[M] Lec 04: TORCH Flashcards
What does TORCH stands for?
Toxoplasmosis
Other agents
Rubella
Cytomegalovirus
Herpes simplex
Refers to infections that can cause birth defects, developmental delays, and even death
TORCH
Refers to:
Procedures that specifically evaluate the presence of IgM or IgG antibodies, frequently used to determine infections causing congenital defects
TORCH Test
Also called Torch Syndrome which occurs with maternal exposure for certain infectious diseases
Congenital defect
Other name for Torch Syndrome
Congenital defect
Refers to:
- Caused by Toxoplasma gondii, which is a tissue coccidian
Toxoplasmosis
Toxoplasmosis
Definitive host:
Transmission:
- Cats
- Organ transplantation, blood transfusion, transplacental
Transplacental transmission of Toxoplasma gondii that occurs from mother to fetus is also called _________
Congenital toxoplasmosis
T or F: Toxoplasmosis can also infect cold-blooded animals like humans
False (warm-blooded)
Study the life cycle of Toxoplasma gondii
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Familiarize the stages of Toxoplasma gondii
- Oocyst formation
- Oocyst shedding
- Infection of the intermediate host
- Tachyzoite formation
- Tissue cyst formation
- Infection of cat
Toxoplasma gondii
- The oocyst containing the _______ form in the intestinal cells of the _______
- The oocyst are released by the definitive host through _______
- Oocyst can survive in ____ and other environment
- It will undergo asexual reproduction in the cells of the _________
- The tissue cyst formation can be in the muscles, brain, and other tissues of the ________
- The tissue cyst can infect cat where the _______ undergo sexual reproduction forming oocyst
- Sporozoites, cats
- Feces
- Soil
- Intermediate host
- Intermediate host
- Bradyzoites
Familiarize the modes of transmission of Toxoplasma gondii
- Ingestion of undercooked meat
- Transplacental transmission
- Organ transplantation
- Blood transfusion
- Ingestion of contaminated soil and water
High risk groups of Toxoplasmosis
- Pregnant women
- Immunocompromised indivual (HIV, cancer patients, immunosupressive therapies)|
- Organ transplant recipient from infected donor
T or F: Toxoplasmosis mostly are symptomatic at birth
False (asymptomatic)
However, there are some indiv that may develop symptoms later in life particularly if the infection affects the CNS or the eyes
Classic triad symptoms of Congenital toxoplasmosis
Chorioretinitis
Hydrocephalus
Intracranial calcification
Classic triad of Congenital toxoplasmosis
- Inflammation of the colloid and the retina of the eye that may lead to blindness
- Accumulation of fluid in the brain (leading to intracranial pressure, headache, vomiting, and seizures)
- Deposits of calcium salts in brain tissue (detected by imaging studies like CT scan or MRI
- Chorioretinitis
- Hydrocephalus
- Intracranial calcification
Familiarize the serologic tests of Toxoplasmosis (especially in pregnant women and immunocompromised patients)
- IgM and IgG antibodies
- IgA antibodies
- Sabin-Feldman Dye Test
- IFA Test
- Avidity Test
- PCR
- Histology
- Cell Culture
Toxoplasmosis serologic test that refers to
- Chemiluminescent immunoassay
- The IgG antibodies test detects the IgG antibodies which indicate past or chronic infection
- The IgM antibodies detect IgM antibodies that detect recent or acute infection
IgM and IgG antibodies
Toxoplasmosis serologic test that refers to
- Detects the infection in newborn or young children
IgA antibodies
Toxoplasmosis serologic test that refers to
- Detecting presence of Ab against Toxoplasma gondii in Px serum
- Principle: Live virus organism will not take up the Methylene Blue dye when they are exposed to antibodies against the parasite
- Dye Test: Px serum + Toxoplasma antigen + Methylene Blue Dye
Sabin-Feldman Dye Test
Sabin-Feldman Dye Test
- Does not take up the methylene blue dye (presence of antibodies)
- Take up the dye (absence of antibodies against Toxoplasma gondii)
A. Positive
B. Negative
- Positive
- Negative
Toxoplasmosis serologic test that refers to
- Detects the presence of Ab against Toxoplasma gondii in Px serum
- Uses fluorescent dye to visualize
- Toxoplasma gondii antigens are fixed on a slide (incubated with the Px serum)
- Fluorescent label is applied to the slide and examined under fluorescence microscope
POSITIVE: Fluorescent pattern (there is binding of Ag and Ab)
Immunofluorescence Assay Test
Toxoplasmosis serologic test that refers to
- Confirmatory tool in patients with positive IgM test
Avidity Test