What are the signs and symptoms of toxoplasmosis?

Signs and Symptoms of Toxoplasmosis

Toxoplasmosis presents with variable clinical manifestations ranging from asymptomatic infection to severe disease, with symptoms differing significantly between congenital cases, immunocompetent individuals, and immunocompromised patients. 1

Congenital Toxoplasmosis

Presentation at Birth

• 70-90% of infants with congenital toxoplasmosis are asymptomatic at birth 1
• When symptomatic, two main presentations occur:

  1. Generalized disease:

     • Maculopapular rash
     • Generalized lymphadenopathy
     • Hepatosplenomegaly
     • Jaundice
     • Hematologic abnormalities (anemia, thrombocytopenia, neutropenia)

  2. Predominantly neurologic disease:

     • Hydrocephalus
     • Intracerebral calcification
     • Microcephaly
     • Chorioretinitis
     • Seizures 1

Late Sequelae

• Most asymptomatic infants develop complications months to years later:
  • Retinitis
  • Visual impairment
  • Intellectual impairment
  • Neurologic impairment 1

Acquired Toxoplasmosis in Immunocompetent Individuals

• Often asymptomatic (most common presentation)
• When symptomatic, typically presents with:
  • Malaise
  • Fever
  • Sore throat
  • Myalgia
  • Cervical lymphadenopathy (most characteristic finding)
  • Mononucleosis-like syndrome with:
    • Maculopapular rash
    • Hepatosplenomegaly 1
• Rarely, polymyositis with muscle pain and progressive muscle weakness 2

Toxoplasmosis in Immunocompromised Patients

Central Nervous System Manifestations

• Toxoplasma encephalitis (most common severe manifestation)
  • Focal neurologic findings (typical)
  • Diffuse CNS disease (variable presentation)
  • Fever
  • Reduced alertness
  • Seizures 1, 3

Ocular Toxoplasmosis

• White retinal lesions with minimal hemorrhage
• Visual loss may occur early
• Rarely occurs in isolation (usually associated with CNS infection) 1

Other Presentations in Immunocompromised Patients

• Systemic toxoplasmosis
• Pneumonitis
• Hepatitis
• Cardiomyopathy/myocarditis 1, 4

Diagnostic Considerations

• Symptoms in immunocompromised patients are often nonspecific, making diagnosis challenging 4
• HIV-infected women have increased risk of transmitting Toxoplasma to fetuses
• Serologic testing is the primary diagnostic method, but interpretation can be difficult 1
• PCR testing of body fluids (CSF, amniotic fluid, blood) can detect Toxoplasma DNA 1

Risk Factors to Consider

• Consumption of raw/undercooked meat containing tissue cysts
• Ingestion of raw vegetables or water contaminated with oocysts from cat feces
• Risk varies with cultural and eating habits 5
• Immunosuppression significantly increases risk of severe disease 6, 4

Clinical Pitfalls

1. Missing the diagnosis in immunocompetent patients: Symptoms may be mild and non-specific, resembling mononucleosis or other common viral infections
2. Overlooking ocular involvement: Always perform neurologic examination in patients with chorioretinitis
3. Delayed diagnosis in immunocompromised patients: Consider toxoplasmosis in any immunocompromised patient with new neurologic findings
4. Failure to screen pregnant women: Congenital transmission risk increases with gestational age at maternal infection