RSV Infection in Adults in Their 40s
Yes, adults in their 40s can and do contract RSV, though it typically causes mild to moderate illness in this age group unless specific risk factors are present.
Frequency and Recognition of RSV in Adults
RSV infects all age groups throughout life, with community-based studies estimating yearly incidence at 3-7% in older adults, though the infection is largely underdetected and underestimated in the adult population. 1, 2
- RSV is identified in 6-11% of outpatient respiratory tract infection consultations in older adults and accounts for 4-11% of adults hospitalized with respiratory tract infections 2
- All RSV infections in adults represent reinfection, as immunity from childhood infection is incomplete 3
- The infection often goes unrecognized in adults unless highly sensitive molecular diagnostic tests (PCR) are used, as viral culture and antigen detection are insensitive due to lower viral titers in adult nasal secretions 4, 3, 5
Clinical Presentation in Adults
RSV infection in adults typically presents with:
- Nasal congestion 4, 5
- Cough 4, 5
- Wheezing (commonly noted) 3, 5
- Low-grade fever 4, 5
- Chest radiographs are often normal despite significant lower respiratory symptoms and hypoxia 3
Distinguishing RSV from other acute viral infections on clinical grounds alone is not possible with sufficient precision to be clinically useful. 2
Risk Stratification for Adults in Their 40s
Low-Risk Adults (No Comorbidities)
Adults in their 40s without underlying conditions typically experience mild to moderate illness that is self-limited 3
High-Risk Adults (With Comorbidities)
Adults in their 40s with the following conditions are at significantly higher risk for severe RSV disease:
- Chronic lung disease (COPD, asthma, interstitial lung disease) 6, 4
- Chronic cardiovascular disease (heart failure, coronary artery disease, congenital heart disease) 6
- Severe immunocompromise (bone marrow transplant recipients, solid organ transplant recipients) 4, 3, 5
- Severe obesity (BMI ≥40 kg/m²) 6
- Diabetes with complications (requiring insulin or with end-organ damage) 6
- End-stage renal disease or dialysis dependence 6
- Chronic liver disease (cirrhosis) 6
Vaccination Considerations for Adults in Their 40s
Currently, RSV vaccines are NOT routinely recommended for adults in their 40s. The 2024 ACIP guidelines focus on adults aged ≥60 years 6, 7
Exception for Ages 50-59
- Only RSVPreF3 (Arexvy) is FDA-approved for adults aged 50-59 years with specific risk factors that increase risk for RSV disease 7, 8
- This would apply to individuals in their late 40s approaching 50 who have qualifying chronic conditions 8
Important Clinical Pitfalls
The major pitfall is underdiagnosis: Most adult RSV disease goes unrecognized because standard viral culture and antigen detection tests are insensitive in adults 4, 5. PCR testing is the reference standard but is not always performed 2.
Testing from a single respiratory tract site can result in underdetection, so consider multiple sampling sites if clinical suspicion is high 2.
Do not assume absence of fever rules out RSV: Adults with RSV frequently present without fever, unlike influenza 2.