Pediatric Infectious Disease
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Transcript of Pediatric Infectious Disease
Pediatric Infectious Disease
Russell LamJanuary 12, 2012
Objectives Measurement of a fever Acute Otitis Media UTI Pharyngitis
Case 1 A 1 year old baby has had a typical febrile
seizure. You are planning on discharging the patient home with the usual advice.
On her way out, the mother asks you about the best way to measure the baby’s temperature so she can treat it.
What do you recommend?
What is a fever? 38°C (100.4°F) measured rectally Ways of measurement
Rectal Axillary Oral Tympanic Temporal
Rectal Thermometry Traditionally gold
standard May be slow to change
in relation to core temperature
Affected by depth of measurement, local blood flow, presence of stool
Uncomfortable Perforation is possible
but rare (1/2 000 000 measurements)
Axillary Thermometry
Easy to do but inaccurate Works best if placed directly over axillary artery but
affected by local temperature CPS recommends this as screening test in neonates
Oral Thermometry
Reflects temperature of sublingual arteries
Affected by recent ingestion of food/liquid and mouth breathing
Mouth must be sealed Accuracy lies between
axillary and rectal, better with increasing age.
Mercury?
Mercury thermometers are no longer recommended by the CPS
Read thermal radiation from TM and ear canal
Crying, AOM, or earwax does not change measurement
Accuracy is again questionable
Temporal artery thermometry More accurate than
tympanic and better tolerated than rectal
Not yet recommended when definitive measurements are required
Take home point #1
Case 2 A 4 month old boy has a fever and a runny
nose for 5 days. You fully examine the child and are about to call this a URTI when you remember to check the ears!
You see this:
Other details Never had an ear infection before Never has had antibiotics What antibiotic (and dose) would you
prescribe (if any)?
Identify the normal landmarks
Normal ear landmarks
Diagnosis of AOM 3 things
Acute onset Middle ear fluid Inflammation
Pathogens Pre-Pneumococcal vaccine =
S Pneumo 42% H Flu 31% Moraxella 16%
Post-Pneumococcal vaccine = S Pneumo 44% (1998-2000) to 31% (2001-2003) H Flu non-typeable 43% (1998-2000) to 57% in (2001-
2003) Viral only
20-30%
Duration CPS (2009)
5 days in all except for <2 years Frequent AOM AOM with perforation Failure of initial abx
Cochrane Review Kozyrskyj 2010
Short (<7 days) vs long (>7 days) course abx Treatment failure higher if short course OR 1.37 CI
1.15-1.64 at eight- to nineteen days At 30 days, treatment failure similar OR 1.17 CI 0.95-
1.43 No differences if ceftriaxone used < 7 days or
azithromycin. Better GI adverse events in short-term abx and
azithromycin.
Case 2 continued A 4 month old boy,
AOM, no prior AOM, no recent abx, febrile, NKDA
Antibiotic – yes or no?
Which one? How long?
Take home point #2 AOM is 3 things: acute, inflammation, middle
ear fluid Top 3 bugs: S Pneumo, H Flu, Moraxella First line therapy: Amoxicillin 80mg/kg/day for
5 days
Case 3 Same kid is 2 years old. No AOM since his first
one. Complains of ear pain and mom states he is tugging at his left ear.
You again diagnose AOM. Antibiotics – yes/no?
Differences between CPS/TOP/AAP CPS statement (revised 2009)
6months lower limit for treatment 1st line abx amoxicillin 75-90mg/kg/day
TOP doc statement (revised 2008) 2 years lower limit for treatment 1st line abx amoxicillin 40mg/kg/day
AAP policy statement (revised 2004) 2 years lower limit for treatment
Watchful waiting Reasoning
Viruses can be found in middle ear fluid in absence of bacteria, though usually bacteria is present
Spontaneous resolution occurs in most cases NNT for symptom resolution at 48h is 15 (CPS
2009) NNT for symptom resolution at 14 days is 9 (JAMA
2010) NNH for diarrhea is 10 (JAMA 2010)
CPS (2009) Watchful waiting approach appropriate if:
>6 mos with mild signs and symptoms Observation is possible in 48-72h
Aboriginal children Unknown if watchful waiting increase risk as they
have high incidence of chronic suppurative OM
CPS (2009) Not appropriate if:
Severe symptoms (appear toxic, otalgia, high fever 39 degrees)
Chronic disease = Immunodeficiency, chronic cardiac/pulmonary disease, Down syndrome
Anatomic abnormality of the head/neck Complications of AOM (suppurative complication
or chronic perforation)
Risks of watchful waiting Mastoiditis/Meningitis/Intracranial abscess
Exceedingly rare! 2500rx to prevent 1 case of mastoiditis
Cochrane Reviews Sanders 2009
Analyzed 10 RCTs abx versus placebo Pain reduced at 2-7 days (RR 0.72 CI 0.70-0.74)
NNT 16 to reduce ear pain 1 case of mastoiditis in antibiotic treated child (out
of 2000 pts) Vomiting, diarrhea, rash higher if on abx
NNH 24
Who needs ENT referral? TOP (2008)
>3 episodes in 6 months >4 episodes in 12 months Cleft palate or craniofacial malformation OME for 3 months with hearing loss > 20dB
Take home point #3 AOM is rarely associated with suppurative
complications Treatment is primarily based on symptom
relief Symptoms generally self resolve without
therapy Watchful waiting approach is appropriate for
many over age 6 months
Case 3 A 2 year old girl presents with fever,
decreased intake. She is previously healthy. You examine her and she looks unwell and her
HR is 150 sleeping. You bolus her, write some orders for antibiotics, and get some blood work. You also want to check a urine.
What kind of sample should you get?
What is an appropriate specimen?• Most children with UTI present to primary care
givers• Therefore, the collection of a urine specimen
must be– Simple, Reliable, Cost effective, Acceptable
• Current methods– Suprapubic aspiration– Urethral catheterization– Perineal bag specimen– Clean catch
Suprapubic Aspiration• Procedure: Needle and syringe used to collect
urine from bladder through aseptic area of skin
• Pros: Most microbiologically accurate• Cons:– invasive– requires technical skill– yield varies
• U/S guidance can increase yield from 60% to 97%
Urethral catheterization Procedure: Insertion of a sterile number 5
feeding tube into cleansed urethra Pros: Very accurate
83% specific versus 89% in SPA Very low risk of introducing infection
Cons: Invasive Risk of urethral trauma Success rate quite varied, from 23-90%
Perineal Bag Procedure: Taping a sterile plastic collection
bag over the genitalia and waiting for patient to void
Pros: Simple, non-invasive Cons: High rate of contamination (up to 50%)
Higher overall cost from misdiagnosis If antibiotics are appropriate, a bag specimen is
insufficient to document presence of UTI Bags are good for urinalysis and microscopy, only
good for culture if negative Transport cultures to lab ASAP after collection
Clean Catch Procedure: Like it sounds, where you catch
urine in a sterile container Pros: Microbiologically accurate Cons: Difficult to obtain
Evidence:• Bag versus catheter– Culture of a urine bag was 100% sensitive, 70%
specific– Culture of a catheter sample was 95% sensitive
and 99% specific• AAP Recommendation (2011)– If 2 mos-2years, if you diagnose UTI with a bag,
you need confirmatory testing
What is an appropriate specimen? (NICE 2007) If toilet trained (>3 years) =
Clean catch! If not toilet trained (<3 years) =
Catheter if sick (as you will likely start abx) and cannot do confirmatory testing afterwards
Bag if left on <30 minutes only for microscopy and urinalysis culture useful only if negative if positive, must perform confirmatory testing
Take home point #4 If you need to start antibiotics, do not obtain a
bag specimen. You must use SPA or catheterization.
Clean catch is an option if the child is old enough and cooperative.
A negative bag culture rules out UTI.
Case 3 continued You get an in and out and the urinalysis
suggests UTI. She looks quite sick so you want to admit her and will start her on antibiotics.
What parenteral antibiotic should you choose?
What are the common UTI organisms? KEEPS
Klebsiella Enterobacter/Enterococcus E. Coli Pseudomonas Proteus Staph saprophyticus
Which IV antibiotic to use? Bugs and drugs 2006 – Amp/Gent or Cefotax
or Ceftriaxone
NICE 2007 - No real difference between of the any parenteral antibiotics Clavulin IV vs Cefotaxime Cefepime vs Ceftazidime Cefotaxime vs Ceftriaxone
AAP 2011 – Careful with aminoglycosides if evidence of renal toxicity
Case 4 2 yo girl who looks well but has 4 days of
fever of 39 degrees and no focus. She is walking around the ED and looks great despite her fever.
Would you SPA or catheterize her? Would you bag her?
If not so sick… AAP 2011
If 2 mos-2yrs, suggest urinalysis by most convenient method if parents/clinician resistant to SPA or catheterization.
If urinalysis supports UTI, then need culture specimen (SPA or cath).
Case 4 continued The pt voids into a bag and it is promptly
removed within 30 minutes and immediately dipped, then sent to the lab for microscopy
Urinalysis: - nitrites/ + WBC / - RBC Now what?
How do I interpret a urinalysis?• Nitrites– Created when bacteria reduce urinary nitrates to
nitrites• Not all bacteria do this (streptococcus, enterococcus,
staphylococcus)• Require a few hours to form• False negative with Urine bilinogen, low urine pH,
vitamin C, low nitrogen containing food• Leukocyte esterase– Detects esterase, an enzyme in WBC
• False negative with high urine SG, urine glucose, proteinuria, meds (vitamin C, gentamicin, tetracycline, nitrofurantoin)
Case 4 continued Microscopy comes back on the urine WBC 10/HPF, bacteria seen What do you prescribe? Do you refer for an ultrasound? VCUG?
What is good oral therapy? Options
TMP/SMX Cefixime
Once a day and as effective as parenteral therapy Nitrofurantoin
Do not use if renal involvement is likely. Is excreted in urine but does not reach appropriate concentration in blood stream to protect kidneys
Amoxicillin Increasing E coli resistance
Duration of therapy and prophylaxis? AAP 2011
If 2 mos-2years, strong recommendation to complete 7-14 day oral course regardless of whether or not parenteral antibiotics were given
After course, should start prophylaxis until imaging performed TMP/SMX Nitrofurantoin Nalidixic acid
What imaging should you perform? AAP 2011 – Fair evidence only
If 2 mos-2 years, if good response to antibiotics in 48 hours, then U/S at earliest convenience
If poor response to antibiotics in 48 hours, then prompt U/S
No VCUG needed for first UTI VCUG for recurrent febrile UTI or if abdominal
ultrasound is abnormal
Rationale Older children with 1st UTI likely do not have
significant reflux/kidney abnormality If no improvement in a young child, need to
look urgently for anatomic abnormality (obstruction) or abscess
Take home point #5 Cefixime is a good option for > 6 months, well
looking child Duration of oral therapy is 7-14 days
regardless if IV abx were used Ultrasound but timing depends on pts
response to treatment No VCUG for first time UTI Antibiotic prophylaxis is needed until imaging
is complete
Case 5 A 5 year old male is complaining of sore
throat, and has a tactile temperature. He has no other signs of URTI. He has cervical lymphadenopathy.
You look into his throat and see this:
How likely is he to have strep throat? Should you swab his throat? Should you start empiric antibiotics?
Diagnosis of GAS TonsillopharyngitisModified Centor Score (McIsaac score)
CMAJ 1998;158:75; CMAJ 2000;163:811
Criteria Score
Temp > 38C 1
No cough 1
Tender AC LN 1
Tonsils swollen/exudate
1
Age 3 – 14 1
Age 15 – 44 0
Age >44 -1
Total 0 - 5
Total Score Likelihood GAS
%
0 1 – 3
1 5 – 10
2 11 – 17
3 28 – 35
4 or 5 51 – 53
Complications of Streptococcal Tonsillopharyngitis
Suppurative Peritonsillar abscess Retropharyngeal abscess Cervical adenitis Streptococcal Toxic Shock Syndrome
Non-suppurative Post-streptococcal glomerulonephritis Acute rheumatic fever Post-streptococcal arthritis PANDAS (pediatric autoimmune
neuropsychiatric disorders associated with streptococcus)
Complications of Streptococcal Tonsillopharyngitis
Good evidence that appropriate antibiotic therapy reduces risk of suppurative complications
Improves symptoms by 1 day and infectivity after 24h
Acute rheumatic fever – reduced risk if appropriate antibiotic therapy given within 9d of symptoms and continued for 10d
Post-streptococcal glomerulonephritis – no evidence that antibiotic therapy reduces risk of development once pharyngitis has occurred
Management (TOP 2008) Swab first, treat only if positive Treat with 10 days always with PenVK unless
contraindicated No repeat swab needed unless recurrence of
symptoms
Carriers? Generally don’t get rheumatic fever Document carriage with a swab when pt is
asymptomatic Eradication only if:
Family member with PSGN or rheumatic fever Outbreak of rheumatic fever Outbreak of pharyngitis in closed community Repeat transmission within families >3/year of symptomatic pharyngitis
Take home point #6 Use the strep throat score to predict who
should be swabbed, not who has strep throat You can always wait for the culture to come
back, but you can safely give the parent a wait-and-see prescription
Treatment of strep throat are mainly for the prevention of rheumatic fever, versus symptom control
Questions?