Let’s start thinking about water!

Measles in wastewater

In January 2025, Creegan and friends tested wastewater from two treatment plants serving more than 218,000 residents in the Houston area for evidence of measles. The study marks the first prospective detection of measles in a U.S. wastewater monitoring program using genomic sequencing. The detection included 53 unique reads aligning with 11 genomic regions of measles genotype B3—a wild strain not associated with vaccination.

The findings were further validated using reverse transcriptase droplet digital polymerase chain reaction (PCR), which confirmed the presence of measles RNA at concentrations of ~26,000 genome copies per liter. Notably, measles had not been detected in over 800 wastewater samples collected over nearly three years, highlighting the significance of this event. Subsequent epidemiological investigation identified two unvaccinated individuals with recent international travel who developed measles symptoms and lived in the same sewershed. This temporal and spatial alignment strongly suggests that the wastewater detection corresponded to these cases.

Flu alerts triggered by wastewater

The Houston Health Department, in partnership with Houston Public Works and Rice University, began citywide wastewater surveillance for SARS-CoV-2 in 2020, later expanding to influenza A/B and respiratory syncytial virus (RSV). As part of this effort, a pilot program monitored manholes at 51 schools in Houston’s largest public school district, focusing on areas with high COVID-19 incidence.

In 2023, to improve communication of results to school communities, the Department launched the “School Virus Alert Program”—an SMS and email alert system that sends timely, actionable notifications when viruses are detected in a school’s wastewater. Using the City of Houston’s existing emergency notification platform, the system informs recipients of detected pathogens and recommends protective actions. Alerts link to a Department website with educational resources in English and Spanish.

Enrollment efforts focused on school nurses, staff, and caregivers, with outreach led by a bilingual community involvement coordinator. Sign-up drives relied heavily on in-person engagement at schools, community events, and parent-teacher meetings. A total of 719 individuals enrolled (43 nurses, 219 staff, and 467 public members) with a 98% retention rate. From September 2023 to February 2024, wastewater testing at 43 schools detected target pathogens in 254 samples, triggering 5,178 alerts. Seven schools experienced consecutive flu detections; the Department hosted on-site vaccination events at four schools, administering 29 flu, 8 COVID-19, and 98 routine vaccines.

Key lessons included the importance of face-to-face recruitment, simplifying language, and framing alerts as “virus alerts” rather than “wastewater alerts.” The program demonstrates how wastewater surveillance data can be converted into community action, providing a scalable framework for other jurisdictions to enhance infectious disease prevention and public health engagement.

Who pooped at the beach?

This study examined fecal contamination sources along the Texas Gulf Coast at two barrier island locations—Sargent Beach and Matagorda Peninsula—over 19 months. Dhar and pals collected 110 surface water samples from six sites and analyzed them for culturable enterococci and microbial source tracking markers targeting human, canine, avian, and general Enterococcus genetic markers.

Enterococci were present in all samples, frequently exceeding the U.S. Environmental Protection Agency’s recreational water quality standards, indicating persistent contamination. Enterococci were most abundant overall, but its broad host range limited its value for pinpointing sources. Human markers appeared rarely and only at Sargent Beach, likely linked to seasonal population peaks and septic system inputs. Canine markers were more frequent at Sargent Beach—especially at a lagoon site near housing—suggesting stormwater transport of pet waste. Avian markers were nearly ubiquitous at all sites, reflecting year-round and migratory bird activity, with seasonal peaks in spring.

Statistical analysis revealed significant spatial differences in marker concentrations, with Sargent Beach showing higher fecal contamination than Matagorda Peninsula, correlating with greater nearby development and population density. Moderate positive correlations existed between enterococci and both canine and avian markers, suggesting dogs and birds as major contributors—canine markers correlated with ammonium and nitrate, implying nutrient co-loading. Rainfall generally increased culturable enterococci levels, but effects on microbial source tracking markers varied; canine markers often declined with multi-day rainfall, suggesting dilution effects.

Recommendations include improving pet waste disposal, managing gull populations, maintaining septic systems, and integrating microbial source tracking into routine monitoring. The study demonstrates that combining culturable enterococci monitoring with microbial source tracking provides clearer source identification, supporting targeted interventions to protect coastal water quality and public health.