Toxoplasmosis and Pregnancy Max Brinsmead MB BS PhD May 2015

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

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

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

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

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

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

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