More than 450 public health and clinical laboratories located throughout the United States participate in laboratory-based surveillance through CDC's National Respiratory and Enteric Virus Surveillance System (NREVSS) for respiratory adenovirus, common human coronaviruses (HCOV), human metapneumovirus (HMPV), influenza, parainfluenza viruses (PIV), rhinoviruses/enteroviruses (RV/EV), respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19. The dataset contains aggregate counts of the total tests performed for these viruses and positive detections reported to NREVSS since July 2019. Data from all 50 states, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands are included. These data are reported weekly on a voluntary basis. Laboratories do not report demographic data through NREVSS. Testing practices vary, and the number of participating laboratories changes from year to year. All data are provisional and subject to change. Reporting is less complete for the past 1 week, and more complete (>90%) for the period 2 weeks earlier. Data can be updated for up to 2 years after the initial reporting week. Discrepancies may be noted and updated at the discretion of the NREVSS data stewards and key stakeholders.

While NREVSS strives to present the most precise estimates of respiratory viral trends with reporting burden minimized for participating laboratories, there are several inherent limitations to this surveillance system. NREVSS does not collect patient-specific demographic information, clinical data, or outcomes (e.g., hospitalization or death). Multiple specimens may be collected from a single patient, so NREVSS results reflect the number of tests performed rather than the number of patients tested.

Participating laboratories vary in size, testing capabilities, and areas served. Some institutions may receive specimens from sites across a given state or even from multiple states. NREVSS cannot be used to determine the prevalence or incidence of infection. NREVSS counts reflect the latest data reported from participating laboratories and may not match data presented by various jurisdictions.
The national and regional NREVSS data described here are available, beginning from July 6, 2019. Data are also visualized on the NREVSS dashboard at the following URL: https://www.cdc.gov/nrevss/php/dashboard/index.html

For more information on NREVSS and COVID-19 surveillance please visit https://www.cdc.gov/nrevss/php/dashboard/index.html and https://data.cdc.gov/Laboratory-Surveillance/Percent-Positivity-of-COVID-19-Nucleic-Acid-Amplif/gvsb-yw6g/about_data.
The regional RSV data available at https://data.cdc.gov/Laboratory-Surveillance/Percent-Positivity-of-Respiratory-Syncytial-Virus-/3cxc-4k8q/about_data
represent averaged values that CDC calculates from testing reports. These average estimates differ from the raw regional RSV laboratory data displayed on the CDC dashboard. The national RSV data available at https://data.cdc.gov/Laboratory-Surveillance/Percent-Positivity-of-Respiratory-Syncytial-Virus-/3cxc-4k8q/about_data are the same values included in the dashboard.

Data for all NREVSS pathogens are reported at the national and HHS regional levels. The prior two years of state level data are shared for RSV and SARS-CoV-2. Data for all influenza clinical laboratories and public health laboratories (the U.S. Influenza collaborating laboratories [ICL]) are shared through the influenza virologic surveillance and are available here: https://www.cdc.gov/fluview/?CDC_AAref_Val=https://www.cdc.gov/flu/weekly/overview.htm. The ten (10) U.S. Department of HHS regions are defined here: https://www.hhs.gov/about/agencies/iea/regional-offices/index.html.

Adenovirus, HCOV, HMPV, PIV, RSV, RV/EV and SARS-COV-2 data include only nucleic acid amplification test (NAAT) results, which include reverse transcription-polymerase chain reaction (RT-PCR) test results reported from clinical, public health, and commercial laboratories (https://www.cdc.gov/nrevss/php/participating-labs/index.html). These data exclude antigen, antibody, culture, and at-home testing results.

NREVSS data are reported from laboratories in all U.S. states and some territories across the 10 HHS regions. Because the NRVESS data originate from a voluntary, sentinel network of participating laboratories, results may vary geographically because of true geographic variation in circulation or variation in testing practices at participating laboratories. The data do not include all test results from within a jurisdiction; therefore, they do not reflect all NAATs performed on respiratory specimens collected in the area or region, or nationally.

Percent positivity is a surveillance metric used to monitor respiratory virus activity over time and by area. Percent positivity is calculated by dividing the number of positive NAAT results by the total number of NAATs performed, then multiplying by 100 [(number of positive NAAT results / total number of NAATs performed) x 100]. The state-level data are the moving average number of RSV and SARS-CoV-2 tests that were performed, and the moving average percent of those that were positive (positivity) during a 3-week period (i.e., the specified week, and the weeks immediately preceding and following it). This is also known as a centered, 3-week moving average. The state level detections (counts) displayed for RSV and SARS-CoV-2 are the 5-week moving average (i.e., the 4 previous and current weeks) in accordance with the recommendations for assessing RSV trends by detections (https://academic.oup.com/jid/article/216/3/345/3860464). For the 3-week and 5-week moving averages, the most recent reporting week is calculated using only the current and previous weeks, since data for the following week are not yet available.

For more information about NREVSS, please see: https://www.cdc.gov/nrevss/php/dashboard/index.html.

Tags: rsv, human metapneumovirus, human coronaviruses, sars-cov-2, chronic lower respiratory disease, adenovirus, rhinovirus, parainfluenza virus

Last updated: 2026-01-23 21:02:15+00:00