Respiratory syncytial virus infections in infants (original) (raw)

1999, Seminars in Pediatric Infectious Diseases

Respiratory syncytial virus (RSV) is an important pathogen that causes bronchiolitis and pneumonia in infants, young children, and elderly adults throughout the world. This virus causes approximately 90,000 hospitalizations and 4,500 deaths in the United States each year from lower respiratory tract disease primarily among children with underlying cardiac, pulmonary, or immunologic disorders. In the temperate zones, the virus circulates from late October until late April or May, with a peak usually in mid-January to mid-February. Diagnosis usually is by latex agglutination, enzyme-linked immunosorbent assay (ELISA), fluorescent antibody, or tissue culture of nasal secretions. The nosocomial infection rate may be as high as 22 to 50 percent. Various treatment modalities have been used along with supportive care. The first medication to be approved for treatment of RSV infection was the antiviral ribavirin. Ribavirin's use has been accompanied by controversy concerning its efficacy versus cost. Intravenous human IgG with high titer against RSV (RSVIG) has been used to treat patients, including those considered at high risk; it was found to be safe but not efficacious. However, RSVIG has been successful in preventing RSV disease and is now available for immunoprophylaxis in high-risk children, primarily premature infants or those with bronchopulmonary dysplasia (BPD). MEDI-493 or palivizumab (Synagis; Med-Immune, Inc, Gaithersburg, MD), a new humanized monoclonal antibody, also has been studied in a prophylactic trial with 1,500 premature infants and young children with BPD. A 55 percent reduction in hospital admissions resulted when compared with placebo. This prophylactic modality has been approved recently by the Food and Drug Administration (FDA). The use of vaccines for prevention of RSV disease has been fraught with obstacles. Various studies using RSV subunit F and G vaccines are in progress. Live, attenuated vaccines also are under investigation. Copyright 9 1999 by W.B. Saunders Company R espiratory syncytial virus (RSV) is a member of the Paramyxovirideae family. It is an enveloped, singlestranded RNA virus. At least two serotypes are known to exist: group A, considered the more virulent, and group B.l,2 This virus has two major proteins, F (fusion) and G (attachment) glycoproteins. These are the major targets for neutralizing antibodies. The F glycoprotein is more conserved among strains, and certain epitopes are widely conserved. ~ Epidemiology RSV causes yearly epidemics of respiratory illness that include a lower respiratory tract illness (LRI) called bronchiolitis. RSV is From the Children'