What to know
- Wastewater monitoring data helps us understand the risk of avian influenza A(H5), the virus that causes A(H5) bird flu, at a community level.
- CDC updates this data every Friday with the previous week's data. This allows for data to be reviewed for accuracy.
- Data may change as more reports are received.
A(H5) detections in the past week
This interactive map shows current site-level data for detection of A(H5) in wastewater. Each dot on the map represents a wastewater sampling site. For each site, results are reported as "A(H5) Detection" when any of the samples were positive during the week reported. When A(H5) is not detected in any of the samples, the site is classified as "No Detection."
A(H5) detections in the past six weeks
This searchable table shows site-level data for A(H5) detections in wastewater for the past six weeks. The date in the column header is the last day for that week of sample collection. The table shows if:
+ A(H5) was detected at the site
- A(H5) was not detected at a site
No Data No samples were taken for that site or no data is available for that site
To filter for sites with a recent A(H5) detection, type + in the search bar.
What data for A(H5) can tell us
Testing wastewater for A(H5) can provide a signal that animals or humans may be infected with the virus. Wastewater testing cannot tell us whether the virus comes from animals, an animal product (like milk from an infected cow), or humans. Detections of A(H5) in wastewater do not necessarily mean that humans in the community are infected with the virus.
When wastewater testing shows a detection, public health and agriculture partners investigate to better understand what may be contributing to the detection and whether any public health actions should be taken.
About the data
In August 2024, CDC began publicly displaying A(H5) subtyping results from wastewater surveillance.
- Wastewater surveillance may complement other existing human influenza surveillance systems to monitor influenza.
- Each wastewater sampling site can represent all or part of a sewershed, which is the geographic area contributing wastewater to a sampling location. Sewersheds can encompass populations of varying sizes and may cross county or state boundaries.
- A positive detection means that A(H5) was detected within samples collected over the previous week.
- In each wastewater sampling site, wastewater sampling and testing occurs one or more times during the week.
- When multiple samples are collected, or multiple laboratories test samples from the same site in a given week and A(H5) is detected in any sample collected during that week, testing at that site is classified as a detection.
- States or territories that do not test for A(H5) virus or have not reported data in the past two months will not have sites displayed on the map.
- No Samples in Last Week: Sites that have not submitted A(H5) data in the previous week are labeled as 'No samples in last week'.