National Notifiable Diseases Surveillance System (NNDSS)
Annual Summary Data
2016 – 2021

Summary

Incidence:

This database contains the reported occurrence of nationally notifiable infectious diseases in the United States for years 2016 – 2021, as published in the National Notifiable Diseases Surveillance System (NNDSS) Annual Tables.

These statistics are collected and compiled from reports sent by state and territorial health departments to the NNDSS, which is operated by CDC in collaboration with the Council of State and Territorial Epidemiologists (CSTE).

The published annual summary tables are also available from the following resources:

  • NNDSS Annual Tables for years 2016 and later are available at NNDSS Annual Tables.
  • NNDSS annual tables since 1952 are available at CDC Stacks (once in CDC Stacks, select "Annual Reports" in the "Genre" box to the left).
  • Annual summary reports from 1993 –2015 are available as published in the Morbidity and Mortality Weekly Report.
See the NNDSS web site for more information.

Population:   All events reported as cases of a nationally notifiable disease that meet national surveillance case definition and notification criteria are reported to CDC by public health officials in U.S. states, New York City, Washington D.C. and 5 U.S. Territories.

The list of nationally notifiable diseases is revised periodically. For example, a disease may be added to the list as a new pathogen emerges, or a disease may be deleted as its incidence declines. Public health officials at state health departments and CDC collaborate in determining which diseases should be nationally notifiable; CSTE, with input from CDC, makes recommendations annually for additions and deletions to the list of nationally notifiable diseases. However, reporting of nationally notifiable diseases to CDC by the states is voluntary. Reporting is currently mandated (i.e., by state legislation, rules or regulation) only at the state level. The list of diseases that are considered notifiable, therefore, varies by state.

About data release limitations:
Data release policies protect personal privacy. The online database is subject to the same data release limitations that apply to the NNDSS Annual Tables.

  • Data may be grouped by year, disease and by any other single variable.
  • Demographic data (age, race, ethnicity and sex) are available at the national level only.
  • When the national count of some diseases is less than 25 cases, then the data for race and ethnicity are categorized as "Suppressed".

Source

Department of Health and Human Services (DHHS),
Public Health Service (PHS),
Centers for Disease Control and Prevention (CDC),
Summary of Notifiable Diseases,
National Notifiable Diseases Surveillance System (NNDSS)

In WONDER

You can produce tables, charts, maps, and data extracts. Obtain disease specific incidence counts and rates, and select specific conditions, time periods and locations to produce cross-tabulated incidence measures for the listed variables.

Please refer to the following topics:

NNDSS Data Request
Data Source Information
Additional Information

NNDSS Data Requests

Output You can produce tables, charts, maps, and data extracts of incidence counts, population estimates and rates.

Variables You can limit and stratify your data by any and all of these variables:

  1. Location - Regions as published in the 1993 – 2015 annual summary reports in MMWR, or US State or Territory
  2. Disease - Infectious Notifiable Conditions published during the time period
  3. Year Reported - 2016 – 2021
  4. Month Reported - January – December
  5. Race - American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, White, Other or Multi Race, Unknown, Suppressed
  6. Ethnicity - Hispanic, Non-Hispanic, Unknown, Suppressed
  7. Age - under 1 year, 1-4 years, 5-14 years, 15-24 years, 25-39 years, 40-64 years, 65+ years, Unknown
  8. Sex - Female, Male, Unknown
How? The Request screen has sections to guide you through a data request in a step-by-step process. However, to get some experience in terms of how the system works, you might want to simply press any Send button, and execute the default data request. The results for your query appear on the Results screen. After you get your results, try the Chart and Map screens. Or export your data to a file (tab-delimited line listing) for download to your computer.

For more information, see the following:

Quick Start Guide
Step 1, Organize table layout: select cross-tabulations, additional data categories, and whether to calculate incidence rates;
Step 2, Select disease and year reported, and other data categories;
Step 3, Select other options.

'By-Variables' Select variables that serve as keys or indexes to stratify and organize your query results. By default, NNDSS Annual Tables are available by disease and by year. Select the round button at the top to include an additional data field, such as locations, age, race, ethnicity or sex. See How do I organize my data? for more information.

Hints:  

  • Select a round button at the top to include an additional data field, such as locations, age, race, ethnicity or sex. The selected variable will be available in the "Group Results By" list in section 1 on the "Request Form" tab, and the categories in the selected field will be available for filtering data in section 2 on the "Request Form" tab. The default selecton is "None" meaning that none of the addition data for ocations, age, race, ethnicity or sex are included. The "None" option supports queries by Disease and Year, and charts. These limitations allow the interactive queries to comply with the "print rules" for data release and presentation of NNDSS data.
  • To map your data, you must select at least one geographical location field in the top "Group Results By" list in section 1 on the "Request Form" tab. To see the location options, select the one of the round buttons at the top for Regions or States. After the results display, click the Map tab. Use the "Map Options" button and the settings icon on the Map tab to change your maps.
  • To chart your data, you must select only one or two data categories in the "Group Results By" lists in section 1 on the Request Form tab, such as by disease and year. Charts are limited to queries with 2 cross-tabulations. The round "None" button at the top of section 1 on the Request Form tab lets you group results by Disease and Year, which may displayed in charts. After the results display, click the Chart tab. Use the "Chart Options" button on the Chart tab to change your charts.
  • About "Values" and "Codes" in the exported results, maps and charts:  
    The term "Value" refers to to the statistical measures in the results, such as the number of reported cases. The term "Code" refers to the short name for for the data category labels, such as the standard Federal Information Processing System (FIPS) code 12 for the state of Florida. Values and codes appear in separate columns when the results are exported to a file. You may choose to display values using the Chart options. Maps pop-up the values and codes for an area under your Mouse cursor.

Help

Click on any button labeled "Help", located to the right side of the screen at the top of each section. Or click on any label, such as the "Group Results By" label.

Send

Sends your data request to be processed on the CDC WONDER databases. The "Send" buttons are located on the bottom of the "Request Form" page, and in the upper right corner of each section, for easy access.



Step 1. Organize table layout:

Group Results By  

Select up to three variables that serve as keys for grouping your data. These choices are constrained by the current data sharing policies for publishing these data. They conform to the current policies for the published NNDSS Annual Tables. See Group Results By below for hints.

Title  

Enter any desired description to display as the title for your results.

The following statistical measures are available as query results:

  1. Counts
  2. Rates

Group Results By...

Select up to three variables that serve as keys for grouping (break out, summarize, stratify, index, cross-tabulate) the query results. For example, select to group results by disease and by year.

How?   

Hints:   

  • About charts:
    To make a chart, you must request data with no more than 2 variables selected in the "Group Results By" list in section 1 on the "Request Form" tab.
    1. For NNDSS, do so by first clicking the round button for "None" in section 1 on the "Request Form" tab, this setting permits queries by Disease and Year. `
    2. After selecting your query criteria, click any "Send" button to submit the query.
    3. After the results display, then click the "Chart" tab. Click "Chart Options" in the upper left on the "Chart" tab to change the chart. Right click on the image to download and save the image.
  • About maps:
    To make a map, you must request data with a geographic location variable, such as state, in the "Group Results By" list in section 1 on the "Request Form" tab.
    1. For NNDSS, do so by first clicking one of the round buttons for Regions or States in section 1 on the "Request Form" tab.
    2. Set the first "Group Results By" option to a geographic location field, such as Regions or States.
    3. After selecting your query criteria, click any "Send" button to submit the query.
    4. After the results display, then click the "Map" tab. Click "Map Options" in the upper left on the "Map" tab to change the map, or use the settings icon at the upper right. Use the download icon to download and save the image.
  • Refer to data release limitations for more information on the privacy policies for the NNDSS Annual Tables.
Counts

Counts show the sum or the frequency incidence of the selected categories in the data request. For example, when data are grouped by disease, then the count shows the number of times a specific disease was reported for those criteria specified in the data request (person, place and time).

Notes:  

  • Rows reporting sub-totals and totals are not shown when a query groups results by regions or by states. because some of the categories are subsets of other categories.
  • When the national frequency counts of some diseases are less than 25 cases, then the data for race and ethnicity are categorized as "Suppressed."
  • Refer to data release limitations for more information on the privacy policies for the NNDSS Annual Tables.

Rates

The rate is the incidence count divided by the population. Check the box in section 1 on the "Request Form" tab to include rates in the output. The default rate factor is per 100,000 persons. Change the rate factor in section 3 on the "Request Form" tab. Rates are calculated with the populations used as denominators in the published annual tables.

Notes:  

  • The populations shown are disease-specific, because not all diseases in the list are notifiable in all reporting areas, and the notifiable diseases vary over time.
  • The National Center for Health Statistics (NCHS) produces the population figures used to calculate these rates. The population denominators are the July 1st Bridged-race post-censal population estimates from the series issued for the given year, for years 2016 – 2021. For example, the July 1, 2016 estimates from the 2016 series are used as the denominator for incidence rates for 2016 cases. For more information, see Bridged-race Population Estimates. Population estimates for the territories are mid-year estimates for the given year, from the Census Bureau's International Data Base (IDB). See also Population Sources below.
  • Published rates are calculated using the July 1st bridged-race population estimates, from the most recent series of estimates available at the time of publication. For most annual summaries, postcensal estimates are used to calculate rates.

Step 2. Select disease(s), time period, and other filters:
Select the disease categories and time period of the disease reports. The data in the query results are "filtered" or limited the data to match your selections. Limit data for these fields:
  1. Disease,
  2. Year,
  3. Any third data field selected in the round buttons in section 1 on the "Request Form" tab.

Disease

Select specific disease categories to limit the query, if desired.

How?   See "How do I select items from the list box?" for help using the list boxes.

Notes:

  • Notifiable diseases change over time and vary by reporting jurisdiction. For more information, see the NNDSS web site and search for Case Definitions.
  • Select "All Diseases" or any single disease categories to view totals and sub-totals. Some disease categories are subsets of other categories, thus totals and sub-totals are not shown when more than one category is selected.
  • See the "caveats" in the "Notes" section below each results table, chart, map or export data set. for disease-specific footnotes for each reporting time period. Refer to Footnotes below for more information.

Year Reported

Select specific years to limit the query, if desired.

How?   See "How do I select items from the list box?" for help using the list boxes.

Note:   Data are currently available for cases reported in years 2016 – 2021.

Month Reported

Select specific months to limit the query, if desired. Select the round button for "Month" at the top of section 1 on the "Request Form" tab, to make Month available in "Group Results By" options in section 1, and to select specific months to filter data in section 2 on the "Request Form" tab.

How?  
  1. Select the desired round button at the top of section 1 on the "Request Form" tab, See "How do I select a Radio Button?" for help with the round buttons in section 1.
  2. See "How do I select items from the list box?" for help using the list boxes.

Note:   Month is defined using MMWR week. MMWR week calendars can be found at  NNDSS Resources.

Locations - Regions and States

Three location lists are available:

  1. Regions/States as published in the NNDSS Annual Tables;
  2. Regions only, as published in the NNDSS Annual Tables; and
  3. Reporting jurisdictions including 50 states, the District of Columbia, and New York City, and US Territories including American Samoa, Commonwealth of Northern Mariana Islands, Guam, Puerto Rico, the US Virgin Islands, and a category for Non-U.S. Residents for cases reported in 2020 and later years.
Select the button for the desired list of locations at the top of section 1 on the "Request Form" tab, to make these categories available in the "Group Results By" options in section 1, and to select specific locations to filter data from the list in section 2 on the "Request Form" tab.
How?  
  1. Select the desired round button at the top of section 1 on the "Request Form" tab, See "How do I select a Radio Button?" for help with the round buttons in section 1.
  2. See "How do I select items from the list box?" for help using the list boxes.
Hints:  
  • Pick location as the first option in the top "Group Results By" list in section 1 on the "Request Form" tab, to make maps. For example, pick "States."
  • Totals and sub-totals are not available for the "Regions/States" list because some categories are sub-sets of other categories.
Notes:
  • Cases are assigned to the reporting jurisdiction submitting the case to NNDSS if the case's country of usual residence is the United States, a U.S. territory, unknown, or country is not reported; otherwise, the case is assigned to the Non-U.S. Residents category, beginning with cases reported in year 2020. Country of usual residence is currently not reported by all jurisdictions or for all conditions, because this data element is only available in the HL7 generic version 2 and disease-specific message mapping guides. If a jurisdiction sends data in legacy formats, they are not able to send this information. For further information on interpretation of these data, see NNDSS Tables Readers Guides.
  • Note that the Non-U.S. Residents category is not assigned for cases before year 2020. Measures for the number of cases, population and rates for the Non-U.S. Residents category are reported as Not Available for cases reported in years before 2020. Population estimates are not available for the Non-U.S. Residents category in any year, therefore rates are reported as Not Applicable for the Non-U.S. Residents category in 2020 and later years.

Age

The age groups are under 1 year, 1-4 years, 5-14 years, 15-24 years, 25-39 years, 40-64 years, 65+ years, unknown. Select the round button for "Age" in the top of section 1 on the "Request Form" tab, to make these categories available in "Group Results By" options in section 1, and to select specific age groups to filter data from the list in section 2 on the "Request Form" tab.

How?  
  1. Select the desired round button at the top of section 1 on the "Request Form" tab, See "How do I select a Radio Button?" for help with the round buttons in section 1.
  2. See "How do I select items from the list box?" for help using the list boxes.
Notes:
  • Due to data release limitations, data can be reported for only one demographic variable per report. For example, when data are filtered or grouped by age, then race, sex and ethnicity are "all" categories combined.
  • Note that for some disease categories, jurisdictions specifically report cases only for persons under 5 years of age, or for infants.
  • Cases with unknown demographic characteristics have not been redistributed. For this reason, the total number of cases reported here might differ slightly from totals reported in other surveillance summaries.

Race

The race categories are American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, Other or Multi Race, Suppressed, Unknown, and White. Select the round button for "Race" in the top of section 1 on the "Request Form" tab, to make these categories available in the "Group Results By" options in section 1, and to select specific race categories to filter data from the list in section 2 on the "Request Form" tab.

How?  
  1. Select the desired round button at the top of section 1 on the "Request Form" tab, See "How do I select a Radio Button?" for help with the round buttons in section 1.
  2. See "How do I select items from the list box?" for help using the list boxes.
Notes:
  • Due to data release limitations, data can be reported for only one demographic variable per report. For example, when data are filtered or grouped by race, then age, sex and ethnicity are "all" categories combined.
  • When the national frequency counts of some diseases are less than 25 cases, then the data for race and ethnicity are categorized as "Suppressed."
  • Cases with unknown demographic characteristics have not been redistributed. For this reason, the total number of cases reported here might differ slightly from totals reported in other surveillance summaries.
  • Race data were collected using current Office of Management and Budget (OMB) standards for race/ethnicity data and were mapped to bridged race categories.
  • The "Other or Multi Race" category includes individuals reported as other race or multiple races.
  • Any variation of disease incidence by race or ethnicity does not reflect biological differences but reflects systemic, cultural, behavioral, and social factors including structural racism.

Ethnicity

The ethnicity categories are Hispanic, non-Hispanic, unknown, and suppressed. Select the round button for "Ethnicity" in the top of section 1 on the "Request Form" tab, to make these categories available in the "Group Results By" options in section 1, and to select specific ethnicity categories to filter data from the list in section 2 on the "Request Form" tab.

How?  
  1. Select the desired round button at the top of section 1 on the "Request Form" tab, See "How do I select a Radio Button?" for help with the round buttons in section 1.
  2. See "How do I select items from the list box?" for help using the list boxes.
Notes:
  • Due to data release limitations, data can be reported for only one demographic variable per report. For example, when data are filtered or grouped by ethnicity, then age, race and sex are "all" categories combined.
  • When the national frequency counts of some diseases are less than 25 cases, then the data for race and ethnicity are categorized as "Suppressed."
  • Cases with unknown demographic characteristics have not been redistributed. For this reason, the total number of cases reported here might differ slightly from totals reported in other surveillance summaries.
  • Any variation of disease incidence by race or ethnicity does not reflect biological differences but reflects systemic, cultural, behavioral, and social factors including structural racism.

Sex

The sex categories are female, male, unknown. Select the round button for "Sex" in the top of section 1 on the "Request Form" tab, to make these categories available in the "Group Results By" options in section 1, and to select specific sex categories to filter data from the list in section 2 on the "Request Form" tab.

How?  
  1. Select the desired round button at the top of section 1 on the "Request Form" tab, See "How do I select a Radio Button?" for help with the round buttons in section 1.
  2. See "How do I select items from the list box?" for help using the list boxes.
Notes:
  • Due to data release limitations, data can be reported for only one demographic variable per report. For example, when data are filtered or grouped by sex, then age, race and ethnicity are "all" categories combined.
  • Cases with unknown demographic characteristics have not been redistributed. For this reason, the total number of cases reported here might differ slightly from totals reported in other surveillance summaries.

Step 3. Other options:
Export Results  

If checked query results are exported to a local file. More information on how to import this file into other applications can be found here. This function is also available on the Results tab, at the upper right corner.

How? See "How do I use a checkbox?"

Show Totals  

If checked totals and sub-totals will appear in the results table. Note that totals and sub-totals are not available for some data categories. This option is also available on the Results tab, under Quick Options at the upper left corner.

How? See "How do I use a checkbox?"

Show Zero Values  

If checked rows containing zero counts will appear in the results table. If unchecked, rows reporting zero cases are hidden. This option is also available on the Results tab, under Quick Options at the upper left corner.

How? See "How do I use a checkbox?"

Precision  

Select the precision for rate calculations. When the rate calculated for a small numerator (incidence count) is zero, you may increase the precision to reveal the rate by showing more numbers to the right of the decimal point. Note that the option to include rates is in section 1 on the "Request Form" tab.

How? See "How do I select items from the list box?"

Data Access Timeout  

This value specifies the maximum wait time for data access for completing a query. If data access exceeds the maximum time allowed, a message will be displayed. To resolve this issue, the user can increase access time or simplify the query. If assistance is needed to implement the resolution or run the initial query, contact technical support

How? See "How do I select items from the list box?"

Data Source Information

Data Sources

National Notifiable Diseases Surveillance System (NNDSS)

To learn more about the methods and source of these data please refer to:

The published annual tables are also available from the following resources:

  • NNDSS Annual Tables for years 2016 and later are available at NNDSS Annual Tables.
  • NNDSS annual tables since 1952 are available at CDC Stacks (once in CDC Stacks, select "Annual Reports" in the "Genre" box to the left).
  • Annual summary reports from 1993–2015 are available as published in the Morbidity and Mortality Weekly Report.

Population Sources

Population estimates used as denominators for rate calculations are from the following sources:

  • Population estimates for 2021 and 2020 incidence rates are July 1st, 2020 estimates from the National Center for Health Statistics (NCHS) postcensal estimates of the resident population of the United States for April 1, 2010, to July 1, 2020 (Vintage 2020), by year, county, single year of age (range: 0 to 85 years), bridged-race (4 categories: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, White), Hispanic ethnicity (not Hispanic or Latino, Hispanic or Latino), and sex (female, male), prepared under a collaborative arrangement with the U.S. Census Bureau. Population estimates for states released September 21, 2021, are available at https://www.cdc.gov/nchs/nvss/bridged_race/data_documentation.htm. Population estimates for territories are the 2020 mid-year estimates from the U.S. Census Bureau International Data Base, accessed on March 15, 2022, at https://www.census.gov/data-tools/demo/idb/#/country?YR_ANIM=2022.
  • Population estimates for 2019 incidence rates are July 1, 2019 estimates obtained from the National Center for Health Statistics (NCHS) postcensal estimates of the resident population of the United States for April 1, 2010, to July 1, 2019 (Vintage 2019), by year, county, single year of age (range: 0 to 85 years), bridged-race (4 categories: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, White), Hispanic ethnicity (not Hispanic or Latino, Hispanic or Latino), and sex, prepared under a collaborative arrangement with the U.S. Census Bureau. Population estimates for states released July 9, 2020, are available at https://www.cdc.gov/nchs/nvss/bridged_race/data_documentation.htm. Population estimates for territories are the 2019 mid-year estimates from the U.S. Census Bureau International Data Base, accessed on August 6, 2020, at https://www.census.gov/data-tools/demo/idb/#/country?YR_ANIM=2021.
  • Population estimates for 2018 incidence rates are July 1, 2018 estimates obtained from the National Center for Health Statistics (NCHS) postcensal estimates of the resident population of the United States for April 1, 2010 – July 1, 2018 (Vintage 2018), by year, county, single year of age (range: 0 to 85 years), bridged-race (4 categories: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, White), Hispanic ethnicity (not Hispanic or Latino, Hispanic or Latino), and sex, prepared under a collaborative arrangement with the U.S. Census Bureau. Population estimates for states released June 25, 2019 are available at https://www.cdc.gov/nchs/nvss/bridged_race/data_documentation.htm. Population estimates for territories are the 2018 mid-year estimates from the U.S. Census Bureau International Data Base, accessed on June 26, 2019 at https://www.census.gov/data-tools/demo/idb/informationGateway.php.
  • Population estimates for 2017 incidence rates are July 1st, 2017 estimates obtained from the National Center for Health Statistics (NCHS)postcensal estimates of the resident population of the United States for April 1, 2010 – July 1, 2017 (Vintage 2017), by year, county, single year of age (range: 0 to 85 years), bridged-race (4 categories: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, White), Hispanic ethnicity (not Hispanic or Latino, Hispanic or Latino), and sex, prepared under a collaborative arrangement with the U.S. Census Bureau. Population estimates for states released June 27, 2018 are available at https://www.cdc.gov/nchs/nvss/bridged_race/data_documentation.htm. Population estimates for territories are the 2017 mid-year estimates from the U.S. Census Bureau International Data Base, accessed on October 2, 2018 at https://www.census.gov/data-tools/demo/idb/informationGateway.php.
  • Population estimates for 2016 incidence rates are July 1, 2016 estimates obtained from the National Center for Health Statistics (NCHS) postcensal estimates of the resident population of the United States for July 1, 2011 – July 1, 2016 (Vintage 2016), by year, county, single year of age (range: 0 to 85 years), bridged-race (4 categories: American Indian or Alaska Native, Asian or Pacific Islander, Black or African American, White), Hispanic ethnicity (not Hispanic or Latino, Hispanic or Latino), and sex, prepared under a collaborative arrangement with the U.S. Census Bureau. Population estimates for states as of June 26, 2017 are available at https://www.cdc.gov/nchs/nvss/bridged_race/data_documentation.htm. Population estimates for territories are the 2016 mid-year estimates from the U.S. Census Bureau International Data Base accessed on July 24, 2017 at https://www.census.gov/population/international/data/idb/informationGateway.php.
  • Congenital syphilis cases are aggregated by the infant's year of birth. The rate for congenital syphilis is based upon the number of reported cases per the number of live births, using final natality data for the reporting year produced by National Center for Health Statistics, as compiled from data provided by the Vital Statistics Cooperative Program. The mother's race and ethnicity are used for race- and ethnicity-specific rates of congenital syphilis cases.
  • The choice of population denominators for incidence is based on the availability of population data at the time of publication preparation.

Additional Information

Suggested Citation:

Centers for Disease Control and Prevention. National Notifiable Diseases Surveillance System (NNDSS), Finalized Annual Tables of Infectious Disease Data 2016 – 2021. Centers for Disease Control and Prevention (CDC), Office of Public Health Data, Surveillance, and Technology. Available at https://www.cdc.gov/nndss/data-statistics/infectious-tables/.

Acknowledgment:   CDC acknowledges the local, state, and territorial health departments that collected the data from a range of case ascertainment sources (e.g., healthcare providers, hospitals, laboratories) and reported these data to CDC's National Notifiable Diseases Surveillance System.

Contact: NNDSSWeb@cdc.gov
Data Limitations:

Consider the following cautions when using these data:

  • Disease reports to CDC are voluntary.
  • Notifiable diseases vary over time and by reporting jurisdiction.
  • The online database is subject to the same data release limitations that apply to the tables published in each year's annual tables.
    • Data may be grouped by year, disease and by any other single variable.
    • Demographic data (age, race, ethnicity and sex) are available at the national level only.
    • When the national frequency counts of some diseases are less than 25 cases, then the data for race and ethnicity data are suppressed.

Other information:

Statistics for frequency counts and rates display missing values as follows:

  • Zero when no reported cases — The reporting jurisdiction did not submit any cases to CDC.
  • Not reportable — The disease or condition was not reportable by law, statute, or regulation in the reporting jurisdiction.
  • Unavailable — The data are unavailable.

Footnotes are organized below as follows:

  • Information for all years
  • Information for the 2021 reporting year
  • Information for the 2020 reporting year
  • Information for the 2019 reporting year
  • Information for the 2018 reporting year
  • Information for the 2017 reporting year
  • Information for the 2016 reporting year

Information for all years:

  1. These are annual cases of selected infectious national notifiable diseases from the National Notifiable Diseases Surveillance System (NNDSS). NNDSS data reported by the 50 states, New York City, the District of Columbia, and the U.S. Territories are collated and published. Cases are reported by state health departments to CDC on a daily or weekly basis. Because source datasets may be updated as additional information is received, statistics in publications based on that source data may differ from what is presented in these tables.
  2. The list of national notifiable infectious diseases and conditions for a specific year and their national surveillance case definitions are available by navigating to the Surveillance Case Definitions page, selecting the year in the "Notifiable Condition Lists," checking the box for "Infectious" conditions, and clicking "Get Notifiable List by Year." The names of the diseases in the list are linked to their respective national surveillance case definitions from position statements approved by the Council of State and Territorial Epidemiologists.
  3. For most conditions, national incidence rates are calculated as the number of reported cases for each infectious disease or condition divided by the U.S. resident population for the specified demographic population or the total U.S. resident population, multiplied by 100,000. When a national notifiable infectious condition is associated with a specific age restriction, the same restriction was applied to the population in the denominator of the incidence rate calculation. In addition, population data from reporting jurisdictions in which the disease or condition was not reportable or not available were excluded from the denominator of the incidence rate calculations.

    Age restrictions in the numerator and denominator are applied for the following childhood conditions:

    1. Congenital rubella syndrome (age restriction in numerator and denominator is <1 year).
    2. Congenital syphilis data are aggregated by the infant's year of birth. The rate for congenital syphilis is based upon the number of reported cases per the number of live births, using final natality data for the reporting year produced by National Center for Health Statistics, as compiled from data provided by the Vital Statistics Cooperative Program. Congenital syphilis cases are usually assigned to the mother's state of residence at the time of delivery. The mother's race and ethnicity are used for race- and ethnicity-specific rates of congenital syphilis cases.
    3. Haemophilus influenzae, invasive disease <5 years (age restriction in numerator and denominator is <5 years).
    4. Invasive pneumococcal disease <5 years (age restriction in numerator and denominator is <5 years).
    5. Influenza associated pediatric mortality (age restriction in numerator and denominator is <18 years).
    6. Infant botulism (age restriction in numerator and denominator is <1 year).
    7. Perinatal Hepatitis B infection (age restriction in numerator and denominator is ≤24 months).
    8. Perinatal Hepatitis C infection (age restriction in numerator and denominator is ≤36 months).
    9. Zika virus disease, congenital (age restriction in numerator and denominator is <1 year).
    10. Zika virus infection, congenital (age restriction in numerator and denominator is <1 year).
  4. Surveillance data reported by other CDC programs might vary from data reported in these tables because of differences in 1) the date used to aggregate the data, 2) the timing of reports, 3) the source of the data, 4) surveillance case definitions, and 5) policies regarding case-reporting jurisdiction (i.e., which jurisdiction should submit the case notification to CDC).
  5. Chronic hepatitis B and chronic hepatitis C data are not included in NNDSS tables but reported case counts are included in the annual Viral Hepatitis Surveillance Report, published online by CDC's Division of Viral Hepatitis, available at Viral Hepatitis Surveillance – United States.

For the 2021 reporting year:

  1. Publication criteria for the finalized 2021 data are available at Publication criteria for nationally notifiable conditions reported to the National Notifiable Diseases Surveillance System, 2021. This list incorporates the Council of State and Territorial Epidemiologists (CSTE) position statements approved in 2020 by CSTE for national surveillance that were implemented in January 2021. See also the Readers Guides to interpreting provisional and finalized NNDSS data.
  2. CSTE adopted the first coronavirus disease 2019 (COVID-19) national surveillance case definition on April 5, 2020, and they approved a revision to the COVID-19 national surveillance case definition, effective August 5, 2020. On June 17, 2021, a revision to the COVID-19 national surveillance case definition was approved, effective September 1, 2021.
  3. Data for congenital syphilis are aggregated by the infant's year of birth. The rate for congenital syphilis is based upon the number of reported cases per 100,000 live births, using natality data for 2021 (National Center for Health Statistics Natality 2021, as compiled from data provided by the Vital Statistics Cooperative Program). Congenital syphilis cases are usually assigned to the mother's state of residence at the time of delivery. The mother's race and ethnicity are used for race- and ethnicity-specific rates of congenital syphilis cases.
  4. Surveillance data reported by other CDC programs might vary from data reported in these tables because of differences in 1) the date used to aggregate the data, 2) the timing of reports, 3) the source of the data, 4) surveillance case definitions, and 5) policies regarding case jurisdiction (i.e., which jurisdiction should submit the case notification to CDC).
  5. Disease data presented in the 2021 tables reflect impacts of the COVID-19 pandemic, such as changes in exposure-related behavior, healthcare-seeking behavior, disease reporting, and public health investigations.
  6. Month is defined using MMWR week, see https://ndc.services.cdc.gov/wp-content/uploads/2021/02/MMWR_Week_overview.pdf. MMWR week calendars can be found at https://ndc.services.cdc.gov/event-codes-other-surveillance-resources/.
  7. Condition-specific footnotes:
    1. Candida auris, clinical: Candida auris colonization/screening cases are not included in this table. These data are available on the Mycotic Diseases Branch's Tracking Candida auris page (https://www.cdc.gov/fungal/candida-auris/tracking-c-auris.html).
    2. Coronavirus Disease 2019 (COVID-19), probable: Of the reporting areas that submitted 2021 aggregate COVID-19 data to CDC, two did not submit probable cases. New York (excluding New York City) and U.S. Virgin Islands did not collect probable cases.
    3. Dengue virus infections: Counts include confirmed and probable dengue cases.
    4. Hantavirus infection, non-hantavirus pulmonary syndrome: Case counts may include Old World hantavirus infections, such as Seoul virus.
    5. Invasive pneumococcal disease: Counts include drug resistant and susceptible cases of Invasive Pneumococcal Disease. This condition was previously named Streptococcus pneumoniae invasive disease and cases were reported to CDC using different event codes to specify whether the cases were drug resistant or in a defined age group, such as <5 years.
    6. Legionellosis: Beginning in 2020, the CSTE case definition changed such that cases diagnosed by PCR were classified as confirmed, whereas previously those cases were classified as suspect and did not meet the publication/print criteria.
    7. Listeriosis: Before 2019, probable cases were not reported, and cases in neonates ≤60 days of age were counted as one case in a mother-infant pair. Beginning in 2019, confirmed and probable cases are being reported, and maternal and neonatal cases are being counted separately.
    8. Measles: Measles is considered imported if the disease was acquired outside of the United States and is considered indigenous if the disease was acquired anywhere within the United States or it is not known where the disease was acquired.
    9. Plague: Beginning in 2020, confirmed and probable plague cases began to be combined and published.
    10. Salmonella Paratyphi infection: Beginning in January 2019, cases began to be reported as Salmonella Paratyphi infection. In 2018, cases were reported as paratyphoid fever. Prior to 2018, cases of paratyphoid fever were considered salmonellosis.
    11. Salmonella Typhi infection: Beginning in January 2019, cases began to be reported as Salmonella Typhi infection. In previous years, cases were reported as typhoid fever.
    12. Salmonellosis (excluding S. Typhi infection and S. Paratyphi infection): Beginning in January 2019, cases began to be reported as salmonellosis (excluding Salmonella Typhi infection and Salmonella Paratyphi infection). In 2018, cases were reported as salmonellosis (excluding paratyphoid fever and typhoid fever). Prior to 2018, cases of paratyphoid fever were considered salmonellosis.
    13. Syphilis:
      • Syphilis Total, all stages: Includes the following categories: primary; secondary; early non-primary non-secondary (includes cases previously reported as early latent); unknown duration or late (includes cases previously reported as late latent syphilis and cases previously reported as late syphilis with clinical manifestations) and congenital syphilis.
      • Syphilis, Congenital: Congenital syphilis cases are usually assigned to the mother's state of residence at the time of delivery. Data for congenital syphilis are aggregated by the infant's year of birth.
    14. Vancomycin-resistant Staphylococcus aureus: Vancomycin-resistant Staphylococcus aureus cases reported in this table may not have been verified by CDC. CDC verified 2 vancomycin-resistant Staphylococcus aureus cases in 2021.
    15. Zika virus disease, congenital and Zika virus infection, congenital: Data reported to ArboNET using the national surveillance case definition for congenital Zika virus infection (CSTE Position Statement 16-ID-01).
  8. Source datasets for the 2021 annual tables were officially closed on March 29, 2023.

For the 2020 reporting year:

  1. Publication criteria for the finalized 2020 data are available at Publication criteria for nationally notifiable conditions reported to the National Notifiable Diseases Surveillance System, 2020. This list incorporates the Council of State and Territorial Epidemiologists (CSTE) position statements approved in 2019 by CSTE for national surveillance that were implemented in January 2020. See also the Readers Guides to interpreting provisional and finalized NNDSS data.
  2. Revised case definitions were implemented for the following conditions in 2020: plague, legionellosis, acute hepatitis C, spotted fever rickettsiosis, and pertussis. In addition, CSTE adopted the first coronavirus disease 2019 (COVID-19) national surveillance case definition on April 5, 2020, and they approved a revision to the COVID-19 national surveillance case definition, effective August 5, 2020.
  3. The following reporting areas may have incomplete data, due to technical or programmatic challenges while reconciling data during the COVID-19 pandemic: California, Guam, and Minnesota.
  4. The following five reporting areas may have incomplete data due to updates made to their data after the 2020 reconciliation period ended and there was not sufficient time before publication of the annual tables to confirm the updated counts: Idaho, Kansas, Maryland, Vermont, and Virgin Islands.
  5. Disease data presented in the 2020 tables reflect impacts of the COVID-19 pandemic, such as changes in exposure-related behavior, healthcare-seeking behavior, disease reporting, and public health investigations.
  6. Condition-specific footnotes:
    1. Candida auris colonization/screening cases are not included here. These data are available on the Mycotic Diseases Branch's Tracking Candida auris page.
    2. Coronavirus Disease 2019 (COVID-19): of the reporting areas that submitted 2020 aggregate COVID-19 data to CDC, three did not submit probable cases. New York (excluding New York City) and Utah did not collect probable cases. U.S. Virgin Islands collected probable cases, but did not report them to CDC.
    3. Dengue virus infections include confirmed and probable dengue cases.
    4. Hantavirus infection, non-hantavirus pulmonary syndrome cases may include Old World hantavirus infections, such as Seoul virus.
    5. Invasive pneumococcal disease counts include drug resistant and susceptible cases of Invasive Pneumococcal Disease. This condition was previously named Streptococcus pneumoniae invasive disease and cases were reported to CDC using different event codes to specify whether the cases were drug resistant or in a defined age group, such as <5 years.
    6. Legionellosis: in 2020, the CSTE case definition changed such that Legionellosis cases diagnosed by PCR were classified as confirmed, whereas previously those cases were classified as suspect and did not meet the publication/print criteria.
    7. Listeriosis: before 2019, probable cases were not reported, and cases in neonates ≤60 days of age were counted as one case in a mother-infant pair. Beginning in 2019, confirmed and probable cases are being reported, and maternal and neonatal cases are being counted separately.
    8. Measles is considered imported if the disease was acquired outside of the United States. Measles is considered indigenous if the disease was acquired anywhere within the United States or it is not known where the disease was acquired.
    9. Plague: beginning in 2020, confirmed and probable plague cases are being combined and published. In 2019, only confirmed plague cases were published.
    10. Salmonella Paratyphi infection: beginning in January 2019, cases began to be reported as Salmonella Paratyphi infection. In 2018, cases were reported as paratyphoid fever. Prior to 2018, cases of paratyphoid fever were considered salmonellosis.
    11. Salmonella Typhi infection: Beginning in January 2019, cases began to be reported as Salmonella Typhi infection. In previous years, cases were reported as typhoid fever.
    12. Salmonellosis (excluding S. Typhi infection and S. Paratyphi infection): Beginning in January 2019, cases began to be reported as salmonellosis (excluding Salmonella Typhi infection and Salmonella Paratyphi infection). In 2018, cases were reported as salmonellosis (excluding paratyphoid fever and typhoid fever). Prior to 2018, cases of paratyphoid fever were considered salmonellosis.
    13. Syphilis:
      • Syphilis, Total all stages includes the following categories: primary; secondary; early non-primary non-secondary (includes cases previously reported as early latent); unknown duration or late (includes cases previously reported as late latent syphilis and cases previously reported as late syphilis with clinical manifestations) and congenital syphilis.
      • Congenital syphilis cases are usually assigned to the mother's state of residence at the time of delivery. Data for congenital syphilis are aggregated by the infant's year of birth.
    14. Vancomycin-resistant Staphylococcus aureus cases reported in this table may not have been verified by CDC. CDC verified zero (0) vancomycin-resistant Staphylococcus aureus cases in 2020.
    15. Zika virus disease, congenital and Zika virus infection, congenital: data reported to ArboNET using the national surveillance case definition for congenital Zika virus infection (CSTE Position Statement 16-ID-01).
  7. Cases are assigned to the reporting jurisdiction submitting the case to NNDSS if the case's country of usual residence is the United States, a U.S. territory, unknown, or country is not reported; otherwise, the case is assigned to the Non-U.S. Residents category, beginning with cases reported in year 2020. Country of usual residence is currently not reported by all jurisdictions or for all conditions, because this data element is only available in the HL7 generic version 2 and disease-specific message mapping guides. If a jurisdiction sends data in legacy formats, they are not able to send this information. For further information on interpretation of these data, see NNDSS Tables Readers Guides.
  8. Source datasets for the 2020 annual tables were officially closed on September 27, 2022.

For the 2019 reporting year:

  1. Publication criteria for the finalized 2019 data are available at Publication criteria for nationally notifiable conditions reported to the National Notifiable Diseases Surveillance System, 2019. See also the Readers Guides for the NNDSS data.
  2. Candida auris, clinical became a new national notifiable condition in January 2019, and revised case definitions were implemented for the following conditions: diphtheria, acute hepatitis A, listeriosis, yellow fever, Salmonella Paratyphi infection and Salmonella Typhi infection. Salmonella Paratyphi infection and Salmonella Typhi infection replaced Paratyphoid fever and Typhoid fever, respectively, as national notifiable conditions. Salmonellosis (excluding S. Typhi infection and S. Paratyphi infection) replaced Salmonellosis (excluding paratyphoid fever and typhoid fever) as a national notifiable condition. In addition, Carbapenemase Producing Carbapenem-Resistant Enterobacteriaceae (CP-CRE) represents a consolidation of CP-CRE species Klebsiella spp, CP-CRE E. coli, and CP-CRE Enterobacter spp.
  3. The following 24 jurisdictions may have incomplete data reported in the 2019 Annual Tables, due to the coronavirus disease 2019 (COVID-19) pandemic: Alaska, California, Connecticut, Delaware, District of Columbia, Florida, Idaho, Indiana, Kansas, Massachusetts, Minnesota, Missouri, Montana, Nebraska, New Hampshire, New York (excluding New York City), New York City, North Dakota, Ohio, Oklahoma, South Carolina, Tennessee, Texas, and West Virginia. In addition, the following 2 U.S. Territories may have incomplete data due to the COVID-19 pandemic: American Samoa and the U.S. Virgin Islands.
  4. Condition-specific footnotes:
    1. Candida auris colonization/screening cases are not included here. These data are available on the Mycotic Diseases Branch's Tracking Candida auris page.
    2. Coccidioidomycosis is reportable in <25 states in 2019.
    3. Dengue virus infections include confirmed and probable dengue cases.
    4. Hantavirus infection, non-hantavirus pulmonary syndrome includes data for old world hantavirus infections, such as Seoul virus and Puumala virus infections.
    5. Invasive Pneumococcal Disease counts include drug resistant and susceptible cases of Invasive Pneumococcal Disease. This condition was previously named Streptococcus pneumoniae invasive disease and cases were reported to CDC using different event codes to specify whether the cases were drug resistant or in a defined age group, such as <5 years.
    6. Listeriosis: Before 2019, probable cases of Listeriosis were not reported, and cases in neonates ≤60 days of age were counted as one case in a mother-infant pair. Beginning in 2019, confirmed and probable cases are being reported, and maternal and neonatal cases are being counted separately.
    7. Measles is considered imported if the disease was acquired outside of the United States and is considered indigenous if the disease was acquired anywhere within the United States or it is not known where the disease was acquired.
    8. Salmonella Paratyphi infection: Beginning in January 2019, cases began to be reported as Salmonella Paratyphi infection. In 2018, cases were reported as paratyphoid fever. Prior to 2018, cases of paratyphoid fever were considered salmonellosis.
    9. Salmonella Typhi infection: Beginning in January 2019, cases began to be reported as Salmonella Typhi infection. In previous years, cases were reported as typhoid fever.
    10. Salmonellosis (excluding S. Typhi infection and S. Paratyphi infection): Beginning in January 2019, cases began to be reported as salmonellosis (excluding Salmonella Typhi infection and Salmonella Paratyphi infection). In 2018, cases were reported as salmonellosis (excluding paratyphoid fever and typhoid fever). Prior to 2018, cases of paratyphoid fever were considered salmonellosis.
    11. Syphilis Total, all stages: Includes the following categories: primary; secondary; early non-primary non-secondary (includes cases previously reported as early latent); and unknown duration or late (includes cases previously reported as late latent syphilis and cases previously reported as late syphilis with clinical manifestations); and congenital syphilis.
    12. Zika virus disease, congenital and and Zika virus infection, congenital: Data reported to ArboNET in 2019 using the national surveillance case definition for congenital Zika virus infection (CSTE Position Statement 16-ID-01).

For the 2018 reporting year:

  1. Publication criteria for the finalized 2018 data are available at Publication criteria for nationally notifiable conditions reported to the National Notifiable Diseases Surveillance System, 2018. See also Guide to Interpreting Provisional and Finalized NNDSS Data.
  2. Case definition changes implemented in January 2018, including updated surveillance case definitions for anthrax, shiga toxin-producing Escherichia coli, and syphilis.
  3. Condition-specific footnotes:
    1. Perinatal hepatitis c virus infection became a new nationally notifiable condition in 2018.
    2. While Carbapenemase Producing Carbapenem-Resistant Enterobacteriaceae (CP-CRE) was added to the list of nationally notifiable diseases in 2018, reporting jurisdictions could not submit data for this condition since Office of Management and Budget Paperwork Reduction Act approval was pending during 2018.
    3. Coccidioidomycosis is reportable in <25 states in 2018.
    4. Dengue virus infections include confirmed and probable dengue cases.
    5. Invasive pneumococcal disease counts include drug resistant and susceptible cases of Invasive Pneumococcal Disease. This condition was previously named Streptococcus pneumoniae invasive disease and cases were reported to CDC using different event codes to specify whether the cases were drug resistant or in a defined age group, such as <5 years.
    6. Prior to 2018, cases of paratyphoid fever were considered salmonellosis.
    7. Prior to 2018, cases of paratyphoid fever were included as salmonellosis, but beginning in 2018 they are being published as paratyphoid fever.
    8. Syphilis, Total, all stages includes the following categories: primary; secondary; early non-primary non-secondary (includes cases previously reported as early latent); and unknown duration or late (includes cases previously reported as late latent syphilis and cases previously reported as late syphilis with clinical manifestations); congenital syphilis.
    9. Zika virus disease, congenital and Zika virus infection, congenital: Data reported to ArboNET in 2018 using the national surveillance case definition for congenital Zika virus infection (CSTE Position Statement 16-ID-01).

For the 2017 reporting year:

  1. Publication criteria for the finalized 2017 data are available at Publication criteria and CDC program responsible for finalizing the data with reporting jurisdictions for notifiable conditions reported to the National Notifiable Diseases Surveillance System, 2017. See also Guide to Interpreting Provisional and Finalized NNDSS Data.
  2. Case definition changes implemented in January 2017, including updated surveillance case definitions for salmonellosis, shigellosis, vibrioisis, perinatal hepatitis B virus infection, invasive pneumococcal disease, Lyme disease, and tularemia reported through August 7, 2018.
  3. Rates are calculated using population less than 1 year of age for the following conditions in 2017: Botulism, infant; Rubella, congenital syndrome; Syphilis, congenital; Zika virus disease, congenital; Zika virus infection, congenital.
  4. Condition-specific footnotes:
    1. Coccidioidomycosis is reportable in <25 states in 2017.
    2. Dengue virus infections in 2017 represent the total number of reported laboratory-positive dengue cases, including all confirmed cases [by anti-dengue virus (DENV) molecular diagnostic methods or seroconversion of anti-DENV IgM] and all probable cases (by a single, positive anti-DENV IgM).
    3. Haemophilus influenzae, invasive disease, age <5 years rates are calculated using population less than 5 years of age in 2017.
    4. Hepatitis B, perinatal infection rates are calculated using population less than 2 years of age in 2017.
    5. Influenza-associated pediatric mortality rates are calculated using population less than 18 years of age in 2017.
    6. Invasive pneumococcal disease cases in 2017 include drug resistant and susceptible cases of Invasive Pneumococcal Disease. This condition was previously named Streptococcus pneumoniae invasive disease and cases were reported to CDC using different event codes to specify whether the cases were drug resistant or in a defined age group, such as <5 years.
    7. Shiga toxin-producing Escherichia coli cases in 2017 include Escherichia coli O157:H7 and Shiga toxin-positive Escherichia coli (including O157, non-O157, and not serogrouped).
    8. Zika virus disease, congenital and Zika virus infection, congenital: data reported to ArboNET in 2017 using the national surveillance case definition for congenital Zika virus disease or infection (CSTE Position Statement 16-ID-01). Additional data reported to the US Zika Pregnancy Registry for outcomes of pregnancies with laboratory evidence of possible Zika virus infection are available in the US Zika Pregnancy Registry. Cases reported to the US Zika Pregnancy Registry might not meet the national surveillance case definition for congenital Zika virus disease or infection.

For the 2016 reporting year:

  1. Publication criteria for the finalized 2016 data are available at Publication criteria and CDC program responsible for finalizing the data with reporting jurisdictions for notifiable conditions reported to the National Notifiable Diseases Surveillance System, 2016. See also Guide to Interpreting Provisional and Finalized NNDSS Data.
  2. Case definition changes implemented in January 2017, including updated surveillance case definitions for acute hepatitis C and chronic hepatitis C virus infections. 2016 data are reported through June 30, 2017.
  3. Rates are calculated using population less than 1 year of age for the following conditions in 2016: Botulism, infant; Rubella, congenital syndrome; Syphilis, congenital; Zika virus disease, congenital; Zika virus infection, congenital.
  4. Condition-specific footnotes:
    1. Coccidioidomycosis is reportable in <25 states in 2016.
    2. Dengue virus infections in 2016 represent the total number of reported laboratory-positive dengue cases, including all confirmed cases [by anti-dengue virus (DENV) molecular diagnostic methods or seroconversion of anti-DENV IgM] and all probable cases (by a single, positive anti-DENV IgM).
    3. Incidence rates for the category "Haemophilus influenzae, invasive disease, age <5 years" in 2016 are calculated using population less than 5 years of age.
    4. Chronic hepatitis B and C data are not included in the 2016 NNDSS tables but reported case counts are included in the annual Summary of Viral Hepatitis, published online by CDC's Division of Viral Hepatitis, available at Surveillance for Viral Hepatitis – United States, 2017.
    5. Hepatitis B, perinatal infection rates are calculated using population less than 2 years of age in 2016.
    6. Influenza-associated pediatric mortality rates are calculated using population less than 18 years of age in 2016.
    7. Shiga toxin-producing Escherichia coli cases in 2016 include Escherichia coli O157:H7; shiga toxin-positive, serogroup non-O157; and shiga toxin positive, not serogrouped.
    8. Syphilis, Total, all stages category in 2016 includes syphilis of all stages, including cases where stage of syphilis is not stated.
    9. Zika virus disease, congenital and Zika virus infection, congenital: data reported to ArboNET in 2016 using the national surveillance case definition for congenital Zika virus disease or infection (CSTE Position Statement 16-ID-01). Additional data reported to the US Zika Pregnancy Registry for outcomes of pregnancies with laboratory evidence of possible Zika virus infection are available in the US Zika Pregnancy Registry. Cases reported to the US Zika Pregnancy Registry might not meet the national surveillance case definition for congenital Zika virus disease or infection.



This page last reviewed: Monday, April 22, 2024
This information is provided as technical reference material. Please contact us at cwus@cdc.gov.