Prevalence of allergic sensitization to imported fire ants in children living in an endemic region of the southeastern United States.
BACKGROUND
Imported fire ant (IFA) stings are common in children in the southeastern United States, but little is known about antibody responses to stings.


OBJECTIVE
To examine the prevalence of detectable IgE and IgG antibodies to IFA venom (IFAV) and to assess the frequency of IFA stings in children in an endemic region.


METHODS
We measured IFAV specific IgE using the ImmunoCAP assay and IgG anti-IFAV using protein G solid-phase radioimmunoassay in 183 serum samples from children living in the southeastern United States. A questionnaire was used to collect information about insect stings and bites from 182 children in a general pediatric clinic.


RESULTS
Serum IgE anti-IFAV was detected (0.1 kUa/L) in 7.1% of 0- to 1-year-olds, 57.1% of 2- to 5-year-olds, and 64.4% of 6- to 10-year-olds. The prevalence of IgG anti-IFAV antibodies increased from 11.9% in 0- to 1-year-olds to 97.5% in 11- to 20-year-olds. Of children in the pediatric clinic, almost 40% had been stung by an IFA in the past month, with 23.9% receiving more than 6 stings per month.


CONCLUSIONS
In endemic areas, the onset of sensitization (IgE positivity) to IFAV occurs in the first years of life, with more than half of the children demonstrating sensitization by 2 to 5 years of age. Exposure to IFAV as evidenced by a positive IgG anti-IFAV antibody increased with age, and by the second decade, more than 97% of children had detectable antibody. Children living in an endemic region frequently encounter IFAs and, when stung, often receive multiple stings.
Partridge
Megan E
ME
Department of Allergy/Immunology, Medical College of Georgia, Augusta, Georgia 30912, USA. mpartridge@mcg.edu
Blackwood
Wesley
W
Hamilton
Robert G
RG
Ford
Jan
J
Young
Penny
P
Ownby
Dennis R
DR
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000862:Ant Venoms / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007223:Infant; D007299:Insect Bites and Stings / Q000453:epidemiology / Q000276:immunology; D008297:Male; D015995:Prevalence; D015144:Southeastern United States / Q000453:epidemiology; D011795:Surveys and Questionnaires
D000862:Ant Venoms; D007074:Immunoglobulin G; D007073:Immunoglobulin E