Toxoplasmosis

I thought the first zoonotic disease I’d cover would be Toxoplasmosis.  It's an infection that most people commonly associate with cats and pregnant women.  But as you will soon learn there are other ways you can become infected. 

What is Toxoplasmosis?

It's a disease caused by a parasite called Toxoplasma gondii.  It is estimated in the United States approximately 22.5% of the population 12 years and older are infected with the parasite and worldwide it has been estimated that in certain places up to 95% of some populations carry the parasite (CDC).  The majority of healthy people and cats infected with the parasite don’t have any symptoms.

How does one become infected?

There are three major modes of transmission 

• Congenital - a woman newly infected during pregnancy can pass the infection to her unborn child  
• Ingestion of undercooked contaminated meat, especially pork, lamb and venison 
• Worldwide this is the cause of the majority of infections
• Ingestion of oocyst passed in cat’s feces
• Cats become infected by eating infected rodents, birds or raw meat and then pass the parasite in their feces in the form of an oocyst.
• For as long as 3 weeks after becoming infected cats shed millions of oocysts in their feces.  Older cats are less likely to shed.
• Most infected cats will not show any signs of illness. 
• People become infected by:
• Ingestion of oocysts when cleaning a cat’s litter box when the cat is shedding
• Ingestion of oocysts in contaminated soil.  Remember not all cats use litter boxes!
• Eating unwashed fruits and vegetables
• Not washing their hands after gardening
• Drinking contaminated water
• Uncommon causes of transmission 
• Blood transfusion 
• Tissue or organ transplants

What does the disease look like?

•  Healthy people as stated before who become infected generally have no symptoms.  If symptoms do occur they are  typically mild “flu-like” symptoms that last for a few weeks and then resolve.  The parasite will remain in the body in a latent form and can cause illness again if the person becomes immunosuppressed.

• Immunosuppressed individuals can have more severe symptoms including fever, headache, nausea, and seizures.

• Pregnant women

o   If a woman has already been infected prior to becoming pregnant the woman has developed immunity and the baby will be protected.

o   If a woman is pregnant and becomes newly infected she can then pass the infection on to the unborn child.  Congenital abnormalities for the child include abnormal enlargement or smallness of the head, potential vision loss, mental disability and seizures.

Prevention

• Cook your food! 
• Whole cut meat cook to at least 145
• Ground meat at least 160 F
• Poultry at least 165 F
• Freeze meat at 0 F for several days prior to cooking.
• Wash fruits and vegetables before eating.
• Do not drink unpasteurized milk.
• Drink clean water.
• Wear gloves when gardening or when in contact with soil or sand and wash your hands after.

I’m pregnant do I need to give away my cat?

NO.  But you will want to take some extra precautions:

• Have someone else change the litter box.  If no one else is available wear gloves and wash your hands well afterwards.  Remember transmission is fecal-oral, so washing your hands is key. 
• Clean the litter box daily.   This is very important because the parasite does not become infectious until 1 to 5 days after it is passed in a cat’s feces.  So try to have someone clean the litter box right after your cat has defecated. 
• Don’t feed your cat raw or undercooked meat.
• Keep your cat inside. 
• Do not get a new cat while you are pregnant and avoid contact with stray cats. 
• You should also follow the above mentioned recommendations.

If you have any further questions or concerns please contact your veterinarian or physician.