Respiratory Syncytial Virus (RSV)

 Definition

Respiratory Syncytial Virus (RSV) is an enveloped, negative-sense single-stranded RNA virus in the Paramyxoviridae family and is the leading cause of bronchiolitis and viral pneumonia in infants and young children. RSV also causes substantial morbidity and mortality in older adults, immunocompromised patients, and those with chronic cardiopulmonary disease. Virology & Pathophysiology

  • Enveloped, negative-sense RNA virus
  • Key surface proteins:
    • F (fusion) protein: mediates cell entry and syncytia formation
    • G protein: viral attachment
  • Causes airway inflammation, mucus plugging, and epithelial cell necrosis
  • Reinfection common due to incomplete immunity

Epidemiology

  • Worldwide distribution
  • Seasonal outbreaks (typically late fall to early spring in temperate climates)
  • Transmitted via:
    • Respiratory droplets
    • Direct contact with secretions
    • Contaminated surfaces (virus survives hours)
  • Incubation period: 2–8 days

Clinical Presentation

Infants and young children

  • Bronchiolitis:
    • Tachypnea
    • Wheezing
    • Nasal flaring
    • Retractions
    • Poor feeding
  • Apnea (especially in premature infants)

Older children and adults

  • Mild upper respiratory symptoms
  • Severe disease in:
    • Older adults ≥60 years
    • COPD or heart failure
    • Immunocompromised patients

Complications

  • Hypoxemia
  • Respiratory failure
  • Secondary bacterial infection
  • Increased risk of recurrent wheezing and asthma later in life

Diagnosis

  • Usually clinical
  • RSV PCR or antigen testing in:
    • Hospitalized patients
    • High-risk populations
  • Imaging only if complications suspected

Pharmacist’s Role & Clinical Pearls Treatment

  • Supportive care is the cornerstone
    • Oxygen
    • Hydration (oral or IV)
    • Nasal suctioning
  • No routine role for:
    • Antibiotics
    • Bronchodilators
    • Corticosteroids

      (unless specific comorbid indications exist)

Severe cases

  • High-flow nasal cannula or mechanical ventilation
  • Ribavirin: rarely used, limited to select severe immunocompromised cases

Prevention & Immunoprophylaxis (Key Pharmacist Area)

Monoclonal antibodies

  • Nirsevimab: single-dose long-acting antibody for infants
  • Palivizumab: monthly injections for high-risk infants (limited indications)

Vaccines

  • RSV vaccines approved for:
    • Older adults (≥60 years)
    • Maternal immunization during pregnancy to protect newborns

Counseling & Safety Points

  • Emphasize infection control (hand hygiene, surface cleaning)
  • Avoid smoke exposure in infants
  • Educate caregivers on warning signs:
    • Apnea
    • Cyanosis
    • Poor feeding
    • Increased work of breathing