The New Jersey Department of Health announced on March 26 that the measles virus was detected in a wastewater sample collected on March 20 at a treatment plant in Essex County, which serves areas of Bergen, Passaic, Hudson, Union, and Essex counties. A subsequent sample taken on March 23 from the same location tested negative. No clinical cases have been identified among residents in this region at this time.
The department said that detection levels in wastewater can fluctuate and a single positive result may not persist. The last confirmed case of measles in a New Jersey resident was reported in October 2025.
According to the department’s statement, “the test for measles detects wild-type measles virus; it does not detect the vaccine strain.” This means that people who currently have or recently had measles could be present in the community. The group noted this could include local residents or workers as well as travelers passing through the area, including Newark Liberty International Airport.
Wastewater surveillance is used to identify viruses shed by infected individuals before they enter treatment plants and can serve as an early warning system for infectious diseases. The department clarified that this detection does not mean there is an outbreak and that wastewater results cannot be linked directly to specific individuals but do indicate at least one person with measles was present in the region. Measles spreads through airborne transmission or close contact with an infected person; it is not known to spread via wastewater.
Routine testing for measles has been conducted by New Jersey Public Health and Environmental Laboratories since September 2025 across multiple sites statewide. However, this recent detection occurred at one of six locations monitored by WastewaterSCAN, a national commercial company. Additional samples will be tested next week by both NJPHEL and WastewaterSCAN.
As spring and summer travel increases along with large gatherings, health officials recommend staying up-to-date with the MMR (measles-mumps-rubella) vaccine as protection against infection. “With high levels of measles cases nationally and more opportunities for international travel,” residents are encouraged to ensure their vaccinations are current. Infants aged six to eleven months should receive one dose before traveling internationally followed by two more doses after their first birthday.
Anyone experiencing symptoms such as high fever, cough, runny nose, red watery eyes or rash—or those who suspect exposure—should call their local health department or healthcare provider before visiting any medical facility so arrangements can be made to protect others.
