Toxoplasmosis and Toxoplasmosis and PregnancyPregnancy

Max Brinsmead MB BS PhDMax Brinsmead MB BS PhDMay 2015May 2015

ToxoplasmosisToxoplasmosis Caused by the protozoan parasite Caused by the protozoan parasite Toxoplasma gondiToxoplasma gondi Is endemic in most societiesIs endemic in most societies And the definitive host is catsAnd the definitive host is cats Has a complex life cycle but infectious oocysts can live Has a complex life cycle but infectious oocysts can live

for many months in soilfor many months in soil 10 – 25% of adults have serologic evidence of previous 10 – 25% of adults have serologic evidence of previous

infectioninfection In most it causes a mild illness with fever, malaise and In most it causes a mild illness with fever, malaise and

lymphadenopathylymphadenopathy But transplacental infection can cause congenital But transplacental infection can cause congenital

diseasedisease

Congenital ToxoplasmosisCongenital Toxoplasmosis

Mental retardationMental retardationLearning difficultiesLearning difficultiesCerebral calcificationsCerebral calcificationsChorioretinitis Chorioretinitis blindnessblindnessHydrocephalusHydrocephalusEpilepsyEpilepsy

Vertical TransmissionVertical Transmission

50% of congenital Toxoplasmosis is due to 50% of congenital Toxoplasmosis is due to eating contaminated meat, mostly porkeating contaminated meat, mostly pork

Remainder to to contact with cats’ faeces or Remainder to to contact with cats’ faeces or contaminated soilcontaminated soil

~1:200 women will become infected during ~1:200 women will become infected during pregnancypregnancy

Of these Of these ~1:10 will deliver a baby with ~1:10 will deliver a baby with congenital Toxoplamosiscongenital Toxoplamosis

Infection in early pregnancy is less likely to cross Infection in early pregnancy is less likely to cross the placenta the placenta

But this has more serious effects when it doesBut this has more serious effects when it does

Diagnosis of ToxoplasmosisDiagnosis of Toxoplasmosis

Requires identification of both IgM and IgG in a Requires identification of both IgM and IgG in a previously seronegative womanpreviously seronegative woman

IgM can persist for months after primary IgM can persist for months after primary infectioninfection

False positive IgM can occurFalse positive IgM can occur Infections acquired prior to pregnancy pose no Infections acquired prior to pregnancy pose no

risk to the fetusrisk to the fetus

TreatmentTreatment

Acute infections can be treated with Spiramycin Acute infections can be treated with Spiramycin or sulphadiamine/pyrimethamineor sulphadiamine/pyrimethamine

This will reduce the risk of vertical transmission This will reduce the risk of vertical transmission by by ~50%~50%

Preventing Congenital Preventing Congenital ToxoplasmosisToxoplasmosis

Pregnant women should:Pregnant women should:

Cook meat thoroughly and check core Cook meat thoroughly and check core temperature with a cooking thermometertemperature with a cooking thermometer

Prevent contamination of food by uncooked Prevent contamination of food by uncooked meatmeat

Avoid contact with cat faecesAvoid contact with cat faeces Wash or peel vegetables and avoid contact with Wash or peel vegetables and avoid contact with

soilsoil

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