Serosurvey of anti-Toxocara antibodies and risk factors in adolescent and adult pregnant women of southeastern Brazil.

Louise Bach Kmetiuk,Susana Zevallos Lescano,Alexander Welker Biondo,Sriveny Dangoudoubiyam,Vamilton Alvares Santarém,Christine A Petersen,Andrea Pires Dos Santos,Priscila De Oliveira Azevedo,Rogério Giuffrida

doi:10.1371/journal.pntd.0009571

Abstract

Toxocariasis is worldwide endemic parasitic anthropozoonosis with high risk to those in in vulnerable populations and particularly during pregnancy and childhood. Although the prevalence of anti-Toxocara spp. antibodies has been extensively studied, risk factors of pregnant women of different ages remains to be established. This study was designed to i) assess the presence of anti-Toxocara spp. antibodies in pregnant women that presented to the public health system in a city of southeastern Brazil, and ii) determine the risk factors for toxocariasis in adolescent and adult pregnant women. This cross-sectional study included 280 pregnant women (71 aged up to and including 17 years [adolescents] and 209 aged 18 years and older [adults]). Pregnant women voluntarily agreed to complete a socioeconomic questionnaire and provide serum samples. Anti-Toxocara IgG antibodies were screened by Enzyme-Linked Immunosorbent Assay (ELISA). Univariable and multivariable logistic regression models were performed to assess the risks for toxocariasis. Overall, 20.7% of pregnant women were seropositive (33.8% of adolescents and 16.3% of adults). Prevalence in pregnant adolescents was 2.6-fold higher than in adults (Odds ration [OR]: 2.63; 95% CI: 1.42–4.86, p = 0.003). Multivariate analysis revealed that contact with soil (p = 0.01; OR = 4.76) and being in the first trimester of pregnancy (p = 0.03; OR = 0.17) had significantly greater risk of toxocariasis for adolescents, and attainment of elementary through middle school education level (p = 0.05; OR = 8.33) was a risk factor in adult pregnant women. Toxocariasis is likely underreported and neglected in adolescent pregnant women; this age group should always be monitored for toxocariasis and correspondent clinical signs, particularly at late pregnancy.

Highlights

Toxocariasis has been described as a worldwide cosmopolitan and endemic parasitic anthropozoonosis, primarily transmitted to human beings by accidental ingestion of food, water or soil containing Toxocara spp. eggs, T. canis of dogs and T. cati of cats [1,2]
Our results show that Toxocara spp. seroprevalence in pregnant women may be influenced by age; with younger age identified as a risk factor for Toxocara spp. seropositivity
This data may be useful as background information for educational programs on toxocariasis prevention in pregnant women, adolescents

Summary

Introduction

Toxocariasis has been described as a worldwide cosmopolitan and endemic parasitic anthropozoonosis, primarily transmitted to human beings by accidental ingestion of food, water or soil containing Toxocara spp. eggs, T. canis of dogs and T. cati of cats [1,2]. Migration of Toxocara larvae causes various tissues of the human host in a spectrum of clinical disease [2]. Clinical toxocariasis is classified into covert, visceral, ocular, or neurotoxocariasis according to clinical signs and the organ involved [4,5] Clinical signs may vary depending on larval load, continuous reinfection, tissue distribution, and intensity of the host inflammatory response [6]. Over 1.5 billion people have been infected with soil-transmitted helminths worldwide, in areas with poor sanitary conditions [7]. The prevalence of anti-Toxocara antibodies is higher in populations with low or lower-middle incomes and living in areas where the Human Development Index is low or medium [8]

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Results

Discussion

Conclusion