Being a veterinarian, almost 30 years old, and female, I find myself at a point in my life when it seems all of my friends are pregnant. I work with two pregnant veterinarians, my sister-in-law is pregnant, and so are many of my friends. From February to March, I am scheduled to attend an of average one baby shower every other week.
It’s a joyous time for my expecting friends and family, but with their excitement comes trepidation as they learn all about what’s headed their way during the next nine months.
As a veterinarian, I’ve found that once many women realize they are expecting, they seem to become fearful of contracting a disease from their pets and spreading it to their unborn child, as there is a lot of questionable advice out there on this topic. The most common concern I hear about from my expecting cat-lover friends is a protozoan parasite known as Toxoplasma gondii. According to the CDC, it has been estimated that 22.5 percent of the U.S. population 12 years and older have been infected with Toxoplasma, so it’s very common.
People typically become infected with Toxoplasma by one of three routes: via food, animal-to-human contact or mother-to-child transmission. In the first case, Toxoplasma has a tissue form called a bradyzoite that can be transmitted to people who eat undercooked meat (especially pork, lamb and venison). Accidental ingestion of undercooked, contaminated meat can also occur when a person handles the meat but fails to wash his/her hands properly afterward — or uses utensils that have been in contact with contaminated meat.
Second, people can become infected by cats. As we all know, many cats enjoy hunting prey such as rodents, birds and other small animals when they’re outside. Unfortunately, prey can be infected with Toxoplasma, which can then be transmitted to the cat. Once they’ve acquired Toxoplasma, cats then shed the parasite in the oocyst form for just a short period of time, 1-3 weeks after infection. However, it has been shown that even during that short time, a large number of oocysts are shed. Once in the environment for 1-5 days, the oocysts sporulate and at this point are infectious to humans and other mammals.
Not all cats that become infected with Toxoplasma will develop clinical symptoms — some owners, in fact, never notice a change in their cats. When cats are clinically affected and symptomatic, owners may notice one or more of the following signs: fever, loss of appetite, lethargy, and/or neurologic signs (e.g., blindness, incoordination, personality change or circling). These symptoms typically prompt a cat owner to bring their pet to the veterinarian, who will then make a diagnosis based on history, clinical signs, and laboratory tests — including the measurement of antibodies to Toxopasma. If such an infection is found, the parasite is usually treated with an antibiotic known as clindamycin.
The final route of infection — and the one that has my friends avoiding the litter box like the plague — is mother-to-child transmission via the mother’s food ingestion (as discussed above) or by accidental ingestion of a sporulated oocyst after the mother comes in contact with infected cat feces. Unfortunately, toxoplasmosis can have serious effects on an unborn child — and possibly also later on in the course of that child’s development. Up to half of the fetuses who become infected with toxoplasmosis during pregnancy are born prematurely, and congenital toxoplasmosis can damage a baby’s eyes, nervous system, skin and ears. There may or may not be evidence of infection in the baby at birth, and newborns with milder infections may not have symptoms or problems for months or even years. If they are not treated, however, almost all such infected children will develop problems (especially in the eyes) as teenagers.
However, while toxoplasmosis does present serious risks, if you become pregnant you don’t need to send your cat packing! You can minimize the risk by taking a few precautions. Make sure you cook all of your meat thoroughly and wash your hands and utensils/cutting boards after using them. Wear gloves when gardening. Cover outdoor sandboxes (which outdoor cats use as litter boxes). Scoop the litter box daily while wearing gloves, and wash your hands thoroughly afterward. Or, better yet, take this opportunity to let your husband or loved one clean the litter box for you during this nine-month stretch!
Dr. Jessica Hudak
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