10: Infectious disease Flashcards
Infections whose complications increase during pregnancy
UTIs
Bacterial vaginosis
Surgical wound
GBS
Infections more common in pregnancy and the puerperium
Pyelonephritis
Endomyometritis
Mastitis
TSS
Infections specific to pregnancy
Chorioamnionitis
Septic pelvic thrombophlebitis
Episiotomy or perineal lacerations
Infections that affect the fetus
Neonatal sepsis (e.g., GBS, Escherichia coli) HSV, VZV, Parvovirus B19, CMV, Rubella, HIV, Hep B and C, Gonorrhea, Chlamydia, Syphilis Toxoplasmosis
Five percent of pregnant women have ASB and are at increased risk for ? and ?
cystitis and pyelonephritis.
Lower UTIs can be treated with ?, whereas pyelonephritis in pregnancy is usually treated initially with ? then switched to ?
oral antibiotics
IV antibiotics
-change to oral regimen once afebrile for 24 to 48 hours.
Pyelonephritis may be complicated by
septic shock and ARDS
symptomatic BV is associated with
PTD
BV tx:
oral metronidazole x7d
GBS screening is performed between
35-37 weeks
Chorioamnionitis is diagnosed by
maternal fever, uterine tenderness, elevated maternal WBC count, and fetal tachycardia.
Although the infection is often polymicrobial, GBS colonization has a high correlation with both
chorioamnionitis and neonatal sepsis
tx chorioamnionitis with
IV abx and delivery
The gold standard for diagnosing acute cystitis has been a quantitative culture containing at least ?
100,000 CFU/mL.
initial treatment of ASB is usually with
amoxicillin, nitrofurantoin (Macrodantin), trimethoprim/-sulfamethoxazole (Bactrim), or cephalexin
3-7 day course
test of cure 1-2 weeks after abx completed; if +, new regimen
if women have 2+ UTIs during pregnancy
Continuous nightly antibiotic prophylaxis: Macrodantin or Bactrim
treatment for the dysuria or bladder pain
phenazopyridine (Pyridium)
- acts as a local anesthetic
- will turn urine orange
Pyelo orgs (similar to ASB and acute cystitis)
E. coli (70%), Klebsiella–Enterobacter (3%), Proteus (2%), and gram-positive bacteria, including GBS(10%)
complications of pyelo
PTL, septic shock, ARDS
Endotoxin release results in increase capillary permeability and decreased perfusion of vital organs
management of pyelo during pregnancy
admit, IVF, IV abx: cephalosporins (cefazolin, cefotetan, or ceftriaxone) or ampicillin and gentamicin until the patient is afebrile and asymptomatic for 24 to 48 hours
-10-14 days of IV and oral abx
if pyelo is not improving after abx course ?
a renal ultrasound should be performed to evaluate for a perinephric or renal abscess
BV orgs ?
BV increases risk for ?
Gardnerella vaginosis, Bacteroides, and Mycoplasma hominis.
PPROM, PTD, puerperal infection
Amsel’s criteria for dx BV (3/4 of the following)
(1) presence of thin, white or gray, homogeneous discharge coating the vaginal walls;
(2) an amine (or “fishy”) odor noted with addition of 10% KOH (“whiff” test)
(3) pH of greater than 4.5
(4) presence of more than 20% of the epithelial cells as “clue cells” (squamous epithelial cells so heavily stippled with bacteria that their borders are obscured) on microscopic examination.
(generally few leukocytes and less lactobacilli than usual on wet mount)
what given instead of PCN G for GBS due to difficulty obtaining correct dosage in emergent situations
ampicillin
if allergy to PCN but low risk for anaphylaxis to (i.e., rash allergy) ?
significant penicillin allergy (i.e., high risk for anaphylaxis) ?
severe penicillin allergy where GBS is resistant to clindamycin or of unknown susceptibility ?
cefazolin (Ancef)
clindamycin
vancomycin
what is the most common precursor of neonatal sepsis?
chorioamnionitis
intrauterine infection (chorioamnionitis) is associated with increased risk of ?
fetal: neonatal respiratory distress, pneumonia, meningitis, periventricular leukomalacia, cerebral palsy
maternal: uterine atony, postpartum hemorrhage, need for cesarean delivery, endomyometritis, septic shock
chorioamnionitis diagnosis
maternal fever (body temperature >100.4°F or 38°C), elevated maternal WBC count (>15,000/mL), uterine tenderness, maternal tachycardia and/or fetal tachycardia (>160 bpm), and foul-smelling amniotic fluid
the most sensitive and specific marker for predicting a positive amniotic fluid culture
an elevated interleukin 6 (IL-6) level in the amniotic fluid (due to fetal immune response syndrome (FIRS), which results in the release of cytokines)
acute chorionamniotis management
IV antibiotics and delivery of the fetus
-2nd/3rd generation cephalosporin, or amp+gent
HSV diagnosis
(1) viral detection techniques: viral culture and HSV antigen detection by PCR
(2) antibody detection techniques: blood test to detect Abs to HSV-1 or 2
Patients with an HSV genital outbreak during their pregnancies are offered
acyclovir prophylaxis from week 36 until delivery to prevent recurrent lesions
why does primary genital herpes infection during pregnancy constitutes a higher risk for perinatal (fetal and neonatal) transmission than recurrent infection?
(30% to 60% vs. 1% to 3%)
- reduced or no transplacental passage of protective HSV specific antibodies
- neonatal exposure to the virus in the genital tract may be increased
- genital viral shedding is of higher concentration and longer duration (15 days)
- cervical shedding also occurs
how to determine whether an HSV lesion is primary or secondary
IgM and type-specific IgG HSV antibodies may be ordered, previously infected mother will have circulating IgG antibodies
Neonatal HSV infections can be classified as
disseminated disease (25%); CNS disease (30%); and disease limited to the skin, eyes, or mouth (45%)
complications of neonatal HSV
how to tx?
viral sepsis, pneumonia, and herpes encephalitis, which can lead to neurologic devastation and death
-IV acyclovir as soon as infection is suspected
do what for women who are screened for VZV titers and are negative prior to conception
give varicella vaccine (Varivax); it is a live virus vaccine that is highly immunogenic and therefore contraindicated in pregnancy to avoid transmission to the fetus
Congenital varicella syndrome
skin scarring, limb hypoplasia, chorioretinitis, and microcephaly.
- typically btw 8-20 wga
- higher risk if closer to term
Infants of mothers who develop varicella disease within 5 days before delivery or 2 days after should also receive ?
VZIG and/or treatment with antiviral agents such as acyclovir or valacyclovir
If a susceptible pregnant patient is exposed to someone with varicella, how to treat ?
within 72 to 96 hours
VZIG (does not prevent transmission of the disease to the fetus)
-alternative:oral acyclovir (800 mg, five times daily x7) or oral valacyclovir (1,000 mg, TID x7)
Parvovirus diagnosis
IgM and IgG to determine prior exposure vs active infection
- if IgM positive: serial US
- Doppler velocimetry to examine the peak systolic velocity of the middle cerebral artery (MCA); Increases in peak systolic velocity are associated with fetal anemia
- if anemic, cordocentesis should be performed to determine the fetal hematocrit; perform intrauterine blood transfusion
CMV diagnosis
negative to positive or a significant increase (greater than fourfold, e.g., from 1:4 to 1:16) in anti-CMV IgG titers is evidence of infection
-IgM titers may not be positive during an acute infection, or they may persist for months after the primary infection
CMV is the most common congenital infection, occurring in approximately 1% to 2% of all neonates, and is the leading cause of ?
congenital hearing loss
-most risk in 3rd trimester
cytomegalic inclusion disease
hepatomegaly, splenomegaly, thrombocytopenia, jaundice, cerebral calcifications, chorioretinitis, and interstitial pneumonitis
The most common clinical manifestations of severe neonatal infection
hepatosplenomegaly, intracranial calcifications, jaundice, growth restriction, microcephaly, chorioretinitis, hearing loss, thrombocytopenia, hyperbilirubinemia, and hepatitis
maternal–fetal rubella transmission rate is highest during the ? trimester, as are the rates of congenital abnormalities
first
four most common anomalies associated with congenital rubella syndrome (CRS)
deafness (affecting 60% to 75% of fetuses), eye defects such as cataracts or retinopathy (10% to 30%), CNS defects (10% to 25%), and cardiac malformations (10% to 20%) (PDA, supravalvular pulmonic stenosis)
how to diagnose rubella
amniocentesis, ultrasound to see if fetal injury occurred: (growth restriction, microcephaly, CNS abnormalities, and cardiac malformations)
HIV three-part regimen in pregnancy
zidovudine (ZDV) administered during pregnancy and labor and to the newborn could reduce the risk of perinatal transmission by two-thirds (from approximately 25% down to 8%)
-start at beginning of 2nd trimester
As discussed below, cesarean deliveries are recommended for women whose viral loads exceed ? copies
initiate treatment with ?
1,000 copies
HAART
All HIV-infected women should be monitored with
(1) viral loads every month until the virus is undetectable and then every 2 to 3 months
(2) CD4 counts (absolute number or percent) each trimester
(3) resistance testing if they have recently seroconverted or if the therapy failed.
it is recommended that HIV screening be offered to all pregnant women at ? on an informed “opt-out” basis and again in the ? trimester if the woman has specified risk factors for HIV infection (i.e., other sexually transmitted infections diagnosed during pregnancy)
their first prenatal visit
third trimester
Women identified as HIV infected in labor should be treated with either
(1) zidovudine—in labor IV and 6 weeks to the neonate; (2) nevirapine—as a single dose to the mother in labor and as a single dose to the neonate; (3) zidovudine–lamivudine—in labor and to the neonate for 1 week; or (4) both nevirapine as above and the zidovudine regimen as above.
can HIV+ women breastfeed?
breastfeeding is contraindicated in HIV-infected women (in resource-rich nations), as virus is found in breast milk and can lead to HIV transmission to the infant
Gonococcal infections are associated with
PID in early pregnancy, PTD, PPROM, puerperal infections throughout pregnancy, chorioamnionitis, neonatal sepsis, and maternal postpartum sepsis
amniotic infection syndrome (manifestation of G/C infection in pregnancy)
placental, fetal membrane, and umbilical cord inflammation that occurs after PROM and is associated with infected oral and gastric aspirate, leukocytosis, neonatal infection, and maternal fever
-PTD is common
neonatal G/C infection can affect ? and lead to ?
eye, oropharynx, external ear, and anorectal mucosa
can disseminate and lead to arthritis and meningitis
if G/C ophthalmia is untreated, can lead to corneal ulceration, scarring, blindness
Screening for gonorrhea should be performed for pregnant women with risk factors when?
with what test?
in the first prenatal visit and again in the third trimester
nucleic acid amplification tests (NAAT) or culture
G/C treatment
IM ceftriaxone, oral cefixime, IM spectinomycin (if cephs cannot be tolerated)
+azithromycin or amoxicillin for presumed chlamydial infection
Chlamydia during pregnancy is associated with
PTD, PROM, LBW, neonatal death, conjunctivitis, pneumonia
Approximately 25% to 50% of infants exposed to chlamydia acquire ? in the first 2 weeks of life, and 10% to 20% develop ? within 3 or 4 months.
conjunctivitis
pneumonia
it is recommended that all pregnant women should be screened for chlamydia in the ? and, if deemed as high risk, again ?
in the first prenatal visit
in the third trimester
treatment of choice for chlamydial infection in pregnancy
azithromycin (1x dose), amoxicillin, or erythromycin (tetracycline and doxy are CI in pregnancy)
screen who for Hep B and when?
all patients during the prenatal period
Neonates delivered to seropositive mothers should receive ?
hepatitis B immune globulin within 12 hours after birth and hepatitis B vaccination series before discharge
CDC recommendations for Hep B vaccine
universal vaccination of all infants for hepatitis B. In addition, the vaccine should be offered to all women of reproductive age.
Syphilis during pregnancy that results in vertical transmission may lead to
a late abortion, intrauterine fetal demise, hydrops, preterm delivery, neonatal death, early congenital syphilis, and the classic stigmata of late congenital syphilis
-most severe outcomes occur with primary or secondary syphilis
Neonates with early congenital syphilis (onset at younger than 2 years of age) present with
a systemic illness accompanied by a maculopapular rash, snuffles (a flu-like syndrome associated with a nasal discharge), hepatomegaly, splenomegaly, hemolysis, lymphadenopathy, jaundice, pseudoparalysis of Parrot due to osteochondritis, chorioretinitis, and iritis
(2/3 are asymptomatic at birth and do not develop evidence of disease 3-8 weeks)
congenital syphilis diagnosis
identification of IgM antitreponemal antibodies, which do not cross the placenta
If early congenital syphilis is untreated, manifestations of late congenital syphilis can develop including
saber shins, mulberry molars, Hutchinson’s teeth, saddle nose, and neurologic manifestations (CN 8 deafness, mental retardation, hydrocephalus, optic nerve atrophy, and Clutton joints)
all RPR/VDRL positives must be
confirmed with FTA-Abs, as there are false positives with both RPR and VDRL
- Confirmatory tests include the fluorescent treponemal antibody absorption (FTA-ABS) test and the T. pallidum particle agglutination (TP-PA) test
- rescreen at 28 weeks of gestation
syphilis treatments
primary syphilis: one dose of 2.4 million units benzathine penicillin G
secondary or latent syphilis: weekly treatments of 2.4 million units of benzathine penicillin G for 3 consecutive weeks
if suspect neurological involvement in patient with syphilis
LP to assess the CSF for evidence of neurosyphilis
treat with high doses of aqueous penicillin G
For primary and secondary syphilis, patients should be reexamined clinically and serologically at ? after treatment.
how to define response ?
6 and 12 months
A two-dilution (fourfold) decline in the nontreponemal titer at 1 year after treatment is used to define response.
Toxo transmission is most common but less severe in the ? trimester and less common by more severe in the ? trimester
third
first
Severe congenital toxoplasmosis infection
fevers, seizures, chorioretinitis, hydro- or microcephaly, hepatosplenomegaly, and jaundice
usual clinical manifestations of congenital toxoplasmosis
a disseminated purpuric rash, enlargement of the spleen and liver, ascites, chorioretinitis, uveitis, periventricular calcifications, ventriculomegaly, seizures, and mental retardation
what to do if If maternal diagnosis of toxoplasmosis is made or suspected early in pregnancy
evaluation of amniotic fluid with DNA PCR for T. gondii via amniocentesis at least 4 weeks after maternal infection is the recommended procedure for evaluation of fetal infection.
-if positive, targeted US exam is indicated to look for specific findings suggestive of severe fetal injury
maternal toxoplasmosis treatment
spiramycin (no teratogenic effects, but does not cross the placenta so doesn’t protect baby)
-pyrimethamine (not first trimester) and sulfadiazine for documented fetal infection + folic acid to prevent BM suppression
Aggressive early treatment of infants with congenital toxoplasmosis is indicated and consists of ?
combination therapy with pyrimethamine, sulfadiazine, and leucovorin for 1 year
C-section reduces HIV transmission by
roughly two-thirds compared to vaginal delivery in patients on no therapy and particularly without onset of labor or ROM or in the setting of high viral load >1000 copies/mL
