Physiologic risk factors for respiratory viral infections and immunoprophylaxis for respiratory syncytial virus in young children with congenital heart disease

Background. Infants and children with congenital heart disease (CHD) are a population at increased risk for infection with respiratory syncytial virus (RSV) and its inherent complications compared with the general population. RSV infection increases morbidity from respiratory complications in young CHD patients. Methods. In an effort to guide strategies for reducing RSV-associated risk in patients with CHD, predisposing factors for severe RSV as well as experimental approaches for prevention were reviewed. Conclusions. Risk factors that may exacerbate the adverse effects of respiratory disease in young CHD patients include compromised cardiorespiratory status at baseline, altered pulmonary mechanics, potential cyanosis and/or pulmonary hypertension and ventilation-perfusion mismatch. Furthermore patients with such conditions are at increased risk from RSV lower respiratory tract infection, making RSV prevention in patients with CHD an important goal. Because the efficacy and safety of active immunization for RSV have not yet been established, a number of approaches toward passive immunoprophylaxis have been investigated. Monthly prophylaxis with palivizumab, a humanized murine monoclonal anti-F glycoprotein antibody preparation, reduced the rate of hospitalization in children with CHD by 45%, as well as hospital time and oxygen use in those admitted. Thus palivizumab prophylaxis should be considered in young patients with hemodynamically significant CHD.