Soil contamination by Toxocara canis and human seroprevalence in the Attica region, Greece

Vasilios Papavasilopoulos; Vassiliki Pitiriga; Konstantinos Birbas; John Elefsiniotis; Gerasimos Bonatsos; Athanasios Tsakris

doi:10.18683/germs.2018.1143

Soil contamination by Toxocara canis and human seroprevalence in the Attica region, Greece

Germs. 2018 Sep 3;8(3):155-161. doi: 10.18683/germs.2018.1143. eCollection 2018 Sep.

Authors

Vasilios Papavasilopoulos¹, Vassiliki Pitiriga², Konstantinos Birbas³, John Elefsiniotis³, Gerasimos Bonatsos⁴, Athanasios Tsakris⁵

Affiliations

¹ MD, PhD, National School of Public Health, 196 Leoforos Alexandras Avenue, 11521 Athens, Greece.
² Assist Prof, Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece.
³ Assoc Prof, Faculty of Nursing, School of Public Health, National and Kapodistrian University of Athens, 123 Papadiamantopoulou Street, 11526 Athens, Greece.
⁴ Prof, Faculty of Nursing, School of Public Health, National and Kapodistrian University of Athens, 123 Papadiamantopoulou Street, 11526 Athens, Greece.
⁵ Prof, Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, Greece.

Abstract

Background: Toxocara canis is one of the most widespread public health and economically important zoonotic parasitic infections humans share with canids, mainly dogs. Human infection occurs by the accidental ingestion of embryonated eggs or larvae from a range of wild and domestic paratenic hosts. The aim of the present study was to examine the soil contamination of public places by the parasitic ova and to estimate serologically the prevalence of T. canis human infection in the Attica region, Greece.

Methods: In this region, public areas are permanently inhabited by dogs, mostly stray dog population that is hardly kept down to a manageable level. A total of 1,510 soil samples were collected from 33 public places of six regional units of Attica from March 2014 to April 2014 and ova were detected using a microscopic assay. In addition, sera were collected from 250 residents, routinely active in the sampled areas, and tested for T. canis IgG antibodies using an enzyme immunoassay.

Results: T. canis eggs were isolated from 31 (94%) of the examined public areas. Of the total samples, T. canis ova were recovered from 258 samples, suggesting an overall T. canis ova contamination of 17.2%. The areas of higher socioeconomic status presented lower percentages of soil contamination in a statistically significant level, compared to the areas of lower socioeconomic status. T. canis IgG seropositivity was detected in 40 (16%) serum samples. Similar rates were established among T. canis seropositivity and soil contamination within the same geographical areas. The proportion of seropositive samples in the group of children was significantly higher compared to the proportion of adults (48% versus 8%, p<0.001).

Conclusion: The level of environmental T. canis contamination as well as human infection found in the Attica region calls for a greater awareness towards this public issue. Preventing measures should be implemented to control the spread of this parasitic infection.

Keywords: Greece; Toxocara canis; Toxocara ova; seroprevalence; soil contamination; toxocariasis.