Significance of Serum Antibody Test for Toxocariasis in Healthy Healthcare Examinees with Eosinophilia in Seoul and Gyeongsangnam-do, Korea

Abstract

There have been numerous reports on the relationship between eosinophilia and toxocariasis. The present study investigated seropositive rates of toxocariasis among healthy people with or without eosinophilia in urban and rural areas, and assessed risk factors for positive antibody test. A total of 610 healthy people, who visited health check-up (Medicheck®, Korea Association of Health Promotion), 310 from Seoul and 300 from Gyeongsangnam-do, were subjected for this study. Their serum samples were tested by ELISA with the crude antigen of Toxocara canis larvae. Cross-reactions with other tissue invading helminth antigens were also investigated. Total antibody positive rate of toxocariasis was 8.7% of the 610 subjects. When the subjects were grouped into 3 by their eosinophil counts, the antibody positive rates significantly differed by the groups; 5.9% (18/306) in the group<350/µL, 10.0% (11/110) in the group 350-500/µL, and 12.4% (24/194) in the group>500/µL (P=0.028). A total of 22 serum samples cross-reacted with other tissue-invading helminth antigens. A questionnaire analysis recognized drinking alcohol and smoking as significant risk factors of toxocariasis. In conclusion, toxocariasis antibody positive rate is correlated with eosinophil counts. It is recommended that healthy subjects with eosinophilia by routine health examination and risk factors undergo Toxocara serology by multiantigen ELISA to investigate etiology.Graphical Abstract

Clinical usefulness of Western blotting and ELISA avidity for the diagnosis of human toxocariasis

“…Most patients in the past stage of the infection, despite sustaining positive levels of IgG, do not require pharmacotherapy. Early treatment brings obvious benefits for patients in an active phase of toxocariasis in terms of improved effectiveness of treatment, faster eradication of larvae and protection of vital organs against damage . Determination of IgG AI is commonly used to indicate the stage of invasion in toxoplasmosis and cytomegalovirus infection.…”

The Prevalence of Toxocariasis and Diagnostic Value of Serologic Tests in Asymptomatic Korean Adults

“…Several researchers reported that Toxocara -seroprevalence rates in the general population in Korea vary from 5.0% to 11.3% as asassessed by using a self-made ELISA kit. 23 28 29 This discrepancy may have resulted from differences in diagnostic ELISA kits with different sensitivity and from differences in study populations. Because the definite tissue confirmation of toxocariasis is extremely difficult, toxocariasis is usually diagnosed by measuring IgG antibody to Toxocara , although the currently used cutoff value cannot clearly discriminate the current active infection from remote or past infections.…”

Field evaluation of a rapid diagnostic test to detect antibodies in human toxocariasis

“…The rather high prevalence rate in our study is probably because in this village, a number of households kept dogs as pets as well as stray dogs were often seen wandering around the vicinity of the houses and the majority of children in the village walked around barefooted. Elsewhere, Korea showed a positive toxocariasis rate of 8.7% (Kim et al, 2014), Brazilian school children showed a rate of 12.1% (Coêlho et al, 2005) and 15.5% (Cassenote et al, 2014), and 57.5% rate was reported for aboriginal school children from Taiwan (Fan et al, 2005). Orang Asli remain one of the most socially marginalized populations in Malaysia (Masron et al, 2013).…”