Old virus, new data
Tracking the resurgence of measles with wastewater
The past year has been a stark reminder that even diseases thought to be under control can surge back. In 2025, the US experienced the worst measles outbreak we’ve seen in nearly three decades, with more than 2,200 confirmed cases. In 2026, the same trends are repeating—we’ve already reported more that 1,000 cases in the first six weeks of the year.
As outbreaks spread like wildfire, health departments and clinicians across the country are rushing to rapidly identify cases, increase vaccinations, and put out the sparks that could ignite outbreaks.
With developments from Biobot and our partners last year, health practitioners have a new tool in their kits to rapidly detect and reduce the spread: wastewater monitoring for measles. Biobot searched for signals of measles across our national network of wastewater treatment plants in 2025. Here’s what we found and how our data was used to slow the spread of measles.
What We’re Seeing across Biobot’s Network
During our investigation period—August through November, 2025—we detected measles in 12 counties, representing over 5.5 million people. Detections were spread across 11 states, including locations in both urban metros and rural communities.
Our investigation found that:
Measles was found in states with no reported cases. Not all states had known measles cases when wastewater detected the virus—highlighting gaps in case detection. In Hawaii, Biobot’s signal led the health department to issue public notices alerting clinicians and the public, as no recent measles cases had been identified.
Detections were brief and isolated. In Biobot Network communities, measles signals were short-lived, suggesting they came from one or two community cases, rather than sustained transmission or an outbreak.
Measles was not detected between spikes. Outside of these brief detections, measles was not found in wastewater—consistent with how rare it is in the general population.
This investigation illustrates a key point: despite measles’ low-level, sporadic presence in wastewater compared to endemic viruses like influenza or Covid-19, wastewater can pick up real signals when a rare or emerging virus is circulating.
Why Wastewater for Measles?
Measles is a highly contagious virus that typically spreads through respiratory droplets. Clinical surveillance (counting reported cases from clinics and labs) remains a key component of outbreak tracking. But clinical data only captures infections that get tested and reported, representing only the tip of the iceberg. Infections can be missed due to access barriers or healthcare seeking habits, mild illness, or delays in reporting.
Wastewater surveillance offers a complementary view, revealing more of the iceberg. Infected individuals shed virus in bodily fluids, including feces and urine. These viral signals, even for pathogens primarily transmitted via air and respiratory droplets (like measles), can accumulate in the sewer system and be measured.
Unlike something like bird flu (H5N1), measles does not have an animal reservoir, which means that wastewater detections are coming from humans. Additionally, Biobot’s assay is specific to the measles virus, and will not pick up the vaccine, so we can be sure that detections are from infections.
This makes wastewater a non‑invasive, community‑wide indicator, especially useful for detecting rare pathogens and early signals of spread, before clinical case counts climb.
Translating Signals Into Action
What do these wastewater detections mean?
Early warning signal: Wastewater detections can precede clinical trends, offering an early and independent signal that measles is present locally. This early information allows local communities to respond faster to get ahead of outbreaks.
Population‑level insight: Because wastewater represents contributions from thousands to millions of people, it’s a more efficient and cost-effective detection system than relying solely on individuals to present to clinics. Wastewater aggregates information from anyone using the bathroom, allowing for the detection of measles infections from people who may not ever visit a clinic or get tested.
Complementary to clinical data: Clinical reporting remains important for case counts and individual diagnosis and treatment. But wastewater becomes especially valuable when clinical testing lags, is limited by access or healthcare seeking behavior, or undercounts infections.
Looking Ahead
These community measles detections show that wastewater monitoring is a powerful complement to traditional health data systems—one that casts a wider net across populations and can help signal earlier when a virus reemerges or resurges.
By combining wastewater data with health campaigns, clinical testing, and community outreach, we can respond more quickly and efficiently to measles and other rising health threats.
Want to learn how wastewater monitoring can help protect your community?
Reach out to us today at hello@biobot.io or visit www.biobot.io to get started.