Mapped: Measles outbreak forces emergency in New York as Pennsylvania cases surge

In: Health

Measles is surging at historic levels in the United States with nearly 3,900 cases reported in 47 states and Washington, D.C. this year so far.

New York Governor Kathy Hochul declared a state of emergency due to the virus Monday after 109 cases were reported – the most since a 2019 outbreak.

Pennsylvania has experienced the nation’s largest measles outbreak in over three decades with infections surpassing the 1,000 case threshold this week.

The state has reported five deaths linked to measles but that has been disputed by federal health officials who only confirmed two fatalities. Health Secretary Robert F. Kennedy, Jr. claimed in August that Pennsylvania’s measles deaths were “fabricated” and ordered the CDC to change how it counts such fatalities.

Cases have surged over the past year in largely unvaccinated communities. Health experts say vaccine hesitancy and misinformation have led to falling child vaccination rates. The majority of 2025 and 2026 cases are in children and teens, CDC data shows.

Measles is surging at historic levels nationwide. This federal map, last updated October 2, shows which states are reporting more than 500 cases in the darkest blue. The lightest blue indicates states reporting between 1-9 cases
Measles is surging at historic levels nationwide. This federal map, last updated October 2, shows which states are reporting more than 500 cases in the darkest blue. The lightest blue indicates states reporting between 1-9 cases (CDC)
New York Governor Kathy Hochul declared a state of emergency this week as cases spread to the highest levels New York has seen since 2019
New York Governor Kathy Hochul declared a state of emergency this week as cases spread to the highest levels New York has seen since 2019 (Reuters)

South Carolina had a six-month outbreak of nearly 1,000 cases between October 2025 and April 2026. An ongoing outbreak in Utah has led to 724 infections since June 2025.

Measles is a highly-contagious virus that can cause high fever, rash, cough, runny nose and red, watery eyes. If it becomes a serious case, it can cause brain-swelling, pneumonia and death.

The majority of infections are in people who are unvaccinated.

Infections spread easily after a person with measles coughs or sneezes, but the viral droplets they produce can linger in the air for up to two hours or contaminate surfaces.

Receiving two doses of the MMR vaccine, that targets measles, mumps and rubella, provides lifelong protection against infection.

This CDC map, last updated October 2, shows vaccination rates among U.S. kindergarteners. The turquoise states have most coverage, with vaccinate rates above 95 percent, the level needed for immunity. Those in burnt orange have rates below 90 percent and those in light orange are in between 90-94.9 percent
This CDC map, last updated October 2, shows vaccination rates among U.S. kindergarteners. The turquoise states have most coverage, with vaccinate rates above 95 percent, the level needed for immunity. Those in burnt orange have rates below 90 percent and those in light orange are in between 90-94.9 percent (CDC)

Only 10 states have reported kindergarten vaccination levels at 95 percent – the level needed to ensure sufficient immunity to the disease so that it no longer spreads easily.

Vaccination against measles has been proven effective and the virus was declared eliminated from the U.S. in 2000 after most Americans had been vaccinated.

It’s likely that the U.S. will lose its elimination status this year, according to medical experts in Boston. This status indicates there has not been continuous spread of the disease for more than a year.

It has been the most active year for measles in the U.S. since the 1990s.

“Strengthening vaccination efforts, reducing exemption rates and interrupting ongoing local transmission will be essential to reverse this trajectory,” the researchers said in a letter in May.