Toxoplasmosis

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Toxoplasmosis

I adore my cats and like many others I spoil them and get a lot of positive feelings from my relationship with them, however there are many other things that I can get from them as well.

Zoonosis is the term given when disease is communicable from animals to humans under natural conditions. One of the most common zoonoses that we can contract from cats or specifically cat feces is Toxoplasmosis. Toxoplasmosis is an infection caused by a microscopic parasite called Toxoplasma gondii. It is estimated that 60 million people in the United States carry this parasite, which can cause severe illness, particularly in infants infected in utero birth or in persons with a weakened immune system.

When I was pregnant, our veterinarian suggested that my husband clean the cats’ litter box and recommended that the box be changed daily. Today we know that these simple directions are certainly important, but that toxoplasmosis can be problematic in more that just pregnant women and it is not limited to the litter box. In fact, toxoplasmosis gondii can be acquired from many sources such as soil, unwashed fruits and vegetables, raw meat and untreated water. Cat owners or cat handlers are not at significantly higher risk of being infected than the rest of the population.

The cycle of toxoplasmosis is well understood. Cats are the only primary host, and they are the only mammals in which the parasite is passed through the feces. Cats become infected by eating rodents, birds, other small animals, or from anything that becomes contaminated with infected cat feces. Kittens can also acquire it in utero or from their mothers’ milk. This infection persists only for a few weeks before the cat itself becomes immune to the disease. Toxoplasmosis lives in the intestines and the immature form of the parasite is shed through the feces for about 2 weeks after the cat has been infected. The parasite becomes infective 1 to 2 days after it is passed in the feces. The parasite can live in the environment for many months and contaminate soil, water, fruits and vegetables, sandboxes, grass where sheep or goats graze, litter boxes and any place where an infected cat may have defecated. Cockroaches and flies may also serve as transport hosts for T. gondii, carrying cat’s fecal material on their bodies. When one understands the cycle of T. gondii, it is easy to see why its’ transmission is so common.

Health care professionals will need to be vigilant in their education of prenatal women as these are an important target group. A woman, who becomes infected with the parasite for the first time during or just before pregnancy, can pass the infection to her unborn child even if the mother does not have any symptoms. Infants who are infected in utero ( congenital toxoplasmosis ) may range from having no symptoms at birth, but within a few months may develop fever, swollen glands, jaundice, rash, bruising, anemia or enlarged liver or spleen. These may lead to more serious conditions such as blindness or mental retardation, deafness, lung disease, seizures, feeding difficulties, and limp muscle tone. Infection during pregnancy can also cause miscarriage. Education should focus on “The best way to protect your unborn child is by protecting yourself”.

The second group of individuals that are at significant risk are individuals with weakened immune systems, such as those undergoing chemotherapy, organ transplant recipients or those infected with human immunodeficiency virus (HIV), the virus that causes AIDS. During the 1990’s there was a decline in the number of toxoplasmosis cases to about 350 reported annually in the United States, however with an increase in the number of HIV infected individuals, the number of cases is now steadily increasing. These individuals, especially children, may develop toxoplasmic encephalitis exhibiting severe symptoms including headache, confusion, difficulty with speech, vision, movement, possible psychosis and fever as well as seizures, poor coordination, nausea and vomiting. Infection in these individuals can be fatal.

Information about these two groups is well documented and typically a physician closely follows them and monitoring of health status is therefore ongoing.

In terms of public health significance toxoplasmosis education should not be limited to pregnant women or immune suppressed individuals because individuals with healthy immune systems are also at risk. It is estimated that about one half of the world’s human population has been exposed to toxoplasma at some time in their lives. Many of these people received their infection from consuming undercooked meat or from products that were contaminated with cat feces (sheep or goats grazing on contaminated grasses). It is sometimes passed through infected dairy products. These individuals may become infected and not be aware of it because they may not have any or only mild symptoms. However they may present with flu-like symptoms, listlessness, fever, swollen glands and muscles aches / pain, lasting up to several weeks, however some individuals have no symptoms. Once a person has become infected with toxoplasmosis, the infection remains in the body for life, usually in a latent form that won’t cause the person any side effects or harm, but the infection can be reactivated if the immune system becomes compromised. I think this fact alone is relevant as health care professionals begin dealing with an increased aging population.

Flu-like symptoms such as swollen glands, fever, and muscle aches are often the presenting complaints of many individuals in clinics. The fact that these symptoms may be recurring or that the individual does not respond / improve with an initial treatment regime makes this group particularly interesting and also requiring more investigation. It is paramount that individuals with persistent undiagnosed symptoms for periods of several months receive further assessments so the health care professionals has a clear understanding of their clients’ lifestyle, occupation and culture. If we look at the Safety Tips that are part of the education program, we may be able to use these as part of our assessment tool to develop a clearer understanding of the clients’ personal habits. Should the results of the assessment warrant further investigation in this realm, a blood titer may be necessary to establish a diagnosis, since diagnosis cannot be based on clinical signs alone. A definite diagnosis is based on clinical signs in the presence of a high or rising antibody titer level, which can be done through a blood test.

Safety Tips:
1. Cook meat completely until no pink is seen and juices are clear.
2. Freezing meat for several days prior to cooking will greatly reduce the chances of infection.
3. Wash all cutting boards and utensils thoroughly with hot soapy water after each use.
4. Wash hands with soap and water after any exposure to soil, sand, raw meat or unwashed fruits or vegetables.
5. Wash and / or peel all fruits and vegetables before eating them.
6. Wear gloves when gardening or handling sand from a sandbox. Wash hands well afterwards.
7. Avoid drinking untreated water, particularly when traveling in less developed countries.

Assessments:

1. Do you have cats or have you been in a home or yard where cats roam?
2. Have you eaten any raw or rare meat?
3. Have you eaten or drank unpasteurized
milk-products?
4. Are lamb, sheep or goats part of your diet?
5. Have you handled raw meat? Did you thoroughly wash all utensils afterwards?
6. Do you do work with soil or sand? Do you wear gloves? Do wash with soap and water after exposure to the above?
7. Do you wash all fruits and vegetables prior to eating?
8. Have you traveled out of the country recently?
9. Have to drunken water that may not have been treated?
10.
Do you thoroughly wash with hot water and soap on a regular basis during the day and after completing various tasks?

A few simple questions, but directly related to the possible exposure of individuals may prove usefully in guiding the health care professional toward a diagnosis and improved health care of the client.

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