Search

Toxoplasmosis is a zoonotic disease caused by the protozoan parasite Toxoplasma gondii. Ingestion of raw or undercooked meat containing viable cysts has been suggested to be a major source of T. gondii infection in humans. Suboptimal performance of serological assays in cattle has traditionally precluded accurate quantification of the extent to which cattle populations are infected and their meat harbour tissue cysts. In the absence of accurate estimates of the level of infection in the animal population, assessments of likely human exposure through the consumption of cattle meat remain highly speculative. Following the development of novel and sensitive molecular methods that can be applied to the relatively large numbers of samples required in observational studies, the first quantitative estimates of the frequency of T. gondii in meat samples from naturally infected cattle have become available recently. Such estimates are critical for the development of quantitative risk assessment models that could be used to inform food safety policies. The aim of this study was to generate the first estimates of the prevalence of T. gondii infection in a sample of cattle exposed to natural levels of infection and slaughtered for human consumption in the UK under commercial conditions. Such estimates provide great value to the global assessment of T. gondii burden given the scarcity of data available on the frequency of natural infection in cattle populations worldwide. Between October 2015 and January 2016 diaphragm samples were collected from 305 animals, slaughtered in ten commercial slaughterhouses across the UK. Movement histories showed that the animals sampled (41.6% females and 58.4% males) had passed through a total of 614 farms and 40 livestock markets across the country. Five animals (1.6%) were deemed positive for T. gondii following magnetic capture real-time PCR, confirmed by amplicon sequencing. The true prevalence of infection was estimated to be 1.79%. All positive animals were male, none of whom had been on the same farm and/or livestock market before slaughter and there was no apparent geographic pattern. The results from this study suggest a low level of infection in cattle raised and slaughtered in the UK and can be used to populate the first stages of formal risk assessments to quantify the likely extent of human exposure to T. gondii through the consumption of beef with relevance to the UK, EU and rest of the world., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Because the number of wild raccoons in Germany is increasing constantly, it appears to be economic reasonable to use their meat as food. For this purpose, it is essential to generate data regarding the pathogen load of the meat to be consumed and handled. It is known that raccoons, particularly in Germany, show a high seroprevalence of Toxoplasma gondii. Because serological data only indicates contact of a host to a parasite additional direct detection is needed to prove presence of parasitic stages in particular tissues. Therefore, a total of 150 samples from raccoons with known serostatus were tested and quantified using magnetic-capture real-time PCR for Toxoplasma gondii. As it represents potentially consumption-relevant parts of raccoons, meat from forelimb and hindlimb was examined. Samples were stratified into three groups based on the animals' serostatus (each 50 negative, low positive, and high positive). All samples from seronegative animals were found negative by MC-PCR as well. In a total of 56 meat samples from 100 seropositive animals, T. gondii DNA was detected. Statistically significant more samples were positive by MC-PCR in the high positive than in the low positive serostatus group (38/50 vs. 18/50, p < 0.0001). Furthermore, samples from the former group were also found to have statistically significant higher DNA equivalent values compared to samples from the low positive serostatus group (p < 0.0001). These results suggest that meat from seropositive raccoons may contain considerable numbers of T. gondii presenting a potential public health risk for humans whilst handling and consumption. [ABSTRACT FROM AUTHOR]