Toxoplasmosis and Pregnancy

1. Toxoplasmosis and Pregnancy Max Brinsmead PhD FRANZCOG October 2008

2. Toxoplasmosis • Caused by the protozoan parasite Toxoplasma gondi • Is endemic in most societies • And the definitive host is cats • Has a complex life cycle but infectious oocysts can live for many months in soil • 10 – 25% of adults have serologic evidence of previous infection • In most it causes a mild illness with fever, malaise and lymphadenopathy • But transplacental infection can cause congenital disease

3. Congenital Toxoplasmosis • Mental retardation • Learning difficulties • Cerebral calcifications • Chorioretinitis blindness • Hydrocephalus • Epilepsy

4. Vertical Transmission • 50% of congenital Toxoplasmosis is due to eating contaminated meat, mostly pork • Remainder to to contact with cats’ faeces or contaminated soil • ~1:200 women will become infected during pregnancy • Of these ~1:10 will deliver a baby with congenital Toxoplamosis • Infection in early pregnancy is less likely to cross the placenta • But this has more serious effects when it does

5. Diagnosis of Toxoplasmosis • Requires identification of both IgM and IgG in a previously seronegative woman • IgM can persist for months after primary infection • False positive IgM can occur • Infections acquired prior to pregnancy pose no risk to the fetus

6. Treatment • Acute infections can be treated with Spiramycin or sulphadiamine/pyrimethamine • This will reduce the risk of vertical transmission by ~50%

7. Preventing Congenital Toxoplasmosis Pregnant women should: • Cook meat thoroughly and check core temperature with a cooking thermometer • Prevent contamination of food by uncooked meat • Avoid contact with cat faeces • Wash or peel vegetables and avoid contact with soil