Family history of atopy and clinical course of RSV infection in ambulatory and hospitalized infants.
ABSTRACT Respiratory syncytial virus (RSV) infection can be severe in pediatric patients. Risk factors for severe disease include age less than 6 months, prematurity, preexisting heart or lung disease or malformations, gastroesophageal reflux, and immunodeficiency. The aim of the present study was to investigate the influence of family history of allergy on the clinical course of RSV infection in ambulatory and hospitalized infants. In a retrospective study, 172 patients younger than 12 months of age (99 inpatients and 73 outpatients) were enrolled. Information was obtained from hospital charts and from questionnaires sent to pediatricians. Inpatients had a significantly higher rate of atopy in their family history than outpatients, 62% and 29%, respectively (P < 0.001). Bronchiolitis was diagnosed more frequently in patients with an atopic burden than those without, 89% versus 74%, respectively (P < 0.02). Inpatients with an atopic family history had a significantly longer hospital stay than those without such a history, 7.4 +/- 3.7 days and 6.1 +/- 2.3 days, respectively (P < 0.04). Factors other than age that are considered a risk for severe infection with RSV (prematurity, preexisting heart or lung disease or malformation, and gastroesophageal reflux) were not confirmed in the present study. We conclude that infants with a family history of atopy are at increased risk for severe RSV infection as indicated by higher rates of hospitalization, longer hospital stay, and more frequent occurrence of bronchiolitis.
Article: An epidemiological study of respiratory syncytial virus associated hospitalizations in Denmark.[show abstract] [hide abstract]
ABSTRACT: Respiratory syncytial virus (RSV) is the most common viral pathogen that causes lower respiratory tract infections in infants. Studies have implicated severe RSV infections early in life as a risk factor for subsequent development of reactive airway disease. We are conducting a study to validate RSV-associated diagnoses in the Danish National Patient Registry, to assess whether the incidence of severe RSV infection is increasing in Denmark, to identify predisposing and protective factors for RSV-associated hospitalization in Denmark, and to examine the association of severe RSV infection with reactive airway disease. The influence of various biological, social and environmental factors on hospitalization for RSV infection will be studied through several population-based registers, including the Danish National Birth Cohort: 'Better health for mothers and children'. The RSV hospitalization cases will be compared with control individuals selected within the same population groups on a case-control or a cohort basis in order to produce estimates of age-adjusted and sex-adjusted relative risks (odds ratio and relative risk) for hospitalization associated with various risk factors. Using register linkage and unique registration of exposures collected through interviews and blood samples from the Danish National Birth Cohort, we will be able to resolve the issues referred to above in a very large sample of Danish children.Respiratory research 02/2002; 3 Suppl 1:S34-9. · 3.36 Impact Factor
Article: Intrauterine exposure to polycyclic aromatic hydrocarbons, fine particulate matter and early wheeze. Prospective birth cohort study in 4-year olds.[show abstract] [hide abstract]
ABSTRACT: The main goal of the study was to determine the relationship between prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) measured by PAH-DNA adducts in umbilical cord blood and early wheeze. The level of PAH-DNA adducts in the cord blood is assumed to reflect the cumulative dose of PAHs absorbed by the foetus over the prenatal period. The effect of prenatal PAH exposure on respiratory health measured by the incidence rate ratio (IRR) for the number of wheezing days in the subsequent 4 yr follow-up was adjusted for potential confounding factors such as personal prenatal exposure to fine particulate matter (PM(2.5)), environmental tobacco smoke (ETS), gender of child, maternal characteristics (age, education and atopy), parity and mould/dampness in the home. The study sample includes 339 newborns of non-smoking mothers 18-35 yr of age and free from chronic diseases, who were recruited from ambulatory prenatal clinics in the first or second trimester of pregnancy. The number of wheezing days during the first 2 yr of life was positively associated with prenatal level of PAH-DNA adducts (IRR = 1.69, 95%CI = 1.52-1.88), prenatal particulate matter (PM(2.5)) level dichotomized by the median (IRR = 1.38; 95%CI: 1.25-1.51), maternal atopy (IRR = 1.43; 95%CI: 1.29-1.58), mouldy/damp house (IRR = 1.43; 95%CI: 1.27-1.61). The level of maternal education and maternal age at delivery was inversely associated with the IRRs for wheeze. The significant association between frequency of wheeze and the level of prenatal environmental hazards (PAHs and PM(2.5)) was not observed at ages 3 or 4 yrs. Although the frequency of wheezing at ages 3 or 4 was no longer associated with prenatal exposure to PAHs and PM(2.5), its occurrence depended on the presence of wheezing in the first 2 yr of life, which nearly tripled the risk of wheezing in later life. In conclusion, the findings may suggest that driving force for early wheezing (<24 months of age) is different to those leading to later onset of wheeze. As we reported no synergistic effects between prenatal PAH (measured by PAH-DNA adducts) and PM(2.5) exposures on early wheeze, this suggests the two exposures may exert independent effects via different biological mechanism on wheeze.Pediatric Allergy and Immunology 04/2010; 21(4 Pt 2):e723-32. · 2.46 Impact Factor