The Troubling Tale of Toxoplasmosis: Don’t Kiss Your Cat
Michael Garko, Ph.D.
Nationally Syndicated Host & Producer of Let’s Talk Nutrition
What do eating raw or undercooked meat, kissing or owning a cat, working in the garden and receiving an organ transplant or blood transfusion have in common?
The answer is toxoplasmosis, which is a parasitic disease caused by single-celled parasite called Toxoplasma gondii. The September, 2016, issue of Health and Wellness Monthly focuses on the parasitic-caused disease, Toxoplasmosis. If do not know what it is, you might want to read the article and learn about it. It just might be worth the time.
The way in which people who eat raw or undercooked meat containing become infected is by Toxoplasma gondii living in tissue cysts found typically in pork, lamb, goat, or wild game meat, along with beef and field-raised chickens. Recipients receiving an organ transplant or blood transfusion become infected when they receive an organ from an infected donor. Inadvertently ingesting soil (not washing hands after gardening or eating unwashed fruits or vegetables from a garden) contaminated by cat feces, drinking water contaminated by cat feces or cleaning a cat’s litter box make individuals susceptible to becoming infected with Toxoplasma gondii. Finally, when a pregnant woman is infected during or immediately prior to becoming pregnant, she can transmit the infection to the fetus (see Centers for Disease Control and Prevention, n.d., Crowley, 2013)
Startling Statistics and Frightening Facts
Given how frequently people engage in the various means of transmission mentioned above it is not surprising that more than 60 million people in the United States may be infected with the Toxoplasma parasite and that Toxoplasmosis is a leading cause of foodborne illness-related death and hospitalization in the United States.
Toxoplasmosis is responsible for approximately 327 deaths and 4,428 hospitalizations annually. The Toxoplasma gondii parasite infects over 1 million persons annually in our country, with an estimated 4,800 individuals annually developing symptomatic eye disease from the parasite, leading to vision loss.
Further, in the United States there are approximately 400–4,000 reported cases of congenital (mother-to-child) toxoplasmosis, leading potentially to miscarriage or severe disease in the newborn (e.g., developmental delays, blindness and epilepsy). Interestingly, few healthy people who are infected with Toxoplasmosis experience symptoms because a healthy immune system can keep the parasite from causing illness. For those individuals who are immunocompromised can develop encephalitis or experience further spread of disease, which can be fatal. Severe cases of toxoplasmosis can develop from an acute Toxoplasma infection or from an infection which occurred earlier in a person’s life and is now reactivated, capable of damaging the brain, eyes, or other organs. Finally, once infected with Toxoplasma gondii, people generally remain infected for life (see Centers for Disease Control and Prevention, 2013; Centers for Disease Control and Prevention, n.d.; Crowley, 2013).
Signs and Symptoms of Toxoplasmosis
The symptoms associated with toxoplasmosis are varied. As mentioned earlier, most who are infected with Toxoplasma gondii are not even aware that the parasite is in their body, while some people may feel as if they are suffering from the flu, experiencing swollen lymph glands or muscle aches and pains, which can persist for as long as a month or more.
Signs and symptoms of what is termed “ocular toxoplasmosis” include reduced vision, blurred vision, pain (often with bright light), eye redness and tearing. Ophthalmologists sometimes prescribe medicine to treat active disease. The majority of infants who become infected while in the womb experience no symptoms at birth. However, they can develop symptoms later in their life. A small percentage of newborns infected with Toxoplasma gondii suffer from serious eye or brain damage at birth (Centers for Disease Control and Prevention, n.d.; Crowley, 2013).
Treatment of Toxoplasmosis
A majority of healthy people can recover from Toxoplasmosis without treatment. Persons who suffer from Toxoplasmosis are often treated with a combination of drugs such as pyrimethamine and sulfadiazine, plus folinic acid. Those susceptible to becoming infected such as pregnant women, newborns and infants candidates for treatment. However, Toxoplasma gondii is not eliminated completely. It can take up residence within tissue cells in a less active phase and their location in the body can make it difficult for the medication to completely eliminate the parasite. Individuals suffering from ocular Toxoplasmosis are prescribed different medication to treat it by an ophthalmologist. The size of the eye lesion, its location and the characteristics of the lesion (i.e., acute active, versus chronic not progressing) determine whether medication is prescribed. Persons with compromised immune systems need to be treated until they have improvement in their condition. For AIDS patients, continuation of medication for the rest of their lives may be necessary, or for as long as they are immunosuppressed (see Centers for Disease Control and Prevention, 2013).
Preventing and reducing the risk of toxoplasmosis becoming infected with Toxoplasma gondii can be achieved by practicing a number of general sanitation and food safety procedures. The following verbatim recommendations are provided by the Centers for Disease Control and Prevention (CDC) (2013):
- Cook food to safe temperatures. A food thermometer should be used to measure the internal temperature of cooked meat. Do not sample meat until it is cooked. USDA recommends the following for meat preparation.
- For Whole Cuts of Meat (excluding poultry). Cook to at least 145° F (63° C) as measured with a food thermometer placed in the thickest part of the meat, then allow the meat to rest for three minutes before carving or consuming. ‘Rest time’ is the amount of time the product remains at the final temperature, after it has been removed from a grill, oven, or other heat source.
- For Ground Meat (excluding poultry). Cook to at least 160° F (71° C); ground meats do not require a rest time.
- For All Poultry (whole cuts and ground). Cook to at least 165° F (74° C), and for whole poultry allow the meat to rest* for three minutes before carving or consuming.
- Freeze meat for several days at sub-zero (0° F) temperatures before cooking to greatly reduce chance of infection.
- Peel or wash fruits and vegetables thoroughly before eating.
- Do not eat raw or undercooked oysters, mussels, or clams (these may be contaminated with Toxoplasma that has washed into sea water).
- Do not drink unpasteurized goat’s milk.
- Wash cutting boards, dishes, counters, utensils, and hands with hot soapy water after contact with raw meat, poultry, seafood, or unwashed fruits or vegetables.
- Wear gloves when gardening and during any contact with soil or sand because it might be contaminated with cat feces that contain Toxoplasma. Wash hands with soap and warm water after gardening or contact with soil or sand.
- Teach children the importance of washing hands to prevent infection (Centers for Disease Control and Prevention, 2013).
With respect to cat owners, the CDC (2013) offers the following safety precautions to avoid being exposed to Toxoplasma gondii:
- Make sure the cat litter box is changed daily. The Toxoplasma parasite does not become infectious somewhere between 1-5 days after it is shed into the cat’s feces.
- If pregnant or immunocompromised it is best to avoid changing cat litter. If forced to do so, it is advisable to wear disposable gloves. Wash your hands with soap and warm water directly after changing litter.
- If possible, keep cats indoors.
- Avoid adopting or handling stray cats, especially kittens. If pregnant, do not get a new cat.
- Avoid feeding cats raw or undercooked meats. Feed them only canned or dried commercial food or table food that is well-cooked.
- Keep outdoor litter boxes covered.
As one can see, the tale of Toxoplasmosis is terrible. Eating raw or undercooked meat, kissing or owning a cat, working in the garden contaminated with cat feces or receiving an organ transplant or blood transfusion from an infected donor are among the common ways in which people can become infected with the disease. The various recommendations by the CDC mentioned above to avoid being exposed to the parasite, Toxoplasma gondii, that causes Toxoplasmosis make good sense. Think twice before you kiss your cat or eat that raw meat.
Centers for Disease Control and Prevention (2013). Toxoplasmosis frequently asked questions (FAQs). Retrieved from http://www.cdc.gov/parasites/toxoplasmosis/gen_info/faqs.html .
Centers for Disease Control and Prevention. (n.d.) Neglected parasitic infections in the United States: Toxoplasmosis. Retrieved from http://www.cdc.gov/parasites/resources/pdf/npi_toxoplasmosis.pdf
Crowley, L.V. (2013). An introduction to human disease: Pathology and pathophysiology correlations. Burlington, MA: Jones & Bartlett Learning.
Suggested Citation: Garko, M.G. (2016, September). The troubling tale of toxoplasmosis: Don’t kiss you cat. Health and Wellness Monthly. Retrieved (insert month, day, year), from www.letstalknutrition.com.