Toxoplasmosis is a disease that results from infection of the Toxoplasma gondii parasite which can lay inactive in the retina for many years. But if the parasite becomes active again, it can start a new infection. In the eye, Toxoplasma infections frequently cause significant inflammation and subsequent scarring which may temporarily or permanently impair vision. Ocular toxoplasmosis can be congenital or acquired, and across the globe, toxoplasmosis is the most common cause of inflammation in the back of the eye.
Congenital toxoplasmosis is transmitted from the mother to the foetus across the placenta during pregnancy. Normally, newly infected women transmit the Toxoplasma organism to a foetus if they are infected during pregnancy or just before pregnancy. This can happen even if the mother does not have any signs or symptoms of infection. Babies born with congenital toxoplasmosis develop normally after treatment with antibiotics. But in some cases, serious complications can develop within the first years of life including permanent vision loss and permanent brain damage. Retinochoroiditis is a common complication of congenital toxoplasmosis.
The Toxoplasma organism lies in the intestinal tracts of many animals, particularly cats. Infectious organisms are shed in cat faeces, and introduced into the body by ingestion. The risk of infection can be reduced by practicing good hygiene including handwashing and avoiding raw or undercooked meat. It is sensible for pregnant women to avoid handling cat litter boxes, cat faeces, sandboxes, and any insects exposed to cat faeces.
Symptoms of toxoplasmosis in adults
Most of the patients experience no symptoms, and are unlikely to be aware of the infection. Symptoms may occur following an incubation period of one to two weeks after exposure and include mild fever, swollen glands, malaise, muscle or joint pain, headache, sore throat, and skin rash. Symptoms in the eye may vary but may include blurred vision or floaters during active disease. The diagnosis can be confirmed by identifying antibodies to Toxoplasma in the blood. The condition usually resolves without treatment within a few months.
Symptoms of Congenital toxoplasmosis
Most cases of congenital toxoplasmosis are asymptomatic, and initially go unrecognized. Low birth-weight, enlargement of liver or spleen, and jaundice are common. Evidence of retinal infection may be found in most infected babies.
Most cases rarely require treatment. If involvement of the internal organs is severe, treatment with antibiotics is considered. If the infection is recognized during pregnancy, treatment may be used to reduce the risk of maternal-foetal transmission.
Prevention of toxoplasmosis
- Wash hands before handling food
- Thoroughly wash all fruit and vegetables, including ready-prepared salads, before eating them
- Thoroughly cook raw meats and ready-prepared chilled meals
- Avoid cat droppings in cat litter or in soil