Infectious Disease Committee Flashcards
What factors influence the transmission of HSV infection to newborns?
- Nature of maternal infection 2. Mode of delivery 3. Duration of ROM 4. Use of intrapartum instrumentation
How is maternal genital HSV classified? (Two classifications)
- Newly acquired - Either a first episode PRIMARY infection (mother has no serum antibodies to HSV-1 or -2 at onset) or a first episode NONPRIMARY infection (mother has a new infection with one HSV type in the presence of antibodies of another type) 2. Recurrent Mother has pre-existing antibodies to the HSV type that is isolated from the genital tract
What is the most common route of Neonatal HSV acquisition?
Intrapartum (Although In Utero and Postnatal infections can occur, it is not the most common)
What category of maternal genital HSV (Primary or Recurrent) have the highest risk of HSV transmission? Why?
Categorizing the maternal genital HSV infection as either primary or recurrent is important! Mom who have had an HSV infection transmit HSV-neutralizing antibodies to their infant across the placenta, provided that their infant is not born before 32 weeks Therefore, infants born to moms with a first-episode primary infection at time of delivery are at the highest risk of acquiring HSV, with transmission rates up to 60% because the mom has no pre-existing neutralizing antibodies to transmit Second highest risk = First episode non-primary infection Lowest risk = Recurrent infections
What is the role of elective C/S for NHSV transmission?
Elective C/S markedly reduces but does not eliminate the risk for newborn infection
How are pregnant women with recurrent genital HSV treated during pregnancy?
They are given prophylaxis with acyclovir or valcyclovir from 36 weeks until delivery. This helps lower the recurrence of genital HSV and shedding at delivery BUT we are not sure if this translates to a reduced risk for NHSV infection
Why are infant serologies (HSV IgG and IgM) not useful in diagnosing neonatal HSV infections? (Three reasons)
- Transplancental IgG antibodies cannot be differentiated from IgG produced by the infant 2. Severely affected infants can not make antibodies (it is impaired) 3. HSV IgM antibody assays are variable and limited reliability
What is the duration of therapy for NHSV infections?
Depends on the category of disease. SEM disease - 14 day course of IV acyclovir Disseminated/CNS disease - minimum 21 days of IV acyclovir
What are the side effects of using IV acyclovir for the treatment of NHSV?
Neutropenia, Nephrotoxicity
What is the additional medication you give for an infant with ocular HSV manifestations?
1% Trifluridine with the IV acyclovir
What swabs need to be done for an HSV exposed asymptomatic neonate?
When evaluating NHSV infection in exposed asymptomatic infants, mucous membrane swabs should be obtained from the mouth, nasopharynx and conjunctivae AT LEAST 24 h after delivery. Additional swabs may be obtained (eg, from sites of scalp electrodes, if present).
How do you manage an asymptomatic neonate who was delivered via C/S before ROM by a mom with active HSV lesions that is presumed first-episode primary or first-epsiode non-primary HSV infection?
Risk for NHSV is very low If child is asymptomatic, take mucosal swabs (mucous membranes, NP swab) at 24 hours of life. Do HSV PCR by blood if available. Neonate can be discharged pending results If results are positive, then need to be managed as an HSV case
How do you manage an asymptomatic neonate who was delivered vaginally or C/S after ROM by a mom with active HSV lesions that is presumed first-episode primary or first-episode non-primary HSV infection?
Do type-specific antibodies for HSV on mom. Infant’s mucous membrane swabs be obtained and should be started on IV acyclovir. Do blood HSV PCR if available. If positive results - Do LP to determine acyclovir duration If negative results - check mom’s serologies. If mom’s results are more in keeping with recurrent HSV - stop ACV If mom’s results are not available or in keeping with a first HSV infection, baby needs 10 days of ACV despite negative swabs
How do you manage an asymptomatic neonate who was delivered by C/S by a mom with active HSV lesions, thought to be recurrent HSV?
If child is asymptomatic, take mucosal swabs (mucous membranes, NP swab) at 24 hours of life. Do HSV PCR by blood if available. Neonate can be discharged pending results If results are positive, then need to be managed as an HSV case
How do you manage an asymptomatic neonate who was delivered vaginally by a mom with active HSV lesions, thought to be recurrent HSV?
If child is asymptomatic, take mucosal swabs (mucous membranes, NP swab) at 24 hours of life. Do HSV PCR by blood if available. Neonate can be discharged pending results If results are positive, then need to be managed as an HSV case
How do you manage a neonate born to a mom who does not have active HSV lesions at delivery?
Observe for signs for NHSV and educate parents, but no swabs necessary. Consider swabs if active lesions were seen during the third trimester or near delivery
Historically, what are the three top causes of meningitis prior to the introduction of vaccines?
- Strep pneumo 2. Hemophilus Influenza Type B 3. Neisseria Meningitidis
In which circumstances do you consider listeria meningitis beyond the neonatal period? What antibiotic would you add if you suspected listeria?
- Specific host risk factors (i.e. immunosuppression) 2. Brainstem infection as the initial presentation You would add ampicillin to cover for listeria
What are 4 contraindications in performing an LP on a child you suspect meningitis in?
- Coagulopathy 2. Cutaneous lesions at the proposed puncture site 3. Signs of herniation 4. Unstable clinical status such as shock
Based on one adult study, what are the three factors associated with poor prognosis with meningitis?
- Delay in starting antibiotics 2. Severity of clinical state at presentation 3. Isolation of nonpenicillin-susceptible strep pneumoniae
What is the empiric therapy when meningitis is suspected in a child >1 month old?
Ceftriaxone/Cefotaxime + Vancomycin
What antibiotic do we use to treat the close contacts of a child who had meningococcal or HiB meningitis?
Rifampin
In which clinical situation does research support the use of steroids in acute bacterial meningitis?
HiB meningitis where evidence shows that steroids decrease hearing loss in children if they are administered just before or with the initial antimicrobial therapy
What should the CSF gram stain show before you consider starting IV dexamethasone? How long should you continue IV dexamethasone for?
If there are no contraindications to steroid use for a particular infant or child, when a bacterial meningitis is suspected (especially if CSF gram stain shows gram positive diplococci or gram negative coccobacili), some experts recommend starting IV steroids immediately before, concomitant with, or within 30 minutes after the first dose of antimicrobials. If Strep pneumo or HiB is cultured or identified by molecular testing, steroids should be continued for 2 days but if another etiology is found within 48 hours, then steroids should be discontinued

