Notice to Data Users

January 2024

Beginning with the 2024 weekly NNDSS tables, the following changes were made:

• Invasive Cronobacter infection among infants is a new nationally notifiable condition starting in 2024 and was added to the NNDSS tables.
• Zika virus non-congenital and congenital infection (without disease) are no longer nationally notifiable and will no longer be included in the 2024 NNDSS tables.
• Mpox cases are displayed in the 2024 NNDSS tables and include confirmed and probable cases.
• While COVID-19 has been nationally notifiable since 2022, data for this condition are not included in the weekly 2024 NNDSS tables. Case surveillance data (including deaths) and associated demographic information derived from these data will remain available via public use datasets at data.cdc.gov.
• Ehrlichiosis and anaplasmosis (Anaplasma phagocytophilum, Ehrlichia ewingii, and Ehrlichia chaffeensis infections) are no longer included in the weekly tables but will remain in the annual tables. Undetermined ehrlichiosis/anaplasmosis is no longer nationally notifiable and is not included in the NNDSS tables.
• Confirmed and probable cases of acute hepatitis B, chronic hepatitis B, acute hepatitis C, and chronic hepatitis C are included in the 2024 weekly tables. Weekly publication changes for hepatitis viral infections include the addition of:
  • Hepatitis B, acute probable cases
  • Hepatitis B, chronic probable cases
  • Hepatitis C, chronic confirmed and probable cases
• Refer to the NNDSS case definition website for new and revised surveillance case definitions. The Council of State and Territorial Epidemiologists (CSTE) approved revised 2024 case definitions for anaplasmosis; ehrlichiosis; hepatitis B infection; mumps; paralytic and nonparalytic poliovirus infection; varicella disease; and Zika virus disease. The full CSTE position statements can be found on the CSTE position statement archive website.
• As with prior years, conditions under standardized surveillance (CSS) are not included in the weekly NNDSS tables. New CSS are toxoplasmosis and congenital cytomegalovirus infections. Neonatal abstinence syndrome (NAS) is an updated CSS.

July 2023

Due to data processing issues at CDC, data for some conditions for South Dakota are marked as unavailable (U) or not calculated (NC) for weeks 28 and 29.

February 2023

Due to data processing issues at CDC, data for Ohio are marked as unavailable (U) or not calculated (NC) for week 6.

January 2023

Beginning with the 2023 weekly NNDSS tables, the following changes were made:

• The 2023 weekly NNDSS tables were reformatted to display nationally notifiable diseases and conditions alphabetically in a single menu format, as opposed to being displayed alphabetically in a distributed fashion across sequentially numbered tables.
• Melioidosis; Candida auris, screening; carbapenemase-producing organisms (CPO), clinical; and CPO, screening are new nationally notifiable conditions which have been added to the weekly NNDSS tables.
• Carbapenem-resistant Enterobacteriaceae (CP-CRE) has been removed from the 2023 NNDSS tables, because it has been replaced with CPO. CP-CRE is considered a subset of CPO and thus CPO has replaced CP-CRE in the NNDSS tables.
• Starting week 1 of 2023, animal rabies data will no longer be presented in the weekly NNDSS data tables. Animal rabies will only be presented in the annual NNDSS data tables.
• While mpox and COVID-19 were nationally notifiable in 2022 and continue to be nationally notifiable, data for these conditions will not appear in the weekly 2023 NNDSS tables until the public health response for these conditions has transitioned to routine surveillance methods. During the public health response, data for mpox is available on CDC's Mpox web site and data for COVID-19 can be found on the COVID Data Tracker web site.
• Refer to the NNDSS case definition web site for new and revised surveillance case definitions. The Council of State and Territorial Epidemiologists (CSTE) approved revised 2023 case definitions for COVID-19; coccidioidomycosis; Candida auris, clinical; gonorrhea; and animal rabies. CSTE approved new case definitions in 2023 for melioidosis; CPO, clinical; CPO, screening; and Candida auris, screening. In addition, the new 2022 mpox case definition will continue to be used in 2023.

Errata

June 2023

The export files (.txt version) for the 2023 NNDSS weekly tables weeks 1-18 are missing the non-numeric values that are displayed in the corresponding .html version. This causes the data in the export files to be shifted to an incorrect column label. For the correct data display, the reader should refer to the .html version of the data tables for the 2023 NNDSS weekly tables weeks 1-18. The export files are correct for the 2023 NNDSS weekly tables weeks 19 and beyond.

February 2022

Effective Tuesday, February 22, 2022, the 2022 data presented in the NNDSS Weekly Tables on Data.CDC.gov are now available in a single table. This consolidates 42 separate tables, simplifying data extraction. Current NNDSS weekly case counts are now available for all notifiable conditions in one place at https://data.cdc.gov/NNDSS/NNDSS-Weekly-Data/x9gk-5huc.

January 2022

The NNDSS data platform experienced processing delays of some case notifications since January 14, 2022. Additionally, generation of aggregate counts for publication was delayed. These factors may impact the published counts for weeks 2 and 3 of 2022.

January 2022

In 2021, the NNDSS web site moved to https://www.cdc.gov/nndss/. This change impacts where to find supporting documentation and the citation in previously published tables. Specifically, the URLs have changed for the following resources:

1. NNDSS: now https://www.cdc.gov/nndss/ (previously https://wwwn.cdc.gov/nndss/)
2. Infectious tables - see Using and Interpreting Data: now https://www.cdc.gov/nndss/data-statistics/infectious-tables/index.html (previously https://wwwn.cdc.gov/nndss/infectious-tables.html)
3. Readers' Guides: now https://www.cdc.gov/nndss/data-statistics/readers-guides/ (previously
   1. for data tables 2019-current: https://www.cdc.gov/nndss/docs/Readers-Guide-WONDER-Tables-20210421-508.pdf
   2. for data tables 2016-2018: https://ndc.services.cdc.gov/wp-content/uploads/Users_guide_WONDER_tables_cleared_final.pdf
      and https://wwwn.cdc.gov/nndss/document/Users_guide_WONDER_tables_cleared_final.pdf
   3. for data tables 2006-2015: https://ndc.services.cdc.gov/wp-content/uploads/guide_to_interpreting_provisional_and_finalized_nndss_data_tables.pdf
      and https://wwwn.cdc.gov/nndss/document/guide_to_interpreting_provisional_and_finalized_nndss_data_tables.pdf)
4. Five Year Weekly Average: now https://ndc.services.cdc.gov/wp-content/uploads/5yearweeklyaverage.pdf (previously https://wwwn.cdc.gov/nndss/document/5yearweeklyaverage.pdf)
5. Technical Resource Center: now https://www.cdc.gov/nndss/trc/ (previously https://wwwn.cdc.gov/nndss/downloads.html)
6. Surveillance Case Definitions: now https://ndc.services.cdc.gov (previously https://wwwn.cdc.gov/nndss/conditions/)
7. Provisional National Notifiable Diseases Surveillance Data: now https://ndc.services.cdc.gov/wp-content/uploads/ProvisionalNationaNotifiableDiseasesSurveillanceData20100927.pdf (previously https://wwwn.cdc.gov/nndss/document/ProvisionalNationaNotifiableDiseasesSurveillanceData20100927.pdf)
8. MMWR Weeks Fact Sheet: now https://ndc.services.cdc.gov/wp-content/uploads/2021/02/MMWR_Week_overview.pdf (previously http://wwwn.cdc.gov/nndss/document/MMWR_Week_overview.pdf)
9. MMWR Weeks Calendar: now https://ndc.services.cdc.gov/event-codes-other-surveillance-resources/ (previously http://wwwn.cdc.gov/nndss/script/downloads.aspx)

January 2022

The Council of State and Territorial Epidemiologists approved revised national surveillance case definitions in 2021 for Chlamydia trachomatis infection, Lyme disease, and the Viral Hemorrhagic Fevers that will be applied to the 2022 NNDSS data. In addition, Chapare hemorrhagic fever was added to the list of Viral Hemorrhagic Fevers in 2022. Beginning with the 2022 NNDSS data, the following print criteria changes will be implemented in the weekly and annual tables: a) the print criteria for Chlamydia trachomatis infection will change from all reported cases to confirmed cases only; and, b) the print criteria for the Viral Hemorrhagic Fevers will change from confirmed cases only to confirmed and suspect cases. Note that Lyme disease data are only published in the annual NNNDSS tables and in 2022, CDC will continue to publish confirmed and probable Lyme disease cases in those tables.

December 2021

Case counts for measles, mumps, pertussis, and rubella for week 49 of 2021 are erroneously elevated in some jurisdictions due to the inclusion of records that were classified as not a case.

December 2021

Improvements in data processing at CDC were applied to 2020 and 2021 data beginning with the tables published for week 47 of 2021. Case count changes between tables published for week 46 and week 47 may be due to changes in data processing rules and not due to changes in disease levels.

February 2021

Due to data processing issues at CDC, data for the following jurisdictions may be incomplete for week 7: Alaska, Arizona, California, Connecticut, Delaware, Florida, Hawaii, Louisiana, Maryland, Michigan, Missouri, North Dakota, New Hampshire, New York City, Oregon, Pennsylvania, and Rhode Island.

January 2021

In 2020, the Council of State and Territorial Epidemiologists (CSTE) approved the addition of coronavirus disease 2019 (COVID-19) to the list of nationally notifiable conditions. Data for COVID-19 are not currently published in either the 2020 or the 2021 weekly NNDSS tables, but instead are accessible here: https://covid.cdc.gov/covid-data-tracker/#datatracker-home. CSTE adopted the first 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.

Errata

February 2021

In Table 1n of the 2021 NNDSS weekly tables for week 1 only, data for Haemophilus influenzae in children <5 years categorized as "non-b serotype" and "unknown serotype" were updated on 02/26/2021 to correct the data associated with these two serotype categories. The original version of the tables incorrectly displayed data for "non-b serotype" in the "unknown serotype" column and incorrectly displayed data for "unknown serotype" in the "non-b serotype" column. The data are corrected now.

September 2020

Tuberculosis data included in the 2020 weekly NNDSS Table 1jj for weeks 4-31 are incorrect for New York City; the Middle Atlantic region total; U.S. Residents, excluding U.S. Territories total; and the grand total, due to data processing issues.

September 2020

Tuberculosis data included in the 2020 weekly NNDSS Table 1jj for weeks 32-33 are incorrect for the U.S. Residents, excluding U.S. Territories total and the grand total, due to data processing issues.

August 2020

Data for all diseases and conditions from Texas for 2019 and 2020 published in the 2020 week 32 NNDSS tables are incomplete, except for the arboviral diseases, congenital syphilis, and tuberculosis, due to a data processing issue at CDC.

August 2020

Data from California, published in the 2020 weekly NNDSS tables for week 29 for years 2019 and 2020, were incomplete when originally published on July 24, 2020. On August 4, 2020, incomplete case counts were replaced with a "U" indicating case counts are not available for specified time periods. This change impacted data for the following conditions and tables:

• campylobacteriosis (table 1f)
• carbapenemase-producing carbapenem-resistant Enterobacteriaceae, chancroid, and Chlamydia trachomatis infection (table 1g)
• coccidioidomycosis (table 1h)
• gonorrhea and Haemophilus influenzae invasive disease (table 1m)
• Haemophilus influenzae invasive disease (table 1n)
• hepatitis A acute and hepatitis B acute (table 1p)
• hepatitis C acute (table 1q)
• hepatitis C perinatal infection (table 1r)
• listeriosis (table 1u)
• measles (table 1v)
• meningococcal disease (tables 1w and 1x)
• mumps (table 1y)
• pertussis (table 1z)
• shigellosis (table 1ff)
• syphilis congenital and syphilis primary and secondary (table 1hh)

January 2020

Beginning in 2020, tuberculosis data will appear in the weekly NNDSS tables. Spotted fever rickettsiosis will no longer appear in the weekly NNDSS tables, however it will continue to be published in the annual NNDSS tables. The Council of State and Territorial Epidemiologists approved new surveillance case definitions for the following nationally notifiable infectious diseases: acute hepatitis C, chronic hepatitis C, pertussis, plague, legionellosis, and spotted fever rickettsiosis. These case definitions will be applied to new cases in surveillance year 2020. There were no new nationally notifiable conditions added to the NNDSS, as a result of approved 2019 CSTE position statements.

Errata

February 2021

In Table 1n of the 2020 NNDSS weekly tables for weeks 1-53, data for Haemophilus influenzae in children < 5 years categorized as "non-b serotype" and "unknown serotype" were updated on 02/26/2021 to correct the data associated with these two serotype categories. The original version of the tables incorrectly displayed data for "non-b serotype" in the "unknown serotype" column and incorrectly displayed data for "unknown serotype" in the "non-b serotype" column. The data are corrected now.

February 2020

Measles data for weeks 1-4 (in Table 1v) were updated on 02-28-2020 to correct the classification of imported and indigenous. 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.

January 2019

The following changes were made to the weekly 2019 tables of nationally notifiable infectious diseases and conditions:

• The previous Table 1 format (which displayed infrequently reported notifiable diseases) was retired and data for all conditions in that table (except for diphtheria) are displayed using the weekly Table 2 format. Table 2 was renamed to Table 1.
• The 2019 NNDSS data in the new Table 1 are stratified by U.S. Residents, excluding U.S. Territories; U.S. Territories; and non-U.S. Residents; based upon the reported 'country of usual residence' for the case. This stratification is not applied to the 2018 NNDSS data in the 2019 table.
• The previous 52 week median statistic is no longer displayed, but the previous 52 week maximum and cumulative year-to-date counts are retained.
• Changes to the new Table 1 as a result of approved 2018 Council of State and Territorial Epidemiologists position statements include the following:
  • 'Candida auris, clinical cases' was added as a new nationally notifiable disease.
  • Salmonella Paratyphi infection and Salmonella Typhi infection replaced Paratyphoid fever and Typhoid fever, respectively.
  • Salmonellosis (excluding S. Typhi infection and S. Paratyphi infection) replaced Salmonellosis (excluding paratyphoid fever and typhoid fever).
  • Carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) represents a consolidation of CP-CRE species Klebsiella spp, CP-CRE E. coli, and CP-CRE Enterobacter spp.
• The quarterly Tuberculosis Table 3 was renamed Table 2.

Figure 1 only includes data among U.S. residents (and therefore excludes data among U.S. Territories and non-U.S. residents).

October 2019

In 2019, CDC undertook a critical review of the content and method used to create Figure 1. Input from jurisdictions through the Council of State and Territorial Epidemiologists (CSTE) and from CDC programs was sought to determine usefulness and desire to maintain the figure. A determination was made that due to the limited usefulness of Figure 1, it will no longer be published as of the first week in surveillance year 2020.

November 2019

Software data processing failures resulted in incomplete weekly case counts for all 2019 tables for weeks 42 through 46.

November 2019

Software data processing failures resulted in incomplete weekly case counts in Tables 1a - 1pp and in Figure 1 for weeks 42 through 46 of the 2019 data.

December 2019

Starting week 1 of 2020, tuberculosis data will be presented in Table 1 and Table 2 will be discontinued.

March 2020

Measles 2019 data in Table 1v for weeks 1-51 were updated to remove the stratification of cases by imported and indigenous case classification status. Please see week 52, 2019 data for measles cases stratified by imported and indigenous status.

Errata

February 2020

Measles data for week 52 of the 2019 data (Table 1v) were updated on 02-28-2020 to correct the classification of imported and indigenous. 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.

March 2022

The following footnote is missing in Table 1u for listeriosis for weeks 1-14:§ Before 2019, listeriosis cases in neonates less than or equal to 60 days of age were counted as one case in a mother-infant pair. Beginning in 2019, maternal and neonatal listeriosis cases are being counted separately.

January 2018

Beginning with the 2018 NNDSS data, there are a number of changes to the NNDSS display of weekly data.

• Non-congenital Zika virus disease was removed from Table I and added to Table 2.
• Paratyphoid fever was added to Table 1. Prior to 2018, cases of paratyphoid fever were included with salmonellosis cases in Table 2.
• With the removal of paratyphoid fever cases from the salmonellosis case counts in 2018, salmonellosis was replaced with "salmonellosis (excluding paratyphoid fever and typhoid fever)" in Table 2. To obtain data that are comparable to previous years (2017 and earlier), you will need to sum the paratyphoid case count with the "salmonellosis (excluding paratyphoid fever and typhoid fever)" cases count.
• Carbapenemase Producing Carbapenem-Resistant Enterobacteriaceae (CP-CRE), due to Klebsiella spp, Escherichia coli, and Enterobacter spp. were added to Table 2.

Errata

February 2019

Weeks 1-52 data for Haemophilus influenzae, invasive disease in Table 1 of the 2018 data were updated on Monday, February 11, 2019. Labels for "Nontypeable" and "Non-b serotype" were incorrectly placed resulting in the numbers being switched for these two rows. They are now correct.