Infectious Diseases Flashcards
H influenza b is now relatively uncommon in Canada, except in which groups of children?
- unimmunized
- partially immunized
- child new to Canada
- immunocompromised
How do the symptoms of meningitis differ between infants and children/adolescents?
- Infants: more non-specific findings, absence of nuchal rigidity
- Children/Adolescents: more likely to have specific symptoms (headache, nuchal pain/rigidity, impaired LOC)
List 4 contraindications to lumpar puncture
- Coagulopathy
- Cutaneous lesions at the proposed puncture site
- Signs of herniation
- Clinical instability (ie. shock)
- Focal neurological defects (unless head imaging normal)
List two potential complications of acute meningitis
- SIADH
2. Increased ICP
What are the bacterial organisms most likely to cause meningitis in patients older than 1 month?
- Strep pneumoniae
- N meningitidis
- GBS/E coli (only in infants
When should steroids be used in the management of acute meningitis?
- when there are no other contraindications to steroid use, for patient suspected to have meningitis of bacterial aetiology
- to be given before, concomitant with or within 30 minutes after the administration of the first dose of antibiotics.
What are the minimum durations of therapy for meningitis caused by S. pneumo, H influenza b, N meningitidis, GBS, respectively
- S. pneumo = 10-14 days
- H influenza b = 7-10 days
- N meningitidis = 5-7 days
- GBS = 14-21 days
What are the types of maternal genital HSV cases?
- First episode primary infection (mother has no serum antibodies to HSV 1 or 2), newly acquired
- First episode non primary infection (mother has serum antibodies to the opposite type of HSV than she is infected with), newly acquired
- Recurrent infection (mother has pre-existing antibodies to the HSV type with which she is infected.
Which type of maternal genital HSV infection holds the highest risk of transmission to infant?
- First episode primary infection (followed by First episode non primary infection, followed by low risk from Recurrent)
What are ways in which risk of transmission of HSV can be decreased when mother is known to have genital HSV infection?
- elective C/S
- prophylaxis with acyclovir/valacyclovir from 36 weeks onwards until delivery
- avoidance of using scalp sampling/monitoring, forceps/vaccums
- avoidance of PROM
How are perinatal/natal/postnatal HSV infections in the infant classified?
- Skin, eyes, mucous membrane (SEM) infection
- Localized CNS HSV
- Disseminated HSV
What clinical features would raise suspicion of neonatal HSV infection?
- unwell infant
List the different types of tests used to detect HSV
- Viral cultures (oropharynx, nasopharynx, skin lesions, mucous membranes swabs, rectal swabs, blood buffy coat and CSF)
- PCR testing (CSF, skin lesions, mucous membranes, blood)
- Direct immunofluorescent antibody staining of skin lesions
- Enzyme immunoassays for HSV antigens in skin lesions
What is the gold standard diagnostic method for HSV outside the CNS?
- viral culture
What is the gold standard diagnostic method for HSV in the CNS?
- PCR
What are the durations of therapy for treating SEM disease, CNS disease and disseminated disease with HSV, respectively?
- SEM disease = 14 days
- CNS disease = minimum 21 days
- Disseminated disease = minimum 21 days
Follow-up for infants infected with HSV should include what?
- neurodevelopment
- vision/opthalmologic complications
- hearing/audiologic complications
How is an infant born to a mother with suspected first-episode genital HSV via C/S with no rupture of membranes managed?
- mucous membrane swabs
- +/- PCR of blood
How is an infant born to a mother with suspected first-episode genital HSV via C/S with membranes ruptured pre-delivery managed?
- mucous membrane swabs
- IV acyclovir x 10 days
How is an infant born to a mother with suspected first-episode genital HSV via vaginal delivery managed?
- mucous membrane swabs
- IV acyclovir x 10 days
How is an infant with positive HSV mucous membrane swabs managed?
- Admit
- Obtain CSF and blood for HSV PCR
- Obtain liver enzyme levels
- Treatment duration of 14 days for SEM, 21 days for disseminated or CNS infection
How is an infant born to a mother with recurrent genital HSV via vaginal delivery managed?
- Mucous membrane swabs at 24 hours
- Treat only if positive
How is an infant born to a mother with recurrent genital HSV via C/S managed?
- Mucous membrane swabs at 24 hours
- Treat only if positive
Which infants with neonatal HSV infection should receive suppressive therapy with oral acyclovir?
- infants with localized CNS HSV (not as effective for SEM or disseminated disease, but could still be offered)
- duration 6 months
- monitor CBC, BUN, Cr monthly while on acyclovir