Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) is a highly contagious, seasonal negative-sense single-stranded RNA virus that causes respiratory tract infections affecting individuals of all ages. While it typically presents with mild, cold-like symptoms such as runny nose, cough, low-grade fever, and nasal congestion in healthy individuals, RSV can lead to severe lower respiratory tract illnesses—including bronchiolitis and pneumonia—especially in infants under 6 months, premature babies, older adults, and those with underlying medical conditions or weakened immune systems. Transmission occurs via direct contact with infected respiratory secretions, droplets from coughing or sneezing, or indirect contact with contaminated surfaces. Although no specific antiviral treatment is widely available, supportive care including hydration, oxygen therapy, and hospitalization in severe cases is standard. Monoclonal antibody prophylaxis is available for high-risk infants. RSV remains the leading cause of infant hospitalization in the U.S., underscoring the importance of preventive measures and early medical intervention in vulnerable populations.