#151 Cytomegalovirus, Parvovirus B19, Varicella Zoster, and Toxoplasmosis in Pregnancy

Question 1

What type of virus is cytomegalovirus?

Answer 1

Double-stranded DNA herpes virus

Question 2

How is cytomegalovirus trasmitted?

Answer 2

Sexual contact or direct contact with infected blood, urine, or saliva

Question 3

What is the incubation period of cytomegalovirus?

Answer 3

28-60 days (mean, 40 days)

Question 4

When can viremia be detected after CMV infection?

Answer 4

Can be detected for 2-3 weeks after primary infection

Question 5

What are typical symptoms of adult CMV infection?

Answer 5

Usually asymptomatic. May experience a mononucleosis-like syndrome (fever, chills, myalgias, malaise, leukocytosis, lymphocytosis, abnormal liver function, and lymphadenopathy)

Question 6

What is the incidence of primary CMV infection among previously seronegative pregnant women in th US?

Answer 6

0.7-4%

Question 7

What is a secondary CMV infection?

Answer 7

Intermittent viral excretion in the presence of host immunity, can occur after reactivation of the latent endogenous CMV strain or by reinfection with a different viral strain

Question 8

What is the incidence of secondary CMV infection (reactivation vs new strain) during pregnancy in US?

Answer 8

13.5%

Question 9

How does vertical transmission of CMV occur?

Answer 9

Transplacental infection after primary or secondary infection, exposure to contaminated genital tract secretions, breastfeeding

Question 10

What are the clinical findings of congenital CMV?

Answer 10

Most are asymptomatic at birth. Jaundice, petechiae, thrombocytopenia, hepatosplenomegaly,, growth restriction, myocarditis, and nonimmune hydrops

Question 11

What is the most common congenital infection? How often does it occur in neonates?

Answer 11

CMV. Occuring in 0.2-2.2% of all neonates.

Question 12

What type of transmission of CMV is associated with greatest risk of developing clinical sequelae?

Answer 12

Transplacental transmission

Question 13

Is CMV exposure through breast milk associated with severe neonatal sequelae?

Answer 13

No, typically asymptomatic

Question 14

Is CMV exposure through cervical secretions during delivery associated with severe neonatal sequelae?

Answer 14

No, typically asymptomatic

Question 15

What is the risk of transmission of CMV to fetus with primary maternal CMV infection?

Answer 15

30-40%

Question 16

During which trimester is the risk for vertical transmission of CMV the greatest?

Answer 16

3rd

Question 17

What are the transmission rates for primary CMV infection by trimester?

Answer 17

30% in first
34-38% in second
40-72% in third

Question 18

During which trimester is transmission of maternal CMV infection associated with more serious fetal sequelae?

Answer 18

First trimester

Question 19

Of fetuses infected in utero after primary CMV infection, what % will have signs and symptoms of CMV infection at birth and how many will eventually develop sequelae?

Answer 19

12-18% at birth. Up to 25% will develop sequelae.

Question 20

What % of infants severely affected by congenital CMV will die?

Answer 20

approximately 30%

Question 21

What % of infants surviving congenital CMV infection will have severe neurologic morbidity?

Answer 21

65-80%

Question 22

What is the rate of vertical CMV infection after a recurrent infection?

Answer 22

0.15-2%

Question 23

What are the typical outcomes after infant infected with maternal CMV reactivation?

Answer 23

Most infants asymptomatic at birth. Congenital hearing loss is most severe sequela. Unlikely to produce multiple sequelae

Question 24

What type of virus is Parvovirus B19?

Answer 24

Single-stranded DNA virus

Question 25

What does Parvovirus B19 cause in children?

Answer 25

Erythema infectiosum (aka fifth disease). Slapped cheek appearance, fever, body rash, joint pain

Question 26

What is the most common symptom of parvovirus B19 infection in immunocompentent adults?

Answer 26

reticular rash on the trunk and peripheral arthropathy, about 20% are asymptomatic

Question 27

What is a possible manifestation of parvovirus B19, particularly in individuals with underlying hemoglobinopathy?

Answer 27

Transient aplastic crisis

Question 28

How is parvovirus B19 typically transmitted?

Answer 28

Respiratory secretions and hand-to-mouth contact

Question 29

When is someone typically infectious with parvovirus B19?

Answer 29

5-10 days after exposure before onset of rash or other symptoms (no longer infectious with rash)

Question 30

What percentage of reproductive-aged women are seropostiive for parvovirus B19?

Answer 30

50-65%

Question 31

Exposure to a household member with parvovirus B19 conveys what risk of seroconversion?

Answer 31

50%

Question 32

What is the risk of transmission of parvovirus B19 in a classroom setting?

Answer 32

20-50%

Question 33

What are the rates of maternal-to-fetal transmission of parvovirus B19 after acute infection?

Answer 33

17-33%

Question 34

What adverse pregnancy outcome(s) has parvovirus B19 been associated with?

Answer 34

spontaneous abortion, hydrops fetalis, and stillbirth

Question 35

What is the rate of fetal loss among women with parvovirus B19 infection before and after 20wks GA?

Answer 35

Before 20wks=8-17% | After 20wks = 2-6%

Question 36

What percent of nonimmune hydrops fetalis are associated with parvovirus B19 infection?

Answer 36

8-10% (potentially up to 18-27%)

Question 37

How does parvovirus B19 lead to hydrops fetalis?

Answer 37

Virus is cytotoxic to erythroid precursors, most often results from aplastic anemia, although can be related to myocarditis or chronic fetal hepatitis

Question 38

When are severe effects most frequently seen among fetuses affect by maternal parvovirus B19 infection (what GA)?

Answer 38

Prior to 20 weeks, particularly second trimester

Question 39

Within how long after maternal infection with parvovirus B19 would you expect to see hydrops fetalis?

Answer 39

Unlikely to develop if not occurred by 8wks after maternal infection

Question 40

What type of virus is Varicella zoster?

Answer 40

DNA herpes virus

Question 41

How is varicella zoster transmitted?

Answer 41

Respiratory droplets or close contact

Question 42

What is the infection rate among seronegative contacts for varicella zoster?

Answer 42

60-90%

Question 43

What is the incubation period of varicella zoster?

Answer 43

10-20 days, mean of 14 days

Question 44

When is the period of infectivity with varicella zoster?

Answer 44

48 hours prior to rash until vesicles crust over

Question 45

What does primary infection of varicella zoster cause?

Answer 45

Chicken pox: fever, malaise, maculopapular pruritic rash that becomes vesicular

Question 46

What happens with varicella zoster virus reactivation?

Answer 46

Herpes zoster (aka shingles)

Question 47

What percentage of women with varicella infection during pregnancy will develop pneumonia?

Answer 47

10-20%

Question 48

What is the maternal mortality risk of varicella pneumonia during pregnancy?

Answer 48

As high as 40%

Question 49

How does varicella transmit vertically to fetus?

Answer 49

Through the placenta

Question 50

What is the risk of congenital varicella syndrome?

Answer 50

0.4-2%

Question 51

What are the characteristics of congenital varicella?

Answer 51

Skin scarring, limb hypoplasia, chorioretinitis, microcephaly

Question 52

When is neonatal VZV infection associated with highest rake of neonatal death?

Answer 52

When maternal disease develops from 5 days before delivery to 2 days postpartum

Question 53

What is the causative agent of toxoplasmosis?

Answer 53

Intracellular parasite Toxoplasma gondii

Question 54

What is the invasive form of toxoplsam gondii?

Answer 54

A trophozoite

Question 55

How are humans infected with toxoplasmosis?

Answer 55

Human consumption of cysts in undercooked meat and infected animals, consumption of insect-contaminated food, contact with oocysts from the feces of infected cats or contact with infected materials or insects in soil

Question 56

How does toxoplasmosis present in adults?

Answer 56

Typically asymptomatic. most commonly Cervical lymphadenopathy (10-20%). Other symptoms: fever, malaise, night sweats, myalgias, hepatosplenomegaly

Question 57

What is the risk of congenital toxoplasmosis from an infected woman? How does rate change per trimester?

Answer 57

20-50% overall. First trimester 10-15%. 2nd trimester 25% 3rd trimester >60%

Question 58

When during gestation is infection with toxoplasmosis associated with more severe sequelae?

Answer 58

The earlier the worse the disease

Question 59

What are infant sequelae of toxoplasmosis infection?

Answer 59

Chorioretinitis (subsequent severe visual impairment), hearing loss, severe neurodevelopmental delay, rash, hepatosplenomegaly, ascites, fever, periventricular calcifications, ventriculomegaly, and seizures

Question 60

How can you diagnose maternal CMV infection?

Answer 60

- serum samples collected 3-4 wks apart in parallel for IgG - Seroconversion from neg to pos (or increase in titer) - IgG avidity assays (measures maturity of IgG antibody) -- immature (low-avidity) produced in first 2-4 months

Question 61

What percentage of women with CMV-specific IgM have a primary infection?

Answer 61

10-30%. Useful, but not reliable indication of primary infection

Question 62

What ultrasound findings are concerning for congenital CMV?

Answer 62

abdominal and liver calcifications, hepatosplenomegaly, echogenic bowel or kidneys, ascites, cerebral ventriculomegaly, intracranial calcifications, microcephaly, hydrops fetalis, and growth restriction

Question 63

How can you diagnose congenital CMV prenatally? What is the sensitivity?

Answer 63

Culture or PCR of amniotic fluid. culture sensitivity = 70-80% PCR sensitivity = 78 - 98%

Question 64

Does the detection of CMV in amniotic fluid predict severity of infection?

Answer 64

No, just highly predictive of congenital infection

Question 65

What treatments are available for maternal or fetal CMV infection?

Answer 65

No therapies available. Only medications available for patients with AIDS or organ transplants (ganciclovir, valganciclovir, foscarnet)

Question 66

Which pregnant patients are at higher risk of CMV infection?

Answer 66

Day care/child care workers, family with young children, increasing parity

Question 67

Should women be screened for CMV before or during pregnancy?

Answer 67

Routine screening of pregnant women for CMV is not recommended.

Question 68

Does CMV immunity eliminate the possibility of fetal infection?

Answer 68

No, up to 75% of congenital CMV infections worldwide may be due to reactivation of latent virus or reinfection with a new viral strain.

Question 69

Are women with IgM neg IgG pos Parvovirus B19 at risk for vertical transmission?

Answer 69

No, have immunity

Question 70

How should you treat a pregnant woman who is positive for parvovirus B19 IgM?

Answer 70

Monitored for potential infection, regardless of IgG status

Question 71

What is the next step in management for pregnant woman with known parvovirus b19 exposure and negative IgG and IgM results?

Answer 71

Repeat testing in 4 weeks, if either positive, monitor for potential fetal infection

Question 72

How can you diagnose fetal parvovirus B19 infection?

Answer 72

PCR of amniotic fluid.

Question 73

When should testing for fetal parvovirus B19 be considered?

Answer 73

Ultrasound reveals hydrops fetalis

Question 74

What should be assessed on ultrasound in patient with parvovirus b19 infections?

Answer 74

Ascites, placentomegaly, cardiomegaly, hydrops fetalis, and impaired fetal growth, MCA dopplers peak systolic velocity

Question 75

How often and for how long after Parvovirus B19 infection should you ultrasound the fetus?

Answer 75

Every 1-2 weeks for 8-12wks after exposure

Question 76

What is the next step in management for fetus affected by parvovirus B19 and hydrops fetalis or severe fetal anemia?

Answer 76

Fetal blood sampling to test hematocrit in preparation for fetal transfusion

Question 77

Should all women be screened for parvovirus B19 before or during pregnancy?

Answer 77

Not recommended given low incidence of seroconversion during pregnancy

Question 78

How do you diagnose maternal varicella zoster virus infection?

Answer 78

Diagnosed on clinical findings (pruritic, vesicular rash). Can unroof lesion and test w/ PCR

Question 79

What is the risk of congenital varicella syndrome after maternal infection?

Answer 79

1-2%, but these rates may be overestimated

Question 80

What ultrasound findings are suggestive of congenital varicella?

Answer 80

Hydrops, hyperechogenic foci in the liver and bowel, cardiac malformations, limb deformities, microcephaly, and fetal growth restriction

Question 81

What should you give and when to pregnant women who contract varicella zoster virus?

Answer 81

Oral acyclovir started within 24 hours of developing the rash. IV acyclovir for varicella pneumonia.

Question 82

Does maternal treatment of varicella decrease risk of fetal congenital varicella syndrome?

Answer 82

No

Question 83

What should infants receive if mom develops varicella around birth? How much around birth?

Answer 83

Varicella-zoster immune globulin if mom develops varicella between 5 days before or 2 days after delivery

Question 84

What should infants who develop varicella within first 2 months of life receive?

Answer 84

Treatment with IV acyclovir

Question 85

How long after varicella vaccine should a woman wait to conceive?

Answer 85

Delay for 3 months since there is a small chance of mild varicella infection after life, attenuated vaccine

Question 86

How often does congenital varicella develop after accidental administration of varicella vaccine during pregnancy?

Answer 86

No reports of it happening

Question 87

How quickly after exposure to person with varicella should a pregnant woman receive treatment and what kind of treatment?

Answer 87

varicella immunoglobulin as soon as possible, ideally within 96 hours of exposure, but up to 10 days after exposure

Question 88

How do you test for maternal toxoplasmosis infection?

Answer 88

Serologic testing for detection of the specific antibody is primary method

Question 89

What is the next step to try and identify acute parvovirus b19 infection in a woman with positive IgM and IgG?

Answer 89

Repeat serologic testing in 2-3 weeks, increase in IgG antibodies is consistent with recent infection

Question 90

Do avidity assays have a role in detecting Parvovirus B19 infection?

Answer 90

Yes, low avidity indicative of primary infection within the past 5 months

Question 91

What ultrasound findings are found with congenital toxoplasmosis?

Answer 91

Ventriculomegaly, intracranial calcifications, microcephaly, ascites, hepatosplenomegaly, and IUGR

Question 92

What should be offered to pregnant women when feteal toxoplasmosis is suspected?

Answer 92

Amniocentesis should be offered with PCR

Question 93

When should amniocentesis be performed for suspected toxoplasmosis infection? Why?

Answer 93

After 18wks gestation to lessen chance of false-negative test result

Question 94

What is the goal of maternal treatment of suspected Parvovirus B19 infection?

Answer 94

Reduce congenital disease severity. Does not prevent fetal infection.

Question 95

What should be used to treat maternal toxoplasmosis infection?

Answer 95

Spiramycin, reduces transplacental parasitic transfer

Question 96

What type of antibiotic is spiramycin?

Answer 96

Macrolide antibiotic

Question 97

Why is spiramycin the choice for treatment of pregnant women with toxoplasmosis infection (without suspected fetal infection)?

Answer 97

It concentrates in, but does not readily cross, the placenta

Question 98

How is fetal toxoplasmosis infection treated?

Answer 98

Combination of pyrimethamine, sulfadiazine, and folinic acid. can lessen the severity of disease in the affected fetus

Question 99

How are infants with symptomatic congenital toxoplasmosis treated?

Answer 99

Pyrimethamine, sulfadiazine, and folinic acid for 1 year

Question 100

How should women be counseled on prevention of toxoplasmosis?

Answer 100

Proper hand washing techniques, pet care measures, and dietary recommendations. [cat feces, contaminated meat, dairy, produce, water; working in soil without gloves]

Question 101

Should women be screened for toxoplasmosis before or during pregnancy?

Answer 101

Not recommended, except for women who are immunosuppressed or HIV positive