2026 at a Glance
- 733 confirmed cases nationwide as of February 5, 2026
- 20 states with reported cases
- 92% of cases are linked to known outbreaks
- South Carolina's Upstate outbreak is the largest single outbreak in the U.S. in over 30 years
Major Outbreak States
| State | 2026 Cases | Notes |
|---|---|---|
| South Carolina | 546+ | Epicenter. Over 920 total since late 2025. Centered in Upstate/Spartanburg region. 270+ in quarantine. |
| Utah | 56+ | Ongoing outbreak since 2025. 251 total cases across both years. |
| Arizona | 43+ | Ongoing since 2025. 25 cases in Mohave County. |
Other States Reporting Cases
| State | 2026 Cases |
|---|---|
| California | 17 |
| Georgia | <10 |
| Idaho | <10 |
| Kentucky | <10 |
| Minnesota | <10 |
| Nebraska | <10 |
| North Carolina | 17 |
| North Dakota | <10 |
| Ohio | <10 |
| Oklahoma | <10 |
| Oregon | <10 |
| Pennsylvania | 5 |
| South Dakota | <10 |
| Virginia | <10 |
| Washington | 19 |
| Wisconsin | <10 |
Key Details by Outbreak Region
South Carolina (Upstate Outbreak)
The South Carolina outbreak began in the fall of 2025 and is now the largest measles outbreak in the United States since the early 1990s. The outbreak is concentrated in the Upstate region, particularly Spartanburg County. Nearly 90% of cases involve children, including over 240 children under age 5. Multiple schools have had exposure incidents. Over 500 people have been placed in quarantine at various points during the outbreak.
For the latest South Carolina numbers: SC Department of Public Health
Utah
Utah's outbreak started in mid-2025 and has produced 251 total cases, with 56 reported in 2026. Case counts have accelerated in recent weeks, with 48 new cases reported in a three-week span.
For the latest Utah numbers: Utah Department of Health and Human Services
Arizona
Arizona has reported 43 cases in 2026, concentrated in Mohave County in the northern part of the state. This outbreak also began in 2025.
For the latest Arizona numbers: Arizona Department of Health Services
Florida
Florida has reported 21 confirmed cases in 2026, including a growing outbreak linked to a university campus.
Understanding the Data
- Confirmed cases are lab-confirmed or epidemiologically linked to a confirmed case. The CDC only counts confirmed cases in its official totals.
- Probable cases may be reported by states but are not included in CDC counts.
- CDC updates its national data weekly (Thursdays at noon). State health departments may update more frequently.
- A single outbreak can span multiple states. The CDC may count linked cases across states as one outbreak, while each state reports its own case count separately.
What These Numbers Mean for You
If you live in or plan to travel to a state with active cases, confirm your vaccination status now. The MMR vaccine is widely available at pharmacies, doctor offices, and local health departments. If you are unsure whether you are immune, a simple blood test can tell you.