By: Richard L. Smith
State health officials are alerting residents after a trace of measles virus was found in a wastewater sample collected in Essex County, according to a press release from the New Jersey Department of Health.
The sample, taken on March 20, 2026, came from a treatment facility that services multiple North Jersey counties, including Bergen, Passaic, Hudson, Union, and Essex.
A follow-up test collected on March 23 returned negative, and officials note that wastewater readings can vary from sample to sample.
At this time, there are no confirmed measles cases among New Jersey residents connected to this detection.
The most recent confirmed case in the state was reported in October 2025.
Health officials explained that the testing identified the wild-type measles virus, meaning the presence likely came from someone who currently has or recently had measles in the area.
This could include residents, workers, or travelers passing through the region, including those moving through Newark Liberty International Airport.
Officials emphasized that wastewater monitoring is used as an early warning system and does not indicate an outbreak.
The virus is not spread through wastewater but rather through the air and close contact with an infected person.
The detection was identified through a national wastewater monitoring program, and additional testing is expected in the coming days to determine if any further traces are found.
With increased travel and gatherings during the spring and summer months, health officials are urging residents to stay up to date on the measles, mumps, and rubella (MMR) vaccine. 
Those planning international travel are especially encouraged to ensure full vaccination.
Residents experiencing symptoms such as high fever, cough, runny nose, red eyes, or a rash are advised to contact a healthcare provider or local health department before visiting any medical facility to help prevent potential spread.