Massachusetts Wastewater Surveillance Dashboard — Mpox
Mpox Wastewater Surveillance
Mpox
Latest sample: October 19, 2026
2 sites reporting
Paired NVO / Clade II assay. An NVO-positive, Clade II-negative result is presumptive Clade I.
Mpox monitoring in Massachusetts currently covers 2 sites: MWRA North, MWRA South.
Site-level data from DPH in-house laboratory testing (NVO and Clade II paired detection assays).
Column headers with sort buttons can be activated to sort the table by that column.
Data Source
Mpox wastewater testing is performed by the Massachusetts State Public Health Laboratory (DPH) at a subset of its in-house monitoring sites.
Paired Assay Interpretation
Each mpox sample is tested with two companion assays run on the same physical sample: a broad orthopoxvirus screen (NVO) and a Clade II–specific assay. Because both assays come from the same sample, they are interpreted together rather than as two independent results:
- Clade II Detected — both the NVO screen and the Clade II–specific assay are positive. This is a confirmed Clade II mpox detection.
- Presumptive Clade I — the NVO screen is positive but the Clade II–specific assay is negative. This pattern suggests a non-Clade-II orthopoxvirus is present.
- Inconsistent — Needs Review — the Clade II assay is positive but the broader NVO screen is negative, an unexpected combination that is flagged for manual review rather than auto-classified.
- Partial (NVO only / Clade II only) — Pending — only one of the two paired assays has resulted so far; the site’s status is shown as pending until the companion result arrives.
- Not Detected — both assays are negative. No orthopoxvirus genetic material was found above the assay detection threshold.
Site Coverage
The site table above includes monitoring sites with at least one Mpox sample collected within the past 90 days, the same active-site window used for SARS-CoV-2, Influenza, and RSV elsewhere in this report’s surveillance program. Sites with no sample in that window are not shown.
What This Report Does Not Calculate for Mpox
Unlike SARS-CoV-2, Influenza, and RSV, this report does not calculate a Wastewater Viral Activity Level (WVAL) signal tile, a two-week concentration trend, or a Local Signal (SURGE) status for Mpox. Instead, Mpox status is reported as the paired detect/not-detect classification described above, based on each site’s most recent sample.
Limitations
- Mpox wastewater data reflect community-level presence or absence of viral genetic material and cannot be used to estimate the number of individual infections.
- Site coverage is limited to DPH in-house laboratory capacity and does not represent all regions of the state.
- As with the other pathogens in this surveillance program, wastewater signal can be influenced by factors unrelated to infection, including rainfall, population changes, treatment plant operations, and the size of the sewershed.
About This Surveillance Program
This report is produced by the Massachusetts Department of Public Health (DPH) Bureau of Infectious Disease and Laboratory Sciences (BIDLS). For more information about DPH infectious disease surveillance, visit mass.gov/DPH.