2018-19 USA Influenza & Pneumonia Mortality Surveillance Data from the National Center for Health Statistics Mortality Surveillance System

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 29
Week 46: 25
Week 47: 31
Week 48: 35
Week 49: 54
Week 50: 48
Week 51: 83
Week 52: 112
Week 1: 172
Week 2: 212
Week 3: 177
Week 4: 158
Total: 1,224

Pneumonia deaths
Week 40: 2,933
Week 41: 2,817
Week 42: 2,953
Week 43: 3,032
Week 44: 2,949
Week 45: 2,931
Week 46: 3,058
Week 47: 3,080
Week 48: 3,159
Week 49: 3,210
Week 50: 3,321
Week 51: 3,154
Week 52: 3,154
Week 1: 3,254
Week 2: 3,153
Week 3: 3,007
Week 4: 2,298
Total: 51,463

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 4 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 1,224
2017-18: 7,426
2016-17: 1,878
2015-16: 377
2014-15: 5,028
2013-14: 2,294
2012-13: 2,833

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 29
Week 46: 25
Week 47: 31
Week 48: 35
Week 49: 54
Week 50: 48
Week 51: 84
Week 52: 122
Week 1: 177
Week 2: 217
Week 3: 194
Week 4: 191
Week 5: 182
Total: 1,477

Pneumonia deaths
Week 40: 2,941
Week 41: 2,844
Week 42: 2,953
Week 43: 3,034
Week 44: 2,953
Week 45: 2,934
Week 46: 3,062
Week 47: 3,089
Week 48: 3,177
Week 49: 3,226
Week 50: 3,353
Week 51: 3,239
Week 52: 3,302
Week 1: 3,339
Week 2: 3,255
Week 3: 3,228
Week 4: 2,794
Week 5: 2,367
Total: 55,090

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 5 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 1,477
2017-18: 8,782
2016-17: 2,229
2015-16: 438
2014-15: 5,611
2013-14: 2,679
2012-13: 3,225

[Ronan Kelly]

2018-2019 U.S. Flu Season: Preliminary Burden Estimates



Language: English (US)

• Espa?ol

*These estimates are preliminary and based on data from CDC’s weekly influenza surveillance reports summarizing key influenza activity indicators.
On This Page

• Limitations
• Frequently Asked Questions

This web page provides weekly preliminary estimates of the cumulative in-season numbers of flu illnesses, medical visits and hospitalizations in the United States. CDC has estimated the burden of flu since 2010 using a mathematical model that is based on observed rates of laboratory-confirmed influenza-associated hospitalizations collected through a surveillance network that covers approximately 8.5% of the U.S. population (~27 million people). Estimates of flu-related deaths will be provided at a later time, when there is sufficient data to support a more precise estimate for that outcome.
The 2018-2019 flu season is the first season CDC has reported in-season burden estimates of flu in the U.S. These in-season estimates will be updated over the course of the flu season.


Limitations

The estimates of the cumulative burden of seasonal influenza are subject to several limitations.
First, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations reported during the season may be an under-estimate of the rate at the end of the season because of identification and reporting delays.
Second, rates of laboratory-confirmed influenza-associated hospitalizations were adjusted for the frequency of influenza testing and the sensitivity of influenza diagnostic assays. However, data on testing practices during the 2018-2019 season are not available in real-time. CDC used data on testing practices from the 2014-2015 influenza season as a proxy. Burden estimates will be updated at a later date when data on contemporary testing practices become available.
Third, estimates of influenza-associated illness and medical visits are based on data from prior seasons, which may not be accurate if the seriousness of illness or patterns of care-seeking have changed.
Frequently Asked Questions

What does the cumulative burden of influenza for the 2018-2019 season mean?

The cumulative burden of influenza is an estimate of the number of people who have been sick, seen a healthcare provider, been hospitalized, or died as a result of influenza since October 01, 2018. CDC does not know the exact number of people who have been sick 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 mathematical model, based on observed rates of laboratory-confirmed influenza-associated hospitalizations.
How does CDC estimate the cumulative burden of seasonal influenza?

Preliminary estimates of the cumulative burden of seasonal influenza during the 2018-2019 season in the United States are based on crude rates of laboratory-confirmed influenza-associated hospitalizations, reported through the Influenza Hospitalization Surveillance Network (FluSurv-NET), which were adjusted for the frequency of influenza testing during recent prior seasons and the sensitivity of influenza diagnostic assays. Rates of hospitalization were then multiplied by previously estimated ratio of hospitalizations to symptomatic illnesses, and frequency of seeking medical care to calculate symptomatic illnesses, medical visits, and deaths associated with seasonal influenza, respectively.
Why does the estimate of cumulative burden change each week?

The estimates of cumulative burden of seasonal influenza are considered preliminary and may change each week as new laboratory-confirmed influenza-associated hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the reporting week and also 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 number of hospitalizations estimated so far this season is lower than end-of-season total hospitalization estimates for any season since CDC began making these estimates. This table also summarizes all estimated influenza disease burden, by season, in U.S. from 2010-11 through 2017-18.

Top of Page

Preliminary Cumulative Estimates of Hospitalizations in the U.S. 2018-2019 Flu Season


*These estimates are preliminary and based on data from CDC’s weekly influenza surveillance reports summarizing key influenza activity indicators.
508 text for this chart:
Estimated number of influenza-associated hospitalizations
The y-axis extends from 0 to 1 million.
The x-axis is a timeline starting November 24 and extending to April 27.
There is a single blue-shaded curve labeled with “2018/19”.
There are several other lines on the right side of the graph under Total hospitalizations at end of past seasons. The lines are labeled, from top to bottom, as 2017/18, 2014/15, 2016/17, 2012/13, 2013/14, 2015/16, 2010/11, and 2011/12.




[/COLOR]

https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 29
Week 46: 25
Week 47: 31
Week 48: 35
Week 49: 54
Week 50: 48
Week 51: 85
Week 52: 123
Week 1: 180
Week 2: 222
Week 3: 205
Week 4: 218
Week 5: 236
Week 6: 205
Total: 1,784

Pneumonia deaths
Week 40: 2,944
Week 41: 2,844
Week 42: 2,956
Week 43: 3,037
Week 44: 2,958
Week 45: 2,943
Week 46: 3,067
Week 47: 3,092
Week 48: 3,184
Week 49: 3,238
Week 50: 3,371
Week 51: 3,286
Week 52: 3,360
Week 1: 3,417
Week 2: 3,433
Week 3: 3,485
Week 4: 3,112
Week 5: 2,964
Week 6: 2,263
Total: 58,954

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 6 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 1,784
2017-18: 10,022
2016-17: 2,648
2015-16: 531
2014-15: 6,095
2013-14: 2,994
2012-13: 3,492

[Ronan Kelly]

2018-2019 U.S. Flu Season: Preliminary Burden Estimates

*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
On This Page

• Limitations
• Frequently Asked Questions

This web page provides weekly preliminary estimates of the cumulative in-season numbers of flu illnesses, medical visits, hospitalizations, and deaths in the United States. CDC has estimated the burden of flu since 2010 using a mathematical model that is based on observed rates of laboratory-confirmed influenza-associated hospitalizations collected through a surveillance network that covers approximately 8.5% of the U.S. population (~27 million people).
The 2018-2019 flu season is the first season CDC has reported in-season burden estimates of flu in the U.S. These in-season estimates will be updated over the course of the flu season.


Limitations

The estimates of the cumulative burden of seasonal influenza are subject to several limitations.
First, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations reported during the season may be an under-estimate of the rate at the end of the season because of identification and reporting delays.
Second, rates of laboratory-confirmed influenza-associated hospitalizations were adjusted for the frequency of influenza testing and the sensitivity of influenza diagnostic assays. However, data on testing practices during the 2018-2019 season are not available in real-time. CDC used data on testing practices from the 2014-2015 influenza season as a proxy. Burden estimates will be updated at a later date when data on contemporary testing practices become available.
Third, estimates of influenza-associated illness and medical visits are based on data from prior seasons, which may not be accurate if the seriousness of illness or patterns of care-seeking have changed.
Frequently Asked Questions

What does the cumulative burden of influenza for the 2018-2019 season mean?

The cumulative burden of influenza is an estimate of the number of people who have been sick, seen a healthcare provider, been hospitalized, or died as a result of influenza since October 01, 2018. CDC does not know the exact number of people who have been sick 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 mathematical model, based on observed rates of laboratory-confirmed influenza-associated hospitalizations.
How does CDC estimate the cumulative burden of seasonal influenza?

Preliminary estimates of the cumulative burden of seasonal influenza during the 2018-2019 season in the United States are based on crude rates of laboratory-confirmed influenza-associated hospitalizations, reported through the Influenza Hospitalization Surveillance Network (FluSurv-NET), which were adjusted for the frequency of influenza testing during recent prior seasons and the sensitivity of influenza diagnostic assays. Rates of hospitalization were then multiplied by previously estimated ratio of hospitalizations to symptomatic illnesses, and frequency of seeking medical care to calculate symptomatic illnesses, medical visits, and deaths associated with seasonal influenza, respectively.
Why does the estimate of cumulative burden change each week?

The estimates of cumulative burden of seasonal influenza are considered preliminary and may change each week as new laboratory-confirmed influenza-associated hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the reporting week and also 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 number of hospitalizations estimated so far this season is lower than end-of-season total hospitalization estimates for any season since CDC began making these estimates. This table also summarizes all estimated influenza disease burden, by season, in U.S. from 2010-11 through 2017-18.

Top of Page

Preliminary Cumulative Estimates of Hospitalizations in the U.S. 2018-2019 Flu Season


*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
508 text for this chart:
Estimated number of influenza-associated hospitalizations
The y-axis extends from 0 to 1 million.
The x-axis is a timeline starting November 24 and extending to April 27.
There is a single blue-shaded curve labeled with ?2018/19?.
There are several other lines on the right side of the graph under Total hospitalizations at end of past seasons. The lines are labeled, from top to bottom, as 2017/18, 2014/15, 2016/17, 2012/13, 2013/14, 2015/16, 2010/11, and 2011/12.

https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 29
Week 46: 26
Week 47: 31
Week 48: 35
Week 49: 54
Week 50: 49
Week 51: 85
Week 52: 129
Week 1: 183
Week 2: 228
Week 3: 211
Week 4: 233
Week 5: 260
Week 6: 268
Week 7: 289
Total: 2,198

Pneumonia deaths
Week 40: 2,946
Week 41: 2,849
Week 42: 2,960
Week 43: 3,043
Week 44: 2,964
Week 45: 2,951
Week 46: 3,071
Week 47: 3,101
Week 48: 3,198
Week 49: 3,257
Week 50: 3,402
Week 51: 3,336
Week 52: 3,437
Week 1: 3,531
Week 2: 3,547
Week 3: 3,624
Week 4: 3,369
Week 5: 3,271
Week 6: 3,033
Week 7: 2,487
Total: 63,377

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 7 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 2,198
2017-18: 11,201
2016-17: 3,192
2015-16: 680
2014-15: 6,500
2013-14: 3,265
2012-13: 3,701

[Ronan Kelly]

2018-2019 U.S. Flu Season: Preliminary Burden Estimates



Language: English (US)

• Espa?ol

*These estimates are preliminary and based on data from CDC’s weekly influenza surveillance reports summarizing key influenza activity indicators.
On This Page

• Limitations
• Frequently Asked Questions

This web page provides weekly preliminary estimates of the cumulative in-season numbers of flu illnesses, medical visits, hospitalizations, and deaths in the United States. CDC has estimated the burden of flu since 2010 using a mathematical model that is based on observed rates of laboratory-confirmed influenza-associated hospitalizations collected through a surveillance network that covers approximately 8.5% of the U.S. population (~27 million people).
The 2018-2019 flu season is the first season CDC has reported in-season burden estimates of flu in the U.S. These in-season estimates will be updated over the course of the flu season.


Limitations

The estimates of the cumulative burden of seasonal influenza are subject to several limitations.
First, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations reported during the season may be an under-estimate of the rate at the end of the season because of identification and reporting delays.
Second, rates of laboratory-confirmed influenza-associated hospitalizations were adjusted for the frequency of influenza testing and the sensitivity of influenza diagnostic assays. However, data on testing practices during the 2018-2019 season are not available in real-time. CDC used data on testing practices from the 2014-2015 influenza season as a proxy. Burden estimates will be updated at a later date when data on contemporary testing practices become available.
Third, estimates of influenza-associated illness and medical visits are based on data from prior seasons, which may not be accurate if the seriousness of illness or patterns of care-seeking have changed.
Frequently Asked Questions

What does the cumulative burden of influenza for the 2018-2019 season mean?

The cumulative burden of influenza is an estimate of the number of people who have been sick, seen a healthcare provider, been hospitalized, or died as a result of influenza since October 01, 2018. CDC does not know the exact number of people who have been sick 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 mathematical model, based on observed rates of laboratory-confirmed influenza-associated hospitalizations.
How does CDC estimate the cumulative burden of seasonal influenza?

Preliminary estimates of the cumulative burden of seasonal influenza during the 2018-2019 season in the United States are based on crude rates of laboratory-confirmed influenza-associated hospitalizations, reported through the Influenza Hospitalization Surveillance Network (FluSurv-NET), which were adjusted for the frequency of influenza testing during recent prior seasons and the sensitivity of influenza diagnostic assays. Rates of hospitalization were then multiplied by previously estimated ratio of hospitalizations to symptomatic illnesses, and frequency of seeking medical care to calculate symptomatic illnesses, medical visits, and deaths associated with seasonal influenza, respectively.
Why does the estimate of cumulative burden change each week?

The estimates of cumulative burden of seasonal influenza are considered preliminary and may change each week as new laboratory-confirmed influenza-associated hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the reporting week and also 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 number of hospitalizations estimated so far this season is lower than end-of-season total hospitalization estimates for any season since CDC began making these estimates. This table also summarizes all estimated influenza disease burden, by season, in U.S. from 2010-11 through 2017-18.

Top of Page

Preliminary Cumulative Estimates of Hospitalizations in the U.S. 2018-2019 Flu Season

*These estimates are preliminary and based on data from CDC’s weekly influenza surveillance reports summarizing key influenza activity indicators.
508 text for this chart:
Estimated number of influenza-associated hospitalizations
The y-axis extends from 0 to 1 million.
The x-axis is a timeline starting November 24 and extending to April 27.
There is a single blue-shaded curve labeled with “2018/19”.
There are several other lines on the right side of the graph under Total hospitalizations at end of past seasons. The lines are labeled, from top to bottom, as 2017/18, 2014/15, 2016/17, 2012/13, 2013/14, 2015/16, 2010/11, and 2011/12.

https://www.cdc.gov/flu/about/burden...-estimates.htm

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 29
Week 46: 26
Week 47: 31
Week 48: 36
Week 49: 54
Week 50: 49
Week 51: 84
Week 52: 130
Week 1: 193
Week 2: 237
Week 3: 220
Week 4: 244
Week 5: 278
Week 6: 291
Week 7: 344
Week 8: 286
Total: 2,620

Pneumonia deaths
Week 40: 2,951
Week 41: 2,849
Week 42: 2,963
Week 43: 3,044
Week 44: 2,967
Week 45: 2,955
Week 46: 3,069
Week 47: 3,103
Week 48: 3,204
Week 49: 3,267
Week 50: 3,412
Week 51: 3,351
Week 52: 3,465
Week 1: 3,679
Week 2: 3,756
Week 3: 3,809
Week 4: 3,554
Week 5: 3,453
Week 6: 3,297
Week 7: 3,019
Week 8: 2,629
Total: 67,796

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 8 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 2,620
2017-18: 12,087
2016-17: 3,798
2015-16: 867
2014-15: 6,785
2013-14: 3,474
2012-13: 3,868

[Ronan Kelly]

2018-2019 U.S. Flu Season: Preliminary Burden Estimates

*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
On This Page

• Limitations
• Frequently Asked Questions

This web page provides weekly preliminary estimates of the cumulative in-season numbers of flu illnesses, medical visits, hospitalizations, and deaths in the United States. CDC has estimated the burden of flu since 2010 using a mathematical model that is based on observed rates of laboratory-confirmed influenza-associated hospitalizations collected through a surveillance network that covers approximately 8.5% of the U.S. population (~27 million people).
The 2018-2019 flu season is the first season CDC has reported in-season burden estimates of flu in the U.S. These in-season estimates will be updated over the course of the flu season.


Limitations

The estimates of the cumulative burden of seasonal influenza are subject to several limitations.
First, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations reported during the season may be an under-estimate of the rate at the end of the season because of identification and reporting delays.
Second, rates of laboratory-confirmed influenza-associated hospitalizations were adjusted for the frequency of influenza testing and the sensitivity of influenza diagnostic assays. However, data on testing practices during the 2018-2019 season are not available in real-time. CDC used data on testing practices from the 2014-2015 influenza season as a proxy. Burden estimates will be updated at a later date when data on contemporary testing practices become available.
Third, estimates of influenza-associated illness and medical visits are based on data from prior seasons, which may not be accurate if the seriousness of illness or patterns of care-seeking have changed.
Frequently Asked Questions

What does the cumulative burden of influenza for the 2018-2019 season mean?

The cumulative burden of influenza is an estimate of the number of people who have been sick, seen a healthcare provider, been hospitalized, or died as a result of influenza since October 01, 2018. CDC does not know the exact number of people who have been sick 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 mathematical model, based on observed rates of laboratory-confirmed influenza-associated hospitalizations.
How does CDC estimate the cumulative burden of seasonal influenza?

Preliminary estimates of the cumulative burden of seasonal influenza during the 2018-2019 season in the United States are based on crude rates of laboratory-confirmed influenza-associated hospitalizations, reported through the Influenza Hospitalization Surveillance Network (FluSurv-NET), which were adjusted for the frequency of influenza testing during recent prior seasons and the sensitivity of influenza diagnostic assays. Rates of hospitalization were then multiplied by previously estimated ratio of hospitalizations to symptomatic illnesses, and frequency of seeking medical care to calculate symptomatic illnesses, medical visits, and deaths associated with seasonal influenza, respectively.
Why does the estimate of cumulative burden change each week?

The estimates of cumulative burden of seasonal influenza are considered preliminary and may change each week as new laboratory-confirmed influenza-associated hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the reporting week and also 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 number of hospitalizations estimated so far this season is lower than end-of-season total hospitalization estimates for any season since CDC began making these estimates. This table also summarizes all estimated influenza disease burden, by season, in U.S. from 2010-11 through 2017-18.

Top of Page

Preliminary Cumulative Estimates of Hospitalizations in the U.S. 2018-2019 Flu Season


*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
508 text for this chart:
Estimated number of influenza-associated hospitalizations
The y-axis extends from 0 to 1 million.
The x-axis is a timeline starting November 24 and extending to April 27.
There is a single blue-shaded curve labeled with ?2018/19?.
There are several other lines on the right side of the graph under Total hospitalizations at end of past seasons. The lines are labeled, from top to bottom, as 2017/18, 2014/15, 2016/17, 2012/13, 2013/14, 2015/16, 2010/11, and 2011/12.
...

https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 30
Week 46: 26
Week 47: 31
Week 48: 37
Week 49: 54
Week 50: 49
Week 51: 85
Week 52: 132
Week 1: 199
Week 2: 242
Week 3: 225
Week 4: 246
Week 5: 281
Week 6: 304
Week 7: 372
Week 8: 339
Week 9: 321
Total: 3,061

Pneumonia deaths
Week 40: 2,952
Week 41: 2,852
Week 42: 2,964
Week 43: 3,046
Week 44: 2,985
Week 45: 2,997
Week 46: 3,109
Week 47: 3,142
Week 48: 3,236
Week 49: 3,279
Week 50: 3,424
Week 51: 3,368
Week 52: 3,488
Week 1: 3,743
Week 2: 3,839
Week 3: 3,866
Week 4: 3,608
Week 5: 3,524
Week 6: 3,445
Week 7: 3,310
Week 8: 3,188
Week 9: 2,391
Total: 71,756

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 9 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 3,061
2017-18: 12,823
2016-17: 4,333
2015-16: 1,124
2014-15: 6,975
2013-14: 3,635
2012-13: 4,016

[Ronan Kelly]

2018-2019 U.S. Flu Season: Preliminary Burden Estimates


*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
On This Page

• Limitations
• Frequently Asked Questions

This web page provides weekly preliminary estimates of the cumulative in-season numbers of flu illnesses, medical visits, hospitalizations, and deaths in the United States. CDC has estimated the burden of flu since 2010 using a mathematical model that is based on observed rates of laboratory-confirmed influenza-associated hospitalizations collected through a surveillance network that covers approximately 8.5% of the U.S. population (~27 million people).
The 2018-2019 flu season is the first season CDC has reported in-season burden estimates of flu in the U.S. These in-season estimates will be updated over the course of the flu season.


Limitations

The estimates of the cumulative burden of seasonal influenza are subject to several limitations.
First, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations reported during the season may be an under-estimate of the rate at the end of the season because of identification and reporting delays.
Second, rates of laboratory-confirmed influenza-associated hospitalizations were adjusted for the frequency of influenza testing and the sensitivity of influenza diagnostic assays. However, data on testing practices during the 2018-2019 season are not available in real-time. CDC used data on testing practices from the 2014-2015 influenza season as a proxy. Burden estimates will be updated at a later date when data on contemporary testing practices become available.
Third, estimates of influenza-associated illness and medical visits are based on data from prior seasons, which may not be accurate if the seriousness of illness or patterns of care-seeking have changed.
Frequently Asked Questions

What does the cumulative burden of influenza for the 2018-2019 season mean?

The cumulative burden of influenza is an estimate of the number of people who have been sick, seen a healthcare provider, been hospitalized, or died as a result of influenza since October 01, 2018. CDC does not know the exact number of people who have been sick 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 mathematical model, based on observed rates of laboratory-confirmed influenza-associated hospitalizations.
How does CDC estimate the cumulative burden of seasonal influenza?

Preliminary estimates of the cumulative burden of seasonal influenza during the 2018-2019 season in the United States are based on crude rates of laboratory-confirmed influenza-associated hospitalizations, reported through the Influenza Hospitalization Surveillance Network (FluSurv-NET), which were adjusted for the frequency of influenza testing during recent prior seasons and the sensitivity of influenza diagnostic assays. Rates of hospitalization were then multiplied by previously estimated ratio of hospitalizations to symptomatic illnesses, and frequency of seeking medical care to calculate symptomatic illnesses, medical visits, and deaths associated with seasonal influenza, respectively.
Why does the estimate of cumulative burden change each week?

The estimates of cumulative burden of seasonal influenza are considered preliminary and may change each week as new laboratory-confirmed influenza-associated hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the reporting week and also 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 number of hospitalizations estimated so far this season is lower than end-of-season total hospitalization estimates for any season since CDC began making these estimates. This table also summarizes all estimated influenza disease burden, by season, in U.S. from 2010-11 through 2017-18.

Top of Page

Preliminary Cumulative Estimates of Hospitalizations in the U.S. 2018-2019 Flu Season


*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
508 text for this chart:
Estimated number of influenza-associated hospitalizations
The y-axis extends from 0 to 1 million.
The x-axis is a timeline starting November 24 and extending to April 27.
There is a single blue-shaded curve labeled with ?2018/19?.
There are several other lines on the right side of the graph under Total hospitalizations at end of past seasons. The lines are labeled, from top to bottom, as 2017/18, 2014/15, 2016/17, 2012/13, 2013/14, 2015/16, 2010/11, and 2011/12.

https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 30
Week 46: 26
Week 47: 31
Week 48: 37
Week 49: 54
Week 50: 49
Week 51: 87
Week 52: 134
Week 1: 200
Week 2: 242
Week 3: 228
Week 4: 247
Week 5: 286
Week 6: 312
Week 7: 395
Week 8: 368
Week 9: 395
Week 10: 331
Total: 3,540

Pneumonia deaths
Week 40: 2,953
Week 41: 2,856
Week 42: 2,965
Week 43: 3,049
Week 44: 2,987
Week 45: 3,002
Week 46: 3,113
Week 47: 3,149
Week 48: 3,242
Week 49: 3,302
Week 50: 3,469
Week 51: 3,390
Week 52: 3,519
Week 1: 3,765
Week 2: 3,870
Week 3: 3,889
Week 4: 3,644
Week 5: 3,589
Week 6: 3,543
Week 7: 3,411
Week 8: 3,417
Week 9: 2,977
Week 10: 2,415
Total: 75,516

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 10 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 3,540
2017-18: 13,327
2016-17: 4,802
2015-16: 1,418
2014-15: 7,134
2013-14: 3,760
2012-13: 4,119

[Ronan Kelly]

2018-2019 U.S. Flu Season: Preliminary Burden Estimates

*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
On This Page

• Limitations
• Frequently Asked Questions

This web page provides weekly preliminary estimates of the cumulative in-season numbers of flu illnesses, medical visits, hospitalizations, and deaths in the United States. CDC has estimated the burden of flu since 2010 using a mathematical model that is based on observed rates of laboratory-confirmed influenza-associated hospitalizations collected through a surveillance network that covers approximately 8.5% of the U.S. population (~27 million people).
The 2018-2019 flu season is the first season CDC has reported in-season burden estimates of flu in the U.S. These in-season estimates will be updated over the course of the flu season.


Limitations

The estimates of the cumulative burden of seasonal influenza are subject to several limitations.
First, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations reported during the season may be an under-estimate of the rate at the end of the season because of identification and reporting delays.
Second, rates of laboratory-confirmed influenza-associated hospitalizations were adjusted for the frequency of influenza testing and the sensitivity of influenza diagnostic assays. However, data on testing practices during the 2018-2019 season are not available in real-time. CDC used data on testing practices from the 2014-2015 influenza season as a proxy. Burden estimates will be updated at a later date when data on contemporary testing practices become available.
Third, estimates of influenza-associated illness and medical visits are based on data from prior seasons, which may not be accurate if the seriousness of illness or patterns of care-seeking have changed.
Frequently Asked Questions

What does the cumulative burden of influenza for the 2018-2019 season mean?

The cumulative burden of influenza is an estimate of the number of people who have been sick, seen a healthcare provider, been hospitalized, or died as a result of influenza since October 01, 2018. CDC does not know the exact number of people who have been sick 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 mathematical model, based on observed rates of laboratory-confirmed influenza-associated hospitalizations.
How does CDC estimate the cumulative burden of seasonal influenza?

Preliminary estimates of the cumulative burden of seasonal influenza during the 2018-2019 season in the United States are based on crude rates of laboratory-confirmed influenza-associated hospitalizations, reported through the Influenza Hospitalization Surveillance Network (FluSurv-NET), which were adjusted for the frequency of influenza testing during recent prior seasons and the sensitivity of influenza diagnostic assays. Rates of hospitalization were then multiplied by previously estimated ratio of hospitalizations to symptomatic illnesses, and frequency of seeking medical care to calculate symptomatic illnesses, medical visits, and deaths associated with seasonal influenza, respectively.
Why does the estimate of cumulative burden change each week?

The estimates of cumulative burden of seasonal influenza are considered preliminary and may change each week as new laboratory-confirmed influenza-associated hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the reporting week and also 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 number of hospitalizations estimated so far this season is lower than end-of-season total hospitalization estimates for any season since CDC began making these estimates. This table also summarizes all estimated influenza disease burden, by season, in U.S. from 2010-11 through 2017-18.

Top of Page

Preliminary Cumulative Estimates of Hospitalizations in the U.S. 2018-2019 Flu Season


*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
508 text for this chart:
Estimated number of influenza-associated hospitalizations
The y-axis extends from 0 to 1 million.
The x-axis is a timeline starting November 24 and extending to April 27.
There is a single blue-shaded curve labeled with ?2018/19?.
There are several other lines on the right side of the graph under Total hospitalizations at end of past seasons. The lines are labeled, from top to bottom, as 2017/18, 2014/15, 2016/17, 2012/13, 2013/14, 2015/16, 2010/11, and 2011/12.

https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm

[Ronan Kelly]

Influenza deaths
Week 40: 10
Week 41: 12
Week 42: 18
Week 43: 24
Week 44: 24
Week 45: 30
Week 46: 26
Week 47: 31
Week 48: 37
Week 49: 54
Week 50: 49
Week 51: 87
Week 52: 134
Week 1: 202
Week 2: 245
Week 3: 229
Week 4: 250
Week 5: 298
Week 6: 322
Week 7: 401
Week 8: 380
Week 9: 416
Week 10: 412
Week 11: 306
Total: 3,997

Pneumonia deaths
Week 40: 2,954
Week 41: 2,856
Week 42: 2,967
Week 43: 3,051
Week 44: 2,988
Week 45: 3,002
Week 46: 3,116
Week 47: 3,154
Week 48: 3,245
Week 49: 3,305
Week 50: 3,473
Week 51: 3,395
Week 52: 3,526
Week 1: 3,780
Week 2: 3,896
Week 3: 3,929
Week 4: 3,676
Week 5: 3,652
Week 6: 3,585
Week 7: 3,479
Week 8: 3,490
Week 9: 3,150
Week 10: 2,887
Week 11: 2,483
Total: 79,039

https://gis.cdc.gov/grasp/fluview/mortality.html

Comparison of influenza death certificates Weeks 40 - 11 with corresponding period from previous years (note figures for 2018-19 are preliminary and are likely to increase)
2018-19: 3,997
2017-18: 13,769
2016-17: 5,178
2015-16: 1,769
2014-15: 7,273
2013-14: 3,853
2012-13: 4,228

[Ronan Kelly]

2018-2019 U.S. Flu Season: Preliminary Burden Estimates

*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
On This Page

• Limitations
• Frequently Asked Questions

This web page provides weekly preliminary estimates of the cumulative in-season numbers of flu illnesses, medical visits, hospitalizations, and deaths in the United States. CDC has estimated the burden of flu since 2010 using a mathematical model that is based on observed rates of laboratory-confirmed influenza-associated hospitalizations collected through a surveillance network that covers approximately 8.5% of the U.S. population (~27 million people).
The 2018-2019 flu season is the first season CDC has reported in-season burden estimates of flu in the U.S. These in-season estimates will be updated over the course of the flu season.


Limitations

The estimates of the cumulative burden of seasonal influenza are subject to several limitations.
First, the cumulative rate of laboratory-confirmed influenza-associated hospitalizations reported during the season may be an under-estimate of the rate at the end of the season because of identification and reporting delays.
Second, rates of laboratory-confirmed influenza-associated hospitalizations were adjusted for the frequency of influenza testing and the sensitivity of influenza diagnostic assays. However, data on testing practices during the 2018-2019 season are not available in real-time. CDC used data on testing practices from the 2014-2015 influenza season as a proxy. Burden estimates will be updated at a later date when data on contemporary testing practices become available.
Third, estimates of influenza-associated illness and medical visits are based on data from prior seasons, which may not be accurate if the seriousness of illness or patterns of care-seeking have changed.
Frequently Asked Questions

What does the cumulative burden of influenza for the 2018-2019 season mean?

The cumulative burden of influenza is an estimate of the number of people who have been sick, seen a healthcare provider, been hospitalized, or died as a result of influenza since October 01, 2018. CDC does not know the exact number of people who have been sick 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 mathematical model, based on observed rates of laboratory-confirmed influenza-associated hospitalizations.
How does CDC estimate the cumulative burden of seasonal influenza?

Preliminary estimates of the cumulative burden of seasonal influenza during the 2018-2019 season in the United States are based on crude rates of laboratory-confirmed influenza-associated hospitalizations, reported through the Influenza Hospitalization Surveillance Network (FluSurv-NET), which were adjusted for the frequency of influenza testing during recent prior seasons and the sensitivity of influenza diagnostic assays. Rates of hospitalization were then multiplied by previously estimated ratio of hospitalizations to symptomatic illnesses, and frequency of seeking medical care to calculate symptomatic illnesses, medical visits, and deaths associated with seasonal influenza, respectively.
Why does the estimate of cumulative burden change each week?

The estimates of cumulative burden of seasonal influenza are considered preliminary and may change each week as new laboratory-confirmed influenza-associated hospitalizations are reported to CDC. New reports include both new admissions that have occurred during the reporting week and also 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 number of hospitalizations estimated so far this season is lower than end-of-season total hospitalization estimates for any season since CDC began making these estimates. This table also summarizes all estimated influenza disease burden, by season, in U.S. from 2010-11 through 2017-18.

Top of Page

Preliminary Cumulative Estimates of Hospitalizations in the U.S. 2018-2019 Flu Season


*These estimates are preliminary and based on data from CDC?s weekly influenza surveillance reports summarizing key influenza activity indicators.
508 text for this chart:
Estimated number of influenza-associated hospitalizations
The y-axis extends from 0 to 1 million.
The x-axis is a timeline starting November 24 and extending to April 27.
There is a single blue-shaded curve labeled with ?2018/19?.
There are several other lines on the right side of the graph under Total hospitalizations at end of past seasons. The lines are labeled, from top to bottom, as 2017/18, 2014/15, 2016/17, 2012/13, 2013/14, 2015/16, 2010/11, and 2011/12.

https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm