Can RSV Present with High Persistent Fever?
Yes, RSV can present with fever, though it is not the most prominent or persistent feature compared to respiratory symptoms, and high persistent fever (hyperpyrexia) is uncommon in typical RSV presentations.
Fever Patterns in RSV Infection
Children
- Fever is commonly reported in pediatric RSV infections, occurring in ≥40% of children across multiple studies and clinical settings 1
- Fever typically presents alongside nasal discharge/congestion, cough, shortness of breath, and feeding abnormalities 1
- The fever is generally part of the acute illness presentation rather than a persistent, dominant feature 2
Adults and High-Risk Populations
- In high-risk adults with RSV infection, fever or feverishness is commonly reported (≥40% of adults) 1
- Among adults presenting with influenza-like illness, fever was documented in 68% of those with confirmed influenza, suggesting fever is less prominent in RSV compared to influenza 3
- The most frequent symptoms in adults with RSV are primarily lower respiratory tract symptoms (cough, sputum, dyspnea) rather than high fever 1
Clinical Context and Differential Diagnosis
RSV vs. Influenza Fever Patterns
- When influenza is circulating, the presence of both cough and fever within 48 hours of symptom onset is a strong predictor of influenza infection rather than RSV 3
- Individuals with influenza are significantly more likely to have fever (68% vs 40%) compared to those with influenza-like illness from other causes, including RSV 3
- In RSV outbreaks, intense coughing (96%) is more characteristic than high fever 3
Important Clinical Pitfall
A common mistake is assuming high persistent fever automatically indicates bacterial infection or influenza rather than RSV. However, the absence of prominent fever should not exclude RSV from the differential diagnosis, as respiratory symptoms predominate 1. Conversely, if a patient presents with hyperpyrexia as the dominant feature with minimal respiratory symptoms, alternative diagnoses should be strongly considered 3.
Symptom Duration and Severity Markers
- RSV symptoms can last for weeks and are variable based on geography and patient population 1
- In children, median hospital stays range from 2 days (United States) to 7.5 days (China), suggesting variable severity 1
- In high-risk adults, median hospital length of stay ranges from 6 to 15 days, indicating more severe disease burden 1
Diagnostic Approach
- Nucleic acid-based testing (RT-PCR) is recommended for diagnosis of RSV in elderly and high-risk patients 4
- In high-risk populations presenting with severe illness, respiratory virus testing should prioritize influenza and COVID-19 first, as specific antiviral drugs exist for these diseases 5
- Routine testing for RSV in people with respiratory illness is not recommended unless they are in high-risk categories 5