people died from influenza. The vast majority of deaths due to influenza occur among the elderly, with those aged 65 years and older accounting for 15,399 deaths during the 2022-2023 flu season. During this time, the mortality rate from influenza among those aged 65 years and older was around 26.6 per 100,000 population, compared to a mortality rate of .7 per 100,000 population among those aged 18 to 49 years. Influenza deaths Although most people recover from influenza without the need of medical care, influenza and pneumonia are still major causes of death in the United States. Influenza is a common cause of pneumonia and cases in which influenza develops into pneumonia tend to be more severe and more deadly. However, the impact of influenza varies from year to year depending on which viruses are circulating. For example, during the 2017-2018 flu season around 51,000 people died due to influenza, whereas in 2022-2023 total deaths amounted to 21,000. Preventing death The most effective way to prevent influenza is to receive a yearly influenza vaccination. These vaccines have proven to be safe and are usually cheap and easily accessible. Each year, flu vaccinations prevent thousands of influenza cases, hospitalizations and deaths. It was estimated that during the 2022-2023 flu season, vaccinations prevented the deaths of around 2,479 people aged 65 years and older.

In 2022, the highest death rate from influenza and pneumonia in Canada per 100,000 population was reported among those aged 90 years and older, with around 588 deaths. Individuals between 85 and 89 years followed, with a mortality rate from influenza and pneumonia of almost 210 deaths per 100,000 people. This statistic displays the death rate from influenza and pneumonia per 100,000 population in Canada during 2022, by age.

The burden of influenza in the United States can vary from year to year depending on which viruses are circulating, how many people receive an influenza vaccination, and how effective the vaccination is in that particular year. During the 2019-2020 flu season, around 25,000 people lost their lives to the disease. Although most people recover from influenza without needing medical care, the disease can be deadly among young children, the elderly, and those with weakened immune systems or chronic illnesses.

Deaths due to influenza Even though most people recover from influenza without medical care, influenza and pneumonia can be deadly, especially for older people and those with certain preexisting conditions. Influenza is a common cause of pneumonia and although most cases of influenza do not develop into pneumonia, those that do are often more severe and more deadly. Deaths due to influenza are most common among the elderly, with a mortality rate of around 7.4 per 100,000 population during the 2021-2022 flu season. In comparison, the mortality rate for those aged 50 to 64 years was just 1.2 per 100,000 population.

Flu vaccinations The most effective way to prevent influenza is to receive a yearly influenza vaccination. These vaccines have proven to be safe and are usually cheap and easily accessible. Nevertheless, every year a large share of the population in the United States still fails to get vaccinated against influenza. For example, in the 2021-2022 flu season only 37 percent of those aged 18 to 49 years received a flu vaccination. Unsurprisingly, children and the elderly are the most likely to get vaccinated. It is estimated that during the 2021-2022 flu season vaccinations prevented over 618 thousand influenza cases among children aged 6 months to 4 years.

This statistic shows the deaths with influenza as an underlying cause in England and Wales in 2023, by age and gender. In this year, influenza was the underlying cause of 347 deaths for women aged 90 years and over.

Project Tycho datasets contain case counts for reported disease conditions for countries around the world. The Project Tycho data curation team extracts these case counts from various reputable sources, typically from national or international health authorities, such as the US Centers for Disease Control or the World Health Organization. These original data sources include both open- and restricted-access sources. For restricted-access sources, the Project Tycho team has obtained permission for redistribution from data contributors. All datasets contain case count data that are identical to counts published in the original source and no counts have been modified in any way by the Project Tycho team. The Project Tycho team has pre-processed datasets by adding new variables, such as standard disease and location identifiers, that improve data interpretabilty. We also formatted the data into a standard data format.

Each Project Tycho dataset contains case counts for a specific condition (e.g. measles) and for a specific country (e.g. The United States). Case counts are reported per time interval. In addition to case counts, datsets include information about these counts (attributes), such as the location, age group, subpopulation, diagnostic certainty, place of aquisition, and the source from which we extracted case counts. One dataset can include many series of case count time intervals, such as "US measles cases as reported by CDC", or "US measles cases reported by WHO", or "US measles cases that originated abroad", etc.

Depending on the intended use of a dataset, we recommend a few data processing steps before analysis:

• Analyze missing data: Project Tycho datasets do not inlcude time intervals for which no case count was reported (for many datasets, time series of case counts are incomplete, due to incompleteness of source documents) and users will need to add time intervals for which no count value is available. Project Tycho datasets do include time intervals for which a case count value of zero was reported.
• Separate cumulative from non-cumulative time interval series. Case count time series in Project Tycho datasets can be "cumulative" or "fixed-intervals". Cumulative case count time series consist of overlapping case count intervals starting on the same date, but ending on different dates. For example, each interval in a cumulative count time series can start on January 1st, but end on January 7th, 14th, 21st, etc. It is common practice among public health agencies to report cases for cumulative time intervals. Case count series with fixed time intervals consist of mutually exxclusive time intervals that all start and end on different dates and all have identical length (day, week, month, year). Given the different nature of these two types of case count data, we indicated this with an attribute for each count value, named "PartOfCumulativeCountSeries".

In 2022, a total of 5,985 people died from influenza and pneumonia in Canada. With 2,068 deaths reported during that year, individuals aged 90 years and older were the most affected age group by these diseases. This statistic shows the number of deaths from influenza and pneumonia in Canada in 2022, by age.

This file contains the provisional percent of total deaths by week for COVID-19, Influenza, and Respiratory Syncytial Virus for deaths occurring among residents in the United States, by sex, age group, and race and Hispanic origin. Provisional data are based on non-final counts of deaths based on the flow of mortality data in National Vital Statistics System.

Influenza and pneumonia caused around 12.3 deaths in the U.S. per 100,000 population in 2019. Influenza and pneumonia are among the leading causes of death in the United States, accounting for around 1.6 percent of all deaths in 2020. Influenza, or the flu, is a viral infection that is highly contagious and especially common in the winter season. Influenza is a common cause of pneumonia, although most cases of the flu do not develop into pneumonia. Pneumonia is an infection or inflammation of the lungs and is particularly deadly among young children and the elderly.

Influenza cases

Influenza is very common in the United States, with an estimated 35 million cases reported in 2019-2020. Common symptoms of the flu include cough, fever, runny or stuffy nose, sore throat and headache. Symptoms can be mild but can also be severe enough to require medical attention. In 2019-2020, there were around 16 million influenza-related medical visits in the United States.

Prevention

To prevent contracting the flu people can take everyday precautions such as regularly washing their hands and avoiding those who are sick, but the best way to prevent the flu is by receiving the flu vaccination every year. Receiving a flu vaccination is especially important for young children and the elderly as they are most susceptible to flu complications and associated death. In 2021, around 75 percent of those aged 65 years and older received a flu vaccine, while only 38 percent of those aged 18 to 49 years had done so.

This file contains the complete set of data reported to 122 Cities Mortality Reposting System. The system was retired as of 10/6/2016. While the system was running each week, the vital statistics offices of 122 cities across the United States reported the total number of death certificates processed and the number of those for which pneumonia or influenza was listed as the underlying or contributing cause of death by age group (Under 28 days, 28 days - 1 year, 1-14 years, 15-24 years, 25-44 years, 45-64 years, 65-74 years, 75-84 years, and - 85 years). U:Unavailable. - : No reported cases.* Mortality data in this table were voluntarily reported from 122 cities in the United States, most of which have populations of >100,000. A death is reported by the place of its occurrence and by the week that the death certificate was filed. Fetal deaths are not included. Total includes unknown ages.
More information on Flu Activity & Surveillance is available at http://www.cdc.gov/flu/weekly/fluactivitysurv.htm.

*Bold figures correspond to significant estimates.

Over 12 million people in the United States died from all causes between the beginning of January 2020 and August 21, 2023. Over 1.1 million of those deaths were with confirmed or presumed COVID-19.

Vaccine rollout in the United States Finding a safe and effective COVID-19 vaccine was an urgent health priority since the very start of the pandemic. In the United States, the first two vaccines were authorized and recommended for use in December 2020. One has been developed by Massachusetts-based biotech company Moderna, and the number of Moderna COVID-19 vaccines administered in the U.S. was over 250 million. Moderna has also said that its vaccine is effective against the coronavirus variants first identified in the UK and South Africa.

Contact: PD Dr. Kaspar Staub kaspar.staub@iem.uzh.ch

For the LEAD Hub we digitized and analyzed the following historical demographic and epidemiological data for the city and the canton of Zurich the first time: Since the end of the 19th century, the Federal Health Office (Eidgenössisches Gesundheitsamt) published a weekly bulletin on vital statistics, newly reported cases of notifiable infectious diseases, and hospitalisations. For the period January 1910 to December 1970, we have digitized and transcribed the following weekly series:

1. Weekly deaths for residents and non-residents of the city of Zurich. The quality of these historical vital statistics is assessed to be very good in the literature, incompleteness and migration are no longer a problem as compared to earlier years. However, age-, sex- and cause-specific death numbers were not available on the weekly level.
2. Weekly newly reported cases of influenza-like-illness for the canton and the city of Zurich. This series begins with the introduction of the reporting obligation for influenza in the canton of Zürich in mid-July 1918. As these figures do not include mild cases not treated by a doctor and misdiagnoses, they are probably underestimates, but can still track pandemic and seasonal waves. The reporting system and obligation did not change in the observed time period.
3. Weekly new hospitalisation due to influenza in the canton of Zurich. This series ends in 1938.

The original data format in the weekly bulletins are printed, aggregated tables that have been converted into PDFs using a professional book scanner. Transcription of the data was performed by student assistants using a software and running extended quality-controls. The original tables were in German and French, the digitised data set was annotated in English.

The digitized data are organized as a spreadsheet and stored in csv format. The data are organized as rows (representing reporting weeks) and columns (see variable list below). For a few weeks, information in the original sources was missing (indicated by 1 in the “interpolated” variable). In these cases, the missing values were interpolated by averaging the numbers of the week before and the week afterwards.

Codebook:

Worksheet "Data"

• StartReportingPeriod = Start date of the reporting week (dd.mm.yyyy)
• EndReportingPeriod = End date of reporting week (dd.mm.yyyy)
• Interpolated: 1=value for this week has been interpolated; 0=not interpolated
• CityDeathsTotal = Total absolute number of deaths (all-causes) in the City of Zurich (residents and non-residents)
• CityDeathsResidents = Absolute number of deaths (all-causes) in the City of Zurich for residents
• CityDeathsNonresidents = Absolute number of deaths (all-causes) in the City of Zurich for non-residents
• CantonCases = Absolute number of reported new influenza-like-illness cases by physicians in the Canton of Zurich (including the City)
• CityCases = Absolute number of reported new influenza-like-illness cases by physicians in the City of Zurich
• CantonHospitalisationsFluInfections = Absolute number of new hospitalisations due to influenza-like-illness in the Canton of Zurich (including the City)

Worksheet "Population"

• Yearly population numbers for the City and the Canton of Zurich (source)

This dataset includes Influenza associated pediatric death count by Respiratory Season, Geography(Region) and Age Group. This dataset corresponds to the data on https://www.vdh.virginia.gov/epidemiology/respiratory-diseases-in-virginia/data/.

In the United States, the highest rate of hospitalizations due to influenza are among those aged 65 years and older. During the 2022-2023 flu season, the rate of hospitalizations due to influenza among this age group was about 332 per 100,000 population, compared to a rate of around 46 per 100,000 for those aged 5 to 17 years. Influenza is a common viral infection that usually does not require medical treatment. However, for the very young, the old, and those with certain pre-existing conditions, influenza can be serious and even deadly.

The burden of influenza in the United States The impact of influenza in the United States varies from year to year depending on the strain that is most prevalent during that season and the immunity in the population. Nevertheless, influenza and pneumonia are often among the top ten causes of death in the United States. Preliminary estimates show that around 21,000 people died from influenza during the 2022-2023 flu season. However, during the 2017-2018 flu season, an estimated 51,000 people lost their lives to influenza.

The importance of flu vaccines The best way to avoid catching the flu and to reduce the virus’s overall burden on society is by receiving an annual flu vaccination. The CDC currently recommends that everyone over 6 months of age should get a flu vaccination every year, preferably by the end of October. The flu vaccine is safe, efficient, and reduces the number of illnesses, hospitalizations, and deaths caused by the virus. For example, during the 2018-2019 flu season it was estimated that vaccinations averted around 58 thousand influenza-related hospitalizations. However, despite the proven benefits and wide availability of flu vaccinations, a large percentage of people in the United States fail to receive a vaccination every year. During the 2021-2022 flu season, only about 37 percent of those aged 18 to 49 years were vaccinated against influenza, compared to 74 percent of those aged 65 years and older.

Results data for the thesis on estimating the age-, sex-, cause-specific excess mortality during the COVID-19 pandemic in Hong Kong and South Korea.Thesis abstractBackgroundFew studies used a consistent methodology and adjusted for the risk of influenza-like illness (ILI) in historical mortality trends when estimating and comparing the cause-specific excess mortality (EM) during the COVID-19 pandemic. Previous studies demonstrated that excess mortality was widely reported from CVD and among the elderly. This study aims to estimate and compare the overall, age-, sex-, and cause-specific excess mortality during the COVID-19 pandemic in Hong Kong (HK) and South Korea (SK) with consideration of the impact of ILI.MethodsIn this population-based study, we first fitted a generalized additive model to the monthly mortality data from Jan 2010 to Dec 2019 in HK and SK before the COVID-19 pandemic. Then we applied the fitted model to estimate the EM from Jan 2020 to Dec 2022. The month index was modelled with a natural cubic spline. Akaike information criterion (AIC) was used to select the number of knots for the spline and inclusion of covariates such as monthly mean temperature, absolute humidity, ILI consultation rate, and the proxy for flu activity.FindingsFrom 2020 to 2022, the EM in HK was 239.8 (95% CrI: 184.6 to 293.9) per 100,000 population. Excess mortality from respiratory diseases (RD) (ICD-10 code: J00-J99), including COVID-19 deaths coded as J98.8, was 181.3 (95% CrI: 149.9 to 210.4) per 100,000. Except for RD, the majority of the EM in HK was estimated from cardiovascular diseases (CVD) (22.4% of the overall EM), influenza and pneumonia (16.2%), ischemic heart disease (8.9%), ill-defined causes (8.6%) and senility (6.7%). No statistically significant reduced deaths were estimated among other studied causes.From 2020 to 2022, the EM in SK was 204.7 (95% CrI: 161.6 to 247.2) per 100,000 population. Of note, COVID-19 deaths in SK were not included in deaths from RD but were recorded with the codes for emergency use as U07.1 or U07.2. The majority of the EM was estimated from ill-defined causes (32.0% of the overall EM), senility (16.6%), cerebrovascular disease (6.8%) and cardiovascular diseases (6.1%). Statistically significant reduction in mortality with 95 CrI lower than zero was estimated from vascular, other and unspecified dementia (-26.9% of expected deaths), influenza and pneumonia (-20.7%), mental and behavioural disorders (-18.8%) and respiratory diseases (-7.7%).InterpretationExcluding RD in HK which includes COVID-19 deaths, the majority of the EM in HK and SK was from CVD and senility. Mortality from influenza and pneumonia was estimated to have a statistically significant increase in HK but a decrease in SK probability due to different coding practices. HK had a heavier burden of excess mortality in the elderly age group 70-79 years and 80 years or above, while SK had a heavier burden in the age group of 60-69 years. Both HK and SK have a heavier burden of excess mortality from males than females. Better triage systems for identifying high-risk people of the direct or indirect impact of the epidemic are needed to minimize preventable mortality.

BackgroundEstimating the global influenza burden in terms of hospitalization and death is important for optimizing prevention policies. Identifying risk factors for mortality allows for the design of strategies tailored to groups at the highest risk. This study aims to (a) describe the clinical characteristics of hospitalizations with a diagnosis of influenza over five flu seasons (2016–2017 to 2020–2021), (b) assess the associated morbidity (hospitalization rates and ICU admissions rate), mortality and cost of influenza hospitalizations in different age groups and (c) analyze the risk factors for mortality.MethodsThis retrospective study included all hospital admissions with a diagnosis of influenza in Spain for five influenza seasons. Data were extracted from the Spanish National Surveillance System for Hospital Data from 1 July 2016 to 30 June 2021. We identified cases coded as having influenza as a primary or secondary diagnosis (International Classification of Diseases, 10th revision, J09-J11). The hospitalization rate was calculated relative to the general population. Independent predictors of mortality were identified using multivariable logistic regression.ResultsOver the five seasons, there were 127,160 hospitalizations with a diagnosis of influenza. The mean influenza hospitalization rate varied from 5/100,000 in 2020–2021 (COVID-19 pandemic) to 92.9/100,000 in 2017–2018. The proportion of influenza hospitalizations with ICU admission was 7.4% and was highest in people aged 40–59 years (13.9%). The case fatality rate was 5.8% overall and 9.4% in those aged 80 years or older. Median length of stay was 5 days (and 6 days in the oldest age group). In the multivariable analysis, independent risk factors for mortality were male sex (odds ratio [OR] 1.14, 95% confidence interval [95% CI] 1.08–1.20), age (

Social factors have been shown to create differential burden of influenza across different geographic areas. We explored the relationship between potential aggregate-level social determinants and mortality during the 1918 influenza pandemic in Chicago using a historical dataset of 7,971 influenza and pneumonia deaths. Census tract-level social factors, including rates of illiteracy, homeownership, population, and unemployment, were assessed as predictors of pandemic mortality in Chicago. Poisson models fit with generalized estimating equations (GEEs) were used to estimate the association between social factors and the risk of influenza and pneumonia mortality. The Poisson model showed that influenza and pneumonia mortality increased, on average, by 32.2% for every 10% increase in illiteracy rate adjusted for population density, homeownership, unemployment, and age. We also found a significant association between transmissibility and population density, illiteracy, and unemployment but not homeownership. Lastly, analysis of the point locations of reported influenza and pneumonia deaths revealed fine-scale spatiotemporal clustering. This study shows that living in census tracts with higher illiteracy rates increased the risk of influenza and pneumonia mortality during the 1918 influenza pandemic in Chicago. Our observation that disparities in structural determinants of neighborhood-level health lead to disparities in influenza incidence in this pandemic suggests that disparities and their determinants should remain targets of research and control in future pandemics.

During the 2022-2023 influenza season, the influenza vaccination prevented an estimated 2,479 deaths among adults aged 65 years and older. This statistic shows the estimated number of influenza A- and B-associated deaths prevented by influenza vaccination in the U.S. during the 2022-2023 influenza season, by age group.