Limitations
The estimates of the preliminary, accumulative charge of seasonal influenza are capable to several limitations .
first, the accumulative rate of lab-confirmed flu-related hospitalizations reported during the season may be an lowball of the pace at the end of the season because of identification and report delays .
second, rates of lab-confirmed flu-related hospitalizations were adjusted for the frequency of influenza quiz and the sensitivity of influenza diagnostic assays. however, data on testing practices during the current influenza temper are not available in real-time. To make these estimates, CDC uses data on testing practices from the past influenza seasons as a proxy. If more examination is being done compared to past influenza seasons, these estimates may be inflated. preliminary in-season load estimates are finalized when data on contemporary quiz practices become available, and the estimates may decrease if test has increased. During the ongoing COVID-19 pandemic, testing may be higher and it is potential these estimates will be higher than our final examination estimates .
Third, estimates aesculapian visits for flu-like illnesses are based on data from prior seasons, which may not be accurate if the severity of illness or patterns of care-seeking have changed.
Frequently Asked Questions
What is cumulative burden of flu?
CDC does not know the exact issue of people who have been ill and affected by influenza because influenza is not a reportable disease in most areas of the United States. however, these numbers are estimated using a numerical exemplar, based on observe rates of lab-confirmed The accumulative load of influenza is an appraisal of the count of people who have been ghastly, seen a healthcare provider, been hospitalized, or died as a result of influenza within a certain timeframe. The in-season preliminary effect estimates are supply weekly during influenza season when sufficient data are available to make an appraisal, and end-of-season preliminary estimates are given at the end of each influenza temper. End-of-season preliminary estimates will be updated year-to-year and are considered final examination when all data are available ( used to calculate these estimates are on a biennial stay ) .
How does CDC estimate the cumulative burden of seasonal flu?
preliminary estimates of the accumulative burden of seasonal worker flu are based on crude rates of lab-confirmed flu-related hospitalizations, reported through the Influenza Hospitalization Surveillance Network ( FluSurv-NET ), which are adjusted for the frequency of influenza testing during holocene anterior seasons and the sensitivity of influenza diagnostic tests. Rates of hospitalization are then multiplied by previously estimated proportion of hospitalizations to diagnostic illnesses, and frequency of seeking checkup care to calculate diagnostic illnesses, checkup visits, hospitalizations, and deaths associated with seasonal worker influenza, respectively.
Read more: Having SARS-CoV-2 once confers much greater immunity than a vaccine—but vaccination remains vital
Why does the preliminary, in-season estimate of flu burden change each week?
The in-season estimates of influenza burden are preliminary and transfer week-by-week as new influenza hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the report week and besides patients admitted in previous weeks that have been newly reported to CDC .
How does the number of flu hospitalizations estimated so far this season compare with previous end-of-season hospitalization estimates?
The estimates on this page are preliminary, accumulative and will increase as the season progresses. past end-of-season estimates ( 2010-2020 ) have ranged from 140,000-710,000 and are available here.
Read more: Having SARS-CoV-2 once confers much greater immunity than a vaccine—but vaccination remains vital
What was the estimated burden for 2020-2021?
CDC was not able to calculate the accumulative charge of influenza for the 2020-2021 influenza season, due to historically low numbers of influenza .
More information on the 2020-2021 influenza temper burden estimates is available here .
For information about the calculate burden of COVID-19, visit : Estimated COVID-19 Burden | CDC .
