Nosocomial Respiratory Virus Infection Research Articles

Outbreaks of human coronavirus in a paediatric and neonatal intensive care unit

Human coronavirus 229E (HCoV) has been recently recognized as a potential agent of nosocomial viral respiratory infections (NRVI) in high-risk infants. We have confirmed this as fact through the study of a 1-year period of HCoV outbreaks occurring during a prospective survey of NRVI in a paediatric and neonatal intensive care unit (PNICU) using new molecular techniques for HCoV detection. Nasal samples obtained at admission and weekly thereafter for all hospitalised children, as well as monthly nasal samples from staff, were analysed using immunofluorescence for respiratory syncitial virus (RSV), influenza viruses A and B, paramyxoviruses 1, 2, 3 and adenoviruses. RT-PCR was used for HCoV detection. During the year 1998, 43 HCoV-related NRVI were detected in 152 neonates (incidence 28.3%), and 7 HCoV-related NRVI were found in 92 children (incidence 7.6%). Three HCoV-related outbreaks were observed (February, August and December), associated with a high prevalence of HCoV infection in the staff. During the August outbreak, 50% to 78% of hospitalised neonates and children were infected. Seventy-five percent of hospitalised preterm neonates with a gestational age less than 32 weeks and 52.4% of staff members were infected. Risk factors for NRVI in neonates were birth weight, gestational age, ventilation, oxygenation and hospitalisation length. Ninety-two percent of infected preterm neonates were symptomatic, mainly with bradycardia and respiratory worsening. These data provide additional evidence for a possibly significant role of HCoV in NRVI in a PNICU. The role of staff or hospitalised children in spreading HCoV is hypothesised.

Detection of human Coronavirus 229E in nasal specimens in large scale studies using an RT-PCR hybridization assay

A novel human Coronavirus (HCoV) was this year recognized as the etiological agent of the Severe Acute Respiratory Syndrome. Two other HCoV (HCoV-229E and HCoV-OC43) have been known for 30 years. HCoV-229E has been recently involved in nosocomial respiratory viral infections in high-risk children. However, their diagnosis is not routinely performed. Currently, reliable immunofluorescence and cell culture methodologies are not available. As part of a four-year epidemiological study in a Pediatric and Neonatal Intensive care unit, we have performed and demonstrated the reliability of a reverse transcription-PCR-hybridization assay to detect HCoV of the 229E antigenic group in 2028 clinical respiratory specimens. In hospitalized children (children and newborns) and staff members we found a high incidence of HcoV-229E infection. This reverse transcription-PCR-hybridization assay gave a high specificity and a sensitivity of 0.5 50% Tissue Culture Infective Dose per ml. This technique is reliable and its application for screening large number of clinical samples would improve the diagnosis of HCoVs respiratory infection and our knowledge of these viruses epidemiology.

Respiratory Viral Infections in Hospitalized Children: Implications for Infection Control

Identification of children with respiratory viral infections may augment infection-control practices on inpatient units. There are clinical syndromes leading to morbidity among hospitalized children, however, in which a viral etiology of the illness might not be considered. Virus infection rates among 243 children aged <1 to 19 years hospitalized between October 1993 and April 1994 with asthma, pneumonia, bronchiolitis, fever, apnea, croup, or respiratory distress were evaluated as part of a University of Maryland Medical Center infection-control protocol. Anonymous data collected included admission diagnoses, age, and virus-identification result. Seventy-one children (29%) had a virus identified, including 19 of 123 (15%) with asthma, 4 of 12 (33%) with pneumonia, 27 of 47 (57%) with bronchiolitis, 13 of 41 (32%) with fever, 4 of 9 (44%) with apnea, 2 of 3 (67%) with croup, and 2 of 8 (25%) with unspecified respiratory distress. This study reinforces the concept that clinicians should consider respiratory viruses for a broad range of diagnoses. This heightened awareness may help reduce the number of nosocomial respiratory viral infections.

Coronavirus-related nosocomial viral respiratory infections in a neonatal and paediatric intensive care unit: a prospective study

The incidence of nosocomial viral respiratory infections (NVRI) in neonates and children hospitalized in paediatric and neonatal intensive care units (PNICU) is unknown. Human coronaviruses (HCoV) have been implicated in NVRI in hospitalized preterm neonates. The objectives of this study were to determine the incidence of HCoV-related NVRI in neonates and children hospitalized in a PNICU and the prevalence of viral respiratory tract infections in staff. All neonates (age≤28 days) and children (age>28 days) hospitalized between November 1997 and April 1998 were included. Nasal samples were obtained by cytological brush at admission and weekly thereafter. Nasal samples were taken monthly from staff. Virological studies were performed, using indirect immunofluorescence, for HCoV strains 229E and OC43, respiratory syncytial virus (RSV), influenza virus types A and B, paramyxoviruses types 1, 2 and 3 and adenovirus. A total of 120 patients were enrolled (64 neonates and 56 children). Twenty-two samples from 20 patients were positive (incidence 16.7%). In neonates, seven positive samples, all for HCoV, were detected (incidence 11%). Risk factors for NVRI in neonates were: duration of hospitalization, antibiotic treatment and duration of parenteral nutrition (P<0.01). Monthly prevalence of viral infections in staff was between 0% and 10.5%, mainly with HCoV. In children, 15 samples were positive in 13 children at admission (seven RSV, five influenza and three adenovirus) but no NVRI were observed. In spite of a high rate of community-acquired infection in hospitalized children, the incidence of NVRI with common respiratory viruses appears low in neonates, HCoV being the most important pathogen of NRVI in neonates during this study period. Further research is needed to evaluate the long-term impact on pulmonary function.

Epidemiology and prevention of pediatric viral respiratory infections in health-care institutions.

Nosocomial viral respiratory infections cause considerable illness and death on pediatric wards. Common causes of these infections include respiratory syncytial virus and influenza. Although 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.

A Survey of Nosocomial Respiratory Viral Infections in a Children's Hospital: Occult Respiratory Infection in Patients Admitted During an Epidemic Season

To define the extent of shedding of respiratory viruses and Mycoplasma pneumoniae among a population of pediatric patients admitted to the hospital during a winter epidemic period and to identify nosocomial infections within this population. An open, prospective survey of patients admitted to three wards (General Medical, Respiratory Infectious, and Infectious Diseases) of a pediatric hospital during a defined three-month period. All patients with medical, respiratory, and infectious conditions admitted to three wards of the Adelaide Children's Hospital had nasopharyngeal aspirations performed at the time of admission with the purpose of documenting viral and M pneumoniae shedding. Patients were monitored daily for the development of symptoms of respiratory infection or new symptoms of respiratory disease. Such patients underwent a further nasopharyngeal aspiration for the purpose of diagnosing hospital-acquired infection. Nasopharyngeal aspirations were obtained from 601 patients. Forty-seven percent of asymptomatic patients were positive for a respiratory virus or M pneumoniae, and 61% of patients with respiratory symptoms were also positive. Gastroenteritis patients shed viruses in 66% of cases. Respiratory symptoms were initially overlooked by admitting physicians but subsequently identified in 110 cases, and 46% of these were found to be positive for a respiratory virus or M pneumoniae. There were 18 possible hospital acquired infections among the 293 initially virus-negative patients. Multiple isolates were obtained from a substantial number of patients, especially those with respiratory symptoms. A substantial proportion of all patients admitted to a pediatric hospital during winter represent a potential source of infection, and strict infection control measures should be enacted to limit the spread of these infections.

A Survey of Nosocomial Respiratory Viral Infections in a Children's Hospital: Occult Respiratory Infection in Patients Admitted During an Epidemic Season

AbstractObjective:To define the extent of shedding of respiratory viruses and Mycoplasma pneumoniae among a population of pediatric patients admitted to the hospital during a winter epidemic period and to identify nosocomial infections within this population.Design:An open, prospective survey of patients admitted to three wards (General Medical, Respiratory Infectious, and Infectious Diseases) of a pediatric hospital during a defined three-month period.Patients:All patients with medical, respiratory, and infectious conditions admitted to three wards of the Adelaide Children's Hospital had nasopharyngeal aspirations performed at the time of admission with the purpose of documenting viral and M pneumoniae shedding. Patients were monitored daily for the development of symptoms of respiratory infection or new symptoms of respiratory disease. Such patients underwent a further nasopharyngeal aspiration for the purpose of diagnosing hospital-acquired infection.Results:Nasopharyngeal aspirations were obtained from 601 patients. Forty-seven percent of asymptomatic patients were positive for a respiratory virus orMpneumoniae, and 61% of patients with respiratory symptoms were also positive. Gastroenteritis patients shed viruses in 66% of cases. Respiratory symptoms were initially overlooked by admitting physicians but subsequently identified in 110 cases, and 46% of these were found to be positive for a respiratory virus or M pneumoniae. There were 18 possible hospital acquired infections among the 293 initially virus-negative patients. Multiple isolates were obtained from a substantial number of patients, especially those with respiratory symptoms.Conclusions:A substantial proportion of all patients admitted to a pediatric hospital during winter represent a potential source of infection, and strict infection control measures should be enacted to limit the spread of these infections.

Nosocomial viral respiratory infections: Perennial weeds on pediatric wards

The frequency and importance of nosocomial infections of the respiratory tract in pediatrics have generally been underestimated. In part this has resulted from the emphasis on bacterial infections which occur primarily in select at-risk populations. Most respiratory infections in pediatric patients, hospital- and community-acquired, are viral and all patients are potentially susceptible. The epidemiologic patterns of these viral respiratory agents on the ward mirror those seen in the community in terms of frequency, season, age affected and severity of illness. Hence, the most frequent nosocomial agents are the viruses that occur in outbreaks or epidemics and cause respiratory illness, epidemic respiratory viruses—respiratory syncytial virus, which causes the greatest morbidity and mortality; influenza, and the parainfluenza viruses. Their import, as exemplified by respiratory syncytial virus, results from (1) the severity of disease produced in young children, which is magnified in those hospitalized with certain underlying conditions; (2) the abundant and prolonged viral shedding, allowing easy spread; (3) the potential susceptibility of all patients and staff, since infections recur throughout life; and (4) the difficulty in controlling nosocomial spread.

Acquisition of parainfluenza 3 virus infection by hospitalized children. I. Frequencies, rates, and temporal data.

Among 197 hospitalized, uninfected, contact infants, one-fifth acquired parainfluenza 3 virus infection during hospitalization. These secondary cases of infection occurred throughout the year. Acquisition of parainfluenza 3 virus by uninfected contacts was temporally related to the admission of a cluster of index patients and usually occurred between the fourth and 15th day of hospitalization. Secondary cases as a group remained hospitalized significantly longer than uninfected contacts; about one-third of the secondary cases developed a new, mild respiratory tract illness. It is suggested that the institution of minimal procedures of isolation, restriction of the numbers of personnel on the ward, and shorter hospital stays might help to decrease the frequency of nosocomial respiratory virus infections.