Toxoplasmosis

Question 1

How is maternal infection with toxoplasmosis diagnosed?

Answer 1

• IgG with low avidity (infection in the past five (5) months)
• IgM +/- and IgG (repeat in two (2) - three (3) weeks to look for increase in IgG)

** IgM can be positive for a long time though **

Question 2

Do you routinely recommend screening for toxoplasmosis in pregnancy? Why or why not?

Answer 2

No due to low incidence of acute infection lack of standardized assay. Screen in HIV patients only.

Question 3

How do you counsel a patient with a positive toxoplasmosis IgM and negative IgG results?

Answer 3

• recent infection

- false positive

Question 4

How do you counsel a patient with a positive toxoplasmosis IgM and positive IgG results?

Answer 4

• recent infection
• false positive result
• IgG avidity testing can help

Question 5

How is toxoplasmosis infection transmitted?

Answer 5

Blood or body fluids

Question 6

What are maternal risks of toxoplasmosis infection?

Answer 6

• undercooked food (has trophozoites)
• insect contaminated food
• feces of infected cats (has oocytes)

Question 7

What are maternal symptoms of toxoplasmosis infection?

Answer 7

• asymptomatic cervical lymphadenopathy
• fever
• malaise
• night sweats
• myalgia
• hepatosplenomegaly

Question 8

What percentage of patients infected with toxoplasmosis are symptomatic?

Answer 8

10-20%

Question 9

What ultrasound findings are consistent with in utero toxoplasmosis infection?

Answer 9

• periventricular calcifications
• ascites
• hepatosplenomegaly
• fetal growth restriction
• microcephaly

Question 10

How is utero toxoplasmosis infection confirmed?

Answer 10

PCR of amniotic fluid; best to perform after 18 weeks

Question 11

If performing an amniocentesis for suspected toxoplasmosis infection, what tests will you order on the amniotic fluid?

Answer 11

Toxoplasmosis PCR

Question 12

What is the risk of fetal transmission of toxoplasmosis in the first trimester?

Answer 12

6% transmission risk

Question 13

What is the risk of fetal transmission of toxoplasmosis in the second trimester?

Answer 13

25% transmission risk

Question 14

What is the risk of fetal transmission of toxoplasmosis in the third trimester?

Answer 14

Highest in later gestation

60% transmission risk

Question 15

In which trimester of pregnancy is the greatest risk of fetal infection with toxoplasmosis?

Answer 15

infection worse in first trimestsr

Question 16

Which patients are candidates for toxoplasmosis serology?

Answer 16

HIV positive / AIDS

Question 17

What are fetal risks of in utero toxoplasmosis infection?

Answer 17

The earlier gestation age the more likelihood for fetal infection and its severity

Question 18

How do you counsel a patient regarding fetal and neonatal outcomes following in utero toxoplasmosis infection?

Answer 18

• 90% develop sequelae
• chorioretinitis
• visual impairment
• hearing loss
• severe neurodevelopment delay

Treatment:
pyrimethamine + sulfadiazine + leukovorin x 1 year

Spiramycin can be given in pregnancy in the setting of infection