North America 28 Sep 2026 · Dr Natalya Mathur
ENCLAI ID ENCLAI-2026-0000455-4 · Cite

Meningococcal disease in the US: 101 cases in 90 days

ENCLAI SURVEILLANCE BRIEFING · 28 SEPTEMBER 2026Meningococcal disease in the US: 101cases in 90 daysInvasive meningococcal disease · The US · reported cases38reported cases in the 30 days to 28 September▲ 9% more than the 30 days before (35)35The 30 daysbefore75Same 30 days, ayear earlier10190 days to 28September4702026 so farThree 30-day windows75A year earlier3530 days before38Last 30 daysLargest counts, last 90 daysThe UK154The US101Australia23Germany12New Zealand10Finland39 countries with a reported count in this windowWhat this briefing shows1Reported cases rose from 35 to 38 between the two latest 30-daywindows, 9% more.2The latest count of 38 is below the 75 reported in the same 30 daysa year earlier.3The US accounts for 50.6% of the meningococcal disease casesreported to ENCLAI worldwide in 2026 and ranks 1 of 14 reportingcountries.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 2026-09-28 ·enclai.net/newsVerify every figure against the source data before use; ENCLAI does not guarantee accuracy orcompleteness.
  1. Reported cases rose from 35 to 38 between the two latest 30-day windows, 9% more.
  2. The latest count of 38 is below the 75 reported in the same 30 days a year earlier.
  3. The US accounts for 50.6% of the meningococcal disease cases reported to ENCLAI worldwide in 2026 and ranks 1 of 14 reporting countries.
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Largest included reported counts (6 of 9 countries) · 2026-07-01 through 2026-09-28 · source-record dates; coverage varies
United Kingdom154
United States101
Australia23
Germany12
New Zealand10
Finland3
Invasive meningococcal disease — United States · reported surveillance count · 2026-07-01 through 2026-09-28 · inclusive source-record dates
Invasive meningococcal disease — United States · reported surveillance count · 2026-08-30 through 2026-09-28 · inclusive source-record dates
Invasive meningococcal disease — United States · reported surveillance count · 2026-07-31 through 2026-08-29 · inclusive source-record dates
Invasive meningococcal disease — United States · reported surveillance count · 2025-08-30 through 2025-09-28 · inclusive source-record dates
Invasive meningococcal disease · combined reported surveillance count · 2026-07-01 through 2026-09-28 · inclusive source-record dates
Invasive meningococcal disease · weekly reported-count series · Weeks starting 2026-06-22 through 2026-09-07
Largest included reported counts (6 of 9 countries) · 2026-07-01 through 2026-09-28 · source-record dates; coverage varies

The full briefing

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

The US reported 101 meningococcal disease cases in the 90 days to 28 September. 38 of them came in the 30 days to 28 September, against 35 in the 30 days before. The same 30 days a year earlier had 75.

Why it matters

The US accounts for 50.6% of the meningococcal disease cases reported to ENCLAI worldwide so far in 2026. It ranks 1 of 14 reporting countries.

The numbers

PeriodReported cases
Last 30 days (to 28 September)38
The 30 days before that35
Same 30 days a year earlier75
90 days to 28 September101
2026 so far (ENCLAI export)470
The card shows meningococcal disease in the US. It compares the last 30 days with the 30 days before, as reported to ENCLAI.
The card shows meningococcal disease 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

Invasive meningococcal disease in the US: the 2026 picture · Invasive meningococcal disease worldwide · the US: all diseases · How to read these counts

Retained reporting context

Included reporting countries

Invasive meningococcal disease

310

combined reported surveillance count

2026-07-01 through 2026-09-28 · inclusive source-record dates

For Invasive meningococcal disease, the combined reported surveillance count across the 9 countries with positive reported counts in this selection is 310. The selection uses source-record dates 2026-07-01 through 2026-09-28, inclusive. This covers only these reporting countries; source periods and completeness vary.

Exact included country membership
CountryReported countSource-record dates
Australia232026-07-01 through 2026-09-28
Canada22026-07-01 through 2026-09-28
Germany122026-07-01 through 2026-09-28
Finland32026-07-01 through 2026-09-28
United Kingdom1542026-07-01 through 2026-09-28
South Korea32026-07-01 through 2026-09-28
New Zealand102026-07-01 through 2026-09-28
Singapore22026-07-01 through 2026-09-28
United States1012026-07-01 through 2026-09-28

Snapshot 2026-09-28

Weekly reporting history

Invasive meningococcal disease

weekly reported-count series

Weeks starting 2026-06-22 through 2026-09-07

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
2026-06-22 through 2026-06-284
2026-06-29 through 2026-07-056
2026-07-06 through 2026-07-129
2026-07-13 through 2026-07-1911
2026-07-20 through 2026-07-2622
2026-07-27 through 2026-08-0247
2026-08-03 through 2026-08-0932
2026-08-10 through 2026-08-1631
2026-08-17 through 2026-08-2316
2026-08-24 through 2026-08-3019
2026-08-31 through 2026-09-0629
2026-09-07 through 2026-09-1336

Snapshot 2026-09-27

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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