Infectious Disease Flashcards
What are the risk factors for Hib meningitis?
Partially immunized Unimmunized New to Canada Immunosuppressed Immune-incompetent
Who is at risk for listeria meningitis?
Age (neonate)
immunocompromised
brainstem symptoms as initial presentation
Drug of choice for GBS infection?
Penicillin
What are the contraindications to an LP?
Coagulopathy
Cutaneous lesion at proposed puncture site
Signs of herniation
Unstable pt
What are your empiric Abx choices for meningitis >1 mo and why?
What Abx do you add if worried about listeria?
Ceftriaxone 100mg/kg/day div q12
(Or cefotaxime 300 mg/kg/day div q6h)
Vanco 60 mg/kg/day div q6h
- ceftriaxone bc some strep pneumo and n menin are penicillin resistant
- vanco bc a small portion of strep pneumo is resistant to 3rd gen cephalo
Ampicillin 300mg/kg/day div q4-6h
What is the drug of choice for close contacts of pt with meningococcal disease or Hib?
Rifampin
When do we give steroids for meningitis and why?
Hib
Shown to decrease hearing loss
-some experts say if suspect bacterial etiology start iV steroids within 30mins of antibiotics and continue q6h (total 2 days doe strep pneumo and Hib)
In which cases of meningitis should you do a repeat LP?
Gram negatives (eg E. coli) at 24 to 48h HSV meningitis (near end of 21 day course)
How long do we treat meningitis due to: A) strep pneumo B) Hib C) n meningitides D) GBS
A) 10-14 days
B) 7-10 days
C) 5-7 days
D) 14-21 days
What are the main bugs for kids with meningitis >1 month?
H flu type b (rare…now more non typable)
N meningitides
Strep pneumo
GBS and E. coli if child is
How is C. diff spread and what is the incubation period from time of exposure?
Fecal-oral
2-3 days
What are risk factors for C diff infection?
Duration of hospital stay Older age Exposure to multiple Abx classes Chemotherapy Immunosuppression Hypogammaglobulonemia GI surgery
What are the important pathophysiological features of C diff?
Heat resistance of spores
Acid resistance of spores
Toxin production (A enterotoxin, B cytotoxin)
What are the diagnostic criteria for C diff?
Presence of symptoms (usually diarrhea) PLUS stool test positive for toxin OR scope showing pseudomembranous colitis
Which populations are most likely to have complications from c diff?
Neutropenic oncology kids
Stem cell transplant recipients
Infants with hirschsprungs
IBD pts
What tests are commonly used for dx of C diff?
- Enzyme immunoassay (EIA) for glutamate dehydrogenase
- EIA for toxins A and B
- Cell cytotoxic assay
What is the treatment for mild, mod, severe, severe/complicated c diff?
Mild - stop Abx
Mod - stop Abx, metronidazole PO 30 mg/kg/day div q6h x 10-14 days
Severe - stop Abx, vanco PO 40 mg/kg/day div q6h x 10-14 days
Severe/complic - stop Abx, Vanco PO PLUS IV flagyl 30/mg/kg/day q6h x 10-14 days
How do we treat first and second recurrences of c diff?
First recurrence- same as initial
Second - Vanco PO wih tapered or pulsed regimen
*there may be a role for probiotics in preventing recurrences
How recently should a pt have had Abx in order to include c diff in the differential?
Within the past 12 wks
What is the worst manifestation of pseudomembranous colitis?
Toxic megacolon
What groups are at risk for invasive meningococcal disease?
- Anatomical or functional asplenia
- Primary antibody deficiency disorders
- Complement, properdin or factor d def
- Travelers to areas where meningococcal risk is high
- Lab personnel with exposure to meningococcus
- The military
What are the 2 types of meningococcal vaccines, what strains do they cover and what age should they be given?
Meningococcal serogroup C conjugate (MCV-C)
- serogroup C
- all infants age 12 months (even if had doses before age 1 yr they need a dose at 12 mo)
- high risk kids can start with doses at 2 and 4 months
- adolescent booster if don’t get quadrivalent
Quadrivalent Meningococcal conjugate (MCV-4) -Types A, C, Y, W-135 -booster in adolescence -kids >2 yrs at increased risk for meningococcal disease
What is the most common cause/strain of meningococcal infection in Canada and why don’t we vaccinate against it?
Meningococcal serogroup B
(Esp in kids under 5 yrs)
-polysaccharide of serogroup B is poorly immunogenic in humans so hard to dev a vaccine
-vaccine came out last year against it (bactero) but not publicly funded yet
Does having a primary rsv infection confer protective immunity?
No. Reinfections continue into adulthood