Toxoplasmosis

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii. Most infections in healthy people cause no symptoms, but the infection can be serious in people with weakened immunity and in babies infected during pregnancy.

• Most infections in healthy people cause no symptoms at all
• Some people experience mild, flu-like symptoms — swollen lymph nodes, muscle aches, and mild fever
• In people with significantly weakened immunity, such as advanced HIV infection, it can reactivate and cause serious brain infection (encephalitis), with headache, confusion, weakness, or seizures
• Infection acquired during pregnancy can affect the developing baby, potentially causing eye or brain problems

• Caused by the parasite Toxoplasma gondii, commonly found in cat faeces, contaminated soil, and undercooked meat.
• Transmitted through accidental ingestion of the parasite, such as from contaminated food, water, or soil, or from handling cat litter.
• Can also be transmitted from mother to baby during pregnancy if the mother is newly infected.

• Often not diagnosed in healthy people, as infection is usually mild or symptomless.
• Blood testing for Toxoplasma antibodies can confirm infection, particularly important during pregnancy or in people with weakened immunity presenting with relevant symptoms.
• Brain imaging may be used to assess for toxoplasmosis-related brain infection in people with advanced HIV and relevant neurological symptoms.

Healthy people with mild symptoms usually do not need specific treatment, as the immune system controls the infection on its own.

Pregnant women with a new infection, or babies with congenital toxoplasmosis, are treated with specific antiparasitic medicines under specialist guidance to reduce the risk of complications.

People with weakened immunity and toxoplasmosis affecting the brain require a combination of antiparasitic medicines for an extended period, together with optimisation of any underlying immune suppression, such as starting or adjusting antiretroviral therapy for HIV.

Ongoing preventive antiparasitic treatment may be continued in people with advanced HIV until their immune system has sufficiently recovered.

• Cook meat thoroughly and wash fruits and vegetables before eating.
• Wash hands after handling raw meat or gardening in soil that may contain cat faeces.
• Pregnant women should avoid changing cat litter where possible, or wear gloves and wash hands thoroughly if unavoidable.
• People with advanced HIV should discuss toxoplasmosis prevention with a health worker, including the role of preventive medicine at very low CD4 counts.