Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Toxoplasmosis

Symptoms

In people with normal immune defenses, up to 90% of cases of toxoplasmosis do not cause any symptoms, so the infection often is not recognized. In the relatively few cases in which symptoms do develop, the most common symptoms are:

• Painless swelling of the lymph nodes

• Headache

• Malaise (a general sick feeling)

• Fatigue

• Low-grade fever

In rare cases, patients also have experienced muscle aches, sore throat, abdominal pain, rash or neurological symptoms.

In people with weakened immune systems, especially those with AIDS, symptoms of toxoplasmosis are often brain-related and severe. These symptoms can include:

• Disturbances in mental functions, especially disorientation, difficulty concentrating, or behavioral changes

• Fever

• Headache

• Seizures

• Disturbances in nerve function, especially abnormal movements, difficulty walking, difficulty speaking and partial loss of vision

Also, if toxoplasmosis affects the eyes of a person with a weakened immune system, there may be blurred vision, "spots" in the field of vision, eye pain and extreme sensitivity to light. If toxoplasmosis affects the lungs, there can be shortness of breath, fever, a dry cough, coughing up of blood and, eventually, respiratory failure.

If a woman develops toxoplasmosis during pregnancy or within six weeks before becoming pregnant, her child may be born with congenital toxoplasmosis. The child often does not have any symptoms at birth. However, a thorough exam usually will uncover signs of infection in the infant's eyes. Other symptoms in newborns can include:

• Unusually small body size

• Strabismus, an eye that wanders or is misaligned, or other eye problems

• Head size that is unusually large or unusually small

• Convulsions

• Jaundice

• Enlarged lymph nodes

• Abnormal bruising

• Rash

• Developmental delays and, sometimes, mental retardation

In addition, congenital toxoplasmosis increases the risk of fetal death or premature birth.