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 team that developed the program, which includes researchers at Baylor College of Medicine, the School of Public Health at University of Texas Health Science Center – Houston, the Houston Health Department and Rice University, published their findings in the American Journal of Public Health.
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 2023 , we showed that systematically sequencing the genetic material in wastewater reveals dynamic changes in human viruses circulating in a community. Importantly, analyzing these viral changes in wastewater can improve our understanding of outbreaks and transmission and inform public health preparedness, just as one uses meteorological data to better understand and predict weather patterns to anticipate potentially dangerous conditions," said co-corresponding author Dr. Anthony Maresso , Joseph Melnick Endowed Chair and Professor in Molecular Virology and Microbiology at Baylor.
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."
"As a reference, the 821 Houston wastewater samples we sequenced from the same area were negative for measles virus in the previous 31 months," she added.
"Because no other cases have been reported and the detections occurred in the same area where the travelers resided, it is reasonable to assume that the measles signal detected in wastewater is from the two infected cases, which underscores the high sensitivity of the method," Maresso said.
"With lessons learned from the Houston measles detection event, we are now working with our public health partners to gather data on the current measles outbreak in West Texas. Although not reported here, our program has been monitoring measles in wastewater from those sites as well, hoping the information can help officials get ahead of this virus," said co-first author Dr. Michael Tisza , assistant professor of molecular virology and microbiology at Baylor.
Currently, the researchers are not detecting measles viruses in wastewater in Houston but are detecting it in West Texas cities. The team continues to record the weekly activity of possible concerning viruses and report the results in the first of its kind sequencing-based health dashboard that is publicly available at https://tephi.texas.gov/early-detection .
Dr. Eric Boerwinkle , dean of the UTHealth Houston School of Public Health and co-corresponding author, said that "This work underscores the ability of sophisticated wastewater analyses to serve as an early detection system benefitting public health, healthcare and communities in preventing a measles outbreak in Houston."
He goes on to remind us that "The best protection from contracting the measles virus is the MMR vaccine, which has been shown to be safe and effective."
