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

TABLE 2i. Annual reported cases* of notifiable diseases, by region and reporting area, United States, U.S. Territories, and Non-U.S. Residents, 2021†
Reporting Area Human immunodeficiency virus diagnoses Influenza-associated pediatric mortality Invasive pneumococcal disease § Legionellosis  Leptospirosis
All ages Age <5 years
Confirmed Probable Confirmed Probable
U.S. Residents, excluding U.S. Territories 31,269 6 11,832 266 739 31 8,442 69
New England 586 — 467 1 30 — 599 —
Connecticut 200 — 123 — 7 — 118 N
Maine 30 — 87 — — — 39 —
Massachusetts 269 — 152 — 19 — 284 N
New Hampshire 30 — 50 — 2 — 58 —
Rhode Island 51 — 31 1 1 — 87 —
Vermont 6 — 24 — 1 — 13 —
Middle Atlantic 3,577 — 1,360 49 87 4 1,677 19
New Jersey 902 — 249 39 23 2 246 —
New York (excluding New York City) 492 — 401 5 24 1 614 N
New York City 1,353 — 336 2 18 1 363 17
Pennsylvania 830 — 374 3 22 — 454 2
East North Central 3,009 1 2,024 63 119 10 2,464 7
Illinois 844 — N N 16 — 523 4
Indiana 485 — 511 — 19 — 275 1
Michigan 628 — 499 22 30 2 577 1
Ohio 822 1 724 41 33 8 864 1
Wisconsin 230 — 290 — 21 — 225 —
West North Central 1,198 1 1,020 60 62 4 458 5
Iowa 120 — N N N N 44 N
Kansas 155 — 166 6 7 1 47 —
Minnesota 286 1 308 — 25 — 130 —
Missouri 507 — 308 41 20 2 167 3
Nebraska 85 — 90 — 4 — 44 1
North Dakota 21 — 66 — 2 — 5 1
South Dakota 24 — 82 13 4 1 21 —
South Atlantic 9,668 1 2,076 30 151 5 1,363 10
Delaware 81 — 72 — 2 — 24 1
District of Columbia 97 — 18 — — — 3 1
Florida 4,443 — 681 14 58 3 502 5
Georgia 1,689 — 589 — 50 — 147 —
Maryland 636 — 202 — 14 — 213 3
North Carolina 1,298 1 N N N N 164 —
South Carolina 527 — 297 15 16 1 87 —
Virginia 766 — 11 1 10 1 163 —
West Virginia 131 — 206 — 1 — 60 —
East South Central 1,910 1 1,106 9 77 1 406 1
Alabama 386 — 311 2 27 — 91 —
Kentucky 351 — 139 7 13 1 116 1
Mississippi 390 1 151 — 18 — 36 N
Tennessee 783 — 505 — 19 — 163 N
West South Central 5,182 2 1,514 37 130 6 501 2
Arkansas 337 — 186 — 19 — 45 —
Louisiana 957 — 290 4 24 1 71 2
Oklahoma 261 — N N 10 — 32 —
Texas 3,627 2 1,038 33 77 5 353 N
Mountain 1,857 — 2,033 16 77 1 348 1
Arizona 726 — 792 6 18 — 112 —
Colorado 356 — 457 — 16 — 108 N
Idaho 36 — N N 11 — 20 —
Montana 21 — 109 4 6 — 15 —
Nevada 450 — 205 2 6 — 25 —
New Mexico 143 — 232 — 2 — 22 —
Utah 119 — 196 4 14 1 39 1
Wyoming 6 — 42 — 4 — 7 —
Pacific 4,282 — 232 1 6 — 626 24
Alaska 22 — 184 1 3 — 3 —
California 3,538 — N N N N 460 6
Hawaii 58 — 48 — 3 — 13 14
Oregon 193 — N N N N 65 2
Washington 471 — N N N N 85 2
U.S. Territories 350 — 1 — — — 13 46
American Samoa — — N N N N N —
Commonwealth of Northern Mariana Islands — — — — — — — —
Guam 1 — — — — — 2 7
Puerto Rico 346 — 1 — — — 8 39
U.S. Virgin Islands 3 — — — — — 3 —
Non-U.S. Residents — — — — — — 3 —
Total 31,619 6 11,833 266 739 31 8,458 115
  • —: 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.
  • § 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.
  • ¶ 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.
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.