Chapter 15 Perinatal Infections

Question 1

toxoplasmosis

Answer 1

infection by protozoan Toxoplasma gondii. transmission by eating cysts in undercooked meat of infected animals / oocysts from feces of an infected CAT.

Question 2

primary infection of toxo is usually asymptomatic , but may cause congenital infection in the fetus.

Answer 2

Risk of fetal infection highest if infected in 3rd trimester (60%) but risk of SEVERE fetal injury is highest if materal infection occurs in 1st trimester.

Question 3

complications of fetal toxo infection (fetal infection in 1/3 of cases)

Answer 3

1. fetal demise
2. impaired vision resulting from chorioretinitis
3. uveitis
4. seizures
5. mental retardation
6. enlarged spleen and liver
7. disseminated purpuric rash
8. significant learning disabilities.
   the classic triad consists of chorioretinitis, hydrocephalus, intracranial calcifications

Question 4

US findings of toxoplasmosis infection in infant:

Answer 4

ventriculomegaly, intracranial calcifications, microcephaly, ascites, hepatosplenomegaly, intrauterine growth restriction

Question 5

treatment of toxo in pregnancy:

Answer 5

SPIRAMYCIN may reduce risk of congenital infection by 50% (only availabe through FDA after serologic confirmation). PYRIMETHAMINE and SULFADIAZINE is indicated if diagnosis is confirmed in the fetus. FOLINIC ACID must be adminstered with PYRIMETHAMINE to rescue human cells.

Question 6

in untreated neonates with congenital infection:

Answer 6

poor prognosis with high rates of chorioretinitis, seizures, and severe psychomotor retardation

Question 7

SYPHILIS

Answer 7

infection by spirochete TREPONEMA PALLIDUM. transmission by DIRECT sexual contact with ulcerative lesions on skin / mucous membranes. congenital infection results from TRANSPLACENTAL PASSAGE OF SPIROCHETES, which has highest risk in the 2nd half of pregnancy and in mothers with primary or secondary syphilis.

Question 8

congenital infection of syphilis results in

Answer 8

stillbirth 25%, fetal hydrops, preterm labor.

Question 9

diagnosis of syphilis

Answer 9

direct visualization of spirochetes under darkfield microscopy or direct fluorescent antibody tests from the lesion.

Question 10

screening tests for syphilis (nontreponemal tests)

Answer 10

1. veneral disease research laboratory (VDRL)
2. rapid plasma reagin (RPR)
   once screening tests are positive, specific treponemal tests (MICROHEMAGGLUTINATION and FLUORESCENT TREPONEMAL ANTIBODY ABSORPTION) are used for confirmation.

Question 11

treponemal tests remain positive for life with or without treatment

Answer 11

true

Question 12

US findings of syphilis

Answer 12

fetal hepatomegaly, ascities, hydrops, thickened placenta

Question 13

TX of syphilis

Answer 13

parenteral penicillin drug of choice for all stages of syphilis.

Question 14

Jarisch-Herxheimer

Answer 14

occurs within several hours of treatment of primary or secondary syphilis and resoles by 24-36 hours.
Fever, chills, malaise, headache, hypotension, transient worsening of cutaneous lesions.
Increases risk of preterm labor / fetal distress if treatment given in 2nd half of pregnancy with this reaction.

Question 15

Rubella (German measles)

Answer 15

transmission via respiratory droplets. fetal transmission depends on time of exposure to virus. 50-80% of infants exposed to virus within 12 weeks after conception will manifest signs of congenital infection. Rate declines with advancing gestational age. (few fetuses are affected if infection occurs after 18 weeks gestation)

Question 16

clinical rubella:

Answer 16

3-5 days , non puritic, erythematous maculopapular rash. approximately 60% of infected fetuses will have IUGR

Question 17

diagnosis of rubella:

Answer 17

isolation if VIRUS from nasal secretions, throat swab, blood, urine , or cerebrospinal fluid (CSF).
SEROLOGIC TESTING : 4 fold increase in the antibody titer indicates infection. Rubella specific IgM antibody = acute infection. rising titers of IgG suggestive of congenital infection.

Question 18

US findings of rubella:

Answer 18

growth restriction, microcephaly, CNS abnormalities, cardiac abnormalities.

Question 19

treatment of rubella

Answer 19

none

Question 20

Cytomegalovirus (CMV)

Answer 20

double stranded DNA herpesvirus transmitted by close personal contact. Risk of fetal infection is highest if mother has a primary CMV infection in the 3rd trimester. Risk of severe fetal sequelae is highest if infection occurs in 1st trimester.

Question 21

most common congenital CMV infection affecting 0.2-2% of all neonates; leading cause of

Answer 21

hearing loss

Question 22

risk of transmission with primary maternal CMV infection is ___. risk with recurrent maternal infection is ___.

Answer 22

30-40%

0.15%-2%

Question 23

CMV clinical symptoms:

Answer 23

asymptomatic in adults; occasionally mild flulike illness. 85-90% of infants with congenital CMV are asymptomatic; of these, 10%-15% develop hearing loss, chorioretinitis, dental defects by age 2 years.

Question 24

diagnosis of CMV: routine screening not recommended.

Answer 24

maternal dx: seroconversion from NEG to POS or greater than 4 fold increase in anti-CMV IgG titers is evidence of infection.

Question 25

US findings for CMV:

Answer 25

intracerebral calcifications, ventriculomegaly, microcephaly, oligohydramnios, growth restrction, and hydrops (less common: heart block, echogenic bowel, meconium peritonitis, renal dysplasia, ascities, pleural effusions)

Question 26

treatment for CMV:

Answer 26

Intravenous CMV specific hyperimmune globulin every month throughout pregnancy.

Question 27

Herpes Simplex Virus (HSV)

Answer 27

oropharyngeal or genital infection by double stranded DNA herpesvirus. transmission via sexual contact.

Question 28

diagnosis of HSV:

Answer 28

viral culture of vesicle fluid; results usually available in 48-72 hours.

Question 29

treatment: for HSV

Answer 29

supportive measures: 1. oral analgesics, topical anesthetics, frequent bathing followed by drying affected area with hair dryer; oral acyclovir therapy (valacyclovir and famciclovir)
2. neonatal infection prevented by cs in PRESENCE of herpes lesions.
3 women with nongenital herpes should utilize barriers and avoid contact of newborn with infected maternal skin until lesions have encrusted.

Question 30

prevention: HSV

Answer 30

suppressive viral therapy encouraged at or beyond 36 weeks. (in women with active recurrent genital herpes)

Question 31

Gonorrhea

Answer 31

gram NEGATIVE Neisseria gonorrhoeae. 2nd most commonly reported communicable disease in US.
- risk of transmission from infected male to female partner is 50-90%

Question 32

clinical Gonoorrhea:

Answer 32

most women asymptomatic; but may report vaginal discharge / dysuria. Women in 2nd and 3rd trimesters are at increased risk of disseminated disease: 1st stage: chills, fevers, vesicles -> pustules with hemorrhagic base; rarely, perihepatitis, endocarditis meningitis.
2nd stage: septic arthritis.

Question 33

gonorrhea increases risk for

Answer 33

premature rupture of membraes (PROM), chorioamnionitis, preterm delivery, IUGR, neonatal sepsis, postpartum endometritis.

Question 34

neonatal sequelae:

Answer 34

ophthalmia neonatorum ilateral conjunctivitis, which can lead to corneal ulceration and blindness if untreated, and disseminated gonococcal infection.

Question 35

group b streptococcal infection (GBS)

Answer 35

gram positive bacteria. caused by streptococcus agalactiae. overall case fatality rate of 4% to 6%.
2-3% in term.
16-30% in preterm
early onset neonatal infection within 1st week of life, usually in first 48 hrs. rapid clinical deterioration and high mortality rate; which may lead to death within hours from SEPTIC SHOCK and RESPIRATORY DISTRESS. MENINGITIS in 10-30%

Question 36

negative predictive value of GBS cultures performed gestation before delivery is

Answer 36

95-98%. clinical utility decreases at >5 weeks before delivery.

Question 37

GBS in urine

Answer 37

give intrapartum antibiotic prophylaxis . prenatal screening at 35-37 weeks is not indicated.
- treat bacteriuria as usual at time of culture positivity. this will not eradicate recolonization from genitourinary and gastrointestinal tracts; therefore IAP still indicated.

Question 38

women with previous birth of infant with GBS DISEASE should receive IAP

Answer 38

true.

they do not require prenatal screening.

Question 39

Varicella Zoster irus (VZV)

Answer 39

causes varicella (chickenpox) and herpes zoster infections (Shingles)

Question 40

transmission of VZV

Answer 40

respiratory droplets and direct contact with vesicular lesions.

Question 41

clinical sx of VZV:

Answer 41

rash, disseminated, puritic, vesicular rash in multiple stages of evolution.
20% adults develop pneumonia; 1% encephalitis.
FEtal complications: spontaneous abortion, fetal death, congenital anomalies (ris <1% at less than 1 2 weeks gestation, and 2% weeks 13-20).
40% will have IUGR. neonatal varicella occurs when mother develops acute varicella between 5 days prior to delivery to 2 days after delivery. manifestations of neonatal varicella: mucocutaneous lesions, visceral infection, pneumonia, encephalitis; 30% will die without immediate treatment.

Question 42

diagnosis of varicella zoster virus

Answer 42

identification of anti VZV IgM antibody.

Question 43

US findings for VZV in neonate:

Answer 43

IUGR, microcephaly, ventriculomegaly, echogenic foci in liver and bowel, limb anomalies, hydrops.

Question 44

if susceptibe pregnant pt exposed to varicella, she should receive

Answer 44

IM varicella zoster immune globulin (VZIG) or oral acyclovir within 72-96 hrs.

Question 45

prevention: varicella vaccine is a live virus vaccine. it is contraindicated in pregnancy.

Answer 45

true