North America 25 Sep 2026 · Dr Natalya Mathur
ENCLAI ID ENCLAI-2026-0000436-X · Cite

Measles in the US: 966 cases in 90 days, 378 in the last 30

ENCLAI SURVEILLANCE BRIEFING · 25 SEPTEMBER 2026Measles in the US: 966 cases in 90days, 378 in the last 30Measles · The US · reported cases378reported cases in the 30 days to 25 September▼ 23% fewer than the 30 days before (494)494The 30 daysbefore121Same 30 days, ayear earlier96690 days to 25September2,4742026 so farThree 30-day windows121A year earlier49430 days before378Last 30 daysLargest counts, last 90 daysMexico3,895The US966The UK100Germany22Canada13Singapore139 countries with a reported count in this windowWhat this briefing shows1Reported cases fell from 494 to 378 between the two latest 30-daywindows, 23% fewer.2The latest count of 378 is above the 121 reported in the same 30days a year earlier.3The US accounts for 3.6% of the measles cases reported to ENCLAIworldwide in 2026 and ranks 2 of 43 reporting countries.Read with care: reports to official surveillance, not people and not a rate. A change between30-day windows can come from reporting timing as much as from transmission.Source: official surveillance reports compiled by ENCLAI · data as of 2026-09-25 ·enclai.net/newsVerify every figure against the source data before use; ENCLAI does not guarantee accuracy orcompleteness.
  1. Reported cases fell from 494 to 378 between the two latest 30-day windows, 23% fewer.
  2. The latest count of 378 is above the 121 reported in the same 30 days a year earlier.
  3. The US accounts for 3.6% of the measles cases reported to ENCLAI worldwide in 2026 and ranks 2 of 43 reporting countries.
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Largest included reported counts (6 of 9 countries) · 2026-06-27 through 2026-09-25 · source-record dates; coverage varies
Mexico3,895
United States966
United Kingdom100
Germany22
Canada13
Singapore13
Measles — United States · reported surveillance count · 2026-06-27 through 2026-09-25 · inclusive source-record dates
Measles — United States · reported surveillance count · 2026-08-26 through 2026-09-25 · inclusive source-record dates
Measles — United States · reported surveillance count · 2026-07-26 through 2026-08-25 · inclusive source-record dates
Measles — United States · reported surveillance count · 2025-08-26 through 2025-09-25 · inclusive source-record dates
Measles · combined reported surveillance count · 2026-06-27 through 2026-09-25 · inclusive source-record dates
Measles · weekly reported-count series · Weeks starting 2026-06-15 through 2026-08-31
Largest included reported counts (6 of 9 countries) · 2026-06-27 through 2026-09-25 · source-record dates; coverage varies

The full briefing

Full 2026 picture: Measles in United States — reported cases by year, monthly records and every briefing for this pair.

The US reported 966 measles cases in the 90 days to 25 September. 378 of them came in the 30 days to 25 September, against 494 in the 30 days before. The same 30 days a year earlier had 121.

Why it matters

The US accounts for 3.6% of the measles cases reported to ENCLAI worldwide so far in 2026. It ranks 2 of 43 reporting countries. 2025 closed at 1,901 cases, 1660% above the three-year baseline of 108 a year. 2026 so far stands at 2,474.

The numbers

PeriodReported cases
Last 30 days (to 25 September)378
The 30 days before that494
Same 30 days a year earlier121
90 days to 25 September966
2026 so far (ENCLAI export)2,474
Three-year baseline (a year)108
The card shows measles in the US. It compares the last 30 days with the 30 days before, as reported to ENCLAI.
The card shows measles in the US. It compares the last 30 days with the 30 days before, as reported to ENCLAI.

What the source says

These figures come from official surveillance reports. They count reports, not people. They are not an incidence rate, the rate of new cases in a population. They do not cover the whole population. The reporting periods do not match these dates exactly. Some reports are incomplete or still in progress. Some run past the window. Some reports do not say which date they use: symptom onset, notification, or confirmation.

Caveats

  • A change between two 30-day windows can come from reporting timing as much as from transmission. The source does not say which.

Where to learn more

Measles in the US: the 2026 picture · Measles worldwide · the US: all diseases · How to read these counts

Retained reporting context

Included reporting countries

Measles

5,020

combined reported surveillance count

2026-06-27 through 2026-09-25 · inclusive source-record dates

For Measles, the combined reported surveillance count across the 9 countries with positive reported counts in this selection is 5,020. The selection uses source-record dates 2026-06-27 through 2026-09-25, inclusive. This covers only these reporting countries; source periods and completeness vary.

Exact included country membership
CountryReported countSource-record dates
Australia82026-06-27 through 2026-09-25
Canada132026-06-27 through 2026-09-25
Germany222026-06-27 through 2026-09-25
United Kingdom1002026-06-27 through 2026-09-25
South Korea22026-06-27 through 2026-09-25
Mexico3,8952026-06-27 through 2026-09-25
New Zealand12026-06-27 through 2026-09-25
Singapore132026-06-27 through 2026-09-25
United States9662026-06-27 through 2026-09-25

Snapshot 2026-09-25

Weekly reporting history

Measles

weekly reported-count series

Weeks starting 2026-06-15 through 2026-08-31

A retained retrospective weekly reported-count series across included reporting countries. Country membership and reporting completeness can vary by week. Missing weeks remain gaps. This is a separate report-series measure; it does not establish exact incidence or laboratory confirmation.

Retained weekly report series
WeekReported count
2026-06-15 through 2026-06-216341
2026-06-22 through 2026-06-281967
2026-06-29 through 2026-07-05805
2026-07-06 through 2026-07-12158
2026-07-13 through 2026-07-19117
2026-07-20 through 2026-07-26128
2026-07-27 through 2026-08-02159
2026-08-03 through 2026-08-09260
2026-08-10 through 2026-08-16321
2026-08-17 through 2026-08-23262
2026-08-24 through 2026-08-30378
2026-08-31 through 2026-09-06350

Snapshot 2026-09-24

Sources and limitations

  • Window. Each quantity keeps its recorded source-selection dates and coverage notes. Dated batches and weekly or genomic observations retain their separate measures. Publication or capture dates do not establish case onset, equal cohorts or period completeness.
  • Denominator. The retained counts do not establish complete populations, equal reporting cohorts or incidence rates. Source period bounds and definitions can differ.
  • Case definition. Case definitions are set nationally and change over time. Counts for the same disease in different countries may not be counting the same thing.
  • Revisions. Agencies restate figures. Values here are as reported at the time of publication; see the update history below.

ENCLAI counts reflect verified records available from reporting sources for the stated window. They are not estimates of total incidence and should not be interpreted as medical advice. Full methodology: the dataset.

Review and corrections

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