Comparison of Different Commercial Serological Tests for the Detection ofToxoplasma gondiiAntibodies in Serum of Naturally Exposed Pigs

Abstract

SummaryToxoplasma gondiiis the aetiological agent of the zoonotic disease toxoplasmosis and transmitted among other ways by chemically and physically untreated, that is, raw pork to humans. The detection ofToxoplasma gondiiis impossible by currently practiced meat inspection, but serological tests can be used to detectToxoplasma gondiiantibodies in pig herds and can consequently be helpful to identify potentially contaminated pork. Therefore, appropriate serological tests are required. In this study, serum samples of 1368 naturally exposed slaughter pigs from 73 Austrian farms were collected. Serum samples of at least 16 slaughter pigs per farm were tested. The prevalence ofToxoplasma gondiiantibodies in serum was measured by a commercial available modified agglutination test (MAT) and compared to three different commercial available enzyme‐linked immunosorbent assays (ELISA). TheMATdetected 6.5%,ELISAI 6.7%,ELISA II4.8% andELISA III4.3% of the pigs asToxoplasma gondiiantibody positive. The agreement, according to the kappa coefficient (κ), was substantial between theMATandELISAI (κ = 0.62),II(κ = 0.64) andIII(κ = 0.67). A better agreement was determined betweenELISAI andII(κ = 0.715),ELISAI andIII(κ = 0.747) andELISA IIandIII(κ = 0.865). At least one pig per farm was detectedToxoplasma gondiiantibody positive in 17 (23.3%) farms by theMAT, 26 (35.6%) farms byELISAI, 16 (21.9%) farms byELISA IIand 11 (15.1%) farms byELISA III. Pig farms with a high number ofToxoplasma gondiiantibody‐positive pigs or high antibody titres were identified by all of the four used serological tests. Concerning the occurrence ofToxoplasma gondiiantibodies in Austrian pig farms, a monitoring and surveillance programme would be reasonable to find high‐risk farms.