Toxocara seroprevalence among clinically healthy individuals, pregnant women and psychiatric patients and associated risk factors in Shandong Province, Eastern China

PLoS Negl Trop Dis. 2014 Aug 7;8(8):e3082. doi: 10.1371/journal.pntd.0003082. eCollection 2014 Aug.

Abstract

Background: Toxocarosis is a widespread zoonosis caused by the ascarid nematodes Toxocara canis and Toxocara cati, which primarily infect dogs and cats, respectively. Most human infections with Toxocara are asymptomatic; however, some infected individuals may develop a serious illness and even death. Nevertheless, epidemiological knowledge regarding the prevalence and risks associated with Toxocara infection is limited in China. Therefore, we performed a cross-sectional pilot study and estimated the seroprevalence of Toxocara infection in humans in Shandong Province, eastern China for the first time, from June 2011 to July 2013, involving clinically healthy individuals, pregnant women and psychiatric patients, aiming to attract public attention to Toxocara infection.

Methodology/principle findings: Seroprevalence of Toxocara was determined using an enzyme-linked immunosorbent assay based on a cross-sectional study conducted in Qingdao and Weihai, Shandong Province, eastern China. Factors potentially associated with Toxocara infection were identified by logistic regression analysis. The overall Toxocara seroprevalence among the study population (n = 2866) was 12.25%, and a significantly higher seroprevalence in psychiatric patients (16.40%, 73/445) than that in clinically healthy individuals (13.07%, 187/1431) and pregnant women (9.19%, 91/990) was revealed. Univariate analyses suggested that keeping dogs at home (OR = 0.06, 95% CI 0.05-0.08, P<0.001), contact with cats and dogs (OR = 0.42, 95% CI 0.33-0.53, P<0.001) and exposure with soil (OR = 0.37, 95% CI 0.28-0.49, P<0.001) were risk factors associated with Toxocara infection.

Conclusions/significance: The present study revealed, for the first time, that human infection with Toxocara is common in eastern China, posing a significant public health concern. Increasing human and dog populations, population movements and climate change all will serve to increase the importance of this zoonosis. Further studies under controlled conditions are necessary to define potential morbidity associated with Toxocara infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Antibodies, Protozoan / blood
  • China / epidemiology
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Mental Disorders* / complications
  • Mental Disorders* / epidemiology
  • Middle Aged
  • Pregnancy
  • Pregnancy Complications, Parasitic* / epidemiology
  • Pregnancy Complications, Parasitic* / immunology
  • Risk Factors
  • Seroepidemiologic Studies
  • Toxocara / immunology*
  • Toxocariasis* / complications
  • Toxocariasis* / epidemiology
  • Toxocariasis* / immunology
  • Young Adult

Substances

  • Antibodies, Protozoan

Grants and funding

Project support was provided by the International Science & Technology Cooperation Program of China (Grant No. 2013DFA31840) and the Science Fund for Creative Research Groups of Gansu Province (Grant No. 1210RJIA006). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.