Understanding toxoplasmosis: transmission, diagnosis and prevention

Introduction of toxoplasmosis

Toxoplasmosis is caused by a protozoan toxoplasma gonidi, a member of sporozoa. The tachyzoite directly destroys cells and has a predilection for paranchymal cells and those of reticuloendothelial cells. Humans are relatively resistant, but a low grade lymph node infection resembling infectious mononucleosis may occur. When a tissue cyst ruptures releasing many bradyzoites, a local hypersensitivity reaction may cause inflammation, blockage of blood vessels and cell death near the damage cyst. The organism in humans produces either congenital or postnatal toxoplasmosis. Congenital infection develops only when non immune mothers are infected during pregnancy.  Postnatal toxoplasmosis is much less Sever. Most human infections are asymptomatic cases.  But fatal infections may present in patients with AIDS.

What is toxoplasmosis?

Toxoplasmosis is an infectious disease caused by a parasite known as Toxoplasma gondii, which can infect both humans and animals. The parasite is usually transmitted through eating undercooked or contaminated meat, consuming food or water contaminated with cat feces, or from an infected mother to her baby during pregnancy. Most healthy people do not develop symptoms, but some may experience mild signs such as fever, muscle aches, tiredness, and swollen lymph nodes. Toxoplasmosis disease or infection is found in human, birds, and mammals. Toxoplasmosis carries serious implications, often proving fatal, it can also cause serious birth defects in fetuses if mother is a affected. The parasite is quite common, believed to infect around 60 million people in the us alone however, most people with it do not get symptoms and can live their entire lives without knowing. 

Haw is transmitted toxoplasmosis

• Direct human contact with cat’s faeces.

• Soil contaminated with cat’s faeces.

• By eating contaminated meat of lamb, pork, shellfish, venison, when undercooked.

• Unborn baby get infection from their infected mothers in womb.

• Unpasteurized dairy products and contaminated water with toxoplasma Gondii.

• Infected blood transfusion or organ transplant. 

Symptoms of toxoplasmosis

Symptoms of toxoplasmosis in individuals with weak immune system people with HIV and chemotherapy treatment patients are highly exposed to this infection of toxoplasmosis, some people may develop the following symptoms: Fatigue, Miscarriage, Fever, Headache, Lymph nodes swelling, Body aches, Heart muscles inflammation, and Lungs inflammation. Following symptoms may occur in people with weakened immune system: seizures, brain damage, ocular toxoplasmosis, problem in walking,  and abnormal. Effects of toxoplasmosis on new born babies: body rash, mental rectardation, blindness, deafness, hepatomegaly, splenomegaly   and liver damage. Toxoplasmosis usually does not cause any symptoms to show up and people can spend their entire lives without knowing they have parasite in their bodies. The condition can be quite dangerous for people with compromised or weakened immune system. Toxoplasmosis symptoms often disappear on their own, but in severe cases, a doctor is likely to prescribe antibiotic sulfadiazine, and daraprim.

Laboratory diagnosis of toxoplasmosis

Direct visualization

Biopsy specimen from, brain, liver, myocardium, lymph node, or from body fluids CSF, amniotic fluid peritoneal fluid by using direct fluorescent antibody stains. Tissue culture, mouse inoculation and Serological tests.

Serological diagnosis of toxoplasmosis:

1. Serological test:

Elevation of toxoplasma antibodies indicates infection. Antibodies can be demonstrated within the first two weeks of infection. The antibodies fall slightly but persist for months. Both IgG and IgM antibodies can be detected. The presence of IgM indicates active infection. The test procedures that detect antibodies include indirect fluorescent antibody, indirect heamagglutunation, ELISA, Complement fixation and Sabin Feldman dye test.

2. Sabin Feldman dye test:

Laboratory cultured live T.gonidi + patient serum then add methylene blue. The organism is unstained In the presence of positive serum. Sensitive and specific than Eiken test. Not routinely performed for diagnostic purpose.

3. Eiken Toxoreagent latex agglutination test:

·       Is a simplest test.

·       It shows 94.4% agreement with the dye test and is performed as a quantitative test in microtitration plates.

·       The latex particles are coated with inactivated T.

·       Gondii soluble antigen.

·       The test detects all immunoglobulin classes.

·       The test does not require heat inactivation of serum samples.

·       A positive control is included in each test kit.

4. Interpretation of test results

• Detection of Toxoplasma specific IgM is indicative of  recent infection.

• Specific IgG in the infant’s circulation may be of maternal origin or due to infection.

• Testing of the infant’s blood at 2 monthly intervals will show whether the IgG antibody level is  decreasing. 

How to treatment toxoplasmosis 

• Pyrimethamine

• Sulfadiaz

• Folic acid 

Haw to prevention toxoplasmosis 

• Use of gloves during gardening or working in soil

• Use bottled or boiled water

• Only eat food that is well cooked 

Conclusion

Serologic tests of Toxoplasmosis is very crucial activity in medicine world to list factors affecting each patient and medication. The most reliable test for the diagnosis of acute toxoplasmosis in pregnancy, and to test neonates, is the Sabin-Feldman dye test.This highly sensitive and specific test is a complement-mediated neutralizing antigen- antibody reaction which uses live trophozoites to  measure Toxoplasma specific antibody.