#220 Management of Genital Herpes in Pregnancy Flashcards
What is the prevalence of HSV-2 infection in 14- to 49-year-old females?
15.9%
What type of virus is HSV?
Double-stranded DNA virus
What differentiates HSV 1 and 2?
Glycoproteins in the lipid bilayer envelope. Glycoprotein G1 (HSV1) and G2 (HSV2)
What is HSV 1 the primary etiologic agent of?
Herpes labialis, gingivostomatitis, and keratoconjunctivitis. Increasingly common cause of oral and genital infections
What does HSV2 cause?
genital herpes
How is HSV transmitted?
Person to person through direct contact
What is the incubation period after acquisition of HSV1 or HSV2?
2 days to 12 days
Where does HSV remain latent?
In sensory nerves
When do type-specific antibodies to HSV viral proteins develop after infection?
2-3 weeks after infection
How do you determine a primary HSV outbreak?
HSV1 or HSV2 is detected from a lesion in an individual with no evidence of antibodies to either viral type in the serum
How do you determine a nonprimary first-episode infection of HSV?
When one viral type is detected in lesions from individual with evidence of antibodies to the other viral type in serum
How do you determine a recurrent HSV infection?
When HSV is detected in lesions from individuals with evidence of antibodies to the same viral type in the serum
Approximately what % of patients with infections report recognition of their infections?
5-15%
Approximately what % of US women have serologic evidence of HSV2?
~21%
Among women susceptible to HSV infection, what is the incidence of new HSV infection during pregnancy?
Approximately 2%
When is a woman during pregnancy more likely to be infected with HSV?
Timing of infection is relatively evenly distributed
Among women with recurrent genital HSV, approximately what % will have at least one recurrence during pregnancy?
Approximately 75%
Among women with recurrent genital HSV, approximately what % will have prodromal symptoms or clinical recurrence at delivery?
Approximately 14%
When is neonatal herpes usually acquired?
During intrapartum period through exposure to the virus in the maternal genital tract
Approximately how many cases of neonatal herpes occur annually in the US?
1,200-1,500
What fraction of neonatal herpes cases are caused by HSV-1?
1/3 to 1/2
What types of neonatal HSV infection are there?
Disseminated disease (25%), CNS disease (30%), and disease limited to the skin, eyes or mouth (45%)
What is the risk of mortality for disseminated neonatal HSV?
30%
What is the mortality risk for CNS neonatal HSV?
4%
What % of survivors of neonatal herpes have long-term neurologic sequelae?
~20%
What is the preferred method of testing for patients who present with genital vesicles, ulcers, or other mucocutaneous lesions?
Virologic tests - include viral culture and HSV antigen detection by PCR
How should you collect a genital specimen for HSV culture?
Unroof the vesicle, if present, and vesicular fluid should be collected
How is the sensitivity of viral culture for HSV?
Low. 80% for primary lesions, 40% for recurrent lesions
How does the sensitivity of an HSV PCR compare to culture?
PCR is 3-5x more likely to be positive
Up to what % of first-episode infections during pregnancy are recurrent HSV infections?
15%
What is a primary outbreak of HSV in the first trimester of pregnancy associated with?
Neonatal chorioretinitis, microcephaly, and skin lesions
Is routine HSV screening recommended in pregnant women?
No
What are the three common oral antiviral agents used to treat HSV infections?
Acyclovir, valacyclovir, and famciclovir
True or false, acyclovir is considered safe in the first trimester?
True
How does acyclovir work?
It is a nucleoside analogue that enters virally infected cells and acts specifically to inhibit the viral thymidine kinase and, thus, DNA replication
How is valacyclovir related to acyclovir?
Prodrug of acyclovir, rapidly converted in the liver.
What is the rate of acyclovir resistance in HSV in immunocompetent and immunocompromised patient?
0.3-0.6% in immunocompetent. 6-7% in immunocompromised.
When should you offer suppressive therapy for HSV in pregnant women?
At 36wks, if has had outbreak in pregnancy or clinical hx of genital herpes
What is the dosing of acyclovir for primary or first-episode HSV infection?
Acyclovir 400mg orally, three times daily, for 7-10days. (may extend if healing incomplete after 10d of therapy)
What is the dosing of valacyclovir for primary or first-episode HSV infection?
1g orally, twice daily, for 7-10d (can extend if healing incomplete)
What is the dosing of acyclovir for symptomatic recurrent episode of HSV?
400mg orally, three times daily, for 5 days or 800mg orally, twice daily for 5 days
What is the dosing of valacyclovir for symptomatic recurrent episode of HSV?
500mg orally, twice daily, for 3 days or 1g orally, daily, for 5 days
What is the acyclovir dosing for daily HSV suppression?
400mg orally three times daily, from 36wks until delivery
What is the valacyclovir daily suppression dosing for HSV?
500mg orally, twice daily, from 36wk until delivery.
What is the acyclovir dosing for severe or disseminated HSV disease?
5-10mg/kg IV every 8 hours for 2-7d, then oral therapy for primary infection to complete 10d
What is the risk of vertical HSV transmission when primary outbreak occurs at the time of delivery?
Approx 40-80%
Why do neonates have higher risk of vertical transmission of HSV infection if delivery is at time of primary outbreak?
- Reduced protective HSV-2 specific antibodies that cross the placenta
- Increased virus exposure in genital tract
What is the mean viral shedding length in untreated women with primary herpes infection?
15 days
What % of women with primary herpes infection have cervical shedding?
90%
True or false, dosing for suppressive HSV therapy is the same in pregnant and nonpregnant individuals?
False. Higher renal clearance means higher doses for pregnant women
True or false, cesarean delivery is indicated in women with prodromal HSV symptoms?
True, may indicated viral shedding
What is the risk of neonatal herpes in women with HSV isolated from genital secretions at time of delivery for vaginal vs CS delivery?
Vaginal - 1.2%
CS - 7.7%
True or false, CS performed before ROM prevents HSV transmission to neonate?
False. Can still have transmission, although decreased risk.
Does a primary HSV outbreak during 3rd trimester of pregnancy affect delivery method recommendation?
Can consider CS due to possibility of prolonged viral shedding
Is CS recommended for women with recurrent HSV lesions on back, thigh, or buttock?
No. These lesions may be covered with an occlusive dressing and patient may give birth vaginally
In a patient with active HSV lesions and ROM at term, should CS be performed?
Yes.
In a patient with active HSV lesions and PPROM, should CS be performed?
Risks of prematurity should be weighed against risk of neonatal HSV in considering expectant management.
True or false, transabdominal invasive procedures (CVS, amnio, PUBS) should be deferred during active HSV infection?
False. May be performed when genital lesions are present.
True or false, transcervical invasive procedures should be deferred during active HSV infection?
True. Seems reasonable to delay procedures until lesions appear to have resolved.
Is breastfeeding contraindicated with HSV?
Only if HSV lesions on breast. Should advise women to take special considerations with handwashing
True or false, postnatally acquired HSV is less lethal than HSV acquired during delivery?
False. Can be just as lethal.
True or false, valacyclovir is safe for breastfeeding women?
True
