What is Toxoplasmosis

Prevalance rate Of Toxoplasmosis is about 60 million people in the United states of America in which up to 80% of the Urban people show some exposure to it. This statistic is enough cause for concern about toxoplasmosis. What is its effect to man?

Its causative agent is Toxoplasma gondii.

Morphology

  • Pseudocysts (intracellular collection of trophozoites in cells in the acute stage of infection).
  • Trophozoites (intracellular parasites, about 6 X 2 micrometer crescent shaped with central nucleus and multiply by binary fission forming pseudocysts)
  • Cysts (collection of trophozoites enclosed in a true tissue cyst, in the chronic stage or latent infection);
  • Oocysts (oval, 10 X 12 micrometer, containes two sporocysts each containing four sporozoites, and found in stool of infected cats).

    • Life cycle
    The final host is the cat in which the oocyst producing sexual stage of Toxoplasma can occur. Mammals including humans, birds are in which parasite reproduces asexually are intermediate hosts.
    transmitted to humans

  • Oocysts pass from cat intestine to cat feces.
  • Oocysts sporulate in soil and are viable for longer than one year.
  • Human ingest oocysts either from soil or cat raw tissue infected with cysts.

    • The alimentary route of infection takes place on ingestion of meat, milk, and diary products of animals sick with toxoplasmosis, uncooked eggs of affected birds and water contaminated by sick animals.

  • Transmitted via placenta when mother develops infection during gestation-congenital infection.
  • Toxoplasma gondii invades intestinal wall after entering host (usually orally) and dissiminate via lymphatics and bloodstream forming trophozoites.

    • T.gondii can spread to many host cells (the histophagocytic system, nerve tissue, liver, placenta etc).

    Clinical manifestations
    Typical manifestations are pneumonia, enterocolitis, nephritis, hepatitis, myocarditis, and a high or subfebrile temperature. Infection is often asymptomatic. COngenital toxoplasmosis is characterized by hydro- or microcephalus, lesions in the organs of vision (chorioretinitis), cirrosis of the liver and enlargement of the spleen. Asymptomatic toxoplasmosis in the mother leads to infection of the fetus and this results in abortion or birth of a dead child.

  • Microscopic examination of fluids and organs of sick man (presence of T.gondii.
  • Biological tests with susceptible animals (mice, white rats, guinea pigs).
  • Serology of blood and cerebrospinal fluid.

    • Prophylaxis
    Washing of hands before meals and after handling animals and animal products, and the prohibitiopn of preparing food from insufficiently cooked meat products, in particular liver. All women with a history of spontaneous abortion must be examined by laboratory methods for prevention of congenital toxoplasmosis.

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    July 13, 2010 · 6 Comments ·

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