Toxoplasma gondii infection in pigs in Serbia

Toxoplasma gondii is a common zoonotic intracellular parasite in livestock raised forhuman consumption and is a public health concern. The mode of transmission is ingestion,and meat is considered to be a major vehicle for human and animal infection. AsT. gondii is environmentally transmissible, other important vehicles in particular foranimals include vegetation, soil and water. The seroprevalence of T. gondii infection inpigs is Serbia has been determined in several studies over the past two decades. It hasbeen established that it varies considerably, primarily based on husbandry, with strictlyto mostly indoor animals having a lower prevalence (below 20%) than animals raisedoutdoors, where prevalence exceeds 60%. Experimental data suggests that differentgenotypes of the parasite vary in virulence, but the significance of virulence in terms ofpathology and disease manifestations is still being investigated. Genotypes of T. gondiiisolated from pig tissues in Serbia to date are ToxoDB#1 (archetype II) and ToxoDB#2(archetype III). Archetype II is predominant and, based on historical reports and recentfindings, low to intermediately virulent. The virulence phenotype and mechanisms ofarchetype III, however, have not been extensively studied, but recent data suggests thatits virulence may vary considerably. This review will also summarize the current knowledgeregarding the virulence of archetypes II and III and evaluate it in the context ofthe pig host