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

TABLE 2k. Annual reported cases* of notifiable diseases, by region and reporting area, United States, U.S. Territories, and Non-U.S. Residents, 2021†
Reporting Area Malaria Measles §
Total Imported Indigenous
U.S. Residents, excluding U.S. Territories 1,503 48 19 29
New England 88 2 1 1
Connecticut 7 2 1 1
Maine 3 — — —
Massachusetts 64 — — —
New Hampshire 5 — — —
Rhode Island 6 — — —
Vermont 3 — — —
Middle Atlantic 402 1 — 1
New Jersey 71 1 — 1
New York (excluding New York City) 46 — — —
New York City 211 — — —
Pennsylvania 74 — — —
East North Central 157 23 6 17
Illinois 43 — — —
Indiana 16 — — —
Michigan 12 1 — 1
Ohio 69 — — —
Wisconsin 17 22 6 16
West North Central 126 — — —
Iowa 17 — — —
Kansas 3 — — —
Minnesota 64 — — —
Missouri 14 — — —
Nebraska 7 — — —
North Dakota 13 — — —
South Dakota 8 — — —
South Atlantic 400 21 11 10
Delaware 7 — — —
District of Columbia 12 — — —
Florida 44 — — —
Georgia 40 — — —
Maryland 191 — — —
North Carolina 30 — — —
South Carolina — — — —
Virginia 76 21 11 10
West Virginia — — — —
East South Central 27 — — —
Alabama 8 — — —
Kentucky 5 — — —
Mississippi 1 — — —
Tennessee 13 — — —
West South Central 127 — — —
Arkansas 2 — — —
Louisiana 6 — — —
Oklahoma 7 — — —
Texas 112 — — —
Mountain 61 1 1 —
Arizona 26 — — —
Colorado 18 — — —
Idaho 3 — — —
Montana 2 — — —
Nevada 4 — — —
New Mexico 1 1 1 —
Utah 7 — — —
Wyoming — — — —
Pacific 115 — — —
Alaska 1 — — —
California 83 — — —
Hawaii 1 — — —
Oregon 10 — — —
Washington 20 — — —
U.S. Territories 1 — — —
American Samoa — — — —
Commonwealth of Northern Mariana Islands — — — —
Guam 1 — — —
Puerto Rico — — — —
U.S. Virgin Islands — — — —
Non-U.S. Residents 5 — — —
Total 1,509 48 19 29
  • —: 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.
  • § 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.
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.