On May 22, 2025, Baylor College of Medicine, the School of Public Health at University of Texas Health Science Center – Houston, the Houston Health Department and Rice University announced that an innovative outbreak detection program that tracks disease-causing viruses in wastewater identified the measles virus in Houston samples collected in early January 2025, before cases were reported.

The researchers detected the virus in wastewater using a sequencing-based approach, a highly sensitive and specific method that analyzes genetic material. This strategy might have broad implications for public health, particularly as a sentinel surveillance system to detect viruses before widespread outbreaks occur. The findings are relevant and timely as measles cases are increasing in Texas and the rest of the country and the study offers a promising strategy to get ahead of potential outbreaks.

In the current study, the researchers reported that their wastewater surveillance program detected the measles virus in samples collected on Jan. 7 in two Houston water treatment facilities serving more than 218,000 residents. A parallel investigation confirmed on Jan. 17 the measles virus in two travelers residing in the same area serviced by the sampled water treatment plants.

“In such cases our next step is always validating the signal with a second method, and we were able to do so through a collaboration with the Houston Health Department and Rice University,” said co-first author Dr. Sara Javornik Cregeen, assistant professor in the Alkek Center for Metagenomics and Microbiome Research at Baylor. “They tested for the virus presence in samples from the same date and collection site and confirmed the signal using another technique, PCR.”

To date, the researchers were not detecting measles viruses in wastewater in Houston but were detecting it in West Texas cities. The team continued to record the weekly activity of possible concerning viruses and report the results in the first of its kind sequencing-based health dashboard.