Paeds microbio/infectious disease

Question 1

Define pyelonephritis

Answer 1

Inflammation of the kidney resulting from bacterial infection

Question 2

What bacteria is the most common cause of UTIs?

Answer 2

Escherichia coli

Question 3

What is the primary source of bacteria for UTIs?

Answer 3

From faeces-intestinal bacteria e.g. e coli, klebsiella pneumoniae, enterococci

Question 4

Name 5 presenting symptoms for a young child with a UTI

Answer 4

*Fever
Vomiting
Irritability
Poor feeding
Urinary frequency

Question 5

Name 5 presenting symptoms for an older child with a UTI

Answer 5

Abdo/suprapubic pain
Vomiting
Frequency + urgency + dysuria (painful urination)
Fever
Nocturnal enuresis (bedwetting)

Question 6

What are the 2 criteria for making a diagnosis of an acute upper UTI - pyelonephritis?

Answer 6

Fever over 38°C
Loin pain or tenderness

Question 7

What urine dip finding would suggest a bacterial infection + why?

Answer 7

Nitrites on urine dipstick = bacteria in urine
because gram-negative bacteria (e.g., E. coli) break down nitrates (a normal waste product in urine) into nitrites.

Question 8

Name 3 things tested for on a urine dipstick

Answer 8

Nitrites
Leukocytes
RBC

Question 9

What condition would +ve nitrites + leukocytes on urine dipstick indicate?

Answer 9

UTI

Question 10

What would -ve nitrites + leukocytes on urine dipstick indicate?

Answer 10

Excludes UTI

Question 11

How would you investigate a child under 3mths with a fever?

Answer 11

Full septic screen:
Bloods
Blood culture
Urine culture
Consider lumbar puncture

Question 12

How would you manage a child under 3mths with a fever?

Answer 12

Do full sepsis screen + start immediate IV ABx = ceftriaxone + amoxicillin

Question 13

What is the 1st line Abx for an uncomplicated lower UTI?

Answer 13

3 days of:
trimethoprim 1st line if low risk of resistance
nitrofurantoin = 1st line

Question 14

When do NICE guidelines recommend an US for suspected UTI (3 occasions)?

Answer 14

All children under 6 months with their first UTI (within 6 weeks)
Recurrent UTIs (within 6 weeks)
Atypical UTIs (e.g., very unwell or atypical organisms) (during the illness)

Question 15

What is DMSA?

Answer 15

Dimercaptosuccinic acid scan = radioactive material injected + gamma camera used to determine how well kidneys take up the material, patches not taking it up suggests scarring

Question 16

What is the vesicoureteral reflux (VUR)?

Answer 16

Involves urine flowing back into the ureters from the bladder

Question 17

What does a VUR predispose you to?

Answer 17

Upper UTIs + subsequent renal scarring

Question 18

What is the test for a VUR?

Answer 18

MCUG = micturating cystourethrogram
is used to test for vesicoureteral reflux in infants under 6 months with recurrent or atypical UTIs

Question 19

How do you manage VUR?

Answer 19

Avoiding constipation
Avoiding an excessively full bladder
Prophylactic antibiotics
Surgical input from paediatric urology

Question 20

What is osteomyelitis?

Answer 20

Deep=seated infection in the bone + bone marrow, can be acute or chronic

Question 21

What part of the bone is most commonly affected by osteomyelitis in children?

Answer 21

The metaphysis (wider, neck portion) of the long bones

Question 22

What bacteria is the most common cause of osteomyelitis in children?

Answer 22

Staph aureus

Question 23

How might an osteomyelitic infection start?

Answer 23

Introduced directly into bone e.g. through open fracture
May have travelled to bone through blood after entering through other route e.g. skin/gums

Question 24

In what children is osteomyelitis most common?

Answer 24

Boys
Children under 10

Question 25

Name 4 RFs for osteomyelitis

Answer 25

Open bone fracture Orthopaedic surgery Immunocompromised e.g. HIV Sickle cell anaemia

Question 26

How can osteomyelitis present acutely?

Answer 26

Refusing to use the limb/weight bear Pain Swelling Tenderness Fever

Question 27

How would you investigate osteomyelitis?

Answer 27

Xray initially-but can be normal *MRI Bloods Blood culture Potentially bone marrow aspiration/bone biopsy

Question 28

What would you see on bloods with osteomyelitis?

Answer 28

Raised CRP, ESR + WCC

Question 29

How do you manage osteomyelitis?

Answer 29

1st line = IV cefuroxime for at least 6wks, can switch to OP oral flucloxacillin therapy if responding well May need surgery for drainage and debridement of the infected bone

Question 30

What is meningitis?

Answer 30

Inflammation of the meninges-lining of the brain + spinal cord. Normally due to a bacterial or viral infection

Question 31

What kind of bacteria is Neisseria meningitidis?

Answer 31

Gram-negative diplococcus

Question 32

What is meningococcal septicaemia?

Answer 32

Meningococcus bacterial infection in the bloodstream

Question 33

What are the most common bacterial causes of meningitis in children + adults?

Answer 33

Neisseria meningitidis Strep pneumoniae

Question 34

Why do you get a non-blanching rash in meningitis?

Answer 34

The rash indicates the infection has caused disseminated intravascular coagulopathy (DIC) and subcutaneous haemorrhages

Question 35

What is the most common bacterial cause of meningitis in neonates?

Answer 35

Group B strep contracted during birth from mother's vagina

Question 36

Name the 8 key presenting symptoms of meningitis

Answer 36

Fever Neck stiffness Vomiting Headache Photophobia Altered consciousness Seizures Non-blanching rash

Question 37

How might a neonate/baby present with meningitis?

Answer 37

Non-specific signs and symptoms: Hypotonia, Poor feeding, Lethargy, Hypothermia Bulging fontanelle.

Question 38

When would you do a lumbar puncture on a child?

Answer 38

Under 1 month presenting with fever 1-3 months with fever and are unwell <1 year with unexplained fever and other features of serious illness

Question 39

Name the 2 special tests for meningitis

Answer 39

Kernig’s test Brudzinski’s test

Question 40

What is Kernig's test?

Answer 40

Patient lies on back, flexes one hip and knee to 90 degrees then straightens knee +ve test = spinal pain/resistance to movement

Question 41

What is Brudzinski's test?

Answer 41

Patient lies on back, chin is flexed to chest +ve result = involuntary flexion of hip + knees

Question 42

How should children seen in primary care with suspected meningitis + a non-blanching rash be treated?

Answer 42

IM/IV benzylpenicillin stat then transfer to hospital

Question 43

How should a suspected meningitis be investigated in hospital?

Answer 43

Ideally blood culture + lumbar puncture for CSF pre-Abx but don't delay Abx if they're acutely unwell Bloods for meningococcal PCR EDTA blood (stops clotting + bacteria from forming biofilm layer) for PCR

Question 44

What is the 1st line Tx for suspected meningitis in children in hospital?

Answer 44

IV cefotaxime or ceftriaxone

Question 45

Apart from Abx, what other Tx may children with meningitis receive + why?

Answer 45

Steroids-decrease chance of developing hearing loss/neuro damage Dexamethasone for children >3mths if bacterial meningitis

Question 46

Are bacteria meningitis + meningococcal infection notifiable diseases?

Answer 46

YES-inform public health

Question 47

Who receives PEP after a close contact with someone with meningitis + what would they receive?

Answer 47

Prolonged close contacts within previous 7 days Get single dose of ciprofloxacin ideally with 24hrs of initial diagnosis

Question 48

What are the 2 most common causes of viral meningitis?

Answer 48

HSV-herpes simplex virus VZV-varicella zoster virus

Question 49

How do you manage viral meningitis different to bacterial meningitis?

Answer 49

Viral tends to be milder, only need supportive Tx Aciclovir

Question 50

What is a lumbar puncture?

Answer 50

Involves inserting a needle into the lower back to collect a sample of CSF

Question 51

At what level is a lumbar puncture normally done?

Answer 51

L3-L4 intervertebral space

Question 52

Name the 5 tests done on CSF from a lumbar puncture?

Answer 52

Bacterial culture Viral PCR Cell count Protein Glucose

Question 53

Describe + explain the CSF results for a child with bacterial meningitis

Answer 53

Cloudy appearance-bacteria cloud it High protein-released by bacteria swimming in CSF Low glucose-bacteria using up glucose High neutrophils-released by immune system in response to bacteria Culture-bacteria

Question 54

Describe + explain the CSF results for a child with viral meningitis

Answer 54

Clear appearance Protein-normal/mildly raised Glucose-normal High lymphocytes-released by immune system in response to viruses Culture -ve

Question 55

Name 4 complications of meningitis

Answer 55

*Hearing loss Seizures + epilepsy Cerebral palsy w/ limb weakness/spasticity Memory loss

Question 56

What is encephalitis?

Answer 56

Inflammation of the brain due to infective or non-infective (autoimmune) causes

Question 57

What is the most common cause of encephalitis?

Answer 57

Viral infection by HSV-herpes simplex virus HSV-1 from cold sores in children HSV-2 from genital herpes contracted during birth in neonates

Question 58

Name 4 viral causes of encephalitis

Answer 58

VZV-varicella zoster virus EBV Polio Mumps/measles/rubella

Question 59

How might encephalitis present?

Answer 59

Altered consciousness Altered cognition Unusual behaviour Acute onset of focal neurological symptoms Acute onset of focal seizures Fever

Question 60

How would you investigate suspected encephalitis?

Answer 60

Lumbar puncture MRI Swabs HIV testing

Question 61

How do you treat encephalitis?

Answer 61

IV antiviral e.g. aciclovir Repeat lumbar puncture to confirm successful Tx

Question 62

Name 4 complications of encephalitis

Answer 62

Lasting fatigue Change in personality/mood/cognition/memory Chronic pain Seizures