California Respiratory Virus Laboratory and Hospitalization Surveillance

California Department of Public Health provides weekly laboratory surveillance data for SARS-CoV-2, influenza, RSV, and other respiratory viruses, alongside hospitalization data from CDC's NHSN. The report includes test positivity calculations and hospital admission rates, updated each Friday with data pulled from reporting systems. Laboratory data involves clinical sentinel labs across the state, while hospitalization reporting began November 1, 2024.

Use Cases

• Calculate weekly test positivity rates for SARS-CoV-2, influenza, and RSV by dividing positive results by total specimens tested.
• Monitor trends in RSV admission percentages by analyzing RSV-related admissions against total admissions data from Northern California Kaiser Permanente.
• Analyze time-series patterns in COVID-19 and influenza hospital admissions using CDC NHSN data pulled weekly.
• Compare laboratory-confirmed detections of parainfluenza, adenovirus, or other respiratory viruses across sentinel laboratories in California.

Strengths

• Data is updated on a weekly cadence, providing regular surveillance updates.
• Includes multiple respiratory virus targets: SARS-CoV-2, influenza, RSV, and seven other specified virus types.
• Hospitalization data leverages the CDC's National Healthcare Safety Network (NHSN) system, a standardized national reporting framework.
• Test positivity calculations use specimen collection dates for temporal accuracy, and admission rates use official state population projections.

Limitations

• Los Angeles County SARS-CoV-2 laboratory data has a documented 7-day reporting lag, introducing latency.
• Laboratory specimens are collected from healthcare settings and do not represent all testing conducted in California, creating a selection bias.
• The dataset was archived as of June 28, 2025, indicating it is no longer actively maintained or updated.

Provenance

Source

California Department of Public Health (CDPH) Respiratory Virus Weekly Report, with hospitalization data from CDC's National Healthcare Safety Network.

Collection Method

Laboratory data from electronic reporting by California labs and clinical sentinel laboratories. Hospitalization data pulled from CDC NHSN.

Time Range

Weekly data (Sunday through Saturday); hospitalization reporting effective November 1, 2024.

Freshness

Was updated weekly each Friday; archived as of June 28, 2025.

Geography

State of California, United States.