Health officials have issued a warning that thousands of travelers at one of the United States’ busiest airports may have been exposed to measles during the bustling holiday travel season.

An alert has been released for those who passed through Newark Liberty International Airport, highlighting potential exposure to this highly contagious disease.

The New Jersey Department of Health (NJDOH) has specifically cautioned that anyone who was in terminals B and C between 7 a.m. and 7 p.m. on December 19 might have come into contact with a non-resident carrier of the virus who was traveling through these areas.

While the precise movements of the infected individual remain unclear, officials are actively conducting contact tracing to identify those who may have been at risk.

The NJDOH advises anyone who believes they might have been exposed or is showing symptoms to reach out to their local health department or healthcare provider before seeking in-person medical attention.

The agency also noted that individuals who were potentially exposed could start showing symptoms as late as January 2, 2026.

Measles symptoms include a high fever, cough, runny nose, watery red eyes and a rash that usually appears between three and five days after symptoms begin, according to NJODH. 

Measles can also cause serious complications, such as pneumonia and encephalitis (swelling of the brain), and can lead to miscarriage in pregnant women, premature birth or a low-birth-weight baby. 

Thousands of passengers at New Jersey’s Newark Liberty International Airport (pictured) may have been exposed to measles on December 19

Symptoms of the world’s most infectious disease include a high fever, cough, runny nose, watery red eyes and a rash

As of December 26, 11 measles cases have been reported in New Jersey in 2025. 

Across the US, cases of the measles, the world’s most infectious disease that had been declared eliminated in the US in 2000, continue to grow. 

The spread was spurred by a deadly outbreak in Texas earlier this year among a largely unvaccinated group in a religious community.

Measles has now infected 2,012 Americans and killed three people this year, according to a December 23 update from the CDC.

It is the largest outbreak since 2,126 cases were reported in 1992, and doctors are concerned that more cases will emerge amid busy holiday travel. 

Earlier this month, public health officials in Connecticut reported the state’s first measles case since 2021.

South Carolina also has 142 measles cases, according to the CDC. There was one in 2024. Additionally, more than 250 people are being quarantined in the state due to the ongoing outbreak and possible exposure.

In Arizona, which recorded five measles cases in 2024, a surge has led to 182 this year.

Measles (pictured: a 3D illustration of the virus) is considered the world’s most infectious disease because people who are not vaccinated have a 90 percent chance of getting sick if they are exposed

Anyone who visited Newark airport’s terminals B and C between 7am and 7pm on December 19 may have been exposed (Pictured: travelers at Newark on December 26)

Dr Renee Dua, medical advisor to TenDollarTelehealth, previously told the Daily Mail: ‘The current measles outbreaks in the US are a direct consequence of falling childhood vaccination rates.

‘Measles requires about 95 percent community immunity to prevent spread, and many regions are now below that threshold.’

Measles, mumps and rubella are prevented via the MMR vaccine. The nationwide MMR vaccination rate is 92.5 percent, but in Utah, just 89 percent of kindergartners were vaccinated for the 2023-2024 school year.

In South Carolina, that number is 92 percent, and in Arizona, it is 89 percent. 

The MMR is 97 percent effective in preventing infection for those who receive both doses, according to the CDC. One dose is 93 percent effective.

Dua continued: ‘We are seeing real consequences: preventable outbreaks, hospitalizations, and deaths from diseases that were previously well controlled. These are measurable public-health failures.

‘Vaccines remain among the safest and most effective tools in medicine. Rebuilding trust through clear, evidence-based communication is now as critical as vaccine access itself.’

Measles is considered the world’s most infectious disease because people who are not vaccinated have a 90 percent chance of getting sick if they are exposed, even if they share the same air briefly or hours later with someone who has measles. 

Three in 1,000 people who contract measles will die.

The NJDOH said it was ‘alerting residents about potential exposures associated with a newly identified case of measles in a non-NJ resident who traveled in transit through Newark Liberty International Airport while infectious.’