Toxoplasmosis is an infectious disease caused by the protozoan Toxoplasma gondii. In an immunocompetent host, infection is generally asymptomatic, but toxoplasmosis in pregnancy can cause birth defects.
Asymptomatic lymphadenopathy is the most usual presentation. The main lymph nodes involved are cervical and suboccipital. Fever, malaise and generalised rash will also be present. The clinical picture is very similar to infectious mononucleosis.
Neurological symptoms include neck stiffness and headache. Maculopapular rashes are also present. An acute febrile illness with maculopapular rash and hepatosplenomegaly, uveitis, chorioretinitis and myocarditis may also present.
In an immunosuppressed individual, febrile and neurological symptoms  are very prominent. In all AIDS cases, disease occurs in the CNS where tachyzoites causes necrosis, vasculitis, haemorrhage, oedema and inflammation. Patients are often drowsy, disoriented, confused and may have fever. Seizures may occur .
Congenital toxoplasmosis exhibits signs and symptoms which are indicative of CNS involvement. The characteristic syndrome of Savin which includes internal hydrocephalus, chorioretinitis and convulsions is common. Tremors, nystagmus, microopthalmia and pneumonitis may also be present. Complications in infants can manifest as mental retardation, spastic paraplegia or epilepsy .
Many cases of toxoplasmosis go undetected as the patient exhibits no signs and symptoms; it may be an incidental finding. Serological tests are the mainstay of diagnosis for acquired infections .
Physical examination findings will reveal mainly lymphadenopathy, cervical and suboccipital. Enlargement of suboccipital lymph nodes in particular should raise a high suspicion of toxoplasmosis. The lymph nodes are generally firm, discrete and are usually multiple. Enlarged spleen or liver may be palpable. Patient may be febrile and may appear weak.
Laboratory tests are non-specific. Lymhocytosis and atypical lymphocytes are seen. An elevation of transaminases to non-hepatic levels may be detected. The CSF is under pressure and the levels of proteins are elevated.
Diagnosis is based on a rise in antibodies of IgM class. Serological testing is the only practical method of diagnosing toxoplasmosis. Following an acute infection, the toxoplasma IgG antibodies become positive within two weeks peak at two months and then settle down to lower levels. It remains positive at these lower levels lifetime. IgM antibodies are essentially of use in diagnosing acute infection in healthy indiviuals. Raised antibody levels are common in general population and only raising antibody titres are highly indicative of toxoplasmosis. The IgM- immunofluorescent  antibody (IgM-IFA) test is very ueful.
T. gondii can be isolated by injecting the peritoneum of mice with tissue extracts from bone marrow and body fluids. This is of no practical value.
MRIs are done to observe the brain lesions in neurological involvement. The typical multiple ring lesions are seen.
Most of the cases do not require treatment as the disease is self-limiting provided the immunity is good. In case of persistence of symptoms more than 2 weeks, or any complication, treatment should be offered.
Pyrimthamine and sulphadiazine are given together as they are synergisitic. Therapy should be continued minimum for a month. Folinic acid should be given to prevent pancytopenia which results due to this therapy. Spiramycin is a useful alternative for treatment during pregnancy .
The prognosis is excellent with full recovery in immunocompetent indiviuals. 80-90% of the cases have complete recovery with no residual complications.
The outcome in infants with toxoplasmosis is variable. It depends upon the month in which the fetus gets infected and the severity of the infection. Disease progress and response to treatment also determine the prognosis. Infants affected in the first trimester have a bad prognosis with physical and mental malformations that may lead to death.
Immunosuppressed patients respond to treatment with prompt diagnosis which helps in a better recovery rate. The treatment has to be maintained throughout life.
The causative agent of this infectious disease is an intracellular parasite called as Toxoplasmosis gondii. Infection within the cat is the principal infection and takes place when these feline species ingest material which is infected with cysts in tissue (bradyzoite forms) and these undergo sexual reproduction in the gut of the cat .
Humans get infected with these tissue cysts when they come in contact with cat faeces or contaminated food or water. These tissue cysts enter the human body and can invade almost any part of the body but affect mainly heart, brain, muscles, eyes and lungs. Important factors which help in the etiology of this disease:
The exact route of transmission of Toxoplasmosis is not yet certain .
About 25-30% of human population have been infected with toxoplasmosis, though it cannot be demonstrated as most of the times there are no clinical manifestations.
The main routes of transmission are foodborne, animal to human and mother to child. The prevalence varies amongst different countries and communities.
Since this infection can transmit via placenta to fetus, extra importance is given to its prevalence among childbearing women between 15-44 years of age. About 15-20% of women have known to be infected with this parasite during pregnancy.
The feline species are the definite hosts of this intracellular parasite. The cat primarily gets infected after ingestion of material that contains cysts (bradyzoites) which are released within the gut to undergo sexual reproduction in the uroepithelial cells of the cat gut.
Sexual reproduction by fusion of gametes produces zygotes which are excreted out in cat faeces as unsporulated oocysts. After exposure to proper weather conditions, these oocysts sporulate to form infectious sporozites.
These can be ingested by human when they come in contact with cat litter directly or indirectly. Cats give out millions of oocysts for roundabout 3 weeks, that can remain infective for minimum a year.
Once in human stomach, these bradyzoites and sporozoites invade intestinal epithelial cells where they form vacuoles  and tachyzoites which rapidly multiply causing cells to rupture. These tachyzoites spread all over the body but in particular have an affinity for the lymphatic system, central nervous system and the eyes.
Transplacental transmission takes place at this stage. Cell-mediated and humoral immunity can result in total destruction of these tachyzoites, but inactive cysts remain dormant in the human body maturing and rupturing later on.
Histologically, there is an acute inflammatory response which surrounds a point of cell necrosis. Mononuclear infiltrate is present. Tachyzoites are never visualised and inactive cysts never cause an inflammation. In lymph nodes, there is characteristic hyperplasia of follicles which are surrounded by numerous macrophages. In the eyes, multifocal granulomatous lesions with chorioretinitis and iridocyclitis  will be observed.
In the central nervous system, there will be diffuse meningoencephalitic changes with infiltrates in a perivascular distribution mainly of mononuclear cells with random neutrophillic exudate.
There are few guidelines laid down for prevention of this infectious disease. Prevention mainly includes reducing the chances of ingesting the parasite. Hygiene should be maintained, especially after handling raw uncooked meat, hands should be washed. Fruits and vegetables should be thoroughly washed prior to consumption.
Domesticated cats should be given packaged food. Avoid contact with wild cats. All dairy products should be properly pasteeurised. Pregnant women should take extra precautions to avoid contact with cat litter.
Pregnant women infected with this parasite should start treatment immediately so as to minimise risk to fetus. No vaccine is available presently for prevention.
Toxoplasmosis is an infectious disease caused by Toxoplasma gondii, an intracellular protozoon which requires for completion of its lifecycle, a definite host e.g. a cat, sheep or pig and an intermediate host which are humans.
Infections in humans occur either congenitally or by ingestion of foodstuffs contaminated by cat faeces or raw meat contaminated with T. gondii cysts. Toxoplasmosis produces a clinical picture similar to infectious mononucleosis with an abnormal liver biochemistry .
Clinical manifestations occur only in certain settings, mainly in immunosuppressed conditions. Toxoplasmosis acquired at an early age may remain asymptomatic throughout life and might only be an incidental detection.
Toxoplasmosis produces a flu like clinical picture mainly in pregnant women, infants and immunocompromised individuals.
Treatment may not be required if the individual is healthy with good immunity. Since it is an infectious disease, the best approach is prevention.
Toxoplasmosis is an infection caused by a parasite called Toxoplasma gondii. This is one of the most common parasitic infections in the world. It is acquired when there is contact with cat faeces or consumption of raw uncooked meat which harbours this parasite. This infection may have no symptoms and is usually self-limiting unless the individual immunity is compromised. A pregnant woman who contracts this infection just before or during pregnancy can transmit this infection to her baby which can cause severe complications.
Cat faeces are the main source of these parasites which can spread to other animals as well. Contact with cat faeces or raw uncooked meat is the main source of infection.
The main symptoms are mild flu like signs which are not very severe other symptoms include tiredness and weakness. There may be swollen glands in the neck or underarm. In case of severely immune compromised individuals, they may show more severe signs like a swollen liver or spleen. Pregnant women should immediately consult a medical provider in case of suspected contact with parasite.
Blood tests will be done to detect antibodies in relation to the parasite. Depending upon the severity of the infection, treatment will be started. Due to relapse the treatment should be maintained in spite of improvement.
The best approach to this infection is prevention. Raw uncooked meat should be avoided. Hands should be washed carefully after handling raw meat. All fruits and vegetables should be carefully washed before consumption. Contact with wild cats should be avoided especially by pregnant women. Pregnant women should take all preventive measures as it can affect the unborn baby. Presently, there is no vaccine for this infection, thus, prevention is the best method.
With accurate treatment recovery is complete unless the immunity of the patient is supressed. The outlook of this infection is good with no residual complications.