Thousands of people may have been exposed to measles while visiting Universal Studios Hollywood, health officials say.
An individual infected with the virus is reported to have visited the attraction for 11 hours on Sunday, July 26 while they were still infectious.
No further details about the patient have been revealed, but officials at the Los Angeles County Public Health Department warned anyone who visited the site on the same day to monitor for measles symptoms.
They are now working to identify and contact any park visitors who may have been infected.
About 9.6 million people visit the theme park every year, which is also one of the oldest working film studios in the world, equivalent to about 26,000 people daily.
Measles is considered to be the most infectious disease in the world, and is able to spread to about nine in ten unvaccinated people who are exposed to it.
The virus is transmitted through breathing in tiny droplets expelled in coughs and sneezes that can hang in the air for up to two hours after an infected person has passed.
People who are infected develop a cough and then the characteristic rash about four days later. The infection is particularly dangerous for unvaccinated young children
Thousands of Universal Studios visitors may have been exposed to measles on July 26 after an infected person spent 11 hours at the park
Revealing the case, Dr Muntu Davis, a Los Angeles County public health officer, said: ‘With summer travel underway, the risk of exposure to infectious diseases may increase.
‘We urge everyone to confirm their immunity and get the MMR vaccine if needed, especially before traveling and attending crowded events.’
The patient had visited the park between 10am and 9pm, health officials said.
About 48 cases of measles have been recorded in California so far this year.
Health officials said the most effective way to prevent a measles infection is to receive the measles vaccine.
Called the Measles, Mumps and Rubella (MMR) shot, it slashes the risk of an infection by 97 percent.
The MMR vaccine is typically given once between ages 12 and 15 months and again between ages four and six.
Pregnant women, infants under 12 months, people with weakened immune systems, and those who have not been immunized are most at risk from an infection and should notify their healthcare providers immediately if they develop symptoms.
Health officials urge anyone who develops symptoms to stay home and avoid school, work and any gatherings. They should call a healthcare provider immediately and not go to a clinic or hospital before calling first to avoid exposing others.
In a news release, the health department added: ‘[All] individuals should confirm their protection against measles. Those who have had measles in the past or received the recommended measles vaccine are likely protected but should still monitor for symptoms.’
The map shows the number of measles cases that have been reported across the US as of July 30, 2026
Cold-like symptoms, such as a fever, cough and a runny or blocked nose, are usually the first signal of measles
Nationwide, a total of 2,371 infections have been registered, up slightly on last year and the most recorded in a single 12-month period since 1991.
Health officials are warning the US could soon lose its measles elimination status, which the country earned in 2000 after recording a full year without the virus spreading continuously.
The status is lost if a single outbreak continues to spread for 12 months or more.
A federal committee will review the Centers for Disease Control and Prevention’s annual report this month and determine whether elimination status has been lost. Utah’s outbreak has now lasted more than 12 months, the primary criterion for losing the designation.
Health Secretary Robert F Kennedy Jr, a hero in the anti-vax movement, has framed measles vaccination as a ‘personal choice’ and falsely claimed it is ‘very difficult’ for healthy children to die from measles.
The resurgence is driven by falling vaccination rates. Delaware’s kindergarten MMR vaccination rate dropped from 98.5 percent in 2016 to 94.1 percent today – below the 95 percent herd immunity threshold.
Health officials say Covid vaccine skepticism has spilled over to routine childhood immunizations.
California has already seen three localized measles outbreaks in 2026, according to the state Department of Public Health.
Measles starts with fever and cough, followed by a rash days later and spreads up to four days before and after the rash appears
While all three have ended, this new potential exposure at a major tourist destination has officials on high alert.
The symptoms of measles can be severe. They typically begin with fever, cough, runny nose and red, watery eyes.
Three to five days later, a distinctive rash appears – usually starting on the face and spreading downward across the rest of the body.
Complications can be life-threatening, especially in young unvaccinated children and pregnant women. Severe cases can lead to pneumonia, dangerous brain inflammation called encephalitis, hospitalization and sometimes death.
The US has already surpassed last year’s total measles cases, with 2,371 infections in 2026 compared to 2,289 in all of 2025.
While overall hospitalizations are lower – seven percent versus 11 percent – the outbreak is now hitting older children and adults harder.
In 2026, 49 percent of cases are in five-to 19-year-olds, up from 44 percent last year.
In both years, about 93 percent of cases were in unvaccinated or undervaccinated individuals.
