When is RSV No Longer Contagious?
A person with RSV is typically contagious for 3-8 days after symptom onset in healthy adults, but viral shedding can persist for 1-4 weeks in infants, young children, and immunocompromised individuals. 1, 2
Duration of Contagiousness by Population
Healthy Adults
- Most healthy adults shed virus and remain contagious for 3-8 days after symptoms begin 1, 2
- Viral shedding typically peaks during the first 3-5 days of illness 3
- Individuals can transmit RSV even before symptomatic presentation begins, making presymptomatic transmission an important consideration 1
Infants and Young Children
- Infants and young children shed virus for 1-3 weeks on average, with some continuing to shed for up to 4 weeks 1, 2
- Approximately 75% of pediatric RSV hospitalizations occur in infants under 12 months of age, and these patients have prolonged viral shedding 4
- The extended shedding period in this age group makes them particularly important vectors for nosocomial transmission 5, 6
Immunocompromised Patients
- Severely immunocompromised individuals, including hematopoietic stem cell transplant recipients and those with profound lymphopenia (<100 cells/mm³), can shed virus for weeks to months 4, 1
- Patients on systemic corticosteroids have prolonged viral shedding and are at highest risk for severe outcomes 7
- Solid organ transplant recipients may also experience extended periods of viral shedding 4
Critical Infection Control Implications
Hospital and Healthcare Settings
- Hand decontamination before and after direct patient contact is the single most important measure to prevent RSV transmission, as the virus remains viable on surfaces for several hours 5, 4
- Alcohol-based hand rubs are preferred for hand hygiene when hands are not visibly soiled 5
- RSV RNA has been detected in air samples up to 22 feet from infected patients' bedsides, and secretions can contaminate beds, crib railings, tabletops, and toys 5
Transmission Mechanisms
- RSV spreads primarily through large respiratory droplets requiring close contact and through fomite transmission from contaminated surfaces 1, 6
- Inoculation occurs mainly through the eyes and nose rather than the mouth 6
- The virus does not effectively transmit via small-particle aerosols over long distances 6
Common Pitfalls to Avoid
Do not assume patients are no longer contagious once symptoms improve - viral shedding often continues beyond clinical improvement, particularly in high-risk populations 1, 2
Do not rely solely on symptom resolution to determine when isolation precautions can be discontinued - immunocompromised patients may shed virus asymptomatically for extended periods 4, 1
Do not underestimate the importance of hand hygiene - programs implementing strict hand decontamination and droplet precautions have decreased nosocomial RSV transmission by 39-50% 4
Practical Recommendations for Isolation Duration
- Healthy adults: Maintain isolation precautions for at least 7-8 days from symptom onset 1, 2
- Infants and young children: Continue precautions for at least 2-3 weeks from symptom onset 1, 2
- Immunocompromised patients: Consider RT-PCR testing to document viral clearance before discontinuing isolation, as clinical judgment alone is insufficient 4
- Healthcare workers: Should not return to work with vulnerable populations until at least 7 days after symptom onset and clinical improvement 3, 2