Pregnancy peril from cats is exaggerated
Felines were long  thought to pose a high risk of transmitting toxoplasmosis, but that has been  disproven.
By Denise Flaim

February 21, 2005

The  woman called with a bittersweet announcement.

The good news: She was  pregnant. The bad news: She was returning the kitten
she had bought from Joan  Bernstein, who breeds Tonkinese cats in Center
Moriches, N.Y.

Along with  admonitions to avoid alcohol and hot tubs, pregnant women are
always warned  about contact with cats, because of the concern that feline feces
can transmit  toxoplasmosis.

According to the Centers for Disease Control and  Prevention, more than 60
million Americans carry the Toxoplasma gondii parasite.  Those with healthy
immune systems often do not notice, exhibiting mild flu-like  symptoms or none at

But an active toxoplasma infection during  pregnancy can cause blindness and
brain damage in the unborn infant, as well as  stillbirth or preterm labor.

Bernstein told her caller that there was no  need for her to part with the
cat if she followed a few simple precautions: Wear  a surgical mask and gloves
when cleaning the litter box, or, better yet, have  her husband do it.

Although the current conventional wisdom among  doctors is that pregnant
women who take adequate precautions against  toxoplasmosis need not give up their
cats, some women still get that unfortunate  message.

And some experts go so far as to say that cats have been  unfairly singled
out for spreading this highly infectious disease, when in fact  they carry
little blame.

"The chance of a pregnant woman catching  toxoplasmosis from her cat is
extremely rare," says veterinarian James Richards,  director of the Feline Health
Center at the College of Veterinary Medicine at  Cornell University in Ithaca,

As proof, he points to a study done  in six European cities and published in
the July 2000 issue of the British  Medical Journal. It found, he says, "no
association between toxoplasmosis and  having a cat, litter box cleaning or
having a cat that hunts."

Instead,  the study concluded that the main risk factors for acute
toxoplasmosis infection  were eating undercooked lamb, beef or game (30% to 63% of
infections), contact  with soil (6% to 17%), and travel outside Europe and North
America. "Contact  with cats," the study concluded, "was not a risk factor."

But many  doctors still focus on them. A report in the December issue of
Contemporary  OB/GYN magazine found that of the 1,459 doctors responding, 1,364
advised that  their cat-owning patients not clean the litter box. But only 1,101
mentioned  avoiding raw or undercooked meat, and only 888 recommended gloves
for gardening  even though those activities represented a greater risk of

Feline scapegoating started, Richards explains, when "it was discovered  that
cats shed infectious stages of toxoplasmosis in their stool. It's from that 
that all this fear arose."

Cats can become infected with toxoplasmosis  by eating or licking cat feces
that contain the parasite egg, or oocyst. 

But Richards says that scenario is "unlikely" and suggests that  predation
killing and eating infected mice, birds and other small animals is  the main
way cats get infected. So keeping a cat indoors dramatically cuts down  the
risk of transmission.

Even then, the window for passing the disease  on to humans is a relatively
small one.

"Once cats are infected, they  will for a short period shed these
toxo-organisms in their stool maybe for a  week or two," Richards explains. "And the
instant they are shed, they are not  infectious. They have to mature for a day
or more before they are." 

Which means that frequent cleaning and scooping of a litter box always 
with gloves if a woman is pregnant lowers the negligible risk even further. 

Casual contact with an infected cat is not considered particularly  risky, as
the parasite is not usually carried on the fur.