What is measles? Current measles North American Outbreak for 2026

Measles (Rubeola) is a highly contagious viral infection caused by a morbillivirus that attacks the respiratory system before spreading through the entire body. It is so infectious that if one person has it, up to 90% of the people close to them will also become infected if they are not immune. The virus lives in the nose and throat mucus of an infected person and spreads through coughing and sneezing. Remarkably, the measles virus can hang in the air or survive on surfaces for up to two hours after an infected person has left the room.

The Progression of Measles Symptoms

Measles doesn’t cause a rash immediately. The infection follows a predictable timeline that typically lasts two to three weeks.

• Incubation Period: For the first 10 to 14 days after infection, you won’t have any symptoms at all.
• The “3 Cs” Phase: The illness starts with a high fever, often accompanied by a persistent cough, coryza (runny nose), and conjunctivitis (red, watery eyes).
• Koplik’s Spots: Two or three days after symptoms begin, tiny white spots with bluish-white centers may appear inside the mouth on the inner lining of the cheek.
• The Measles Rash: This is the hallmark of the disease. It usually starts as flat red spots on the face at the hairline and spreads downward to the neck, trunk, arms, legs, and feet. Small raised bumps may also appear on top of the flat red spots.

How Measles Spreads and Replicates

The virus is a respiratory pathogen. When an infected person breathes, talks, or coughs, they expel droplets containing the virus. Once inhaled, the virus invades the lymphatic tissues of the airway. From there, it hitches a ride in the bloodstream to the lymph nodes, spleen, and eventually the skin and central nervous system.

Because it has such a high “R0” (reproduction number), it is much more contagious than the flu or even many variants of COVID-19. You are contagious from about four days before the rash appears until four days after it has broken out.

Potential Complications and Severity

While some view measles as a simple childhood rash, it can lead to severe health problems because it essentially “wipes” the immune system’s memory, making patients more susceptible to other diseases.

• Pneumonia: The most common cause of death from measles in children.
• Encephalitis: Swelling of the brain that can lead to permanent deafness or intellectual disability.
• Ear Infections: Can result in permanent hearing loss.
• SSPE (Subacute Sclerosing Panencephalitis): A very rare but fatal central nervous system disease that develops 7 to 10 years after a person has “recovered” from measles.

Clinical Example: In a typical community outbreak, an unvaccinated child might visit a pediatrician’s waiting room with what looks like a cold. Even if the child leaves 15 minutes before the next patient enters, the air in that room remains infectious. An infant too young for the MMR vaccine who enters that same room later is at extremely high risk of contracting the virus.

Prevention and Immunity

The only effective way to prevent measles is through the MMR (Measles, Mumps, and Rubella) vaccine.

1. The Two-Dose Protocol: The CDC and WHO recommend a first dose at 12–15 months and a second dose at 4–6 years. This provides approximately 97% lifelong protection.
2. Post-Exposure Treatment: If a non-immune person is exposed, receiving the vaccine within 72 hours—or a dose of immune globulin within six days—may prevent the disease or make symptoms less severe.
3. Vitamin A: In severe cases, particularly in children, doctors often prescribe high doses of Vitamin A, which has been shown to reduce the risk of blindness and death.

As of mid-January 2026, the United States and Canada are experiencing a significant surge in measles activity, with South Carolina and the Arizona-Utah border serving as the primary “hot zones.” The CDC has confirmed 171 cases across 9 U.S. jurisdictions in the first two weeks of 2026 alone. Most of these are continuations of large-scale outbreaks that began in late 2025, driven by holiday travel and declining vaccination rates.

Current U.S. and North American Hot Spots

While many states have reported isolated cases, three major regions are currently managing active, widespread transmission:

• South Carolina (Upstate Region): This is the most critical area, with over 434 confirmed cases centered in Spartanburg County. Officials reported 124 new cases in just the last few days of January.
• Arizona-Utah Border: An active outbreak has sickened over 337 people since August 2025. In Utah, specific concerns are currently focused on Kamas, Layton, and St. George.
• Canada: Canada lost its “measles-eliminated” status in late 2025. Major activity continues in Ontario (2,396 cases in 2025/26) and Alberta (2,008 cases).

U.S. Jurisdictions Reporting Cases in 2026:

Specific Public Exposure Sites (January 2026)

If you were at these locations during the specified times, health departments advise you to monitor for symptoms for 21 days or seek immediate medical advice if you are unvaccinated.

South Carolina (Spartanburg)

• Unitarian Universalist Church: Jan. 14 & 15 (11 a.m. – 3 p.m.)
• Various Upstate Schools: Multiple exposures reported throughout Jan. 2–13.

Utah (Kamas, Layton, St. George)

• South Summit Elementary School: Jan. 5 (All day)
• Excalibur Classic Drill Competition (Layton HS): Jan. 2 & 3 (All day)
• Dixie High School: Dec. 30 – Jan. 2 (6:00 a.m. – 11:00 a.m.)
• Redrock Pediatric After Hours Clinic (St. George): Jan. 2 (7:45 p.m. – 11:30 p.m.)

Global Outbreak Context

The U.S. outbreaks are often triggered by travelers returning from countries where measles is currently endemic. The top 10 global hot spots reported by the WHO as of January 2026 include:

1. Indonesia (14,406 cases)
2. Yemen (9,277 cases)
3. Mongolia (8,483 cases)
4. Pakistan (8,310 cases)
5. India (8,184 cases)

Situational Example: A family from North Carolina visited relatives in Spartanburg, SC, over the New Year holiday. Despite being in an area with active transmission for only three days, they brought the virus back to their local school district, demonstrating how travel-related exposures are currently fueling the “spillover” into previously quiet states.

Immediate Next Steps for Protection

If you live in or have recently traveled to a hot spot:

1. Check Records: Ensure you have two documented doses of the MMR vaccine.
2. Infant Care: If you have an infant (6–11 months) in an outbreak area, the CDC now recommends an “early” dose of MMR.
3. Isolation: If symptoms (fever, cough, runny nose) appear, call your doctor before arriving at the clinic to prevent exposing others in the waiting room.