Introduction
Toxoplasmosis disease gets a lot of press because of the terrible harm it can do to human fetus' of pregnant women who contact the disease during their pregnancy.
Women can get this disease by coming into contact with cats or microscopic amounts of cat feces ... so pregnant women are understandably anxious about cats.
But a more common source of infection comes from eating under cooked meat and unwashed vegetables.
At any rate, this page is divided into two parts:
Part One: About the disease in cats and dogs
Part Two: About the disease in humans ... especially pregnant women.
The Disease in Cats and Dogs
Most cats and dogs show no clinical signs when infected with Toxoplasma. Or when first exposed to the disease, they may feel lousy and feverish for a day or two, but successfully fight off the disease as well as gain immunity to future disease.
But sometimes ... especially in kittens and young cats, toxoplasmosis can cause lethargy, depression, loss of appetite, and fever.
And respiratory distress that gradually gets worse is common.
Liver disease, vomiting, diarrhea, pancreatitis, and lymph node disease are also seen with this disease.
But it's the neural diseases that are a flag: the disease can cause retinal and eye inflammation, blindness, personality changes, head pressing, ear twitching, seizures, parlysis, and trouble chewing and swallowing.
Since toxoplasmosis more often affects cats (and people) with suppressed immune systems, cats with leukemia or feline AIDS are more at risk.
Diagnosis
We don't have a simple, accurate test for toxoplasmosis that veterinarians can do in their clinic.
Once we become suspicious of this disease, we have to send blood to a commercial lab for titers.
If the titer is low or negative in a sick cat, that reliably means that toxoplasmosis is not the problem.
If the titer is high in a sick cat, that might mean the cat has a toxoplasmosis problem ... or not ...
We sometimes do titers for toxoplasmosis on healthy cats who live in a household with a pregnant woman.
The presence of significant antibody levels in a healthy cat suggests that the cat has been previously infected and now is immune and not excreting oocysts and therefore NOT a danger to the woman.
The absence of antibody in a healthy cat suggests that the cat is susceptible to infection and thus would shed oocysts for one to two weeks following exposure and could be a danger to pregnant women.
Treatment and Prevention
There isn't a vaccine for this disease.
Out door cats are more at risk and cats fed raw meat diets are at high risk.
Treatment is often unsuccessful and consists of antibiotics (I use clindamycin), the treatment of symptoms and supportive care.
The Disease in Humans
This disease gets a lot of attention in magazines for women since it can cause birth defects in the fetus if women are exposed to the disease during the second trimester of their pregnancy.
Note that this is a problem only if the woman isn't already immune to the disease from previous exposure (apparently, about a third of Americans already have immunity. This can be tested for by your physician if you're concerned.)
One of the ways people can get exposed to this disease is by accidentally ingesting microscopic amounts of cat feces. That is why women gleefully inform their husbands that they should be the ones cleaning out the litter box. But don't get rid of your cat; it's more likely that you will get the disease from another source...the infective organism is in our meats and vegetables. Feral and other infected cats spread the germ in our gardens and pastures which is then eaten by humans or food animals.
Prevention consists of avoiding rare meat (especially in the third world) and washing your hands and vegetables well.
Also, prevent cross contamination from raw meat to your vegetables from using the same cutting board etc.
Most infected people have no signs or symptoms. Those who do might have flu-like symptoms, swollen lymph glands, or muscle aches and pains that last for a few days to several weeks.
People with weakened immune systems can develop severe toxoplasmosis, which results in damage to the eye or the brain.
Infants who are infected before birth can have serious mental or physical handicaps.
Feral and other infected cats spread the germ in our gardens and pastures which is then eaten by humans or food animals. Prevention consists of avoiding rare meat (especially in the third world) and washing your hands and vegetables well. Also, prevent cross contamination from raw meat to your vegetables from using the same cutting board etc.
The disease is usually not apparent in the cat (they're just a host-carrier), but if you need to, we can test your cat.
On This Page:
Toxoplasomosis: about the disease in cats and dogs
Toxoplasmosis: about the disease in humans
A scattering of comments
Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii.
The parasite infects most warm-blooded animals, including humans, but the primary host is the cat family.
Animals are infected by eating infected meat, by contact with cat feces, or by transmission from mother to fetus.
Recommendations for Pregnant Women:
Exclude rare or undercooked meat and unpasteurized dairy products.
Test household cats for antibodies to Toxoplasma. Assuming that a cat is healthy, a positive antibody test indicates that your cat is immune and not excreting oocysts and thus would be an unlikely source of infection.
A healthy antibody-negative cat is most probably susceptible to infection and would shed oocysts for one to two weeks after exposure to Toxoplasma.
Have herself tested for antibodies, preferably before becoming pregnant. A positive test would indicate past infection that will not be transmitted to the fetus.
The presence of antibodies also lessens the likelihood that congenital transmission would occur should she be exposed again to the parasite during pregnancy.
An antibody-negative woman would thus be at greater risk of transmitting Toxoplasma to the fetus should she become infected during pregnancy.
Protect cats from infection (or reinfection) by preventing access to birds, rodents, uncooked meat, and unpasteurized dairy products.
Avoid handling litter boxes. Even if a cat is antibody-positive and hence most likely immune, there exists a potential for reshedding of oocysts (although in much smaller numbers than during the initial infection). For safety, litter boxes should be changed daily or every other day by another person to eliminate any potential for accidental infection.
Avoid handling free-roaming cats, because the fur or paws could be contaminated with oocysts, which might be transmitted by hand-to-mouth contact.
Any cat allowed indoors should be kept off the bed, pillows, blankets, or other furnishings the woman uses.
Avoid handling any cat showing signs of illness.
Wear rubber gloves if working with garden soil. Uncooked vegetables, whether grown in a home garden or supplied commercially, should be washed thoroughly before ingestion, in case they have been contaminated by cat feces.
Make a habit of vigorously and thoroughly washing hands with soap and water after contact with soil, cats, unpasteurized dairy products, or uncooked meat or vegetables.
Update on Toxoplasmosis
Caution: I'm not sure about how accurate this information will turn out to be: Science involves alot of probing into ideas and theories that seem productive or true, but after looking at the evidence carefully (research and then more research to confirm), it turns out to be only somewhat true, or occassionally true, or a total red herring. If you're an adult, you will be used to all kinds of scientific pronouncements ...especially if politics are involved... (environmental issues come to mind) claiming one thing or another only to find out that conclusions were based on very skimpy, politically twisted, or faulty data.
None the less, I found this interesting:
Source: Veterinary Economic Magazine Nov 03 issue
Paraphrase: Scientists from Britian, US, and the Czech Republic say that Toxoplasma gondii, transmitted by cats, may have behavioral side effects for humans.
The Stanley Research Medical Institute of Maryland indicates that people infected with Toxoplasma are more likely to develop schizophrenia and manic depression.
Czech researcher Jaroslav Flegr, professor of Charles University in Prague claims that men infected with Toxoplasmosis MAY become more aggressive, antisocial, and appear scruffy and less attractive. Women, on the other hand, may become less trustworthy, seem more fun loving, and become more promiscuous. (Whoa...that's some scientific conclusion)
Also interesting: about 40% of adults in Britian and the US have titers for Toxoplasmosis indicating that they have been previously infected with the organism. The numbers are about double for adults in Germany and France.
I'm thinking of getting a government grant to go study this in France and Germany.
