How Hospitals Are Now Tracking Respiratory Virus Hospitalizations—And Why It Matters

Starting November 1, 2024, hospitals across the United States began reporting detailed information about COVID-19, influenza, and respiratory syncytial virus (RSV) hospitalizations to the CDC's National Healthcare Safety Network (NHSN). This new requirement from the Centers for Medicare and Medicaid Services (CMS) marks a significant shift in how the nation monitors serious respiratory illness, replacing older surveillance methods with real-time hospital data that tracks not just case counts, but hospital bed capacity and admission trends week by week.

What Changed in How We Track Respiratory Viruses?

For years, the CDC relied on a patchwork of surveillance networks to understand respiratory virus trends. Now, hospitals report directly to NHSN, which monitors national and local trends in healthcare system stress and capacity across all acute care and critical access hospitals in the United States. This means public health officials can see which hospitals are overwhelmed, which regions are being hit hardest, and which virus is driving the most hospitalizations—all in near-real-time rather than weeks later.

The data collected includes several key metrics that paint a clearer picture of respiratory illness severity:

• Weekly Hospitalization Rates: Hospitals report the number of new admissions for COVID-19, flu, and RSV per 100,000 population, allowing comparisons across regions and over time.
• Hospital Bed Occupancy: The system tracks how many beds are occupied, helping identify when hospitals are approaching capacity during surge periods.
• Death Trends: The CDC monitors the weekly percentage of total deaths associated with each of the three major respiratory viruses to understand which poses the greatest mortality risk.

Why Does Real-Time Hospital Data Matter?

The shift to mandatory hospital reporting addresses a critical gap in pandemic preparedness. Under the old system, delays between when someone was hospitalized and when that information reached public health officials could stretch weeks. By then, a surge might already be overwhelming emergency departments. With NHSN reporting, hospital administrators and public health teams can spot trends as they emerge, allowing faster response to outbreaks and better resource allocation.

The CDC also publishes short-term forecasts of COVID-19 hospital admissions at both national and state levels, helping hospitals prepare for expected surges. This forecasting capability didn't exist before the new reporting infrastructure was in place. For the 2024-2025 respiratory virus season, both NHSN data and data from the CDC's Respiratory Virus Hospitalization Surveillance Network (RESP-NET) are being displayed to provide the most complete picture possible.

What Challenges Exist With This New System?

Like any large-scale data collection effort, the new system has growing pains. When the requirement first took effect in November 2024, reporting levels were lower than expected as hospitals adjusted to the new process. The CDC notes that data from the most recent two weeks may be affected by reporting delays, so caution should be taken when interpreting the most current numbers.

Additionally, the hospitalization rates likely underestimate the true burden of these viruses. Some COVID-19, flu, and RSV cases are missed because of undertesting, differences in how hospitals test patients, and variations in diagnostic test accuracy. Testing practices also differ by age, race, ethnicity, and other demographic factors, which means some populations may be undercounted in the official statistics.

The CDC and its hospital partners work continuously to correct reporting errors and improve data quality. Hospitals that reported complete admission data during a given week are included in the rate calculations, and the agency flags weeks when fewer than 80% of hospitals submitted complete data, signaling when results should be interpreted with extra caution.

How Does This Improve Future Pandemic Response?

The infrastructure built through NHSN reporting is designed to be permanent. Starting with the 2025-2026 season, influenza surveillance will be conducted year-round rather than just during the traditional flu season, matching the approach already used for COVID-19 and RSV. This means the nation will have continuous visibility into respiratory virus threats, not just during winter months.

For the general public, this means faster public health guidance during surges, better hospital preparedness, and more accurate information about which viruses pose the greatest risk at any given time. While the system is still ramping up, the foundation is now in place for the kind of real-time disease surveillance that experts say is essential for protecting public health in an era of emerging and recurring respiratory threats.