How does infection occur?
The final host of the parasite is cats: it is in their intestines that it multiplies, and the cysts are excreted in feces and become infectious only after one to five days in the external environment. However, most people do not become infected directly from cats, but through food: by eating raw or insufficiently cooked meat, dried and smoked meat products, unwashed vegetables and herbs, contaminated soil. Transmission through garden soil and sand is possible. The infection is not transmitted from person to person, except from mother to child through the placenta.
- Raw and undercooked meat
- Dried and smoked meat products
- Unwashed vegetables, fruits and herbs
- Contact with soil when working in the garden
- Cleaning cat litter without gloves
- Unboiled water from an unreliable source
- Transmission from mother to fetus through the placenta
Risk for the child
The risk depends on the duration of pregnancy, and the dependence is double. The earlier the infection occurs, the less often the parasite penetrates the placenta, but the more severe the consequences for the child. In the third trimester, transmission occurs much more often, but the manifestations are usually milder, and often the child is born without visible signs, and they appear later, primarily in the eyes. Classic signs of congenital infection include retinal damage, brain calcifications and ventricular enlargement, enlarged liver and spleen, jaundice, and seizures.
- Early infection means less transmission, more severe consequences
- Late infection—more likely to transmit, easier to manifest
- Retinal damage
- Calcifications in the brain
- Dilatation of the ventricles of the brain
- Enlarged liver and spleen, jaundice
- Delayed manifestations in childhood
What do the tests mean?
Two classes of antibodies are assessed. IgG indicates that there has already been an encounter with the parasite: if they are present, but IgM is absent, the infection was suffered a long time ago, re-infection is practically excluded and no additional measures are required. IgM can appear during a recent infection, but they can persist for months or even years, and also give false positive results, so this indicator alone does not solve anything. IgG avidity plays a key role: high means that the infection occurred more than three to four months ago, low indicates recent infection.
- IgG positive, IgM negative – long-standing infection, no risk
- IgG and IgM are negative - there is no immunity, prevention is needed
- IgM positive - clarification required
- High IgG avidity—infection long before pregnancy
- Low IgG avidity—recent infection
- Repeated analysis after 2–3 weeks to assess dynamics
- PCR of amniotic fluid in cases of suspected transmission to the fetus
What to do if there is a confirmed infection
If acute infection during pregnancy is confirmed, the woman is referred to an infectious disease specialist and the pregnancy continues to be monitored. Antiparasitic drugs are prescribed, the choice of which depends on the period: in the early stages, one regimen is used, which reduces the likelihood of transmission to the child, later, and in case of confirmed infection of the fetus, another, more active one is used. At the same time, a detailed ultrasound examination of the fetus is carried out, and if necessary, the study of amniotic fluid is discussed. All medications are prescribed by a doctor; self-medication is unacceptable. After birth, the child must be examined, including an examination by an ophthalmologist.
- Consultation with an infectious disease specialist
- Antiparasitic therapy according to the doctor’s regimen
- Detailed ultrasound of the fetus in dynamics
- Study of amniotic fluid when indicated
- MRI or ultrasound of the fetal brain for changes
- Examination of the newborn, including the eyes
- Long-term observation of the child by specialists
Prevention
For women without antibodies, prevention is simple and very effective. Meat should be fried or boiled until fully cooked, avoid raw and dried meat products, thoroughly wash vegetables, fruits and herbs, wash hands and cutting boards after raw meat. You should wear gloves when working in the garden and with the soil. There is no need to give the cat away: it is important not to clean the litter box yourself or to do it with gloves every day, since cysts become infectious only after a day or more, and to feed the animal with ready-made food without letting it out to hunt.
- Meat is only fully thermally processed
- Refusal of dried, smoked and raw meat products
- Thorough washing of vegetables, fruits and herbs
- Washing hands, knives and cutting boards after raw meat
- Gloves when working with soil and sand
- Daily cleaning of the cat's litter box for someone who is not very pregnant
- Feeding a cat with prepared food
- Drink only safe water
