|The facts you need by Bruce Gummow & Ingrid Weber
Jenna Davies had tried for years to fall pregnant. .. to no avail. The third attempt of artificial insemination finally proved fruitful, and Jenna’s twins were on the way! You can imagine … Jenna wanted to do everything in her power to ensure that her twins came into the world, happy, healthy and with no glitches whatsoever. But some well-meaning friend had her really worried with stories about the risk of keeping cats at this stage of the game. Here, we take a look at the real facts surrounding cats and their potential risk for pregnant women. Cats rarely transmit diseases to humans. Of those infectious diseases that may be transmitted between cats and humans (referred to as zoonotic diseases) most can be avoided if the owner cares properly for the pet and employs recommended preventative measures including regular deworming and control of external parasites such as fleas.
Toxoplasmosis … Throwing The Cat Amongst The Pigeons?
Most of the debate around the safety of cats in pregnancy has centred on the risk of acquiring toxoplasmosis. Toxoplasma gondii is a protozoan parasite that occurs worldwide. There is no order of mammals in which it has not been found. Birds can also become infected and even reptiles and amphibians have been found to be infected. Cats however, are considered as COMPLETE hosts as they serve as both main (definitive) and intermediate hosts for parasites and are therefore usually regarded as the most important host.
How Do Cats Get Infected?
Cats themselves often get infected from eating infected rodents or birds who, in turn, can get infected by coming into contact with infected cat faeces in the soil, thus creating a cycle of infection. A susceptible cat may shed as many as 20 million oocysts (toxoplasma eggs) daily. Shedding occurs for 10 to 15 days and decreases as the cat develops resistance to the disease. This means that your young cats without immunity are your biggest shedders. The group of cats that therefore pose the greatest risk to you are those around 6 – 12 months old, when effective hunting begins. Recurrence of shedding rarely occurs, unless the animal becomes immunocompromised, for example, with simultaneous FeLV (Feline Leukaemia Virus) infection or Isospora felis super infestation. Oocysts may, under the correct environmental conditions, remain infective for up to 18 months, which means your garden can remain contaminated for some time after your cat was infected.
Compromised Immune System?
The presence of toxoplasma differs from country to country and is related to customs, food habits, climate and cat populations. In otherwise-healthy humans, toxoplasmosis usually causes mild disease, if at all. In patients with very low immunity (e.g., AIDS or certain types of cancer), the disease may however be very severe. Previous studies have estimated that around twenty percent of the South African population has antibodies against toxoplasma which means that they have been exposed to the organism before and are not at risk for new infections (although in immuno-compromised individuals, old infections may become active again).
How Are People Infected?
People may get infected through different routes. In some parts of the world the commonest way in which people are infected is by ingestion of raw, undercooked or cured infected meats, especially mutton and pork. Once ingested the organisms spread into the tissues of the affected person (or cat or sheep or pig, etc) and form cysts. Thorough cooking will kill the toxoplasma cysts in infected meat, which is why we recommend below that pregnant women eat well-cooked meat. Another common source of infection occurs when people handle soil contaminated by cat faeces (changing cat litter or gardening in soil where cats defecate) and fail to wash their hands properly before eating or when they eat unwashed fresh fruit and vegetables contaminated by infected soil.
Tips To Avoid Toxoplasmosis
Too frequently preventive measures are aimed at decreasing direct cat contact while neglecting measures to control the likelihood of infection from contaminated meat or oocysts from the environment. Pregnant women are advised to prevent toxoplasmosis infection by taking the following precautions:
Regarding Domestic Cats
In some countries pregnant women are screened for toxoplasmosis during pregnancy by performing blood tests to detect antibodies to infection but the rational practice of such testing depends on the frequency of disease in a population. Your GP or obstetrician can advise you in this regard. Testing for active toxoplasma infection during pregnancy is more complicated because antibody levels may be difficult to interpret and this is best left to a medical professional with expertise in this field. If a woman is infected with the parasite during pregnancy it may cause infections in newborns, and the severity of the disease depends on how far the pregnancy had progressed before the infection occurred. Only ten percent of newborns infected with toxoplasmosis suffer severe disease which primarily affects the central nervous system and symptoms may include mental retardation, skin rash and liver inflammation and possibly death. In some cases the disease only presents itself later in life during infancy, childhood or adolescence and the symptoms then depend on where the cysts are found in the body and can manifest as mental retardation, convulsions, spasticity, palsy, impaired eyesight and deafness. Treatment is available for toxoplasmosis infection in pregnancy but it is not always effective.