- Nov 2017
The most common eye finding in congenital toxoplasmosis is the presence of chorioretinal scars, reported in 79% of patients. These scars may occur anywhere in the retina but with a higher incidence in the macula.
Ocular findings in Congenital Toxoplasomsis:
- 79% patients have chorioretinal scars *Scar may involve macula with significant decrease in visual acuity
- scar may involve periheral area with decreased acuity by dragging of macula
Chorioretinal scar in congenital toxoplasmosis
Other posterior ocular complications include:
- retinal attachment and active chorioretinitis in 10%
- Optic atrophy in 20%
- Other findings may include: cataracts, microphtalmia, microcornea, nystagmus.
Classic triad of findings in congenital toxoplasmosis includes:
- hydrocephalus, and
- intracranial calcifications.
See also: Toxoplasmosis- AAPOS
What are the symptoms of newly acquired toxoplasmosis in an adult?
More than 80% of newly infected persons experience no symptoms, and are unlikely to be aware of the infection.
Symptoms may occur following an incubation period of one to two weeks after exposure and include:
*muscle and/or joint pain
*sore throat, and
*Eye symptoms may include blurred vision or floaters during active disease.
The diagnosis can be confirmed by detecting antibodies to Toxoplasma in the blood. Swelling of the liver or spleen may be noted, and in rare cases the lungs, brain, liver, or heart may be involved. The condition usually resolves without treatment within a few months.
Toxoplasmosis is caused by the obligate intracellular parasite, Toxoplasma gondii. Its life cycle consists of 3 forms, including an oocyst, a tissue cyst, and an active (proliferative) form.
See also: CDC- Toxoplasmosis
Source of Infection in humans:
- Eating under cooked meat of animals harboring tissue cysts
- Consuming food or water contaminated with cat feces or by contaminated environmental samples (such as fecal-contaminated soil or changing the litter box of a pet cat)
- Blood transfusion or organ transplantation
- Transplacentally from mother to fetus
Sources of T. gondi infection
Life cycle of T. gondi
The acronym TORCH was initially proposed by Andres Nahmias in 1971 to represent 4 congenital infections with a similar clinical presentation, including a rash and ocular findings in neonates: toxoplasmosis, rubella, cytomegalovirus (CMV), and herpes simplex virus (HSV). Over the next few years, the acronym was changed to TORCHES to include syphilis.
The “other” category now includes:
*Lymphocytic Choriomeningitis virus (LCMV)
*Human immunodeficiency virus (HIV)
*West Nile virus, and
- Zika virus (ZIKV).
The most complex events in embryogenesis involving the sensory organs take place during the first few weeks of pregnancy, making the eyes and ears particularly vulnerable. The fetus does not have the immunologic mechanisms needed to eliminate the organism, leading to immunologic tolerance and chronic infection.
The most common eye finding of congenital infections is a chorioretinal scar. Congenital cataracts, optic nerve atrophy, or hypoplasia may also be found.
- Maternal Toxoplasmosis
- congenital toxoplasmosis
- fundus in congenital toxo with chorioretinal scar
- ocular findings
- fundus in normal retina
- symptoms in mother
- source of infection
- TORCH infection
- Tissue cysts
- Life Cycle
- Organisms causing TORCH
- T. gondii
- classic triad