@Pregnant Mom: Extremely unfriendly! Beware of Toxoplasma gondii in "cats"

Toxoplasma gondii is an intracellular parasite. Like brucellosis, once it enters the cell, it is very difficult to treat and it is related to the health of the fetus. Therefore, young girls who are preparing to become pregnant are not recommended to feed pet cats before and after pregnancy. Let us learn about this intracellular parasite that can easily cause miscarriage and stillbirth!

1. What is Toxoplasma gondii?

Toxoplasma gondii is a single-celled parasite that can infect a wide range of animals, including birds, mammals, and humans. It has a complex life cycle in nature and can spread between different hosts [1].

1. Cats are the final host of Toxoplasma gondii

Toxoplasma can complete the sexual reproduction stage in cats. When a cat ingests an intermediate host (such as mice, birds, etc.) containing Toxoplasma cysts, Toxoplasma will reproduce in the cat's small intestine. During this process, cats will excrete a large number of oocysts, which will be excreted from the body with the cat's feces. A cat infected with Toxoplasma can excrete millions of oocysts every day, and these oocysts have a strong ability to survive in the external environment. They can survive for months under suitable temperature and humidity conditions. For example, in moist soil or dark corners, oocysts can remain active for a long time. If pregnant women accidentally come into contact with these contaminated environments, such as when cleaning the cat litter box, or when they come into contact with soil contaminated by cat feces outdoors, they are easily infected with Toxoplasma.

Image source: Pixabay

2. Infection routes are difficult to completely avoid

For pregnant women, even if they pay attention to personal hygiene, it is difficult to completely avoid contact with Toxoplasma gondii on cats. For example, when a cat is active, its hair may be contaminated with oocysts in feces, and pregnant women may be exposed to them when petting the cat. Moreover, cats like to move around, and they may move around in places that pregnant women often touch, such as sofas and beds, which increases the risk of pregnant women being exposed to Toxoplasma gondii. In addition, the cat litter box is a concentration of Toxoplasma gondii oocysts. If family members do not clean the cat litter box in time, or do not take correct protective measures during the cleaning process, such as not wearing gloves and washing hands carefully, the oocysts may spread. Pregnant women may inadvertently come into contact with these contaminated items and become infected with Toxoplasma gondii.

3. Serious consequences of infection are detrimental to the fetus

For pregnant women themselves, the first infection with Toxoplasma gondii may cause some non-specific symptoms, such as mild fever, fatigue, muscle aches, etc. But these symptoms are easily ignored because various minor conditions will occur in the body during pregnancy. Once a pregnant woman is infected with Toxoplasma gondii, it can be transmitted to the fetus through the placenta. If the fetus is infected in the early stages of pregnancy, serious consequences such as miscarriage and stillbirth are likely to occur. If infected in the second and third trimesters, although the fetus can survive, congenital toxoplasmosis may occur.

If a pregnant woman is infected with Toxoplasma gondii during pregnancy, especially in the early stages of pregnancy, the risk of fetal infection is high. Once the fetus is infected, serious congenital diseases may occur. For example, the fetus may have calcifications in the brain and abnormal brain development, such as hydrocephalus and microcephaly, and may cause fetal eye lesions, such as retinochoroiditis. This eye disease may cause vision loss and blindness, and may also cause damage to the fetus' heart, liver and other organs, leading to problems such as delayed physical development after birth [2].

Therefore, in order to minimize the risk, pregnant mothers are advised to stay away from cats and dogs that may carry Toxoplasma.

[1] Zhou Ning, Gong Guozhong. Prevention and treatment of Toxoplasma gondii infection during pregnancy[J]. Family Medicine. 2019, (07): 16-17

[2] Wang Yuli, Wang Xietong. Mother-to-child transmission of Toxoplasma gondii[J]. Chinese Journal of Obstetric Emergency. 2020, 9(04): 213-216

Source: Chongqing Science Writers Association

Author: Jiang Xuefei, deputy chief physician, Peng Dan, laboratory technician, Yan Jing, physician, and Zou Jingbo, chief technician, Chongqing Yongchuan District Center for Disease Control and Prevention

Audit expert: Li Hanbin

Statement: Except for original content and special notes, some pictures are from the Internet. They are not for commercial purposes and are only used as popular science materials. The copyright belongs to the original authors. If there is any infringement, please contact us to delete them.