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United States Department of Agriculture

Agricultural Research Service

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Research Project: Identification for Toxoplasma Transmission in Pasture Raised Animals subaward No. Z551401

Location: Animal Parasitic Diseases

2013 Annual Report


1a.Objectives (from AD-416):
Given the increasing demand for organically-raised meat products, it is critical to understand and assess the risk that may arise from consumption of these meat products potentially infected with T. gondii. The objectives of the proposed research are to determine the sero- and tissue prevalence of viable T. gondii in the meat of organic and free-range pigs and lambs available for purchase by consumers at the retail level, and develop a quantitative probabilistic model for the likelihood that pasture raised/organic meat from pigs and lambs could be a vehicle for T. gondii. These data will support science-based decisions on the most effective methods to reduce or eliminate Toxoplasma transmission to humans in the U.S. Additionally, development of current prevalence data in retail meats from free range animals will inform policy makers on the effectiveness of farm level controls of this zoonotic parasite for reduction of risk in the human population.


1b.Approach (from AD-416):
Meat samples will be acquired from a nationwide sampling of retail stores from 25 Metropolitan Statistical Areas (MSA); ten supermarkets, grocery outlets, or wholesale club stores will be randomly selected for sampling within each MSA. Samples (free-range pork and lamb) will be shipped to the Animal Parasitic Diseases Laboratory for Toxoplasma isolation. Digested meat samples will be inoculated into mice, and tissues from mice will be examined microscopically for Toxoplasma after two weeks. Prevalence data will be used to construct model for the likelihood that pasture raised/organic meat from pigs and lambs could be a vehicle for T. gondii.


3.Progress Report:

The ARS laboratory is conducting a nationwide survey of retail organic, free-range pork and lamb to detect the presence of Toxoplasma gondii in these meat products. Meat samples will be acquired from 10 supermarkets, grocery outlets, or wholesale club stores that will be randomly selected for sampling in each of 25 metropolitan statistical areas (MSAs) in the U.S. Thus, samples from 250 retail stores will be collected and tested for sero- and tissue prevalence using ELISA and bioassay in mice, respectively. To date, we have collected organic pork and lamb samples from retail stores in 3 of the planned 25 MSAs (Washington, D.C., Buffalo, NY, and Philadelphia, PA). Bioassays in mice and serological testing is in progress. The data collected will be used to discern consumer risk from meat products from animals raised in uncontrolled management systems.


Last Modified: 10/26/2014
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