Overview
- Two wastewater samples collected at DELCORA’s Western Regional Treatment Plant tested positive for measles genetic material, with the samples taken on June 9 and June 11.
- Delaware County health officials report no confirmed measles patients in the county and say the detection cannot identify whether the infected person was a resident or a visitor.
- The DELCORA plant serves roughly 500,000 people across Delaware and Chester Counties, and the samples were analyzed as part of a Stanford–Emory wastewater surveillance program.
- County and state officials are contacting local providers and urging people to get the MMR vaccine, noting two doses are about 97% effective and stressing there is no evidence measles spreads through untreated wastewater.
- State health data show a related regional outbreak with dozens of cases west of Philadelphia, and officials say the wastewater signal is an early warning that could indicate undiagnosed cases to watch for in the community.