Article Text

Download PDFPDF

Toxoplasma gondii seroprevalence in the Portuguese population: comparison of three cross-sectional studies spanning three decades
  1. Maria João Gargaté1,
  2. Idalina Ferreira1,
  3. Anabela Vilares1,
  4. Susana Martins1,
  5. Carlos Cardoso2,
  6. Susana Silva3,
  7. Baltazar Nunes3,
  8. João Paulo Gomes4
  1. 1National Reference Laboratory of Parasitic and Fungal Infections, National Institute of Health, Lisbon, Portugal
  2. 2Clinical laboratory Dr. Joaquim Chaves, Lisbon, Portugal
  3. 3Department of Epidemiology, National Institute of Health, Lisbon, Portugal
  4. 4Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
  1. Correspondence to Dr Maria João Gargate; m.joao.gargate{at}


Background Toxoplasma gondii is an obligate intracellular protozoan infecting up to one-third of the world's population, constituting a life threat if transmitted from mother to child during pregnancy. In Portugal, there is a lack of knowledge of the current epidemiological situation, as the unique toxoplasmosis National Serological Survey was performed in 1979/1980.

Methods We studied the seroprevalence trends in the Portuguese general population over the past 3 decades, by assessing chronological spread cross-sectional studies, with special focus on women of childbearing age, by age group, region and gender.

Results The T. gondii overall seroprevalence decreased from 47% in 1979/1980 to 22% (95% CI 20% to 24%) in 2013. Generally, we observed that the prevalence of T. gondii IgG increased significantly with age and it decreased over time, both in the general population and in the childbearing women (18% prevalence in 2013).

Conclusions The scenario observed for the latter indicates that more than 80% of childbearing women are susceptible to primary infection yielding a risk of congenital toxoplasmosis and respective sequelae. Since there is no vaccine to prevent human toxoplasmosis, the improvement of primary prevention constitutes a major tool to avoid infection in such susceptible groups.


This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors MJG, BN and JPG developed the study design and were responsible for data management. BN and SS performed the statistical analysis. MJG, IF, AV and SM performed the experimental assays. CC provided the sera samples. MJG and JPG wrote the manuscript.

  • Funding The Portuguese National Institute of Health funded this study.

  • Competing interests None declared.

  • Ethics approval This study was approved by the ethical committee of the Portuguese National Institute of Health.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No additional data are available.