Lamb as a potential source of Toxoplasma gondii infection for Australians

Abstract

Objective: Toxoplasmosis may follow consumption of undercooked meat containing Toxoplasma gondii cysts. Lamb is considered to pose the highest risk for contamination across meats. Red meat is often served undercooked, yet there are no current data on T. gondii contamination of Australian sourced and retailed lamb. We sought to address this gap in public health knowledge.Methods: Lamb mincemeat was purchased at the supermarket counter three times weekly for six months. T. gondii was detected by real-time polymerase chain reaction (PCR) of DNA extracted from the meat following homogenisation. Purchases were also tested for common foodborne bacterial pathogens.Results: Conservative interpretation of PCR testing (i.e. parasite DNA detected in three of four tests) gave a probability of 43% (95% confidence interval, 32%-54%) that lamb mincemeat was contaminated with T. gondii. None of the purchases were contaminated with Campylobacter jejuni, Salmonella species or S. enterica serovar Typhimurium, indicating sanitary meat processing.Conclusions: Australian lamb is commonly contaminated with T. gondii. Future studies should be directed at testing a range of red meats and meat cuts.Implications for public health: Consuming undercooked Australian lamb has potential to result in toxoplasmosis. There may be value in health education around this risk.

Relationship between Toxoplasma gondii seroprevalence and lamb marking in South Australian sheep flocks

“…Humans can be infected by ingestion of oocysts but can also acquire the infection through consumption of the tissue cyst (bradyzoite) stage of the parasite, which may be found in raw or undercooked meat products from infected livestock 3, 4 . Recent testing of meat in South Australia by PCR indicates a probability that 43% of minced sheep meat contains T. gondii (although viability of the organism was not determined in this study) 6 …”

“…3,4 Recent testing of meat in South Australia by PCR indicates a probability that 43% of minced sheep meat contains T. gondii (although viability of the organism was not determined in this study). 6 Despite the parasite being very common and the potential impact T. gondii can have on the reproductive performance in sheep, very little recent research on ovine toxoplasmosis has actually been carried out in Australia. Although few in number, past prevalence studies demonstrate that exposure to the parasite in sheep was common in Australia.…”

Seroprevalence of toxoplasmosis at referral hospitals in the northwestern region, Saudi Arabia

“…Across various meat products, the highest risk of contamination is meat from lambs. [ 39 ] There is currently no data regarding the contamination of T. gondii to locally produced meat products from sheep or lamb in the study area.…”

Toxoplasma gondii in Foods: Prevalence, Control, and Safety

“…In Italy, the meat juices from 28.6% sheep 27.5% goat were positive by commercial ELISA [ 97 ]; in Lebanon, the data are high, with a seroprevalence of 42% and 34% in sheep and goats, respectively [ 92 ], and other countries show even higher seroprevalences [ 94 , 104 ]. However, studies with molecular methods indicated a low prevalence in sheep and goat meat in Iran, with 14.4% and 11.1%, respectively [ 97 ], whereas in Tunisia, the data were 33.3% for sheep and 32.5% for goat meat samples [ 100 ], and in Australia molecular methods detected 43% of positive lambs that were examined [ 102 ]. To decrease this rate of infection, some strategies have been carried out.…”