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

TABLE 2n. Annual reported cases* of notifiable diseases, by region and reporting area, United States, U.S. Territories, and Non-U.S. Residents, 2020†
Data from some reporting areas may be incomplete due to the coronavirus disease 2019 (COVID-19) pandemic or due to post-reconciliation data updates that could not be confirmed or included in the final data set. Please see Note #9 and Note #10, respectively.
Reporting Area Rabies Rubella Rubella, congenital syndrome Salmonella Paratyphi infection § Salmonella Typhi infection 
Animal Human
U.S. Residents, excluding U.S. Territories 4,457 — 6 — 75 182
New England 361 — — — 5 8
Connecticut 39 — — — 2 3
Maine 89 — — — — —
Massachusetts 164 — — — 3 4
New Hampshire 27 — — — — 1
Rhode Island 30 — — — — —
Vermont 12 — — — — —
Middle Atlantic 1,012 — — — 9 45
New Jersey 257 — — — — 8
New York (excluding New York City) 346 — — — 3 5
New York City 38 — — — 5 20
Pennsylvania 371 — — — 1 12
East North Central 171 — 1 — 15 11
Illinois 38 — — — 11 6
Indiana 12 — — — — 1
Michigan 56 — 1 — 3 1
Ohio 40 — — — — 3
Wisconsin 25 — — — 1 —
West North Central 146 — 2 — 4 7
Iowa 12 — — — 3 —
Kansas 30 — 1 — — —
Minnesota 40 — — — 1 3
Missouri 16 — 1 — — 4
Nebraska 25 — — — — —
North Dakota 13 — — — — —
South Dakota 10 — — — — —
South Atlantic 1,404 — — — 7 27
Delaware 6 — — — 1 1
District of Columbia 15 — — — — 2
Florida 81 — — — 1 2
Georgia 189 — — — — 1
Maryland 256 — — — 3 7
North Carolina 301 — — — — 4
South Carolina 168 — — — — 2
Virginia 351 — — — 2 8
West Virginia 37 — — — — —
East South Central 86 — 1 — 2 3
Alabama 51 — 1 — 1 1
Kentucky 17 — — — — 1
Mississippi 2 — — — — —
Tennessee 16 — — — 1 1
West South Central 659 — 1 — 6 13
Arkansas 33 — — — 1 1
Louisiana 5 — — — 1 —
Oklahoma 41 — — — — 2
Texas 580 — 1 — 4 10
Mountain 333 — 1 — 5 6
Arizona 106 — 1 — 2 3
Colorado 92 — — — 1 3
Idaho 17 — — — — —
Montana 13 — — — — —
Nevada 29 — — — 2 —
New Mexico 21 — — — — —
Utah 15 — — — — —
Wyoming 40 — — — — —
Pacific 285 — — — 22 62
Alaska 15 — — — 2 —
California 248 — — — 18 49
Hawaii — — — — — 2
Oregon 14 — — — — 1
Washington 8 — — — 2 10
U.S. Territories 22 — — — 1 —
American Samoa U U — — — —
Commonwealth of Northern Mariana Islands — — — — — —
Guam — — — — 1 —
Puerto Rico 22 — — — — —
U.S. Virgin Islands — — — — — —
Non-U.S. Residents — — — — — —
Total 4,479 — 6 — 76 182
  • —: 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 use population subsets 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.
  • § 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.
  • ¶ Beginning in January 2019, cases began to be reported as Salmonella Typhi infection. In previous years, cases were reported as typhoid fever.
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 2020 annual tables were officially closed on September 27, 2022.
  2. The list of national notifiable Infectious diseases and conditions for 2020 and their national surveillance case definitions are available by navigating to the Surveillance Case Definitions | CDC web page, selecting "2020" for the notifiable condition list year, checking "Infectious" conditions, and clicking "Get Notifiable List by Year". 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. Revised case definitions were implemented for the following conditions: 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. Publication criteria for the finalized 2020 data are available at https://wonder.cdc.gov/nndss/documents/2020_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 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. 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 is ≤24 months, denominator is <24 months)
    • Perinatal hepatitis C infection (age restriction in numerator is ≤36 months, 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 2020 (National Center for Health Statistics Natality 2020, 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. 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.
  10. The following 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.
  11. 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.
  12. 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.
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.