IS THE old wives’ tale saying expecting mothers should stay away from cats anything to go by? Well it is a medically – proven fact, though a
little exaggerated.Toxoplasmosis is a disease caused by a single-celled parasite, Toxoplasma gondii, transmitted to humans mainly by domestic cats
through droppings. Cats become infected by eating infected rodents, birds, or other small animals.Kittens and cats can shed millions of oocysts (fertilised eggs) in their faeces, up to 3 weeks after infection. Mature cats are less likely to shed Toxoplasma if they have been previously infected. A Toxoplasma-infected cat that is shedding the parasite in its faeces contaminates the litter box. If the cat is allowed outside, it can contaminate the soil or water in the environment as well. The parasite can also be ingested through meat, but this is taken care of as it cannot survive freezing temperatures during storage or high temperatures during cooking. In rare cases, organ transplants,including blood transfusion from infected donors, could be a mode of transmission. Most infected people do not present with clinical symptoms owing to the fact that the immune system is able to ward off the infection. Occasionally though, very few infected people may present with non-specific symptoms such as mild flu and tender lymph glands. After recovery from the first infection,most people have life-long immunity against the disease. The immunity is acquired through a process called active immunity.Why then talk about a disease which can easily be dealt with by the immune system unknown to the patient? Well, the answer lies in the ability of the disease to be transmitted to unborn children in the uterus.If a woman is infected for the first time and immediately prior to,or during pregnancy, (i.e. before acquisition of immunity against the disease) there is a likelihood of the disease being passed on to the developing baby in the womb (mother-to-child or congenital transmission). This could happen even if the pregnant mother is not showing symptoms of the disease.
It is this important human aspect of the disease and the animal involvement of transmission that prompted me to share it. Most affected infants are born with no symptoms of the disease, but can develop serious symptoms later in life which include blindness and or mental retardation.Not many studies about the disease have been done in Africa in general and Zambia specifically;therefore, knowledge about the extent of its occurrence is very limited.The good news, however, is that the disease could be prevented by following simple hygiene procedures outlined below.When pregnant, avoid changing cat litter. If no-one is available to change litter, ensure you wear disposable gloves while undertaking the task. After finishing, dispose of the gloves and wash your hands thoroughly with soap.Ensure that the litter box is changed on a daily basis. After being passed in the droppings, the eggs for the parasite take at least 24 hours before becoming infective.Changing the litter frequently ensures the eggs are disposed of before they can cause the disease even if they were accidentally ingested.In case you become infected,your health care provider may suggest a simple test to screen you for the disease. The disease is 100 percent curable when diagnosed in expecting mothers. However, as always, prevention is better than cure.So long as these few steps on hygiene are followed, there is no need to be scared of patting and handling your favourite moggies.The author is a district veterinary officer in Kabwe.