Involvement of Toxoplasma gondii in reproductive disorders in Swiss pig farms

Walter Basso; Martin Handke; Titus Sydler; Nicole Borel; Felix Grimm; Xaver Sidler; Peter Deplazes

doi:10.1016/j.parint.2014.11.017

Involvement of Toxoplasma gondii in reproductive disorders in Swiss pig farms

Parasitol Int. 2015 Apr;64(2):157-60. doi: 10.1016/j.parint.2014.11.017. Epub 2014 Nov 29.

Authors

Walter Basso¹, Martin Handke², Titus Sydler³, Nicole Borel³, Felix Grimm⁴, Xaver Sidler², Peter Deplazes⁴

Affiliations

¹ Institute of Parasitology, Vetsuisse-Faculty, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zurich, Switzerland; Department of Farm Animals, Division of Swine Medicine, Vetsuisse-Faculty, University of Zurich, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland. Electronic address: walter.basso@access.uzh.ch.
² Department of Farm Animals, Division of Swine Medicine, Vetsuisse-Faculty, University of Zurich, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland.
³ Institute of Veterinary Pathology, Vetsuisse-Faculty, University of Zurich, Winterthurerstrasse 268, CH-8057, Zurich, Switzerland.
⁴ Institute of Parasitology, Vetsuisse-Faculty, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zurich, Switzerland.

PMID: 25456854
DOI: 10.1016/j.parint.2014.11.017

Abstract

To determine the role of Toxoplasma gondii in reproductive failure, 108 of 113 sows that had aborted or delivered stillborn or weak piglets from 58 Swiss farms were serologically tested for specific antibodies against T. gondii tachyzoite antigens by ELISA. Additionally, formalin-fixed and paraffin-embedded tissues from 123 foetuses or stillborn piglets derived from 25 seropositive and 27 seronegative sows were analyzed by real-time PCR for T. gondii DNA. Tissues from animals showing a positive reaction in real-time PCR were subsequently tested by immunohistochemistry for the presence of T. gondii antigens. Antibodies against T. gondii were detected in 24.1% (26 out of 108) of sows with reproductive failure, and 37.3% (22 of 58) of the 58 tested farms had seropositive sows. No significant differences in the prevalences were observed in relation to the housing system (exclusive indoor housing, indoor housing with outdoor yard and exclusive outdoor housing) neither at the individual nor at the farm levels. By real time-PCR, T. gondii DNA was detected in three placentas from one seropositive sow (abortion at 71 gestation days [gd]), and in brain tissues from one foetus (abortion at 76 gd), one stillborn (116 gd) and one mummy (112 gd) delivered by three further seropositive sows, but in no sample derived from seronegative dams. By immunohistochemical staining, the presence of T. gondii could be confirmed only in placenta samples. In one of the cases, a co-infection with porcine parvovirus (PPV) was detected. These results suggest vertical transmission of T. gondii and/or placental infection in at least 3.5% (4 of 113) of sows with reproductive disorders. Therefore, T. gondii should be more frequently included in the routine differential diagnosis of reproductive failure in sows. In addition, a proper disposal of placentas and abortion material beyond the reach of cats could help to interrupt the further dissemination of this parasite at the farm level.

Keywords: Abortion; Mummification; Reproduction; Sow; Stillbirth; Toxoplasma gondii.

MeSH terms

Animals
Antibodies, Protozoan
Enzyme-Linked Immunosorbent Assay
Female
Pregnancy
Pregnancy Complications, Parasitic / epidemiology
Pregnancy Complications, Parasitic / parasitology
Pregnancy Complications, Parasitic / veterinary*
Real-Time Polymerase Chain Reaction
Swine
Swine Diseases / epidemiology
Swine Diseases / parasitology*
Swine Diseases / pathology
Switzerland / epidemiology
Toxoplasma / isolation & purification*
Toxoplasmosis, Animal / epidemiology
Toxoplasmosis, Animal / pathology*

Substances

Antibodies, Protozoan