Pediatric Viral Respiratory Infections
Pediatric Viral Respiratory Infections
Nosocomial viral respiratory infections cause considerable illness and death on pediatric wards. Common causes of these infections include respiratory syncytial virus and influenza. While primarily a community pathogen, rhinovirus also occasionally results in hospitalization and serious sequelae. This article reviews effective infection control interventions for these three pathogens, as well as ongoing controversies.
Infection control professionals worldwide rely on the Guideline for Isolation Precautions in Hospitals promulgated by the Hospital Infection Control Practices Advisory Committee of the Centers for Disease Control and Prevention. This widely venerated document has assumed almost ecclesiastical authority. The guidelines have been framed carefully to reflect current evidence and opinion on the modes of transmission of nosocomial pathogens, and it is this rigorous evidence-based process that insures their credibility. However, scrutiny of guidelines addressing the nosocomial spread of viral pathogens reveals the fragile data on which many of the recommendations are based.
Evidence on modes of transmission of viruses tends to be the most fragmentary and unconvincing. When the first Decennial Conference was held, viral diagnostics was in its infancy, and few hospital clinical laboratories were equipped to assist infection control professionals in understanding the epidemiology of nosocomial viral disease. Moreover, our current knowledge about the spread of infection by droplets and droplet nuclei is a relatively recent phenomenon. It was not that long ago that all infections were thought to be spread by miasms, those putrid vapors emanating from decomposing organic matter and environmental filth. William Farr, an excellent epidemiologist and close colleague of Florence Nightingale, firmly believed that the 1849 cholera outbreak in London was caused by miasms rising from the fetid River Thames. Malaria (literally from the Italian root, mal aria, or "bad air") and yellow fever were attributed to miasms before their mosquito vectors were discovered near the turn of the century. Indeed, some authorities predicted with confidence that these diseases, which killed thousands of workers who were trying to dig the Panama Canal, would be eradicated as soon as the canal trench was filled with water, sealing over the miasm-generating tropical ooze. Not until mid-century did Wells et al. at Johns Hopkins demonstrate that tiny droplet nuclei could convey infectious microorganisms over long distances from patient to patient.
What, then, do we know about the transmission of common, clinically important nosocomial viruses? Studies of three viruses of importance to pediatric hospital epidemiologists (respiratory syncytial virus [RSV], influenza virus, and rhinovirus) illustrate that modes of transmission have been clarified somewhat but that serious gaps in our knowledge persist. Many of these studies should provide inspiration for young hospital epidemiologists and infection control professionals. Almost without exception, they were performed by hard-nosed investigators who had little, if any, external funding--investigators who exploited serendipitous events or devised and conducted original studies on a shoestring.
Nosocomial viral respiratory infections cause considerable illness and death on pediatric wards. Common causes of these infections include respiratory syncytial virus and influenza. While primarily a community pathogen, rhinovirus also occasionally results in hospitalization and serious sequelae. This article reviews effective infection control interventions for these three pathogens, as well as ongoing controversies.
Infection control professionals worldwide rely on the Guideline for Isolation Precautions in Hospitals promulgated by the Hospital Infection Control Practices Advisory Committee of the Centers for Disease Control and Prevention. This widely venerated document has assumed almost ecclesiastical authority. The guidelines have been framed carefully to reflect current evidence and opinion on the modes of transmission of nosocomial pathogens, and it is this rigorous evidence-based process that insures their credibility. However, scrutiny of guidelines addressing the nosocomial spread of viral pathogens reveals the fragile data on which many of the recommendations are based.
Evidence on modes of transmission of viruses tends to be the most fragmentary and unconvincing. When the first Decennial Conference was held, viral diagnostics was in its infancy, and few hospital clinical laboratories were equipped to assist infection control professionals in understanding the epidemiology of nosocomial viral disease. Moreover, our current knowledge about the spread of infection by droplets and droplet nuclei is a relatively recent phenomenon. It was not that long ago that all infections were thought to be spread by miasms, those putrid vapors emanating from decomposing organic matter and environmental filth. William Farr, an excellent epidemiologist and close colleague of Florence Nightingale, firmly believed that the 1849 cholera outbreak in London was caused by miasms rising from the fetid River Thames. Malaria (literally from the Italian root, mal aria, or "bad air") and yellow fever were attributed to miasms before their mosquito vectors were discovered near the turn of the century. Indeed, some authorities predicted with confidence that these diseases, which killed thousands of workers who were trying to dig the Panama Canal, would be eradicated as soon as the canal trench was filled with water, sealing over the miasm-generating tropical ooze. Not until mid-century did Wells et al. at Johns Hopkins demonstrate that tiny droplet nuclei could convey infectious microorganisms over long distances from patient to patient.
What, then, do we know about the transmission of common, clinically important nosocomial viruses? Studies of three viruses of importance to pediatric hospital epidemiologists (respiratory syncytial virus [RSV], influenza virus, and rhinovirus) illustrate that modes of transmission have been clarified somewhat but that serious gaps in our knowledge persist. Many of these studies should provide inspiration for young hospital epidemiologists and infection control professionals. Almost without exception, they were performed by hard-nosed investigators who had little, if any, external funding--investigators who exploited serendipitous events or devised and conducted original studies on a shoestring.