Congenital toxoplasmosis

Definition

Congenital toxoplasmosis is a group of symptoms and characteristics caused by infection of the fetus with the organism Toxoplasma gondii.

Causes, incidence, and risk factors

Fetal infection with toxoplasmosis results when a nonimmune pregnant woman is initially infected with toxoplasmosis, or if she has a history of toxoplasmosis during previous pregnancies.

For the mother the disease is generally mild and may not be evident. Infection of the fetus, however, can cause severe problems. Infection early in pregnancy results in more severe problems than later infection.

Congenital toxoplasmosis is characterized by damage to the eyes, nervous system, skin, and ears. The newborn often has a low birth weight, enlarged liver and spleen, jaundice, anemia, petechiae (fine red dots in the skin caused by bleeding of the capillaries), and eye damage evidenced by inflammation of the retina.

Symptoms

• Prematurity
  
• Small birth weight infant
  
• Increased or prolonged jaundice
  
• Skin rash (petechiae or ecchymosis) at birth
  

Signs and tests

The physical examination may show signs of:

• Chorioretinitis
  
• Cerebral calcifications
  
• Hydrocephalus
  
• Macrocephaly or microcephaly
  
• Lymphadenopathy
  
• Anemia
  

Late manifestations (signs and symptoms that occur late in the disease) include:

• Seizures
  
• Mental retardation
  
• Various neurological manifestations
  
• Visual impairment
  
• Hearing loss
  

Tests include:

• Prenatal diagnosis maternal antibodies (see antibody titer)
  
• Ultrasound of the abdomen
  
• Amniotic fluid and fetal blood testing
  

Postnatal diagnosis:

• CT scan
  
• Standard ophthalmic examination
  
• Neurological examinations