NREVSS: Weekly COVID-19 NAAT Percent Positivity by HHS Region

Aggregate weekly counts of SARS-CoV-2 Nucleic Acid Amplification Tests (NAAT) and positive detections reported by over 450 U.S. clinical and public health laboratories to the CDC's National Respiratory and Enteric Virus Surveillance System (NREVSS). Data are reported voluntarily at the national and HHS regional levels, with results available from March 14, 2020 onward. The dataset excludes antigen, antibody, and at-home test results.

Use Cases

• Analyze weekly positivity trends using `percent_pos` and `mmwrweek_end` (from 10 available columns).
• Compare recent 2-week and 4-week testing volumes using `number_tested_2_week` and `number_tested_4_week` (from 10 available columns).
• Track changes in positivity rates over time using `percent_pos_2_week`, `percent_pos_4_week`, and `perc_diff` (from 10 available columns).
• Aggregate or filter data by geographic `level` (e.g., national vs. HHS region) (from 10 available columns).

Strengths

• Data sourced from a sentinel network of over 450 participating laboratories across the United States.
• Provides a multi-year time series with weekly granularity starting March 14, 2020.
• Includes key metrics for trend analysis, such as percent positivity and test counts for 2-week and 4-week intervals.

Limitations

• Data are provisional and subject to change for up to 2 years after the initial reporting week.
• Reporting is voluntary and less complete for the most recent week, with geographic variability in participation.
• Row count and total data volume are unknown, which may limit suitability assessment for large-scale analysis.

Provenance

Source

Centers for Disease Control and Prevention (CDC) via data.cdc.gov.

Collection Method

Voluntary weekly aggregate reporting from a sentinel network of clinical, public health, and commercial laboratories.

Time Range

March 14, 2020 onward.

Freshness

Last updated 2026-04-02 13:00:01; data are reported weekly.

Geography

United States, aggregated at national and 10 HHS regional levels.