Toxoplasmosis is an infectious disease caused by pathogenic simplest Toxoplasma gondii, proceeding with polymorphous clinical picture. There are congenital and acquired toxoplasmosis.
Etiology. Toxoplasma - celled parasites Crescent-shaped size 2-4 microns in width and 4-7 microns in length, mobile, multiply intracellular. Withstand freezing for several days. Heating up to temperature 56-60° kills parasites within 5-15 minutes, and boiling - instantly. Do not tolerate desiccation and direct sunlight. Raw milk is stored 24 hours. Not tolerate acidic environment. In normal gastric juice survive 30 minutes to 1% solution of phenol, 2% solution of bleach, 50% alcohol kill toxoplasm 5-10 min
Epidemiology. Detection of the pathogen in wild animals (rodents, carnivores), and also birds justify the existence of primary natural foci. Sources of infection are and domestic animals (horses, cattle and small cattle, rabbits and others), and poultry (chickens, ducks, pigeons and other). A large epidemiological importance of infected dogs and cats. At the acute toxoplasmosis pathogen is secreted with saliva, urine, faeces, milk, conjunctival secret; with prolonged period - with the saliva, faeces, urine. Infection occurs through the consumption of infected products (meat, milk, raw eggs); the workers of the meat processing plants, abattoirs, animal farms through damaged skin, mucous membranes. Possible vector-borne transmission via mites.

Fig. 1. Toxoplasma in a smear of the organs of the mouse (hold methyl alcohol, paint Romanovsky - Giemsa): a and b - resting stage; - stage division; and Dr. divided form. Fig. 2. Pseudocyst Toxoplasma in macrophage (from the exudate infected mouse). Fig. 3. Toxo, located in the vacuoles in the brain of rats; the 15th day after infection. Fig. 4. Three cysts in the brain of rats, and 25-th day after infection (Fig. 3 and 4 fixation in fluid Carnoy; color Romanovsky - Giemsa). (S., Vasina.)

Pathogenesis and pathological anatomy. In case of infection with Toxoplasma penetrate into lymphatic system and then into the blood stream. The generalization of infection leads to the formation of local lesions in various organs.
In the tissues occur inflammatory proliferative-granulomatous changes reticulo-lymphocytic elements. In necrotic areas again postponed lime, formed a characteristic calcifications (soft brain membranes, cortex, the cerebellum, brain ventricles). May be asymptomatic carriage toxoplasm; the causative agents in the form of cysts long remain in skeletal muscle, cardiac muscle, the brain. The collapse of cysts leads to increased infection, secondary generalization with specific allergies.
The clinical picture of the acquired toxoplasmosis. At the acute acquired toxoplasmosis, there are several clinical forms.
1. Limfogranulema (glandular) form is characterized by enlargement of the lymph nodes (cervical, axillary, inguinal), fever, sore throat, enlarged liver and spleen. In the blood - moderate leukocytosis, lymphocytosis, monocytosis. Glandular form more often observed in children and young people.
2. Eye shape is accompanied by phenomena Central to horioretinit, acute conjunctivitis, uveitis, iritis. Marked decline and loss of vision. Damage to the eyes may be the only manifestation of the disease.
3. Aksenteva form begins with chills and fever, severe General intoxication until the development status typhosus. On 4-7 day you receive abundant makulo-papular rash, continuing to 2 weeks. Can be enlarged lymph nodes, liver, spleen. Often there are pneumonia, myocarditis, lesion of the Central nervous system.
4. Cerebral (meningoencephalitis) form is characterized by high fever, severe symptoms, brain and its meninges.
5. Visceral form manifested in the form of myocarditis, pneumonia, interstitial hepatitis.
The chronic course of the acquired toxoplasmosis long kept low grade fever, headaches, muscle pain, marked sore throat, a slight increase in lymph nodes. Characteristic of neuropsychic and neuroendocrine manifestations paresis, paralysis, epileptiform seizures, vegetative-vascular disorders, abnormalities of gonadal function, pituitary, thyroid, eyes. Often there are hepatitis, splenomegaly, myocarditis, pneumonia. Sometimes only a laboratory study defines toksoplazmozu the etiology of the disease.

toxoplasmosis horioretinit
Fig. 1. Colocoscopy toxoplasmosis horioretinit a man 43 years. Fig. 2. Late relapse toxoplasmose of horioretinit in women is 57 years. Fig. 3 and 4. Congenital alopecia scar horioretinit right (Fig. 3) and the left eye (Fig. 4) the girl of 15 years.