Toxoplasmosis, Biology

Toxoplasmosis
Toxoplasmosis, one of the important parasitic zoonoses, occurs all over the world, and is caused by a protozoan parasite Toxoplasma gondii. Its definitive hosts are cats (and other members of the cat family) and the intermediate stages occur in a wide range of animals including domesticated animals and man.


Epidemiology:
Toxoplasma infection is widespread throughout the world but its incidence may vary in different geographical areas. Toxoplasmosis in man may occur as a congenital or as an acquired infection. The majority of congenital infections occur when the mother acquires infection during pregnancy. Postnatally, toxoplasmosis can be acquired either by ingestion of food contaminated by mature oocysts or by eating uncooked or raw infected meat (cattle, sheep, rabbits and pigs).


Cats and other members of felidae family are the key animals involved in the epidemiology of postnatal toxoplasmosis. After primary infection cats can shed oocysts for about two weeks and millions of these can be present in a single sample of stool. Coprophagous invertebrates like cockroaches and flies may spread oocysts mechanically.Infection may also occur due to laboratory and autopsy accidents and handling of infected meat. Other possible means of transmission are venereal, ingestion of milk, from eggs and by organ transplant.


Clinical features:
Congenital infection is more serious. It may result in abortion, miscarriage, still birth or birth of child with cerebral calcification, chorio-retinitis, hydrocephalus or microcephalus, anemia, jaundice, hepatomegaly and lymphadenitis. Acquired infection in man is usually mild. Lymphadenitis is the common manifestation with or without fever, malaise and rash, but infection persists for longer duration.

Laboratory diagnosis: Two important methods of diagnosis are discussed here.Demonstration and isolation of parasite: Biopsy material (lymph node and muscle) or impression smears can be used for detection of parasite by simple staining or fluorescent staining technique. Toxoplasma can be isolated by inoculating laboratory animals. Young albino mice are highly susceptible and are therefore most commonly used.


Demonstration of antibodies:
As isolation of parasites from all material is difficult and diagnosis largely depend on serological tests. Of the numerous tests available, complement fixation test, direct haemagglutination test indirect immunofluorescence test and enzyme – linked immunosorbent assay are reported to be suitable.
 

Control and prevention:
Man is infected by Toxoplasma from tissue-cysts in meat, oocysts in soil and transplacentally in mother’s womb. So, proper cooking of meat is essential. Proper feeding and management of pet cats and elimination of stray cats. Proper disposal of cat’s faeces is important to check the spread. Immunoprophylaxis of animals against toxoplasmosis also helps in preventing the disease .Routine serological check-up and treatment of infected mothers are essential for protecting the foetus.

Posted Date: 9/20/2012 3:14:25 AM | Location : United States







Related Discussions:- Toxoplasmosis, Assignment Help, Ask Question on Toxoplasmosis, Get Answer, Expert's Help, Toxoplasmosis Discussions

Write discussion on Toxoplasmosis
Your posts are moderated
Related Questions
#question.bacteria and virus are meet so what happen.

Define effect of Fat on quality and quantity of human milk? Fat content of milk appears to be subject to variability as compared to other constituents. The average fat content

How can coacervates be formed of phospholipids or polypeptides? Phospholipids are amphipathic molecules, i.e., they present a polar portion and a nonpolar portion. In contact w

What is the role of Linked Traits in genetics? In his study of inheritance in the fruit fly, Morgan observed that certain genes are distributed together, or linked, rather than

What are the two main classes into which fishes are divided? Fishes are separated into two main classes: chondrichthyes, fishes with cartilaginous skeletons (sharks, rays, dog-

Q. Why is it dangerous to talk while eating? If a person talks when eating, food may be inhaled into the lungs. Generally after food is swallowed, it passes into pharynx and th

Illustrate about the Intra-ocular pressure It is the pressure maintained inside the eye above the atmospheric pressure. It is higher than fluid pressure in any other tissue (2-

The fundamental contractile unit is the sarcomere. Each muscle cell apart from the nucleus, mitochondria and other structures contains parallel fibrils. Sarcomere is a subunit of t

Question 1 How would you perform ABO blood grouping? Add a note on advantages and disadvantages of each method. Also discuss the precautions you may take to avoid errors in variou

B i osecurity in Poultry Health Management Biosecurity includes all the measures that are taken to prevent infection to individual, material and environment from the pathogen