Unpredictable patterns of viral respiratory disease in children.

Abstract

Recent years have witnessed a dramatic surge in understanding of viral upper and lower respiratory tract disease in children (Table 1). The epidemiology of established viral pathogens (eg, respiratory syncytial virus [RSV] and parainfluenza viruses [PIVs]) continues to be clarified, and new pathogens have been identified (eg, human metapneumoviruses and the coronavirus that causes severe acute respiratory syndrome [SARS]). Although the relentless emergence of antigenic variation among influenza viruses continues, progress is being made to prevent or control disease in children caused by this virus through active immunoprophylaxis (trivalent inactivated vaccine, live attenuated vaccine) and new antiviral agents (neuraminidase inhibitors). Development of any new viral vaccine, antibody for immunoprophylaxis, or antiviral drug is a tedious and expensive proposition. To identify which interventions will have the greatest societal benefit and utilize interventions in the most cost-effective fashion, reliable estimates of rates of disease must be known. A report in this issue of Pediatrics 1 describes the results from 1 year of the New Vaccine Surveillance Network (NVSN), an important new program sponsored by the Centers for Disease Control and Prevention. This project initiates a surveillance network to prospectively establish yearly hospitalization rates at sentinel hospitals in Nashville, Tennessee, and Rochester, New York, for acute viral respiratory illness in children <5 years old. View this table: TABLE 1. Viruses Commonly Associated With Respiratory Tract Disease in Children Both RSV and PIVs are enveloped, nonsegmented, negative-sense, single-strand RNA viruses that belong to the paramyxovirus family. Although an RSV vaccine remains the most practical means of reducing the disease burden attributable to this virus, a safe and effective vaccine is not available, and efforts at protection of high-risk infants must rely on passive immunoprophylaxis.2 Approximately 50% of all children will be infected with PIV 3 at least once before 1 year of age.3 PIVs 1 and 2 … Address correspondence to H. Cody Meissner, MD, Pediatric Infectious Disease Division, Tufts-New England Medical Center, 750 Washington St, Boston, MA 02111. E-mail: cmeissner{at}tufts-nemc.org