Respiratory syncytial virus (RSV) is a major nosocomial hazard on pediatric wards during its annual outbreaks. It produces significant morbidity in young children and is most severe in those with underlying conditions, especially cardiopulmonary and immunosuppressive diseases. In older patients, RSV may exacerbate an underlying condition or pulmonary and cardiac manifestations.
RSV is primarily spread by close contact with infectious secretions, either by large-particle aerosols or by fomites and subsequent self-inoculation, and medical staff are often instrumental in its transmission. Thus, integral to any infection control program is the education of personnel about the modes of transmission, the manifestations, and the importance of RSV nosocomial infections. Hand washing is probably the most important infection control procedure. The choice of barrier controls should be decided by individual institutions depending on the patients, the type of ward, and the benefit relative to cost.
Respiratory viruses may be transmitted by any of 3 possible mechanisms. The first is transmission by small-particle aerosols (<10 µm mass median diameter), usually generated by coughing or sneezing, which may traverse distances ≥1.8 m. Transmission by small-particle aerosols, therefore, does not require close or direct contact with the infected subject or with infectious secretions. Typically, viruses spread by small-particle aerosols cause explosive outbreaks of infection in a susceptible population, such as occur with measles, varicella, and sometimes influenza. The second mechanism is transmission by droplets or large particles. In contrast to aerosols of small particles, aerosols of large particles require close person-to-person contact, usually at a distance of ≤0.9 m, for infection to occur. Third, the virus can also be transmitted via fomites; that is, by self-inoculation after touching contaminated surfaces. For this to occur, the virus must be able to remain infectious on environmental surfaces, to be transferred to the skin, and to remain infectious for a time sufficient to allow self-inoculation into the respiratory tract.
