Duration of Fever in RSV Infection of Infants
Fever in infants with RSV infection typically resolves within 5 days, consistent with the general pattern of viral upper respiratory infections. 1
Expected Fever Duration
The American Academy of Otolaryngology-Head and Neck Surgery guidelines indicate that fever, myalgia, and pharyngitis associated with viral upper respiratory infections (including RSV) tend to resolve after 5 days, while nasal congestion and cough may persist into the second and third week. 1 This 5-day fever pattern is well-established for viral respiratory infections in the pediatric population.
Clinical Context and Implications
Fever duration beyond 5 days should prompt consideration of secondary bacterial infection, though fever alone at day 10 is not suggestive of acute bacterial rhinosinusitis. 1
In febrile infants aged 2-6 months with RSV, those with serious bacterial infections had significantly longer fever duration (mean 26.5 hours) compared to those without bacterial infection (mean 18.6 hours). 1 This suggests that prolonged fever beyond the typical 5-day viral pattern warrants evaluation for bacterial complications.
The presence of RSV infection actually reduces the overall risk of serious bacterial infection compared to RSV-negative febrile infants (7.0% vs 12.5%), and no RSV-positive infant had bacterial meningitis in a large multicenter study. 1
Age-Related Considerations
Previously well infants younger than 6 weeks hospitalized with RSV experienced longer and more severe courses than older children, though this refers to overall illness duration rather than fever specifically. 2
Most children with RSV infection recover within 1-2 weeks, with the fever component resolving in the first 5 days as part of the typical viral URI pattern. 3
Important Caveats
Fever persistence beyond 5 days should trigger evaluation for complications such as acute otitis media (present in 50-62% of bronchiolitis cases) or urinary tract infection, particularly in high-risk groups (uncircumcised males, females under 12 months, fever >24 hours duration). 1
The color of nasal discharge is not a reliable indicator of bacterial superinfection, as mucopurulent secretions commonly occur with viral infections due to neutrophil influx. 1
Antibacterial therapy should only be used when specific bacterial coinfection is documented, not based on fever duration alone. 1