Measles outbreaks continue to pose significant public health challenges globally despite the availability of effective vaccines. In this study, we evaluated wastewater-based surveillance for detection of measles virus during an ongoing outbreak in Texas. Weekly wastewater samples collected from two Texas cities between January 2 and March 17, 2025 were analyzed using multiple RT-PCR assays targeting the nucleoprotein and matrix genes of the measles virus. Viral RNA was detected in multiple days from both cities, with City A showing positives from January 13 and City B from January 6, both predating the first confirmed case in the state on January 23. Sequencing of PCR amplicons confirmed the specificity of detection and phylogenetic analysis using global and U.S. measles genome databases further validated that the viral RNA belonged to the currently circulating genotype D8. Our findings demonstrate that wastewater surveillance can provide early evidence of measles virus circulation in communities before clinical cases are recognized and can support public health responses to these re-emerging infectious diseases.

The authors have declared no competing interest.

This work is supported by the National Science Foundation (DMS-2421257) and the Texas Epidemic Public Health Institute (TEPHI).

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