Real-time RSV surveillance from 700+ CDC monitoring sites — especially important for families with infants
View Live RSV MapRespiratory syncytial virus (RSV) is an extremely common respiratory virus that infects virtually every child by age 2. In healthy older children and adults, RSV typically causes a mild cold. But in infants under 6 months, older adults, and immunocompromised individuals, RSV can cause severe lower respiratory illness — including bronchiolitis and pneumonia — that requires hospitalization.
RSV is the leading cause of infant hospitalization in the United States. Approximately 58,000–80,000 children under 5 are hospitalized with RSV each year, and 60,000–160,000 older adults require hospitalization as well.
Unlike flu or COVID-19, RSV has no widely-available rapid home test. Most parents don't know RSV is circulating in their community until their pediatrician mentions it — or until their infant is already sick. Wastewater surveillance changes that: it detects rising RSV levels 4–7 days before emergency departments and pediatricians start seeing cases, giving parents a genuine heads-up.
Check RSV levels in your area before playdates with newborns, daycare decisions in fall, or family gatherings where vulnerable infants will be present.
In most US regions, RSV season begins in September or October, peaks in November or December, and winds down by March. However, season timing varies significantly by geography — the South typically sees RSV earlier than the Northeast, and the timing has shifted in recent years following the disrupted immune debt of the COVID-19 pandemic years.
The Outbreak Radar time slider lets you compare current RSV levels to previous years at the same sites, giving you historical context for whether this season is early or severe.
Purple dots on the map represent RSV monitoring sites. Dot size reflects the percentile of the current week's concentration relative to that site's full RSV history:
RSV in infants often begins like a common cold — runny nose, mild cough, decreased appetite. Within a few days, the cough may worsen and breathing can become labored. Warning signs in infants that require immediate medical attention:
For detailed clinical guidance, see the CDC RSV page.
RSV is the second leading cause of respiratory illness hospitalization in adults 65 and older, after influenza. It can trigger acute exacerbations of COPD, heart failure, and asthma. The same wastewater levels that signal risk for infants also signal risk for grandparents.
RSV prevention has improved dramatically in recent years with new approvals:
RSV wastewater data comes from the CDC NWSS. RSV wastewater surveillance launched in 2022 and has expanded steadily since. Some sites have shorter RSV histories than COVID-19 data at the same location.