In the United States, the highest rate of hospitalizations due to influenza are among those aged 65 years and older. During the 2023-2024 flu season, the rate of hospitalizations due to influenza among this age group was about 401 per 100,000 population, compared to a rate of around 47 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. Preliminary estimates show that around 28,000 people died from influenza during the 2023-2024 flu season. However, during the 2017-2018 flu season, an estimated 52,000 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 2022-2023 flu season, it was estimated that vaccinations averted almost 65 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 2022-2023 flu season, only about 35 percent of those aged 18 to 49 years were vaccinated against influenza, compared to 70 percent of those aged 65 years and older.

The mortality rate from influenza in the United States is by far highest among those aged 65 years and older. During the 2023-2024 flu season, the mortality rate from influenza for this age group was around 32.1 per 100,000 population. The burden of influenza The impact of influenza in the U.S. varies from season to season, but in the 2023-2024 flu season, there were an estimated 40 million cases. These cases resulted in around 470,000 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 2023-2024 flu season, around 28,000 people in the U.S. lost their lives due to influenza. Impact of vaccinations The most effective way to prevent influenza is to receive an annual 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 2022-2023 flu season, only about 35 percent of those aged 18 to 49 years received a flu vaccination.

These data contain the Age-Adjusted Colorado Census Tract Rate of Influenza-Related Hospital Discharges (2015-2019) and Inpatient Hospitalizations per 100,000 persons based on the ICD-10 Code of J10-J11. The rates are calculated using the geocoded billing address of discharged individuals found in the dataset with the selected ICD-10 Codes and 2015-2019 Population Estimates from the American Community Survey. These data are from the Colorado Hospital Association's Hospital Discharge Dataset and are published annually by the Colorado Department of Public Health and Environment.

A. SUMMARY This dataset includes weekly respiratory disease hospital admissions for Influenza, RSV, and COVID-19 into San Francisco hospitals. Columns in the dataset include a count and rate of hospital admissions per 100,000 people. The data are reported by week. B. HOW THE DATASET IS CREATED Hospital admission data is reported to the San Francisco Department of Public Health (SFDPH) from the United States Center for Disease Control’s (CDC) National Healthcare Safety Network (NHSN) program. San Francisco population estimates are pulled from a view based on the San Francisco Population and Demographic Census dataset. These population estimates are from the 2019-2023 5-year American Community Survey (ACS). C. UPDATE PROCESS The dataset is updated every Friday and includes data from the previous Sunday through Saturday. For example, the update on Friday, October 17th will include data through Saturday, October 11th. Data may change as more current information becomes available. D. HOW TO USE THIS DATASET Weekly data represent a count of confirmed admissions of Influenza, RSV, and COVID-19 patients to San Francisco hospitals by week. The admission rate per 100,000 is calculated by multiplying the count of admissions each week by 100,000 and dividing by the population estimate.

Estimates of influenza disease burden in rates per 100,000 and number per U.S. population by age group and influenza season, United States.

These data contain the Age-Adjusted Colorado County Rate of Influenza-Related Hospital Discharges (2015-2019) and Inpatient Hospitalizations per 100,000 persons based on the ICD-10 Code of J10-J11. The rates are calculated using the geocoded billing address of discharged individuals found in the dataset with the selected ICD-10 Codes and 2015-2019 Population Estimates from the American Community Survey. These data are from the Colorado Hospital Association's Hospital Discharge Dataset and are published annually by the Colorado Department of Public Health and Environment.

The estimated annual rate of hospitalizations due to influenza in Canada during the ********* flu season was nine hospitalizations per 100,000 population, a decrease compared to previous years. This statistic shows the hospitalization rates per 100,000 population from influenza in Canada during the flu seasons from 2016 to 2022.

Incidence rates (per 100,000 persons) and 95% confidence intervals for influenza-associated SARI by influenza season and sentinel site.

On 11/14/2025, we launched updated hospitalization reporting using data from the National Healthcare Safety Network (NHSN). The new dataset includes hospital admissions for respiratory viruses including COVID-19, flu, and RSV. You can access the new dataset here. A. SUMMARY This dataset includes information on COVID+ hospital admissions for San Francisco residents into San Francisco hospitals. Specifically, the dataset includes the count and rate of COVID+ hospital admissions per 100,000. The data are reported by week. B. HOW THE DATASET IS CREATED Hospital admission data is reported to the San Francisco Department of Public Health (SFDPH) via the COVID Hospital Data Repository (CHDR), a system created via health officer order C19-16. The data includes all San Francisco hospitals except for the San Francisco VA Medical Center. San Francisco population estimates are pulled from a view based on the San Francisco Population and Demographic Census dataset. These population estimates are from the 2018-2022 5-year American Community Survey (ACS). C. UPDATE PROCESS Data updates weekly on Wednesday with data for the past Wednesday-Tuesday (one week lag). Data may change as more current information becomes available. D. HOW TO USE THIS DATASET New admissions are the count of COVID+ hospital admissions among San Francisco residents to San Francisco hospitals by week. The admission rate per 100,000 is calculated by multiplying the count of admissions each week by 100,000 and dividing by the population estimate. E. CHANGE LOG 11/14/2025 COVID-19 hosipital admissions is tracked in a new dataset 7/18/2025 - Dataset update is paused to assess data quality and completeness. 9/12/2024 - We updated the data source for our COVID-19 hospitalization data to a San Francisco specific dataset. These new data differ slightly from previous hospitalization data sources but the overall patterns and trends in hospitalizations remain consistent. You can access the previous data here.

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 (

BackgroundThe global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden. In this analysis, we use surveillance data to provide an estimate of influenza-associated hospitalizations among children worldwide.Methods and FindingsWe aggregated data from a systematic review (n = 108) and surveillance platforms (n = 37) to calculate a pooled estimate of the proportion of samples collected from children hospitalized with respiratory illnesses and positive for influenza by age group (<6 mo, <1 y, <2 y, <5 y, 5–17 y, and <18 y). We applied this proportion to global estimates of acute lower respiratory infection hospitalizations among children aged <1 y and <5 y, to obtain the number and per capita rate of influenza-associated hospitalizations by geographic region and socio-economic status.Influenza was associated with 10% (95% CI 8%–11%) of respiratory hospitalizations in children <18 y worldwide, ranging from 5% (95% CI 3%–7%) among children <6 mo to 16% (95% CI 14%–20%) among children 5–17 y. On average, we estimated that influenza results in approximately 374,000 (95% CI 264,000 to 539,000) hospitalizations in children <1 y—of which 228,000 (95% CI 150,000 to 344,000) occur in children <6 mo—and 870,000 (95% CI 610,000 to 1,237,000) hospitalizations in children <5 y annually. Influenza-associated hospitalization rates were more than three times higher in developing countries than in industrialized countries (150/100,000 children/year versus 48/100,000). However, differences in hospitalization practices between settings are an important limitation in interpreting these findings.ConclusionsInfluenza is an important contributor to respiratory hospitalizations among young children worldwide. Increasing influenza vaccination coverage among young children and pregnant women could reduce this burden and protect infants <6 mo.

Content

The Coronavirus Disease 2019 (COVID-19)-Associated Hospitalization Surveillance Network (COVID-NET) data are preliminary and subject to change as more data become available. COVID-NET conducts population-based surveillance for laboratory-confirmed COVID-19-associated hospitalizations in children (less than 18 years of age) and adults.

COVID-NET covers nearly 100 counties in the 10 Emerging Infections Program (EIP) states (CA, CO, CT, GA, MD, MN, NM, NY, OR, TN) and four Influenza Hospitalization Surveillance Project (IHSP) states (IA, MI, OH, and UT).

Incidence rates (per 100,000 population) are calculated using the National Center for Health Statistics' (NCHS) vintage 2018 bridged-race postcensal population estimates for the counties included in the surveillance catchment area. The rates provided are likely to be underestimated as COVID-19 hospitalizations might be missed due to test availability and provider or facility testing practices.

Acknowledgements

COVID-NET: COVID-19-Associated Hospitalization Surveillance Network, Centers for Disease Control and Prevention. WEBSITE. Accessed on 04/09/2020.

During the flu seasons from 2016 to 2022, children up to four years and adults aged 65 and older had the highest hospitalization rates due to influenza in Canada. Among individuals aged 65 and older, the rate of influenza hospitalizations was 21 per 100,000 people during the 2021-2022 flu season. This statistic shows the hospitalization rates from influenza per 100,000 population in Canada during the flu seasons from 2016 to 2022, by age group.

This statistic displays the incidence of influenza cases that ended in hospitalization in Ireland during the 2018/19 flu season, by age. In this period, for those aged 65 years and over, approximately *** people per 100,000 in that age group were admitted to hospital as a result of influenza.

The rate of influenza-related inpatient stays in the U.S. for males in flu season 2015-2016 was roughly 45 per 100,000 population. The statistic illustrates the rate of influenza-related inpatient stays in the U.S. between the 2009 and 2016 flu seasons, by gender.

Non-expenditure healthcare data provide information on institutions providing healthcare in countries, on resources used and on output produced in the framework of healthcare provision.

Data on healthcare form a major element of public health information as they describe the capacities available for different types of healthcare provision as well as potential 'bottlenecks' observed. The quantity and quality of healthcare services provided and the work sharing established between the different institutions are a subject of ongoing debate in all countries. Sustainability - continuously providing the necessary monetary and personal resources needed - and meeting the challenges of ageing societies are the primary perspectives used when analysing and using the data.

The resource-related data refer to both human and technical resources, i.e. they relate to:

• Health care staff: 'manpower' active in the health care sector (doctors, dentists, nurses, etc.);
• Heath workforce migration: migration movements of doctors and nurses;
• Healthcare facilities: technical capacity dimensions (hospital beds, beds in nursing and residential care facilities, etc.).

The output-related data ('activities') refer to contacts between patients and the healthcare system, and to the treatment thereby received. Data are available for hospital discharges of in-patients and day cases, average length of stay of in-patients, consultations with medical professionals, and medical procedures performed in hospitals.

Annual national and regional data are provided in absolute numbers, percentages, and in population-standardised rates (per 100 000 inhabitants).

Wherever applicable, the definitions and classifications of the System of Health Accounts (SHA) are followed, e.g. International Classification for Health Accounts - Providers of health care (ICHA-HP). For hospital discharges, the International Shortlist for Hospital Morbidity Tabulation (ISHMT) is used. Surgical procedures are classified according to a shortlist mapped to ICD-9-CM.

These healthcare data are largely based on administrative data sources in the countries. Therefore, they reflect the country-specific way of organising healthcare and may not always be completely comparable.

In the United States, influenza vaccination rates differ greatly by age. For example, during the 2023-2024 flu season, around ** percent of those aged 65 years and older received an influenza vaccination, compared to just ** percent of those aged 18 to 49 years. The CDC recommends that everyone six months and older in the United States should get vaccinated against influenza every year, with a few exceptions. Although influenza is mild for most people, it can lead to hospitalization and even death, especially among the young, the old, and those with certain preexisting conditions. The impact of flu vaccinations Flu vaccinations are safe and effective, preventing thousands of illnesses, medical visits, and deaths every year. However, the effectiveness of flu vaccines varies each year depending on what flu viruses are circulating that season and the age and health status of the person receiving the vaccination. During the 2023-2024 flu season, it was estimated that influenza vaccination prevented almost 64********* hospitalizations among those aged 65 years and older. In addition, flu vaccinations prevented ***** deaths among those aged 65 years and older, as well as *** deaths among children aged six months to four years. The burden of influenza The impact of influenza is different from season to season. However, during the 2023-2024 flu season, there were around ** million cases of influenza in the United States. Furthermore, there were around ****** deaths due to influenza, an increase from the previous year but significantly fewer than in ********** when influenza contributed to ****** deaths. Most of these deaths are among the elderly. In ********* the death rate due to influenza among those aged 65 years and older was around **** per 100,000 population. In comparison, those aged 18 to 49 had an influenza death rate of just *** per 100,000 population.

BackgroundInfluenza-related healthcare utilization among Medicaid patients and commercially insured patients is not well-understood. This study compared influenza-related healthcare utilization and assessed disease management among individuals diagnosed with influenza during the 2015–2019 influenza seasons.MethodsThis retrospective cohort study identified influenza cases among adults (18–64 years) using data from the Transformed Medicaid Statistical Information System (T-MSIS) Analytic Files (TAF) Research Identifiable Files (RIF) and Optum’s de-identified Clinformatics® Data Mart Database (CDM). Influenza-related healthcare utilization rates were calculated per 100,000 patients by setting (outpatient, emergency department (ED), inpatient hospitalizations, and intensive care unit (ICU) admissions) and demographics (sex, race, and region). Rate ratios were computed to compare results from both databases. Influenza episode management assessment included the distribution of the index point-of-care, antiviral prescriptions, and laboratory tests obtained.ResultsThe Medicaid population had a higher representation of racial/ethnic minorities than the CDM population. In the Medicaid population, influenza-related visits in outpatient and ED settings were the most frequent forms of healthcare utilization, with similar rates of 652 and 637 visits per 100,000, respectively. In contrast, the CDM population predominantly utilized outpatient settings. Non-Hispanic Blacks and Hispanics exhibited the highest rates of influenza-related ED visits in both cohorts. In the Medicaid population, Black (64.5%) and Hispanic (51.6%) patients predominantly used the ED as their index point-of-care for influenza. Overall, a greater proportion of Medicaid beneficiaries (49.8%) did not fill any influenza antiviral prescription compared to the CDM population (37.0%).ConclusionAddressing disparities in influenza-related healthcare utilization between Medicaid and CDM populations is crucial for equitable healthcare access. Targeted interventions are needed to improve primary care and antiviral access and reduce ED reliance, especially among racial/ethnic minorities and low-income populations.

Background # Seasonal influenza virus is a common cause of acute lower respiratory infection (ALRI) in young children. In 2008, we estimated that 20 million influenza-virus-associated ALRI and 1 million influenza-virus-associated severe ALRI occurred in children under 5 years globally. Despite this substantial burden, only a few low-income and middle-income countries have adopted routine influenza vaccination policies for children and, where present, these have achieved only low or unknown levels of vaccine uptake. Moreover, the influenza burden might have changed due to the emergence and circulation of influenza A/H1N1pdm09. We aimed to incorporate new data to update estimates of the global number of cases, hospital admissions, and mortality from influenza-virus-associated respiratory infections in children under 5 years in 2018. # Methods # We estimated the regional and global burden of influenza-associated respiratory infections in children under 5 years from a systematic review of 100 studies published between Jan 1, 1995, and Dec 31, 2018, and a further 57 high-quality unpublished studies. We adapted the Newcastle-Ottawa Scale to assess the risk of bias. We estimated incidence and hospitalisation rates of influenza-virus-associated respiratory infections by severity, case ascertainment, region, and age. We estimated in-hospital deaths from influenza virus ALRI by combining hospital admissions and in-hospital case-fatality ratios of influenza virus ALRI. We estimated the upper bound of influenza virus-associated ALRI deaths based on the number of in-hospital deaths, US paediatric influenza-associated death data, and population-based childhood all-cause pneumonia mortality data in six sites in low-income and lower-middle-income countries. # Findings # In 2018, among children under 5 years globally, there were an estimated 109*5 million influenza virus episodes (uncertainty range [UR] 63*1-190*6), 10*1 million influenza-virus-associated ALRI cases (6*8-15*1); 870 000 influenza-virus-associated ALRI hospital admissions (543 000-1 415 000), 15 300 in-hospital deaths (5800-43 800), and up to 34 800 (13 200-97 200) overall influenza-virus-associated ALRI deaths. Influenza virus accounted for 7% of ALRI cases, 5% of ALRI hospital admissions, and 4% of ALRI deaths in children under 5 years. About 23% of the hospital admissions and 36% of the in-hospital deaths were in infants under 6 months. About 82% of the in-hospital deaths occurred in low-income and lower-middle-income countries. # Interpretation # A large proportion of the influenza-associated burden occurs among young infants and in low-income and lower middle-income countries. Our findings provide new and important evidence for maternal and paediatric influenza immunisation, and should inform future immunisation policy particularly in low-income and middle-income countries.

In 2023, there were **** deaths from influenza and pneumonia in Canada per 100,000 population. Influenza, more commonly known as the flu, is a highly contagious viral infection and frequent cause of pneumonia. Pneumonia is a more serious infection of the lungs and is particularly deadly among young children, the elderly, and those with certain chronic conditions. Vaccination There exist vaccines for both influenza and pneumonia, and although effectiveness varies, vaccination remains one of the best ways to prevent these illnesses. Nevertheless, only around ** percent of Canadians received an influenza vaccination in the past year in 2022. The most common reason why Canadian adults received the influenza vaccination was to prevent infection or because they did not want to get sick. Pneumonia hospitalization Every year tens of thousand of people in Canada are hospitalized for pneumonia. In *********, there were over ****** emergency room visits for pneumonia in Canada, a substantial decrease from the numbers recorded from 2010 to 2020. Perhaps unsurprisingly, those aged 65 years and older account for the highest number of emergency room visits for pneumonia. The median length of stay for emergency department visits for pneumonia in Canada has increased in recent years, with the median length of stay around *** minutes in *********.