Toxocariasis and childhood asthma: A case-control study.
The objective of this study is to investigate the association between anti-Toxocara IgG seropositivity and asthma in children.



This was a case-control study conducted in a university hospital in south Brazil between May 2012 and June 2013. Were recruited 208 children up to 12 years old of whom 156 had asthma (cases) and 52 did not have asthma (controls), with a case-control ratio of 3:1 matched by age. Children's parents or guardians were interviewed using a structured questionnaire with closed questions. Serology was performed using enzyme-linked immunosorbent assay (ELISA) with excretory-secretory antigen of Toxocara canis (TES).



The seroprevalence of IgG anti-T. canis antibodies was 12.8% in the cases and 7.7% in the controls. There was no significant association between seropositivity to T. canis and risk of asthma (adjusted odds ratio [OR]: 1.89, 95% CI: 0.52 to 6.89, p = 0.33). Household income < 2 minimum salaries, paternal school years < 9, allergic rhinitis in children, a positive family history of asthma and rhinitis and contact with cats were significantly associated with asthma, with adjusted ORs (95% CIs) of 3.05 (1.21 to 7.73), 2.83 (1.11 to 7.18), 10.5 (4.32 to 25.6), 2.65 (1.14 to 6.17), 2.49 (1.07 to 5.78) and 2.73 (1.03 to 7.27), respectively.



This study did not find a statistically significant association between seropositivity to Toxocara sp. and risk of asthma in children. Low family income, low paternal education level, concomitant allergic rhinitis, family history of asthma and allergic rhinitis and contact with cats were independent factors associated with childhood asthma.
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Priscila Silva
PS
Cadore
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Linjie
L
Zhang
b Graduate Program in Biological Sciences , Federal University of Rio Grande , Rio Grande , Brazil.
Liliam de Lima
Lde L
Lemos
c Graduate Program in Medicine, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Carolina
C
Lorenzi
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Paula de Lima
Pde L
Telmo
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Paula Costa
PC
Dos Santos
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Gabriela Torres
GT
Mattos
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Flávia Saraçol
FS
Vignol
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Silvio O M
SO
Prietsch
d Postgraduate Program in Parasitology, Institute of Biology , Federal University of Pelotas , Pelotas , Brazil.
Maria Elisabeth Aires
ME
Berne
a Postgraduate Program in Health Sciences, Faculty of Medicine , Federal University of Rio Grande , Rio Grande , Brazil.
Carlos James
CJ
Scaini
D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D001249:Asthma / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D002415:Cats; D002648:Child; D002675:Child, Preschool; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D008297:Male; D065631:Rhinitis, Allergic / Q000453:epidemiology; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012959:Socioeconomic Factors; D014119:Toxocara / Q000276:immunology*; D014120:Toxocariasis / Q000453:epidemiology* / Q000276:immunology* / Q000635:transmission
D000909:Antibodies, Helminth; D007074:Immunoglobulin G
Anti-Toxocara IgG; Toxocara canis; asthma; children; seroprevalence