Readership is the name of the game for the media, and headlines are the way to ensure you’re in the game at all. So it’s not surprising that the Los Angeles Times recently ran a story titled, “Study Links Parasite In Cats To Suicide Risk In Humans” and NPR’s health blog brought cats into the equation with its headline: “A Parasite Carried by Cats Could Increase Suicide Risk.” The headlines could have as easily picked on undercooked meat or gardening (both common sources of infection from the parasites), but our beloved pets are more likely to guarantee readership. That’s the nature of journalism in a competitive world.
So let’s do a reality check about the parasite in question, Toxoplasm gondii (T. gondii) — a parasite that is present in about a third of the world’s human population and can cause the disease toxoplasmosis.
Does T. gondii infection cause an increased risk of suicide?
Recently, a large Danish study published in Archives of General Psychiatry
found that mothers infected with T. gondii are 53% more likely to
attempt or commit suicide. The study also points out, ” …we cannot say
with certainty whether the observed association between T. gondii
infection and self-directed violence is causal.”
Just as the infection of T. gondii may not cause the increased risk of
suicide, the study also does not specifically implicate cats as the
causes of the infection in the study’s subjects. In fact, the study did
not ascertain how many of the people with T. gondii even had cats. It
also notes that infection from cat feces is only one of many ways
someone can be exposed to T. Gondii.
What if my cat is infected with T. gondii?
It is true
that cats can be hosts for T.gondii, so if you are concerned you can ask
your vet to test for T. gondii antibodies. However, the time period
when a cat sheds the parasite and is infectious is relatively small —
usually a few weeks according to the ASPCA’s brief on Toxoplasmosis.
When a feline is newly infected, his feces will shed the parasite (or oocysts). According to the American Veterinary Medical Association pamphlet on toxoplasmosis,
“after the initial shedding period, most cats will not continue to pass
oocysts in their feces.” Meaning the risk of T. gondii spreading to
humans after the initial shedding period is very low.
How can I avoid getting T. gondii?
People with cats shouldn’t be unduly concerned about T. gondii, but the
best defense is good hygiene. Here are some things you can do to avoid
- Clean the feces from your cat’s litter box daily or more. The parasites (or oocysts) in the feces do not become infectious until one to five days after they are excreted.
- Wash your hands thoroughly after freshening the litter box, handling uncooked meats or unwashed vegetables and gardening.
- Keep your cat indoors, a best practice for many
reasons. A cat most likely picks up the parasite outside from another
infected animal — like eating an infected bird or rodent — or from the
- Wear gardening gloves when gardening — and remember, to wash your hands thoroughly.
- Keep the kids’ sandbox covered. To feral cats, the sandbox is as welcome as a Porta-Potty at a picnic and the cats may carry T. gondii.
- Feed your cat (and yourself) well-cooked food only.
According to the AVMA, cats and people can become infected by eating
undercooked meat from an animal infected with T. gondii, by handling
fruits and vegetables that have been cut by unclean knives or by
handling unwashed fruits and vegetables that were in contaminated soil.
- Don’t drink untreated drinking water.
What happens if I get infected?
According to the Center for Disease Control,
toxoplasmosis is treatable, but in most cases, if you and your cat are
healthy, you may not even be aware either of you have T. gondii. We’re
generally asymptomatic, thanks to our immune systems. If symptoms do
occur in humans or cats, they usually go away without treatment. If
treatment becomes necessary, antibiotics are prescribed.
A T. gondii infection can be concerning to two special populations of humans: those with compromised immune systems and pregnant women. If you fall into either of those categories, click on the links in this paragraph to learn more.
(But note that the CDC doesn’t recommend that either of these populations give up their cats.)
According to NPR,
the author of the study said, “people should not give their cats away”
because of this study. Now that’s good advice, but unfortunately it
doesn’t make the headlines. You’ll note, of course, that I buried that
important statement at the end of the article, too.
Read more details about T. gondii on the Center for Disease Control website.