Measles Outbreak in Mexico: Cases, Deaths & State Map – 2026 Update

Measles cases are surging across the Americas, with a particularly concerning rise in Mexico and the United States. As of February 5, 2026, the Centers for Disease Control and Prevention (CDC) has reported 733 confirmed measles cases in the U.S. For 2026, with the vast majority – 727 – occurring in 20 states. An additional 6 cases were identified in international visitors to the U.S.

The situation in Mexico is significantly more severe. According to data released by the Secretaría de Salud, as of February 5, 2026, Mexico has confirmed 8,459 measles cases and 27 deaths across all 32 states and 300 municipalities. This represents a substantial increase in cases over the past year, with 7,131 cases reported over the last 12 months and 24 deaths confirmed.

The Pan American Health Organization (PAHO) has issued an alert, noting a 43-fold increase in measles cases across seven countries in the first three weeks of 2026 compared to the same period last year. Mexico currently leads with 740 cases, followed by the United States with 171 and Canada with 67.

Within Mexico, Chihuahua is the most affected state, accounting for 4,502 of the confirmed cases. Jalisco follows with 1,848 cases, and Chiapas has reported 479. The majority of deaths have also occurred in Chihuahua, with 21 fatalities reported in 2025. Additional deaths have been reported in Jalisco (2), Sinaloa (1), Durango (1), Michoacán (1), and Tlaxcala (1).

The most vulnerable age groups appear to be young children. In Mexico, the highest number of cases are occurring in children aged 1 to 4 years old (1,269 cases), followed by those aged 5 to 9 years old (1,018 cases), and 25 to 29 years old (932 cases).

Measles is a highly contagious viral illness that can cause fever, cough, and a characteristic rash. It is so contagious that, according to experts, each infected person can infect an average of 12 to 18 susceptible individuals. Up to 90% of unvaccinated individuals will contract the disease if exposed.

Fortunately, the measles vaccine is highly effective. A single dose protects 93% of individuals, and two doses increase protection to 97%. For most people, this protection is lifelong. When 92% to 94% of the population is immune, either through vaccination or prior infection, the virus struggles to spread, achieving what is known as herd immunity.

The current outbreaks are largely driven by sustained transmission in under-immunized communities. In the U.S., 92% of confirmed cases are outbreak-associated, meaning they are linked to ongoing outbreaks that began in 2025 or 2026. In Mexico, over 90% of confirmed cases are among individuals with no history of vaccination, and severe cases and deaths are concentrated in those with incomplete vaccination schedules, young children, and individuals with weakened immune systems.

While cases in vaccinated individuals are rare and generally mild, they are likely to become more common as exposure to the virus increases. The resurgence of measles underscores the critical importance of maintaining high vaccination rates to protect both individuals and communities.