PICNIC (Pediatric Investigators Collaborative Network on Infections in Canada) Study of the Role of Age and Respiratory Syncytial Virus Neutralizing Antibody on Respiratory Syncytial Virus Illness in Patients With Underlying Heart or Lung Disease

Abstract

ABSTRACT. Objective. To determine the effects of age and respiratory syncytial virus (RSV) antibody status on frequency and severity of RSV infections in children with underlying heart or lung disease.Design. Cohort study conducted during two consecutive RSV seasons.Setting. Ambulatory patients at eight Canadian pediatric tertiary care centers.Methods. Subjects under 3 years old with underlying heart disease who were digoxin-dependent or had not received corrective cardiac surgery or with underlying lung disease were enrolled. Demographic information and an acute sera for RSV neutralizing antibody was obtained on enrollment. Weekly telephone follow-up consisting of a respiratory illness questionnaire was followed with a home visit to obtain a nasopharyngeal aspirate when there was new onset of respiratory symptoms. The specimen was used to detect RSV antigen. RSV illnesses were grouped as upper or lower respiratory tract infection (LRI) based on clinical and radiographic findings. RSV hospitalizations were considered to be those RSV infections that resulted in hospitalization.Results. Of 427 enrolled subjects, 160 had underlying lung disease only, 253 had underlying heart disease only, and 14 had both. Eleven percent and 12% of lung and heart disease groups, respectively, had an RSV LRI. Three percent and 6% of lung and heart disease groups, respectively, were hospitalized with RSV infection. A significant decrease in frequency of RSV LRI and RSV hospitalization occurred with increasing age, with a major drop in those older than 1 year vs those younger than 1 year. Acute sera were available from 422 subjects. Geometric mean RSV antibody titers demonstrated a U-shaped distribution with increasing age. The trend to lower antibody concentrations in premature infants did not reach statistical significance. The frequency of RSV infection and RSV LRI was lower in patients with antibody at a titer more than 100, although the difference for RSV hospitalization was not statistically significant. These differences remained significant after age adjustment.Conclusion. Both age and RSV antibody status impact on RSV illness and LRI. Reduction in illness frequency with increasing age may lead to more informed targeting of those children most likely to benefit from RSV immune globulin prophylaxis. Pediatrics 1997;99(3). URL: http://www.pediatrics.org/cgi/content/full/99/3/e9; respiratory syncytial virus, cohort study, passive prophylaxis, neutralizing antibody.ABBREVIATIONS. RSV, respiratory syncytial virus; LRI, lower respiratory tract infection.Compared with its course in otherwise healthy children, respiratory syncytial virus (RSV) infections lead to higher mortality and morbidity measured by hospital duration, transfer to intensive care, and ventilation in children with underlying heart or lung disease.1,2 Recently, a polyclonal RSV immune globulin preparation, containing high titers of RSV neutralizing antibodies, was approved in the United States for use as a prophylactic agent against severe RSV infections. Licensure fo...

Defining the Risk and Associated Morbidity and Mortality of Severe Respiratory Syncytial Virus Infection Among Infants with Congenital Heart Disease

“…Several studies reported a higher RSVH rate in infants aged <12 months [29, 30, 36, 38]. In a retrospective study by Boyce et al [29], the estimated number of hospitalizations per 1000 children with CHD aged 6 to <12 months and 12 to <24 months were 63.5 and 18.2, respectively.…”

“…The relative risk in comparison with non-CHD patients was 1.4 (0.6–3.1), 1.6 (0.8–3.2), 2.7 (0.7–9.7), and 1.8 (1.0-3.3), respectively [30]. A significant decrease in frequency of RSV LRTI and RSVH was also observed with increasing age in the Canadian PICNIC study [36]. The RSVH rates in children with CHD aged 0–3, 3–6, 6–12 and 12–24 months were 360, 60, 0 and 10 per 1000, respectively [36].…”

RSV604, a Novel Inhibitor of Respiratory Syncytial Virus Replication

“…The infants most at risk of severe disease are those under 6 weeks of age, those with bronchopulmonary dysplasia, congenital heart disease, or immunodeficiency, and those born prematurely. Hospital admission rates for these groups range between 5% and 30% (20,25). The mortality rate among children admitted to hospital is approximately 3% for those with heart and lung problems and up to 1% for those without these risk factors (11,25).…”

“…Hospital admission rates for these groups range between 5% and 30% (20,25). The mortality rate among children admitted to hospital is approximately 3% for those with heart and lung problems and up to 1% for those without these risk factors (11,25). In adults and the elderly, RSV pneumonia is increasingly recognized as a significant cause of morbidity and mortality, being associated with more than 17,000 deaths annually between 1991 and 1998 (9, 22).…”

Natural Infection of Infants with Respiratory Syncytial Virus Subgroups A and B: A Study of Frequency, Disease Severity, and Viral Load

“…Furthermore, more than half of RSV-hospitalized infants and a large percentage of infants who require mechanical ventilation and even die from RSV infection are previously healthy (3,5). These striking disease severity differences cannot be explained by existing neutralizing antibody titers alone (6) and are likely due to a combination of host factors and viral factors. Although this finding is not universally confirmed (7), RSV subgroup A has been shown in several studies to produce more severe disease than RSV-B (8 -12).…”