title: Toxoplasma gondii infection in slaughter pigs in Serbia: seroprevalence and demonstration of parasites in blood.
abstract: A seroepizootiological study of Toxoplasma gondii infection involving a total of 488 slaughter pigs (468 market-weight pigs and 20 sows) in the Belgrade area, also included examination of the presence of T. gondii in the blood. Blood sampled at the slaughter line was examined for specific antibodies by modified direct agglutination, and blood clots of those seropositive at titres of 1:50-1:12800 were bioassayed in mice. The overall seroprevalence was 9.2%, significantly higher (p = 0.0063) in sows (30.0%) than in market-weight pigs (8.3%). Amongst the 22 bioassays performed, a total of 16 (72.7%) were positive, by observation of T. gondii cysts (12), seropositivity (7, including 3 in which cysts were not detected), and/or detection of T. gondii DNA by real-time PCR (12, including one otherwise negative). The positive bioassays originated from the blood of 12 market-weight pigs and 4 sows. Despite a general increase in the rate of demonstration of T. gondii with the increase in the specific antibody level, the association was not significant (p = 0.101). The risk of infection was 41-fold increased in sows vs market-weight pigs, and 15-fold in pigs from smallholders' finishing type farms vs those from large farrow-to-finish farms. The presence of viable T. gondii in a proportion of the samples indicates that some of the pigs had an active parasitaemia at the time of slaughter, which, along with the seroprevalence established, points to a potential source of human infection in Serbia. This is the first report on parasitaemia in naturally infected swine.
authors.affiliation: National Reference Laboratory for Toxoplasmosis, Centre for Parasitic Zoonoses, University of Belgrade Institute for Medical Research, Dr, Subotića 4, 11129 Belgrade, Serbia. olgicadj@imi.bg.ac.rs.
authors.forename: Ivana
authors.initials: I
authors.lastname: Klun
authors.forename: Marija
authors.initials: M
authors.lastname: Vujanić
authors.forename: Hélène
authors.initials: H
authors.lastname: Yera
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Nikolić
authors.forename: Vladimir
authors.initials: V
authors.lastname: Ivović
authors.forename: Branko
authors.initials: B
authors.lastname: Bobić
authors.forename: Siniša
authors.initials: S
authors.lastname: Bradonjić
authors.forename: Jean
authors.initials: J
authors.lastname: Dupouy-Camet
authors.forename: Olgica
authors.initials: O
authors.lastname: Djurković-Djaković
mesh_terms: D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D016054:DNA, Protozoan / Q000032:analysis; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008018:Life Cycle Stages; D008460:Meat / Q000469:parasitology*; D051379:Mice; D018512:Parasitemia / Q000097:blood / Q000662:veterinary; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D018570:Risk Assessment; D055771:Serbia / Q000453:epidemiology; D016036:Seroepidemiologic Studies; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000469:parasitology; D014122:Toxoplasma / Q000302:isolation & purification*; D014124:Toxoplasmosis, Animal / Q000453:epidemiology* / Q000469:parasitology
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan; D007074:Immunoglobulin G