Risk factors for wheezing in a subtropical environment: role of respiratory viruses and allergen sensitization.

Department of Pediatrics, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
Journal of Allergy and Clinical Immunology (Impact Factor: 11.25). 04/2004; 113(3):551-7. DOI: 10.1016/j.jaci.2003.11.027
Source: PubMed

ABSTRACT Risk factors for acute wheezing among children in subtropical areas are largely unknown.
To investigate the role of viral infections, allergen sensitization, and exposure to indoor allergens as risk factors for acute wheezing in children 0 to 12 years old.
One hundred thirty-two children 0 to 12 years of age who sought emergency department care for wheezing and 65 children with no history of wheezing were enrolled in this case-control study. Detection of respiratory syncytial virus antigen, rhinovirus and coronavirus RNA, adenovirus, influenza, and parainfluenza antigens was performed in nasal washes. Total IgE and specific IgE to mites, cockroach, cat, and dog were measured with the CAP system. Major allergens from mites, cockroach, cat, and dog were quantified in dust samples by ELISA. Univariate and multivariate analyses were performed by logistic regression.
In children under 2 years of age, infection with respiratory viruses and family history of allergy were independently associated with wheezing (odds ratio, 15.5 and 4.2; P = .0001 and P = .008, respectively). Among children 2 to 12 years old, sensitization to inhalant allergens was the major risk factor for wheezing (odds ratio, 2.7; P = .03). High-level allergen exposure, exposure to tobacco smoke, and lack of breast-feeding showed no association with wheezing.
Some risk factors for wheezing previously identified in temperate climates were present in a subtropical area, including respiratory syncytial virus infection in infants and allergy in children older than 2 years. Rhinovirus was not associated with wheezing and did not appear to be a trigger for asthma exacerbations.

1 Bookmark
  • Allergy & Clinical Immunology International - Journal of the World Allergy Organization 01/2007; 19(5):185-191. DOI:10.1027/0838-1925.19.5.185 · 0.62 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Epidemiological evidence suggests that helminth infection and rural living are inversely associated with allergic disorders. To investigate the effect of helminth infections and urban versus rural residence on allergy in schoolchildren from Ghana. In a cross-sectional study of 1,385 children from urban-high socioeconomic status (SES), urban-low SES and rural schools, associations between body mass index (BMI), allergen-specific IgE (sIgE), parasitic infections and allergy outcomes were analysed. Allergy outcomes were skin prick test (SPT) reactivity, reported current wheeze and asthma. Helminth infections were found predominantly among rural subjects and the most common were hookworm (9.9%) and Schistosoma spp (9.5%) Overweight was highest among urban-high SES (14.6%) compared to urban-low SES (5.5%) and rural children (8.6%). The prevalence of SPT reactivity to any allergen was 18.3% and this was highest among rural children (21.4%) followed by urban-high SES (20.2%) and urban-low SES (10.5%) children. Overall, SPT reactivity to mite (12%) was most common. Wheeze and asthma were reported by 7.9% and 8.3% respectively. In multivariate analyses, factors associated with mite SPT were BMI (aOR 2.43, 95% CI 1.28 - 4.60, p=0.007), schistosome infection (aOR 0.15, 95% CI 0.05-0.41), and mite sIgE (aOR 7.40, 95% CI 5.62 - 9.73, p< 0.001) but not area. However, the association between mite IgE and SPT differed by area and was strongest among urban-high SES children (aOR = 15.58, 95% CI 7.05-34.43, p<0.001). Compared to rural, urban-low SES area was negatively associated with current wheeze (aOR 0.41, 95% CI 0.20-0.83, p=0.013). Both mite sIgE and mite SPT were significantly associated with current wheeze and asthma. Infection with Schistosoma appeared to protect against mite SPT reactivity. This needs to be confirmed in future studies, preferably in a longitudinal design where schistosome infections are treated and allergic reactions re-assessed. This article is protected by copyright. All rights reserved.
    Clinical & Experimental Allergy 03/2014; 44(7). DOI:10.1111/cea.12307 · 4.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To evaluate the oscillations on the viral detection in adenotonsillar tissues from patients with chronic adenotonsillar diseases as an indicia of the presence of persistent viral infections or acute subclinical infections. Study design: Cross-sectional prospective study. Setting:Tertiary hospital. Methods: The fluctuations of respiratory virus detection were compared to the major climatic variables during a two-year period using adenoids and palatine tonsils from 172 children with adenotonsillar hypertrophy and clinical evidence of obstructive sleep apnoea syndrome or recurrent adenotonsillitis, without symptoms of acute respiratory infection (ARI), by TaqMan real-time PCR. Results: The rate of detection of at least one respiratory virus in adenotonsillar tissue was 87%. The most frequently detected viruses were human adenovirus in 52.8%, human enterovirus in 47.2%, human rhinovirus in 33.8%, human bocavirus in 31.1%, human metapneumovirus in 18.3% and human respiratory syncytial virus in 17.2%. Although increased detection of human enterovirus occurred in summer/autumn months, and there were summer nadirs of human respiratory syncytial virus in both years of the study, there was no obvious viral seasonality in contrast to reports with ARI patients in many regions of the world. Conclusion: Respiratory viruses are continuously highly detected during whole year, and without any clinical symptomatology, indicating that viral genome of some virus can persist in lymphoepithelial tissues of the upper respiratory tract.
    International Journal of Pediatric Otorhinolaryngology 07/2014; DOI:10.1016/j.ijporl.2014.07.015 · 1.32 Impact Factor

Full-text (2 Sources)

Available from
May 15, 2014