Measles
Measles is one of the most contagious human viruses known; it spreads easily through the air and can cause serious complications, especially in unvaccinated children.
Snapshot: 9/5/2026, 11:30:37 PM · 3 tracked locations · 52,989 active cases (dataset)
At a glance
Quick facts
- How it spreads
- Measles virus spreads through respiratory droplets and can also linger in the air of a room for up to two hours after an infected person leaves.
- How serious
- About 1.8 of every 100 confirmed cases died
- Where it's active
- Highest current burden: Democratic Republic of the Congo (CD) and Yemen (YE).
- Vaccine / treatment
- Two doses of measles-containing vaccine (often combined as MMR) provide strong, long-lasting protection and are the single most effective prevention tool.
Important
Virus Tracker provides aggregated outbreak monitoring for education and situational awareness. It is not medical advice, a diagnostic service, or a substitute for guidance from qualified health professionals or official public health agencies. Always consult licensed clinicians and authoritative sources for personal health decisions.
Overview
Measles is caused by a highly transmissible virus that historically infected nearly every child before vaccines became widely available. Because a single infected person can spread the virus to most susceptible people they encounter, sustained high vaccination coverage is needed to prevent outbreaks. Gaps in immunization, whether from access barriers or vaccine hesitancy, have led to a resurgence of measles in various regions in recent years. Virus Tracker surfaces country-level case activity so readers can see where coverage gaps may be translating into active transmission, alongside the broader context that measles remains preventable with two vaccine doses.
Transmission
Measles virus spreads through respiratory droplets and can also linger in the air of a room for up to two hours after an infected person leaves. It is one of the most contagious diseases known, capable of infecting around 90% of susceptible close contacts. People are contagious for several days before and after the telltale rash appears, which makes early containment difficult without high population immunity.
Symptoms & clinical notes
Illness typically begins with high fever, cough, runny nose, and red, watery eyes, followed a few days later by a rash that spreads from the face down the body. Complications can include ear infections, pneumonia, and, less commonly, brain swelling (encephalitis). Malnourished children and infants face the highest risk of severe outcomes.
Prevention & control
Two doses of measles-containing vaccine (often combined as MMR) provide strong, long-lasting protection and are the single most effective prevention tool. Maintaining vaccination coverage above roughly 95% in a community helps prevent outbreaks through herd immunity. Rapid outbreak response, including targeted vaccination campaigns, can limit spread once cases appear.
Surveillance context
Measles surveillance relies on case-based reporting, laboratory confirmation, and tracking of vaccination coverage gaps by district. Because outbreaks can grow quickly in under-vaccinated pockets, health agencies prioritize timely case investigation and genomic sequencing to trace transmission chains across borders.
Live dataset
Key metrics
Active cases
53K
Deaths
6.4K
How fast it's spreading
27.2%
RisingMeasles — global infection heat map
Country shading reflects relative active-case intensity from the current Virus Tracker dataset for this pathogen. Hover countries on desktop for counts.
Darker red = more people currently sick.
Live dataset
Trajectory outlook
Projected case trend with a modeled confidence range.
Projected case trajectory for Measles, with a shaded confidence range, based on the current Virus Tracker dataset.
Illustrative estimateLive dataset
Top regions by active cases
The 3 tracked locations with the most active Measles cases in the current dataset.
Top 3 tracked locations for Measles by active cases, ranked highest to lowest.
Live dataset
Threat intelligence visuals
Threat matrix
How fast vs. how deadly
Each bubble is a threat. Bigger bubbles mean more people are currently sick.
Where this data comes from
10 of 15 sources are reporting normally.
- 10 healthy sourcesHealthy
- 5 sources downDown
- Data reliability
- 42%
- Confidence-adjusted exposure
- 22.2K
Overall threat level
Where it's hitting hardest
- Democratic Republic of the Congo42.7K active · score 23.7
- Yemen9.8K active · score 21.6
- United States500 active · score 19.8
Dataset
Top affected regions
| Location | Active | Deaths | Trend |
|---|---|---|---|
| Democratic Republic of the Congo (CD) | 42,697 | 5,800 | Stable |
| Yemen (YE) | 9,792 | 610 | Stable |
| United States (US) | 500 | 3 | Stable |
Frequently asked questions
How does measles spread?
Through the air, via droplets from coughing or sneezing, and the virus can remain infectious in a room for up to two hours after an infected person has left.
Is there a vaccine for measles?
Yes. Two doses of measles vaccine, usually given as the combined MMR shot, are highly effective and provide long-lasting protection.
Why do outbreaks still happen if a vaccine exists?
Outbreaks occur where vaccination coverage drops below the level needed for herd immunity, whether due to limited access, disrupted health services, or vaccine hesitancy.
Who is most at risk of severe measles?
Infants too young to be vaccinated, malnourished children, and people with weakened immune systems face the highest risk of complications like pneumonia and encephalitis.
Is this page medical advice?
Virus Tracker provides aggregated outbreak monitoring for education and situational awareness. It is not medical advice, a diagnostic service, or a substitute for guidance from qualified health professionals or official public health agencies. Always consult licensed clinicians and authoritative sources for personal health decisions.
What does "outbreak activity" mean on Virus Tracker?
Outbreak activity reflects active-case burden relative to recoveries in our models. It helps compare stressed outbreak zones within the dataset—it is not a clinical score.
How often is this wiki updated?
Figures refresh on the site’s ingestion and revalidation schedule (typically about every 30 minutes in production). Timestamps on the dashboard snapshot indicate the last build of the underlying dataset.
Why might the heat map not match official government totals?
We merge multiple open sources and fallbacks; reporting lag, testing policy, and geographic coverage differ by country. Use national health ministries for authoritative case definitions.
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