A study published in the May 22, 2012 issue of Clinical Infectious Diseases has found that organic meats may have increased toxoplasmosis risk.
Toxoplasmosis gondii is a single-celled parasite that used to be a significant problem in pork. The definitive host for the parasite is cats. When pigs were allowed to forage for food, they often ate food contaminated with infected cat feces, or ate wild animals and birds that contained the oocysts. That’s why your grandmother used to cook pork well done to 160 degrees F, because that destroyed the parasite in all of its forms.
When pork farmers changed the methods of hog raising to eliminate foraging and fed the animals processed food, the risk of toxoplasmosis fell considerably. But the current trend toward free-range food animals, especially pigs and lamb, has increased the toxoplasmosis risk, since those animals are foraging for food. Wild game, such as venison, is also a a source of the toxoplasmosis parasite.
The symptoms of toxoplasmosis include swollen lymph glands, aches and pains that last longer than a month, and the feeling of unwellness that usually accompanies the flu. Treatment is usually not needed in normally healthy people, but some require medication. The parasite can infect the placenta and the fetus in pregnant women, which can cause stillbirth and neurological damage. Toxoplasmosis infections hospitalize 4,000 people and kill 300 every year in the U.S.
Many people carry the parasite but do not become ill or show symptoms because their immune systems are strong.
The USDA recommends these final internal cooked temperatures for meat:
- 145 degrees F with a 3-minute standing time for whole cuts of meat, including pork chops, pork roasts, lamb chops and roasts, and beef roasts.
- 160 degrees F for all ground meats.
- 165 degrees F for all poultry, including chicken and turkey.
Freezing meat at sub-zero temperatures for several days can greatly reduce the Toxoplasmosis oocysts in contaminated meat. If you choose to use this step, make sure that your freezer temperature is below 0 degrees F. Since many people are carriers, following food safety rules is critical to reducing the risk of toxoplasmosis and all foodborne illnesses: always wash your hands after using the bathroom and before and during food preparation, avoid cross-contamination, and do not wash meat before cooking.
The foods with the greatest risk of carrying Toxoplasmosis gondii include raw ground beef, lamb cooked to rare, unpasteurized goat’s milk, wild game, and raw clams, mussels, and oysters.