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

TABLE 3. Annual reported cases of notifiable diseases, by month*, United States, excluding 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.
Disease Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Unknown Total
Anthrax — — — — — — — — — — — 1 — 1
Arboviral diseases
Chikungunya virus disease 10 8 1 2 3 — 1 — 3 2 2 5 — 37
Eastern equine encephalitis virus disease
Neuroinvasive — — — — — — 2 5 5 1 — — — 13
Non-neuroinvasive — — — — — — — — — — — — — —
Jamestown Canyon virus disease
Neuroinvasive — — — — 1 2 5 1 — 1 — — — 10
Non-neuroinvasive — — — — 1 1 — — 1 — — — — 3
La Crosse virus disease
Neuroinvasive — 1 — — — 1 16 32 26 8 — — — 84
Non-neuroinvasive — — — — — — 2 2 — — — — — 4
Powassan virus disease
Neuroinvasive — — — 2 3 6 3 — — 1 2 2 — 19
Non-neuroinvasive — — — — — — — 1 — — — — — 1
St. Louis encephalitis virus disease
Neuroinvasive — — — 1 — 1 3 2 3 1 2 1 — 14
Non-neuroinvasive — — — — — — — 1 1 — — — — 2
West Nile virus disease
Neuroinvasive — 1 — 1 4 6 29 107 266 94 20 30 — 558
Non-neuroinvasive — — 2 — 4 4 11 41 67 21 8 14 — 172
Western equine encephalitis virus disease
Neuroinvasive — — — — — — — — — — — — — —
Non-neuroinvasive — — — — — — — — — — — — — —
Babesiosis
Total 14 10 12 11 39 231 586 517 162 86 46 106 — 1,820
Confirmed 12 6 4 8 35 210 553 461 133 74 44 91 — 1,631
Probable 2 4 8 3 4 21 33 56 29 12 2 15 — 189
Botulism
Total 11 15 9 9 17 14 13 22 18 19 26 16 — 189
Foodborne — — — — 3 — — 1 2 1 1 — — 8
Infant 9 13 8 7 12 12 11 15 14 15 18 12 — 146
Other (wound & unspecified) 2 2 1 2 2 2 2 6 2 3 7 4 — 35
Brucellosis — 6 13 8 8 10 5 7 5 11 5 9 — 87
Campylobacteriosis 4,010 4,888 3,044 2,193 4,165 4,817 4,985 6,218 4,643 5,165 3,200 4,436 — 51,764
Candida auris, clinical † 10 17 11 10 13 12 38 38 27 27 23 29 — 255
Carbapenemase-producing carbapenem-resistant Enterobacteriaceae 166 197 129 99 126 142 122 158 246 189 117 157 — 1,848
Chancroid — — — — — — — — — — — — — —
Chlamydia trachomatis infection 136,161 181,488 115,313 74,501 114,731 115,809 120,653 163,561 128,965 165,558 118,472 144,625 — 1,579,837
Cholera — — — — — — — — 1 — — — — 1
Coccidioidomycosis 1,435 2,005 1,329 857 1,262 1,194 1,154 1,765 1,709 2,131 1,959 2,420 — 19,220
Coronavirus Disease 2019 (COVID-19)
Total 718 1,393 237,279 828,259 786,191 879,911 1,760,192 1,649,270 1,143,635 2,244,093 4,425,759 7,138,430 54,601 21,149,731
Confirmed 587 1,216 233,643 816,152 771,571 864,752 1,722,181 1,582,127 1,055,627 2,030,145 3,932,456 6,120,360 48,539 19,179,356
Probable § 131 177 3,636 12,107 14,620 15,159 38,011 67,143 88,008 213,948 493,303 1,018,070 6,062 1,970,375
Cryptosporidiosis
Total 703 765 441 403 642 605 754 1,112 675 654 344 550 — 7,648
Confirmed 512 586 326 291 477 474 580 892 527 510 268 418 — 5,861
Probable 191 179 115 112 165 131 174 220 148 144 76 132 — 1,787
Cyclosporiasis 12 6 17 15 55 815 535 699 262 85 85 103 — 2,689
Dengue virus infections 
Dengue 85 57 40 6 7 4 19 47 47 40 43 46 — 441
Dengue-like illness 4 — 1 1 — — — — — 1 1 1 — 9
Severe dengue — — — — — — — — — — — — — —
Diphtheria 1 — — — — — — — — — — — — 1
Ehrlichiosis and Anaplasmosis
Anaplasma phagocytophilum infection 17 14 22 94 395 961 717 537 220 218 211 231 — 3,637
Ehrlichia chaffeensis infection 15 16 20 24 126 252 290 191 99 67 21 57 — 1,178
Ehrlichia ewingii infection — 1 — — 1 1 6 6 2 1 — 3 — 21
Undetermined ehrlichiosis/anaplasmosis — 1 1 2 6 11 10 3 5 6 3 2 — 50
Giardiasis 894 1,029 749 393 580 608 731 1,278 948 1,018 548 677 — 9,453
Gonorrhea 49,926 62,609 41,929 33,142 50,922 50,316 52,768 73,103 59,677 76,904 56,754 69,701 — 677,751
Haemophilus influenzae, invasive disease
All ages, all serotypes 577 654 414 175 154 119 124 139 137 149 134 220 — 2,996
Age <5 years
Serotype b 2 2 1 — — — 1 4 2 1 1 1 — 15
Non-b serotype 11 14 10 2 4 — 5 6 5 6 5 8 — 76
Nontypeable 19 34 11 6 6 5 5 — 5 3 3 7 — 104
Unknown serotype 14 28 17 8 10 5 6 4 1 7 8 13 — 121
Hansen's disease 7 10 3 13 2 6 4 5 6 3 5 4 — 68
Hantavirus infection, non-hantavirus pulmonary syndrome ** — — — — — 1 — 1 — — — — — 2
Hantavirus pulmonary syndrome 1 — — 1 1 1 2 2 2 1 — 3 — 14
Hemolytic uremic syndrome post-diarrheal 6 9 11 12 13 12 20 19 15 18 9 23 — 167
Hepatitis, Viral Disease ††
Hepatitis A 889 1,121 690 659 899 710 685 931 807 1,027 720 808 — 9,946
Hepatitis B
Acute 189 260 147 155 189 152 155 195 171 185 106 251 — 2,155
Perinatal infection 1 — 1 — — 2 — 1 1 3 1 — — 10
Hepatitis C
Acute 520 758 466 349 481 521 453 524 432 553 351 617 — 6,025
Confirmed 440 641 360 275 377 401 358 419 332 448 266 481 — 4,798
Probable 80 117 106 74 104 120 95 105 100 105 85 136 — 1,227
Perinatal infection 22 21 13 7 10 10 9 15 16 18 10 14 — 165
Human immunodeficiency virus diagnoses 3,091 2,672 2,208 1,596 1,930 2,315 2,416 2,266 2,285 2,200 1,522 506 — 25,007
Influenza-associated pediatric mortality 43 69 26 9 12 3 1 2 — 5 — 1 — 171
Invasive pneumococcal disease §§
All ages 2,323 2,648 1,660 720 545 388 391 469 458 708 612 1,024 — 11,946
Confirmed 2,279 2,613 1,640 705 526 382 385 458 441 687 602 1,000 — 11,718
Probable 44 35 20 15 19 6 6 11 17 21 10 24 — 228
Age <5 years 98 117 85 37 22 18 16 32 28 38 30 40 — 561
Confirmed 93 108 82 35 22 18 16 32 27 36 29 38 — 536
Probable 5 9 3 2 — — — — 1 2 1 2 — 25
Legionellosis ¶¶ 439 482 307 245 312 481 637 796 773 628 444 766 — 6,310
Leptospirosis 8 6 5 2 3 4 4 6 3 7 1 2 — 51
Listeriosis ***
Total 37 54 38 36 54 57 74 99 80 106 57 88 — 780
Confirmed 36 53 35 35 53 55 71 99 77 103 56 81 — 754
Probable 1 1 3 1 1 2 3 — 3 3 1 7 — 26
Lyme disease
Total 712 925 506 389 1,169 2,884 3,575 3,217 1,365 1,284 805 1,169 — 18,000
Confirmed 447 587 300 249 744 1,960 2,606 2,222 892 856 519 741 — 12,123
Probable 265 338 206 140 425 924 969 995 473 428 286 428 — 5,877
Malaria 129 130 41 22 18 14 22 46 30 42 44 65 — 603
Measles †††
Total 4 7 — — — — — — — — 1 — — 12
Indigenous 1 5 — — — — — — — — — — — 6
Imported 3 2 — — — — — — — — 1 — — 6
Meningococcal disease
All serogroups 41 55 33 17 16 12 13 8 6 18 10 13 — 242
Serogroups ACWY 15 19 8 4 3 8 5 1 3 6 3 5 — 80
Serogroup B 7 15 6 1 2 — 2 1 — 4 1 1 — 40
Other serogroups 4 6 2 1 1 1 — — — 1 — — — 16
Unknown serogroup 15 15 17 11 10 3 6 6 3 7 6 7 — 106
Mumps 164 252 107 41 27 18 9 18 13 16 12 17 — 694
Novel Influenza A virus infections — — — — — — — — — — — — — —
Pertussis 1,523 1,867 1,018 511 340 192 110 116 94 103 97 153 — 6,124
Plague §§§ — — 1 — — 1 2 4 1 — — — — 9
Poliomyelitis, paralytic — — — — — — — — — — — — — —
Poliovirus infection, nonparalytic — — — — — — — — — — — — — —
Psittacosis — — — — 3 — — 2 2 — 1 — — 8
Q fever
Total 8 18 7 5 13 12 11 9 10 6 10 11 — 120
Acute 7 14 5 3 9 8 8 8 7 5 8 8 — 90
Chronic 1 4 2 2 4 4 3 1 3 1 2 3 — 30
Rabies
Animal 270 274 393 364 430 441 445 559 500 360 230 191 — 4,457
Human — — — — — — — — — — — — — —
Rubella 2 — — 1 — 1 — 1 — — — 1 — 6
Rubella, congenital syndrome — — — — — — — — — — — — — —
Salmonella Paratyphi infection ¶¶¶ 15 19 18 4 1 5 3 3 2 3 — 2 — 75
Salmonella Typhi infection **** 32 45 30 9 7 5 6 8 9 11 8 12 — 182
Salmonellosis (excluding S. Typhi infection and S. Paratyphi infection) †††† 2,264 2,653 1,774 1,623 3,145 3,929 5,446 6,995 5,362 5,357 3,145 3,749 — 45,442
Severe acute respiratory syndrome-associated coronavirus disease — — — — — — — — — — — — — —
Shiga toxin-producing Escherichia coli (STEC) 764 932 583 335 676 936 1,094 1,273 962 998 605 764 — 9,922
Shigellosis 1,207 1,611 1,086 426 522 452 506 770 669 760 476 623 — 9,108
Smallpox — — — — — — — — — — — — — —
Spotted fever rickettsiosis
Total 36 46 31 53 135 201 179 157 139 65 70 63 — 1,175
Confirmed 1 2 1 2 8 9 13 9 11 4 3 1 — 64
Probable 35 44 30 51 127 192 166 148 128 61 67 62 — 1,111
Streptococcal toxic shock syndrome 35 46 30 21 19 14 9 12 8 9 5 16 — 224
Syphilis
Total, all stages §§§§ 10,852 14,484 9,725 6,753 10,247 9,740 9,646 13,190 10,936 14,447 10,639 13,274 — 133,933
Congenital ¶¶¶¶ 186 165 138 162 154 151 211 202 197 195 202 185 — 2,148
Primary and secondary 3,216 4,132 2,744 2,277 3,481 3,207 3,022 4,114 3,455 4,474 3,340 4,192 — 41,654
Tetanus — 1 — — 3 3 3 1 — 3 2 1 — 17
Toxic shock syndrome (other than Streptococcal) 1 3 3 1 3 1 — 6 1 3 1 1 — 24
Trichinellosis — — — — — — — — — — — — — —
Tuberculosis 397 707 566 477 603 571 510 631 514 712 509 977 — 7,174
Tularemia — 9 6 3 21 21 20 24 13 17 5 11 — 150
Vancomycin-intermediate Staphylococcus aureus 4 4 1 1 4 5 6 4 5 2 1 8 — 45
Vancomycin-resistant Staphylococcus aureus ***** 1 — — — — — — — — — — — — 1
Varicella morbidity 498 648 290 128 111 167 114 151 190 240 184 206 — 2,927
Varicella mortality 1 — — — — — — — — — — — — 1
Vibriosis
Total 87 117 77 50 101 128 210 391 236 245 99 111 — 1,852
Confirmed 35 44 34 24 50 78 149 272 170 156 61 60 — 1,133
Probable 52 73 43 26 51 50 61 119 66 89 38 51 — 719
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 — — — — — — — — — — — — — —
Zika virus
Zika virus disease, congenital ††††† — — — — — — — — — — — — — —
Zika virus disease, non-congenital — — 1 1 1 — — — — 1 — — — 4
Zika virus infection, congenital ††††† — — — — — — — — — — — — — —
Zika virus infection, non-congenital — 4 3 4 1 — 1 1 2 1 — 2 — 19
  • —: No reported cases — The reporting jurisdiction did not submit any cases to CDC.
  • * Month is defined using MMWR week (https://ndc.services.cdc.gov/wp-content/uploads/2021/02/MMWR_Week_overview.pdf). MMWR week calendars can be found at https://ndc.services.cdc.gov/event-codes-other-surveillance-resources/.
  • † 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)
  • § Please see Note #11.
  • ¶ 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, 2020, 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.
  • ¶¶ 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 are being combined and published. In 2019, only confirmed plague cases were 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 0 vancomycin-resistant Staphylococcus aureus cases in 2020.
  • ††††† 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 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.