Toxoplasmosis Symptoms

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Questions and Answers

What percentage of congenitally infected children do not have detectable T gondii –specific IgM antibodies at birth or early infancy?

40-50%

15-55% (correct)

25-35%

10-20%

What is the most common manifestation of toxoplasmosis in individuals with AIDS?

Toxoplasmic myocarditis

Toxoplasmic encephalitis (correct)

Toxoplasmic pneumonia

Meningoencephalitis

What is a common symptom of toxoplasmosis in immunocompetent personnel?

Hemiparesis

Seizure

Myocarditis

Sore throat (correct)

What percentage of patients with congenital toxoplasmosis have no signs or symptoms of infection?

67% Signup and view all the answers

What is a common neurological sequela of toxoplasmosis in affected survivors?

All of the above Signup and view all the answers

What is the prevalence of sensorineural hearing loss in children who do not receive treatment for congenital toxoplasmosis?

28% Signup and view all the answers

What is a common ocular manifestation of toxoplasmosis in immunocompetent personnel?

Retinochoroiditis Signup and view all the answers

What is a common symptom of toxoplasmic pneumonitis?

All of the above Signup and view all the answers

What is the typical characteristic of lesions in ocular toxoplasmosis?

A yellowish-white, elevated, and cotton-like patch with indistinct margins Signup and view all the answers

What is the primary method of direct detection of T. gondii organisms?

PCR Signup and view all the answers

When is amniocentesis typically performed in suspected congenital toxoplasmosis?

At 20-24 weeks' gestation Signup and view all the answers

What is the primary action of pyrimethamine in treating toxoplasmosis?

Acting against the tachyzoite form of T. gondii Signup and view all the answers

What is a common symptom of ocular toxoplasmosis?

Metamorphopsia Signup and view all the answers

What is the purpose of administering leucovorin with pyrimethamine?

To prevent bone marrow suppression Signup and view all the answers

What is the significance of indirect detection of immunoglobulin G (IgG) in diagnosing toxoplasmosis?

It is possible within 2 weeks of infection Signup and view all the answers

What is the typical laterality of ocular toxoplasmosis in congenital and acquired disease?

Bilateral in congenital disease, unilateral in acquired disease Signup and view all the answers

What is the typical location of tissue cysts in the clinical phase of toxoplasmosis?

In the neural and muscle tissues Signup and view all the answers

What is the result of the released bradyzoites in immunocompetent individuals?

They are destroyed by the host's immune response Signup and view all the answers

What is the characteristic of bradyzoites in terms of immune response?

They have the ability to evade the host immune response Signup and view all the answers

What is the common feature of patients with prolonged fever and malaise during acute acquired T. gondii infection?

Lymphocytosis and increased suppressor T-cell counts Signup and view all the answers

What is the most common cause of retinochoroiditis?

Reactivation of congenital infection Signup and view all the answers

What is the mechanism of ocular toxoplasmosis according to one of the hypotheses?

Infection and inflammatory response after spontaneous cyst rupture Signup and view all the answers

What is the outcome of the majority of bradyzoites in the brain and muscles of immunocompetent individuals?

They remain in the brain and muscles indefinitely and develop lifelong protective immunity Signup and view all the answers

What is the characteristic of the inflammatory response in ocular toxoplasmosis?

It is a delayed-type hypersensitivity reaction to antigens of T. gondii Signup and view all the answers

Study Notes

Signs and Symptoms in Immunocompetent Patients

Cervical lymphadenopathy
Fever, malaise, night sweats, and myalgias
Sore throat
Retroperitoneal and mesenteric lymphadenopathy with abdominal pain
Retinochoroiditis

Symptoms in Immunodeficient Patients

CNS toxoplasmosis occurs in 50% of patients
Seizure, dysequilibrium, cranial nerve deficits, altered mental status, focal neurologic deficits, headache
Encephalitis, meningoencephalitis, or mass lesions
Hemiparesis and seizures
Visual changes
Flulike symptoms and lymphadenopathy
Myocarditis and pneumonitis are reported
Toxoplasmic pneumonitis can occur: nonproductive cough, dyspnea, chest discomfort, and fever

Congenital Toxoplasmosis

Most severe when maternal infection occurs early in pregnancy
15-55% of congenitally infected children do not have detectable T gondii-specific IgM antibodies at birth or early infancy
Approximately 67% of patients have no signs or symptoms of infection
Retinochoroiditis occurs in about 15% of patients
Intracranial calcifications develop in 10%
Infected newborns have anemia, thrombocytopenia, and jaundice at birth
Microcephaly has been reported
Affected survivors may have intellectual disability, seizures, visual defects, spasticity, hearing loss, or other severe neurologic sequelae

Tissue Cysts

Up to 60μm in diameter, each containing up to 60,000 organisms
Extracellular tachyzoites are cleared from host tissues and intracellular parasites differentiate into occult bradyzoite forms
Preferentially located in the neural and muscle tissues
Rupture periodically, releasing bradyzoites that are normally destroyed by the host's immune response

Changes in T-lymphocyte Levels

Alterations in subpopulations of T lymphocytes are profound and prolonged during acute acquired T gondii infection
Correlated with disease syndromes but not with disease outcome
Some patients have lymphocytosis, increased suppressor T-cell counts, and a decreased helper-to-suppressor T-cell ratio

Retinochoroiditis

Results from reactivation of congenital infection
5 hypotheses related to the inflammatory process of ocular toxoplasmosis:
- Infection and inflammatory response after spontaneous cyst rupture
- Parasitic toxic mediators released from T gondii
- Lytic effect of inflammatory mediators
- Delayed-type hypersensitivity reaction to antigens of T gondii
- Cell-mediated immunity against retinal antigens

Ocular Toxoplasmosis

Patients develop retinochoroiditis (focal necrotizing retinitis)
Yellowish white, elevated cotton patch with indistinct margins
Lesions may occur in small clusters
Congenital disease usually is bilateral, and acquired disease usually is unilateral
Symptoms include:
- Impaired vision
- Blurred vision
- Scotoma
- Pain
- Photophobia
- Floaters
- Red eye
- Metamorphopsia

Diagnosis

Direct detection of T gondii organisms in blood, body fluids, or tissue using PCR
Indirect detection of immunoglobulin G (IgG) is possible within 2 weeks of infection using ELISA test
Diagnostic procedures may be performed:
- Lumbar puncture
- Brain biopsy
- Lymph node biopsy
- Amniocentesis (at 20-24 weeks' gestation if congenital disease is suggested)

Treatment

Act primarily against the tachyzoite form of T gondii; do not eradicate the encysted form (bradyzoite)
Pyrimethamine is the most effective agent
Leucovorin (folinic acid) should be administered concomitantly to prevent bone marrow suppression
Unless circumstances preclude using more than 1 drug, a second drug (e.g., sulfadiazine, clindamycin) should be added

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Description

This quiz covers the signs and symptoms of toxoplasmosis in immunocompetent and immunodeficient patients, including cervical lymphadenopathy, fever, and CNS toxoplasmosis.