What are the signs and symptoms of Respiratory Syncytial Virus (RSV) infection in patients of different ages and health statuses?

Signs and Symptoms of Respiratory Syncytial Virus (RSV) Infection

RSV presents with nonspecific respiratory symptoms that are clinically indistinguishable from other viral respiratory infections, making laboratory confirmation essential for diagnosis. 1, 2

Core Respiratory Symptoms

The most common presenting features of RSV infection include:

• Cough occurs in 85% of hospitalized adults with RSV, often described as intense coughing (96% in outbreak settings) 2, 1
• Shortness of breath affects 79% of hospitalized patients 2
• Sputum production is present in 63% of cases 2
• Nasal congestion and rhinorrhea are frequent upper respiratory symptoms 3
• Wheezing occurs in 38% of hospitalized adults 2

Fever Pattern: A Key Distinguishing Feature

Fever is notably LESS common in RSV compared to influenza, occurring in only 40-48% of RSV cases versus 68% in influenza. 1, 2 This relative absence of high fever, combined with intense coughing, should raise clinical suspicion for RSV rather than influenza 1.

Constitutional Symptoms

• Weakness and fatigue affect approximately 50% of patients 2
• Sore throat may be present 3

Age-Specific Presentations

Infants and Young Children

• Bronchiolitis (inflammation of small airways) is the hallmark presentation 4
• Pneumonia can develop in severe cases 4
• Most children recover within 1-2 weeks, though premature infants and those with underlying conditions face higher hospitalization risk 4

Older Adults (≥60 years)

• Lower respiratory tract complications occur in 52% of hospitalized adults 2
• Patients are typically older with more comorbidities compared to influenza patients 5
• More respiratory symptoms but frequently without fever compared to influenza 5

Severe Disease Manifestations

Respiratory Complications

• Pneumonia occurs in 42.3% of hospitalized adults with RSV 6
• Acute bronchitis affects 21.9% 6
• Respiratory failure requiring mechanical ventilation occurs in 8-13% of cases 3
• ICU admission is required in 6-15% of hospitalized adults 5

Exacerbations of Chronic Conditions

COPD/Asthma Exacerbations:

• COPD exacerbation occurs in 27.3% of hospitalized RSV patients and is the direct cause of death in 6.9% 6
• 80.4% of COPD patients hospitalized with RSV experience disease exacerbation 6
• 49.5% of asthma patients experience exacerbation during RSV hospitalization 6
• RSV causes more frequent COPD/asthma exacerbations than influenza (33.3% vs 24.4%) 6

Cardiovascular Complications:

• Acute cardiac events occur in 22.4% of hospitalized adults ≥50 years with RSV 6
• Acute heart failure affects 15.8% of hospitalized patients 6
• Acute ischemic heart disease occurs in 7.5% 6
• 38.2% of older adults with heart failure experience HF exacerbation during RSV hospitalization 6
• Cardiovascular complications are the direct cause of death in 16.7% of RSV patients who die within 60 days 6

Clinical Pitfalls to Avoid

Do not rely on clinical features alone to distinguish RSV from other respiratory viruses - the presence of cough and fever within 48 hours strongly predicts influenza rather than RSV, but nucleic acid-based testing (RT-PCR) is required for definitive diagnosis 1.

Do not assume absence of fever rules out serious disease - RSV patients are frequently afebrile yet can develop severe lower respiratory tract disease, respiratory failure, and death 5, 2.

Do not overlook RSV in adults with chronic conditions - 97% of hospitalized RSV patients have underlying chronic medical conditions, with particularly high risk in those with COPD, heart failure, diabetes, and immunosuppression 2.

Mortality and Severe Outcomes

• In-hospital mortality ranges from 1-12% in hospitalized adults, with 6% mortality in one large cohort 2, 5
• Pneumonia is the direct cause of death in 66.7% of RSV patients who die within 60 days of admission 6
• Patients experiencing acute cardiac events during RSV hospitalization have nearly twice the risk of ICU admission (25.8% vs 16.5%) and in-hospital death (8.1% vs 4.0%) 6

Long-term Sequelae

Functional decline is common following RSV infection - patients admitted from skilled nursing facilities experience 66% decline in Activities of Daily Living scores, and deterioration of underlying diseases (particularly heart failure and COPD) frequently occurs 7, 5.