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U.S. Mpox Wastewater Data
Wastewater (sewage) can be tested to detect the virus that causes mpox circulating in the community. This data can provide an early warning of mpox activity and spread in communities and inform public health action.
Mpox Wastewater Data
Wastewater sites across the United States are testing for traces of the virus that causes mpox. Wastewater data are updated every Friday with the previous week’s data, which allows for data to be reviewed for accuracy. Data may change as more reports are received.
Laboratory tests are used for monitoring wastewater for the virus that causes mpox. These tests can tell us if genetic material from the virus (viral DNA) is present in untreated community wastewater. Based on the results, each wastewater site is assigned a detection category:
- No recent detection means there is no recent evidence from wastewater data that mpox is spreading in the local community. However, wastewater monitoring may not detect the virus if there are very few mpox cases in a community.
- Detection means there is evidence of some mpox infections in the community.
- Persistent detection means mpox infections may be staying stable or increasing in the community.
Learn more about how mpox spreads, how to prevent mpox, and about the current situation of mpox outbreaks in the US and around the world.
Types of Testing for Mpox in Wastewater
Currently, testing methodology for the virus that causes mpox varies between wastewater sites. Some sites are testing for specific types (or clades) of the virus. Some sites use tests that detect clade II only. In December 2024, some sites began using tests that detect clade I only, with CDC’s national contract beginning testing on January 2, 2025. Other sites use non-clade specific tests that can detect both clades of the virus, though they do not distinguish between clade I and clade II. Each site may use one or more tests.
Mpox Testing Summary
Summary of all testing results for each wastewater testing site in the past four weeks. Each site may use one or more types of tests to detect the virus that causes mpox. See definitions for each detection category.
Mpox Results by Test Type
Explore each tab to see testing results based on the type of testing (non-clade specific, clade I, or clade II). Each dot on the map represents a wastewater sampling site.
Detection Categories:
Persistent detection: The virus that causes mpox was detected in more than 80% of samples in the past 4 weeks AND the most recent detection was within the past 2 weeks.
Detection: The virus that causes mpox was detected in 1% to 80% of samples in the past 4 weeks AND the most recent detection was within the past 2 weeks.
No recent detection: The virus that causes mpox was not detected in any samples in the past 2 weeks.
No recent data: Fewer than 3 samples were submitted in the past 4 weeks.
Clade-specific Testing in Wastewater:
There are two distinct genetic clades of the virus that causes mpox: clade I and clade II. Each clade of the virus has subclades, clade Ia and clade Ib; clade IIb. Not all clade-specific wastewater assays will be able to detect or distinguish between clades or subclades (i.e. subtypes).
If a site has a detection using a non-clade specific test but does not have a detection using a clade II test, this does NOT necessarily indicate that clade I is present. Instead, it highlights a need for further public health investigation.
There is currently an outbreak of clade I mpox in Central and Eastern Africa that has also caused some travel-associated cases in other countries. Clade II mpox cases continue to spread at low levels in many countries around the world, including the United States.
Data Notes
- Each dot on the map represents a wastewater site. A site can represent all or part of a sewershed, which is the geographic area contributing wastewater to a sampling location. Sewersheds may cross county or state boundaries.
- Samples from some sites are tested for the virus that causes mpox at different laboratories that may use different collection and testing methods. These sites have more than one dot on the map with the same sewershed number followed by a different letter. These sites may have different detection categories for the different dots.
- Not all communities report wastewater data to CDC. Participation is voluntary. Wastewater samples are collected from sewer systems, so communities that rely primarily on septic systems are not represented.
- Data are plotted in the ZIP code of the sampling location, so dots on the map do not correspond exactly to sampling locations.
- See Data Methods for more information.
Data Sources
- Wastewater surveillance complements other existing surveillance systems to monitor mpox. Mpox wastewater data include data collected and reported to CDC’s National Wastewater Surveillance System (NWSS) by:
- A CDC contract partner (Verily Life Sciences, LLC).
- An academic partner group (WastewaterSCAN): These data were collected as part of a partnership between Stanford University, Emory University, and Verily funded philanthropically through a gift to Stanford University. Find more about these and use at: wastewaterscan.org/about/#15.
- State and local public health departments: Data from state and local health departments were reported through the NWSS program and funded through the Epidemiology and Laboratory Capacity for the Prevention and Control of Emerging Infectious Diseases (ELC) Cooperative Agreement.
- Sources reporting wastewater mpox data to CDC use different methodologies. Some test wastewater solids, others test liquids, and some test both. The data displayed does not differentiate between methodologies.