Chapter 5 - Respiratory Syncytial Virus (RSV)

Abstract

This chapter illustrates the virology, pathogenicity, and epidemiology of the respiratory syncytial virus (RSV). It is highly infectious and the most common cause of acute respiratory illness in infants. Two antigenically distinct strains: strain A and strain B co-circulate independently in the community. A is more prevalent than B, and is associated with more severe respiratory illness in infants. Considerable debate centers around questions related to the pathogenesis of the bronchiolitis that characterizes RSV infections in the very young. While RSV replicates extensively in mucosal cells lining the respiratory tract, immunopathologic mechanisms may contribute to inflammation in the bronchioles. Recent experimental observations in animal models, argue for a cell-mediated disease process. Infants and children with immune deficiency disorders and recipients of corticosteroid agents and chemotherapy are at increased risk of contracting RSV infections and death because of giant cell pneumonia. Symptomatic RSV infections develop in adults of all ages. It is characterized by nasal congestion and rhinorrhea accompanied by pharyngitis and persistent cough and fever. Examination of the chest often reveals rhonchi and wheezes. Clinically, these features help differentiate RSV pulmonary disease from other forms of pneumonia in the older adult.