Nationally Notifiable Infectious Diseases and Conditions, United States: Annual Tables

TABLE 2b. Annual reported cases* of notifiable diseases, by region and reporting area, United States, U.S. Territories, and Non-U.S. Residents, 2021†
Reporting Area Arboviral diseases
La Crosse virus disease Powassan virus disease St. Louis encephalitis virus disease West Nile virus disease
Neuroinvasive Non-neuroinvasive Neuroinvasive Non-neuroinvasive Neuroinvasive Non-neuroinvasive Neuroinvasive Non-neuroinvasive
U.S. Residents, excluding U.S. Territories 39 1 24 1 11 6 2,007 899
New England — — 13 — — — 17 5
Connecticut — — 3 — — — 5 2
Maine — — 3 — — — — —
Massachusetts — — 6 — — — 9 2
New Hampshire — — — — — — 1 —
Rhode Island — — 1 — — — 1 1
Vermont — — — — — — 1 —
Middle Atlantic — — 3 — — — 83 22
New Jersey — — — — — — 26 10
New York (excluding New York City) — — 3 — — — 17 4
New York City — — — — — — 18 3
Pennsylvania — — — — — — 22 5
East North Central 22 1 3 1 — — 116 30
Illinois 1 — — — — — 49 15
Indiana 1 — — — — — 11 3
Michigan 1 — — — — — 38 9
Ohio 17 1 1 — — — 11 2
Wisconsin 2 — 2 1 — — 7 1
West North Central — — 5 — — — 152 104
Iowa — — — — — — 4 2
Kansas — — — — — — 10 7
Minnesota — — 5 — — — 27 9
Missouri — — — — — — 11 1
Nebraska — — — — — — 69 38
North Dakota — — — — — — 12 18
South Dakota — — — — — — 19 29
South Atlantic 10 — — — — — 38 10
Delaware — — — — — — 3 —
District of Columbia — — — — — — 4 2
Florida — — — — — — 5 —
Georgia — — — — — — 3 1
Maryland — — — — — — 7 1
North Carolina 9 — — — — — 8 —
South Carolina — — — — — — 6 3
Virginia — — — — — — 2 3
West Virginia 1 — — — — — — —
East South Central 7 — — — — — 21 7
Alabama — — — — — — 9 3
Kentucky — — — — — — 4 —
Mississippi — — — — — — 5 3
Tennessee 7 — — — — — 3 1
West South Central — — — — 1 — 172 23
Arkansas — — — — — — 6 2
Louisiana — — — — 1 — 17 5
Oklahoma — — — — — — 19 3
Texas — — — — — — 130 13
Mountain — — — — 6 6 1,306 660
Arizona — — — — 6 6 1,138 571
Colorado — — — — — — 101 74
Idaho — — — — — — 12 4
Montana — — — — — — 2 —
Nevada — — — — — — 1 —
New Mexico — — — — — — 31 3
Utah — — — — — — 21 7
Wyoming — — — — — — — 1
Pacific — — — — 4 — 102 38
Alaska — — — — — — 1 —
California — — — — 4 — 96 34
Hawaii — — — — — — — —
Oregon — — — — — — 1 4
Washington — — — — — — 4 —
U.S. Territories — — — — — — — —
American Samoa — — — — — — — —
Commonwealth of Northern Mariana Islands — — — — — — — —
Guam — — — — — — — —
Puerto Rico — — — — — — — —
U.S. Virgin Islands — — — — — — — —
Non-U.S. Residents — — — — — — — —
Total 39 1 24 1 11 6 2,007 899
  • —: No reported cases — The reporting jurisdiction did not submit any cases to CDC.
  • N: Not reportable — The disease or condition was not reportable by law, statute, or regulation in the reporting jurisdiction.
  • U: Unavailable — The data are unavailable.
  • * 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. 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 https://www.cdc.gov/nndss/data-statistics/readers-guides/.
  • † To calculate rates, use the populations provided in Table 8. Note that calculation of rates for the following conditions uses population subgroups as described in note #7 and population counts presented in Table 8: Zika virus infection, congenital; Zika virus disease, congenital; Infant botulism; Congenital rubella syndrome; Perinatal Hepatitis B infection; Perinatal Hepatitis C infection; Haemophilus influenzae, invasive disease; Invasive pneumococcal disease; and Influenza-associated pediatric mortality. Also see Notes #3 and #7.
Notes:
  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 weekly. 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. Source datasets for the 2021 annual tables were officially closed on March 29, 2023.
  2. The list of national notifiable Infectious diseases and conditions for 2021 and their national surveillance case definitions are available by navigating to the Surveillance Case Definitions | CDC web page, selecting "2021" for the notifiable condition list year, checking "Infectious" conditions, and clicking "Get Notifiable List by Year". 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. Publication criteria for the finalized 2021 data are available at https://wonder.cdc.gov/nndss/documents/2021_NNDSS_Publication_Criteria_03162022.pdf. See also Guide to Interpreting Provisional and Finalized NNDSS Data.
  3. Population estimates for incidence rates are July 1st, 2020, 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, 2020, by year, county, single year of age (range: 0 to 85 years), bridged-race (white, black or African American, American Indian or Alaska Native, Asian, or Pacific Islander), Hispanic ethnicity (not Hispanic or Latino, Hispanic or Latino), and sex (Vintage 2020), prepared under a collaborative arrangement with the U.S. Census Bureau. Population estimates for states released September 22, 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. The choice of population denominators for incidence is based on the availability of population data at the time of publication preparation.
  4. Annual tables for 2016 and later years are available on CDC WONDER.
  5. Annual summary reports from 1993–2015 are available as published in the Morbidity and Mortality Weekly Report.
  6. NNDSS annual tables since 1952 are available at CDC Stacks (once in CDC Stacks, select "Annual Reports" in the "Genre" box to the left).
  7. 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:

    • Zika virus disease, congenital (age restriction in numerator and denominator is <1 year)
    • Zika virus infection, congenital (age restriction in numerator and denominator is <1 year)
    • Haemophilus influenzae, invasive disease <5 years (age restriction in numerator and denominator is <5 years)
    • Invasive pneumococcal disease <5 years (age restriction in numerator and denominator is <5 years)
    • Influenza associated pediatric mortality (age restriction in numerator and denominator is <18 years)
    • Infant botulism (age restriction in numerator and denominator is <1 year)
    • Congenital rubella syndrome (age restriction in numerator and denominator is <1 year)
    • Perinatal hepatitis B infection (age restriction in numerator and denominator is ≤24 months)
    • Perinatal hepatitis C infection (age restriction in numerator and denominator is ≤36 months).

    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.

  8. 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).
  9. 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.
Suggested Citation: 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.