The Johns Hopkins University Measles Tracking Team's collection of U.S. measles cases data. For more information about the project, visit the Bloomberg School of Public Health's Measles Tracker.
This project is a collaborative, interdisciplinary effort conducted by researchers at Johns Hopkins University who are tracking and modeling the risk of measles in the U.S. The team includes members from multiple JHU divisions:
- International Vaccine Access Center (IVAC) - Bloomberg School of Public Health
- Center for Systems Science and Engineering (CSSE) - Whiting School of Engineering
- Bloomberg Center for Government Excellence - Johns Hopkins University
Project Leaders: Lauren Gardner, Shaun Truelove, and William Moss
The data are compiled from official sources, including:
- State and county health departments
- Municipal health authorities
- County-level news releases and verified news articles
All data represents laboratory-confirmed measles cases reported by public health authorities in 2025. The complete list of sources is documented in data_sources_by_state.csv, organized by state.
Purpose: Comprehensive documentation of all official sources used to compile measles case data.
| Column | Description |
|---|---|
State |
U.S. state name where measles cases were reported |
Source_Link |
Direct URL to official health department press release or verified news report |
Key Features:
- Multiple source links per state when applicable
- Permanent record of data provenance for transparency
- Essential for data quality assessment and source verification
Purpose: Weekly time series for Kansas, New Mexico, and Texas (the three states with highest case counts), organized by epidemiological week and based on rash onset dates.
Important: This file uses rash onset dates when available from state health departments, providing epidemiologically accurate timing. As a result, some states-provided time series may not match reporting dates of county-level data.
| Column | Description |
|---|---|
week_start |
First day of epidemiological week (YYYY-MM-DD, always Sunday) |
week_end |
Last day of epidemiological week (YYYY-MM-DD, always Saturday) |
KS_cases |
Weekly count of confirmed cases in Kansas by rash onset date |
NM_cases |
Weekly count of confirmed cases in New Mexico by rash onset date |
TX_cases |
Weekly count of confirmed cases in Texas by rash onset date |
Usage Notes:
- Designed for epidemiological trend analysis and outbreak curve visualization
- Data may be subject to backward revision as states complete case investigations
- Preferred for transmission modeling due to biological timing accuracy
Purpose: Daily count of confirmed measles cases by county, providing the most granular temporal and geographic resolution.
| Column | Description |
|---|---|
location_name |
County identifier in "County Name, State Abbreviation" format |
location_id |
Federal Information Processing Standards (FIPS) code of the location |
location_type |
Reporting jurisdiction type (county, region etc.) |
date |
Date of the case update(s) |
Outcome-type |
Including whether the case is imported or local |
value |
Count of new confirmed cases |
Key Features:
- Reporting date basis: Reflects when cases were officially reported by health authorities
- County-level precision: Enables sub-state geographic analysis
- Coverage: All U.S. counties with at least one confirmed case
- Date Format: YYYY-MM-DD (ISO 8601 standard)
- Case Counts: Integer values representing laboratory-confirmed measles cases only
- Geographic Identifiers: Standardized naming conventions across datasets
| Dataset | Time Basis | Best Use Case |
|---|---|---|
| County Daily Data | Administrative reporting dates | Public health response timeline, administrative burden tracking |
| State Weekly Data | Epidemiological rash onset dates where available | Epidemiological analysis, outbreak curves, transmission modeling |
- The state of Kansas does not provide exact case numbers for counties with less than five confirmed cases. As such, we aggregate such cases to an "unknown county" until further information is available.
- The state of Tennessee provides confirmed case reporting on public health region rather than counties. We provide Tennessee cases on the same level.
- The state of Oklahoma does not provide county information on the confirmed cases. As such, we aggregate all cases to an "Unknown county" until further information is available. This data is represented on the map using the state’s geographic centroid.
Data are updated Tuesdays and Fridays at approximately 5:00 PM Eastern Time, but subject to change in response to state reporting..
Note: Historical data is subject to backward revisions as case investigations are completed and additional information becomes available. Previous versions of these data will be maintained through GitHub version-control.
This dataset is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) by Johns Hopkins University on behalf of the JHU Measles Tracking Team.
Attribution: Please cite as "JHU Measles Tracking Team Data Repository at Johns Hopkins University" or "JHU Measles Tracking Team Data" for short.
Copyright: Johns Hopkins University 2025
For general questions or suggestions, please open a GitHub issue and a member of the team will respond. This repository is maintained by the Johns Hopkins University Measles Tracking Team