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

TABLE 1. Annual reported cases of notifiable diseases and rates* per 100,000, United States, excluding U.S. Territories and Non-U.S. Residents, 2021
Disease Case Count Rate
Anthrax — —
Arboviral diseases
Chikungunya virus disease 35 0.01
Eastern equine encephalitis virus disease
Neuroinvasive 5 0.00
Non-neuroinvasive — —
Jamestown Canyon virus disease
Neuroinvasive 21 0.01
Non-neuroinvasive 11 0.00
La Crosse virus disease
Neuroinvasive 39 0.01
Non-neuroinvasive 1 0.00
Powassan virus disease
Neuroinvasive 24 0.01
Non-neuroinvasive 1 0.00
St. Louis encephalitis virus disease
Neuroinvasive 11 0.00
Non-neuroinvasive 6 0.00
West Nile virus disease
Neuroinvasive 2,007 0.61
Non-neuroinvasive 899 0.27
Western equine encephalitis virus disease
Neuroinvasive — —
Non-neuroinvasive — —
Babesiosis
Total 2,674 0.94
Confirmed 2,429 0.86
Probable 245 0.09
Botulism
Total 236 0.07
Foodborne 20 0.01
Infant 171 4.58
Other (wound & unspecified) 45 0.01
Brucellosis 114 0.03
Campylobacteriosis 63,409 19.24
Candida auris, clinical † 608 0.23
Carbapenemase-producing carbapenem-resistant Enterobacteriaceae 2,328 0.78
Chancroid 3 0.00
Chlamydia trachomatis infection 1,613,840 498.98
Cholera 5 0.00
Coccidioidomycosis 20,201 14.40
Coronavirus Disease 2019 (COVID-19)
Total 36,096,494 10,955.46
Confirmed 29,076,268 8,824.79
Probable § 7,020,226 2,130.67
Cryptosporidiosis
Total 9,155 2.78
Confirmed 7,191 2.18
Probable 1,964 0.60
Cyclosporiasis 2,424 0.80
Dengue virus infections 
Dengue 182 0.06
Dengue-like illness 7 0.00
Severe dengue 4 0.00
Diphtheria — —
Ehrlichiosis and Anaplasmosis
Anaplasma phagocytophilum infection 6,729 2.12
Ehrlichia chaffeensis infection 1,337 0.42
Ehrlichia ewingii infection 19 0.01
Undetermined ehrlichiosis/anaplasmosis 77 0.02
Giardiasis 11,643 4.44
Gonorrhea 699,585 216.30
Haemophilus influenzae, invasive disease
All ages, all serotypes 3,042 0.92
Age <5 years
Serotype b 27 0.14
Non-b serotype 137 0.71
Nontypeable 94 0.49
Unknown serotype 172 0.05
Hansen's disease 57 0.02
Hantavirus infection, non-hantavirus pulmonary syndrome ** 2 0.00
Hantavirus pulmonary syndrome 14 0.00
Hemolytic uremic syndrome post-diarrheal 302 0.09
Hepatitis, Viral Disease ††
Hepatitis A 5,726 1.74
Hepatitis B
Acute 2,044 0.62
Perinatal infection 17 0.23
Hepatitis C
Acute 6,028 1.89
Confirmed 5,023 1.57
Probable 1,005 0.31
Perinatal infection 200 2.00
Human immunodeficiency virus diagnoses 31,269 9.49
Influenza-associated pediatric mortality 6 0.01
Invasive pneumococcal disease §§
All ages 12,098 4.92
Confirmed 11,832 4.81
Probable 266 0.11
Age <5 years 770 0.29
Confirmed 739 4.76
Probable 31 0.20
Legionellosis ¶¶ 8,442 2.56
Leptospirosis 69 0.03
Listeriosis ***
Total 977 0.30
Confirmed 941 0.29
Probable 36 0.01
Lyme disease
Total 24,610 7.50
Confirmed 16,211 4.94
Probable 8,399 2.56
Malaria 1,503 0.46
Measles †††
Total 48 0.01
Indigenous 29 0.01
Imported 19 0.01
Meningococcal disease
All serogroups 208 0.06
Serogroups ACWY 83 0.03
Serogroup B 32 0.01
Other serogroups 16 0.00
Unknown serogroup 77 0.02
Mumps 189 0.06
Novel Influenza A virus infections 16 0.00
Pertussis 2,116 0.64
Plague §§§ 4 0.00
Poliomyelitis, paralytic — —
Poliovirus infection, nonparalytic — —
Psittacosis 4 0.00
Q fever
Total 192 0.06
Acute 165 0.05
Chronic 27 0.01
Rabies
Animal 3,641 1.11
Human 5 0.00
Rubella 7 0.00
Rubella, congenital syndrome — —
Salmonella Paratyphi infection ¶¶¶ 64 0.02
Salmonella Typhi infection **** 234 0.07
Salmonellosis (excluding S. Typhi infection and S. Paratyphi infection) †††† 49,249 14.95
Severe acute respiratory syndrome-associated coronavirus disease — —
Shiga toxin-producing Escherichia coli (STEC) 13,943 4.23
Shigellosis 9,999 3.03
Smallpox — —
Spotted fever rickettsiosis
Total 1,257 0.38
Confirmed 43 0.01
Probable 1,214 0.37
Streptococcal toxic shock syndrome 145 0.07
Syphilis
Total, all stages §§§§ 174,367 53.91
Congenital ¶¶¶¶ 2,820 75.25
Primary and secondary 53,034 16.40
Tetanus 28 0.01
Toxic shock syndrome (other than Streptococcal) 15 0.01
Trichinellosis 2 0.00
Tuberculosis 7,882 2.39
Tularemia 162 0.05
Vancomycin-intermediate Staphylococcus aureus 73 0.03
Vancomycin-resistant Staphylococcus aureus ***** 5 0.00
Varicella morbidity 3,496 1.24
Varicella mortality 1 0.00
Vibriosis
Total 2,853 0.88
Confirmed 1,556 0.48
Probable 1,297 0.40
Viral hemorrhagic fevers
Crimean-Congo hemorrhagic fever virus — —
Ebola virus — —
Guanarito virus — —
Junin virus — —
Lassa virus — —
Lujo virus — —
Machupo virus — —
Marburg virus — —
Sabia virus — —
Yellow fever 1 0.00
Zika virus
Zika virus disease, congenital ††††† 1 0.03
Zika virus disease, non-congenital 2 0.00
Zika virus infection, congenital ††††† — —
Zika virus infection, non-congenital — —
  • —: No reported cases — The reporting jurisdiction did not submit any cases to CDC.
  • * For population data, see Table 8. Also see Notes #3 and #7.
  • † 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)
  • § 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.
  • ¶ Counts include confirmed and probable dengue cases.
  • ** Case counts may include Old World hantavirus infections, such as Seoul virus.
  • †† 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, 2021, published online by CDC's Division of Viral Hepatitis, available at https://www.cdc.gov/hepatitis/statistics/SurveillanceRpts.htm.
  • §§ 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.
  • *** 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.
  • ††† 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.
  • §§§ Beginning in 2020, confirmed and probable plague cases began to be combined and published.
  • ¶¶¶ 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.
  • †††† 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.
  • §§§§ 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.
  • ***** 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.
  • ††††† Data reported to ArboNET using the national surveillance case definition for congenital Zika virus infection (CSTE Position Statement 16-ID-01).
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.