Toxoplasmosis

toxoplasmosis [‚tak·sə·plaz′mō·səs]

(medicine)

Infection by the protozoanToxoplasma gondii, manifested clinically in severe cases by jaundice, hepatomegaly, and splenomegaly.

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Toxoplasmosis 

a protozoan disease of man and animals that is caused by parasites of the genus Toxoplasma gondii. The sources of infection are more than 180 species of domestic and wild animals, including dogs, cats, rabbits, predators, herbivores, rodents, and birds. Human infestation occurs through consumption of insufficiently cooked meat products or eggs; it may also occur by means of the mucous membranes and skin injuries, or through transmission. Prenatal infestation has also been observed.

In man, toxoplasmosis may be congenital or acquired, and acute or chronic. Congenital toxoplasmosis may involve the prenatal death of the fetus, the death of the newborn from general infection, or affectation of the newborn’s nervous system, as well as of its eyes and other organs. The acute acquired form of toxoplasmosis has a course similar to that of typhus, with high temperature and enlargement of the liver and spleen. The acute acquired form may also affect primarily the nervous system, with accompanying headaches, convulsions, vomiting, and paralysis. Toxoplasmosis is often chronic, and in this form is marked by subfebrile temperature, headache, enlargement of the lymph nodes and liver, and impairment of working capacity. In the chronic form, the eyes, heart, nervous system, and other organs and systems may be affected. Toxoplasmosis also occurs in a latent form.

Toxoplasmosis is detected by means of serodiagnosis and intradermal allergic tests. The disease is treated with pyrimethamine and with sulfanilamide compounds. Infestation can be prevented by controlling toxoplasmosis in domestic animals, by observing proper sanitary measures when disposing of animal waste and processing food products, and by examining pregnant women for signs of toxoplasmosis.

REFERENCE

Kovaleva, E. P. Toksoplazmoz. Moscow, 1967.
Domestic and wild mammals, as well as birds, are affected by toxoplasmosis. The disease is naturally endemic, and has been recorded in every country of the world. Infestation occurs by ingestión or contamination, and occasionally by means of airborne droplets. Prenatal infestation may also occur. The cysts of the parasites may remain alive within an animal for years, particularly in the brain and skeletal musculature.
In animals, the causative agent of toxoplasmosis is discharged from infected or recovered animals with aborted or stillborn fetuses, as well as with the amniotic fluid, placenta, and vaginal discharges. The causative agent also occurs in the milk, saliva, and discharges from the nose and eyes. In cats, the causative agent may be discharged with the feces.
Depending on the species of the animal affected, miscarriages, intestinal disturbances, and disorders of the skin and nervous system may develop in connection with toxoplasmosis. Toxoplasmosis in animals may be acute or chronic; the disease sometimes results in the affected animal’s death. Diagnosis is based on the findings of epizootiology and is conducted by observing external symptoms, examining the blood serum, and studying animal discharges with a microscope.

N. I. STEPANOVA