Pediatric Infectious Disease

1. Pediatric Infectious Disease Russell Lam January 12, 2012

2. Objectives • Measurement of a fever • Acute Otitis Media • UTI • Pharyngitis

3. 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?

4. What is a fever? • 38°C (100.4°F) measured rectally • Ways of measurement • Rectal • Axillary • Oral • Tympanic • Temporal

5. 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)

6. 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

7. 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.

8. Mercury? • Mercury thermometers are no longer recommended by the CPS

9. Read thermal radiation from TM and ear canal • Crying, AOM, or earwax does not change measurement • Accuracy is again questionable

10. Temporal artery thermometry • More accurate than tympanic and better tolerated than rectal • Not yet recommended when definitive measurements are required

11. Take home point #1

12. 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:

14. Other details • Never had an ear infection before • Never has had antibiotics • What antibiotic (and dose) would you prescribe (if any)?

15. Identify the normal landmarks

16. Normal ear landmarks

19. Diagnosis of AOM • 3 things • Acute onset • Middle ear fluid • Inflammation

21. 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%

23. Duration • CPS (2009) • 5 days in all except for • <2 years • Frequent AOM • AOM with perforation • Failure of initial abx

24. 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.

25. 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?

26. 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

27. 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?

28. 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

29. 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)

30. 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

31. 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)

32. Risks of watchful waiting • Mastoiditis/Meningitis/Intracranial abscess • Exceedingly rare! • 2500rx to prevent 1 case of mastoiditis

33. Cochrane Reviews • Sanders 2009 • Analyzed 10 RCTsabx 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

34. 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

35. 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

36. 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?

37. 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

38. 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%

39. 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%

40. 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

41. Clean Catch • Procedure: Like it sounds, where you catch urine in a sterile container • Pros: Microbiologically accurate • Cons: Difficult to obtain

42. 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

43. 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

44. 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.

45. 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?

46. What are the common UTI organisms? • KEEPS • Klebsiella • Enterobacter/Enterococcus • E. Coli • Pseudomonas • Proteus • Staph saprophyticus

47. 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 vsCefotaxime • CefepimevsCeftazidime • CefotaximevsCeftriaxone • AAP 2011 – Careful with aminoglycosides if evidence of renal toxicity

48. 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?

49. 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).

50. 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?