Paediatric Infectious Diseases COPY

Question 1

Part 1

Question 2

what is the epidemiology of infectious diseases in children?

Answer 2

• Infection in children is common!!
• Average pre-school child will have 8-12 respiratory tract infections per year
• Majority (in the developed world) due to viruses
• Majority self-limiting (do not need treatment)
• Median duration 8-14 days
• Likely to spend 3-5 months per year with a viral infection

Question 3

________ in children is a major source of healthcare-seeking behaviour

Large increase in number of admissions and most of the increase is _________ diseases

Signs of infection in children are often very ___________ and can progress quickly and this brings a lot of anxiety to parents

Answer 3

Infection

infectious

non-specific

Question 4

how has child mortality changed?

Answer 4

it has redued

Primarily through improvements in public health through the provision of clean water, sanitation and hygiene, reducing overcrowding and improving nutrition. But also advances in modern medicine such as antibiotics and immunisations.

Question 5

why worry about infections?

Answer 5

• Mortality outcomes for C&YP in the UK are considerably worse than comparable high income countries
• The UK ranks in the bottom 3 countries in the EU15+ for mortality from common infections in both sexes and across all age groups
• Mortality from treatable infection in the UK is almost 2x that of our best performing European neighbours
• Infections account for: 16.2% deaths in 1-4 year olds, 8% deaths in 5-9 year olds

•Failure to recognise serious illness at the point of 1st healthcare contact is an important avoidable factor in child death

Question 6

Part 2

Question 7

•Severe sepsis is one of the leading causes of death in children

what is the epidemiology in children?

Answer 7

• >½ of all sepsis cases worldwide occurred in children
• Peak incidence in early childhood
• Infants <1y: 1 in 200
• Children 1-4y: 1 in 2000
• Children 5-15y: 1 in 5000
• Case fatality rate ≈10%
• In the UK only 38% compliance with recommended treatment guidelines
• Early recognition and appropriate treatment of sepsis improves survival

Question 8

what is sepsis?

Answer 8

•Sepsis = SIRS + suspected or proven infection

Overwhelming, life-threatening response to infection which, untreated, can lead to tissue damage organ failure and death

Question 9

what is severe sepsis?

Answer 9

•Severe Sepsis = Sepsis + organ dysfunction

Question 10

what is septic shock?

Answer 10

•Septic Shock = Sepsis + CVS dysfunction

Question 11

Hard to recognise sepsis in children as no set criteria

This chart helps to identify children you should be worried about

Children HR do go up with temperature and that is normal

traffic light table

Answer 11

Question 12

what is the recognition tool for sepsis?

Answer 12

Sepsis 6 in middle

Question 13

Infants <3 months - what are they more at risk of? Why do we worry about infants <3 months of age?

Answer 13

• Increased risk bacterial infection
• Increased risk sepsis
• Increased risk meningitis

Question 14

Infants <3 months - how do they present?

Answer 14

• May have minimal signs & symptoms
• Presentation often non-specific
• May not mount a febrile response (~50%)
• Deteriorate quickly

Question 15

what increases the risk of infection in Infants <3 months?

Answer 15

• Prematurity (< 37/40)
• PROM
• Maternal pyrexia/chorioamnionitis
• Maternal GBS (this pregnancy)
• Previous child with GBS
• Maternal STI (Chlamydia, Gonorrhoea, Syphilis, HSV)

Question 16

what is the management of sepsis?

Answer 16

• Airway
• Breathing
• Circulation – 20ml/kg fluid bolus
• DEFG – ‘don’t ever forget glucose’ – 2ml/kg 10% dextrose
• Antibiotics
• 3rd generation cephalosporin (eg Cefotaxime/Ceftriaxone)
• add IV Amoxicillin if <1m old

Paediatric sepsis 6 also has a management tool

Question 17

what investigations could be carried out for sepsis?

Answer 17

Question 18

what are the responsible oranisms for sepsis?

Answer 18

Question 19

what is the Pathogenesis of Sepsis?

Answer 19

Secretion of pro and anti-inflammatory cytokines

Activation of complement

Activation and mobilisation of leukocytes

Activation of coagulation and inhibition of fibrinolysis

Increased apoptosis

Sepsis is generally an overwhelming response to infection

Question 20

take home messages:

• Sepsis is a major cause of _____ in children
• Early _________ improves survival
• Important to think ‘could this be sepsis?’
• Respond appropriately
• If you’re not sure ask!
• Follow guidelines!

•Paediatricians want to know about any child

Answer 20

death

recognition

3

fever

Question 21

Part 3

Question 22

what is meningitis?

Answer 22

• A disease caused by inflammation of the meninges

Meningitis is inflammation of the lining around your brain and spinal cord. It can be very serious if not treated quickly.

3 layers – dura, arachnoid and pia with CSF between your arachnoid and pia mater

Inflammation of underlying brain parenchyma = meningeal encephalitis

Question 23

what is meningism?

Answer 23

The clinical signs and symptoms suggestive of meningeal irritation

Question 24

what are the signs and symptoms of meningitis in older children?

Answer 24

• Fever (In older children may see classical triad of fever, headache and neck stiffness)
• Headache
• Photophobia
• Neck stiffness (nuchal rigidity)
• Nausea & vomiting
• Reduced GCS
• Seizures
• Focal neurological deficits

Question 25

what are the signs and symptoms of meningitis in young infants? (Infants present with non-specific features)

Answer 25

* Fever or hypothermia * Poor feeding * Vomiting * Lethargy * Irritability * Respiratory distress * Apnoea (pause in breathing lasting at least 20 seconds) * Bulging fontanelle (signifies raised ICP)

Question 26

Clinical Signs of Meningitis - what are they?

Answer 26

Nuchal Rigidity (Neck Stiffness) - Palpable resistance to neck flexion Brudzinski’s sign - Hips and knees flex on passive flexion of the neck Kernig’s sign - Pain on passive extension of the knee

Question 27

what are the Causes of Childhood Meningitis (in the post-vaccine era)?

Answer 27

* Bacterial (4-18%) * Viral – Mainly Enterovirus (54-88%) * Fungal – Neonates/Immunocompromised * Unknown/aseptic (40-76%)

Question 28

Bacterial Meningitis - what are the responsible organisms for bacterial meningitis in neonates (\<1 month) and older infants & children?

Answer 28

Question 29

H. influenzae meningitis - how have the cases changed?

Answer 29

6.72/100,000 (1992) -\> 0.28/100,000 (2008) decreased top graph

Question 30

what is Haemophilus influenzae?

Answer 30

* Small, non-motile, gram-negative coccobacillus * Nasopharyngeal carriage * Encapsulated H. influenzae and Non-encapsulated = Non-typeable H. influenzae (NTHI)

Question 31

Haemophilus influenzae - what do encapsulated and non-encapsulated H. influenzae cause?

Answer 31

•Encapsulated H. influenzae: - Resist phagocytosis & complement mediated lysis - 6 serotypes (a-f) - Hib main cause of invasive H. influenzae infection - Bacteraemia, Meningitis, Epiglottitis, Pneumonia - RF – asplenia, sickle cell disease, antibody deficiency •Non-encapsulated = Non-typeable H. influenzae (NTHI): - otitis media & sinusitis - invasive infection rare

Question 32

what is Neisseria meningitidis?

Answer 32

* Gram negative diplococcus * Humans only natural hosts * Nasopharyngeal carriage * Transmission via respiratory secretions * Infection often follows viral URTI * Polysaccharide capsule - capsule composition determines serogroup (eg. A, B, C, W, Y) * Endotoxin (LPS) Neisseria meningitidis, often referred to as meningococcus

Question 33

what ar ethe risk factors for Invasive Meningococcal Disease? Meningococcal disease is a serious infection caused by the bacteria Neisseria meningitidis. In rare instances, it can become invasive and cause meningitis (an infection of the lining of the brain and spinal cord)

Answer 33

* Age \<1 year or 15-24 years * Unimmunised * Crowded living conditions * Household or kissing contact * Cigarette smoking (active or passive) * Recent viral/Mycoplasma infection * Complement deficiency

Question 34

Invasive Meningococcal Disease - what does it cause?

Answer 34

Huge overlap, features of both Petechial – small non blanching spots Purpura – bigger bruise like lesions

Question 35

Invasive Meningococcal Disease - is it dangerous?

Answer 35

* Rapidly progressive * Case fatality rate 5-15% - 50% of deaths in 1st 12h - 80% of deaths in 1st 48h •Significant long term sequelae - Amputation (14%) - Scarring (48%) - Hearing Loss - Cognitive impairment/epilepsy

Question 36

Going on to look at the third big cause of bacterial meningitis in children: what is Streptococcus pnuemoniae (Pneumococcus)?

Answer 36

* Gram positive, lancet-shaped, diplococcus * Facultative anaerobe * Polysaccharide capsule - inhibits neutrophil phagocytosis, inhibits complement mediated cell lysis * \>90 known serotypes - All serotypes can cause invasive disease * Colonises nasopharynx (11-93%!) * Preceeding URTI RF for invasive infection * Respiratory droplet transmission Can cause lots of different infections

Question 37

what are the risk factors for Invasive Pneumococcal Disease?

Answer 37

* Age \<2 years * Cigarette smoking (active or passive) * Recent viral URTI * Attendance at childcare * Cochlear implant * Sickle cell disease * Asplenia * HIV infection * Nephrotic syndrome * Immunodeficiency/Immunosuppression

Question 38

Pneumococcal Meningitis - what can it result in?

Answer 38

* Case fatality in children 8% * Neurological sequelae common: Hydrocephalus, Neurodisability, Seizures, Hearing loss, Blindness

Question 39

what is the management of meningitis? | (same as sepsis)

Answer 39

* Airway * Breathing * Circulation – 20ml/kg fluid bolus, inotropes * DEFG – ‘don’t ever forget glucose’ - 2ml/kg 10% dextrose * Antibiotics - 3rd generation cephalosporin (e.g. Cefotaxime/Ceftriaxone) - add IV Amoxicillin if \<1m old

Question 40

what investigations can be done for meningitis?

Answer 40

Blood culture ideally before antibiotics but if not possible then dont delay antibiotics Lumbar puncture gives you the diagnosis

Question 41

what are the contraindicaitons of a lumbar puncture?

Answer 41

Question 42

what do you want to request on a lumbar pucture and what wold your findings be in meningitis?

Answer 42

viral PCR because Viral causes are the most common in children

Question 43

Bacterial Meningitis - what is the Treatment Duration?

Answer 43

Question 44

Summary: * Meningitis remains a serious cause of morbidity and ________ in children * Bacterial meningitis is a devastating infection with serious long term \_\_\_\_\_\_\_ * Meningitis and sepsis can progress \_\_\_\_\_\_ * Early recognition and treatment are \_\_\_\_\_\_\_ * \_\_\_\_\_\_\_ provides effective prevention against many childhood causes of meningitis

Answer 44

mortality sequelae rapidly imperative Vaccination

Question 45

Part 4

Question 46

Majority skin & soft tissue infections caused by what?

Answer 46

by Staph (mainly S. aureus) or Strep (S. pyogenes) * Both organisms cause osteoarticular infection * Both organisms cause bacteraemia * Both cause toxin-mediated diseases - Staphylococcal & Streptococcal Toxic Shock Syndrome (TSS)

Question 47

what are the micorobiological features of Staphylococcus aureus?

Answer 47

Gram +ve cocci Coagulase +ve Produce exotoxins & form superantigens Colonise skin & mucosa Resistance is a problem (MRSA) Staph forms clusters

Question 48

what are the micorobiological features of Streptococcus pyogenes (GAS)?

Answer 48

Gram +ve cocci β-haemolytic Produce exotoxins & form superantigens Oro-pharyngeal carriage Resistance is not a problem (universally S to penicillin)

Question 49

Staph and strep cause a similar picture of infection, all these pictures could be either whata re some skin and soft tissue infecitons that they can cause?

Answer 49

Question 50

what is Staphylococcal Scalded Skin Syndrome?

Answer 50

* Usually \<5y * Toxin mediated (exfoliatoxin) * Initial bullous lesions * Followed by widespread desquamation * Nikolsky sign * Mild fever * Purulent conjunctivitis

Question 51

how is Staphylococcal Scalded Skin Syndrome managed?

Answer 51

Mx – IV Flucloxacillin + IV Fluids

Question 52

what happens in scalret fever?

Answer 52

Unique to group A strep Scarlet fever is a toxin mediated disease, you have the acute infection but it is the toxin that produces the rash and things associated with it

Question 53

how do you manage scarlet fever?

Answer 53

* Notifiable disease - inform public health * Phenoxymethylpenicillin (Penicillin V) 10 days - Reduces duration and severity illness by ~1 day - Reduces incidence of complications (quincy/acute rheumatic fever/post-streptococcal glomerulonephritis) - Reduces transmission

Question 54

what are the complications of scarlet fever?

Answer 54

* Abscess formation - retropharyngeal or peritonsillar (quincy) * Acute Rheumatic Fever - most common cause acquired heart disease in children worldwide, 2-3/52 after pharyngitis, Presents with: arthritis, carditis, chorea, erythema marginatum, subcutaneous nodules * Post-streptococcal glomerulonephritis

Question 55

what is Toxic Shock Syndrome (TSS)? This is the other significant toxin mediated disease

Answer 55

* Acute febrile illness caused by Gram +ve bacteria (S. aureus & GAS) rapidly progressing to shock and multiorgan failure * Superantigen causes intense T cell stimulation - cessive immune activation, pro-inflammatory cytokine release (TNF-α, IL-1, IL-2, IFN-γ) * Case fatality - 30-60% GAS, 3-6% S. aureus

Question 56

what are the clinical features of TSS?

Answer 56

* Fever * Diffuse, maculopapular, ‘sunburn’ rash * Mucosal changes - non-purulent conjunctivitis, swollen lips, strawberry tongue * Profuse diarrhoea (S. aureus) * Rapid progression to shock & multi-organ failure - tachycardia, prolonged CRT, hypotension, renal impairment, transaminitis, reduced GCS

Question 57

how is TSS managed?

Answer 57

* ABC * Fluid resuscitation +/- inotropes * Cultures - Blood, Throat swabs, Wounds * IV Antibiotics - Flucloxacillin + Clindamycin * IVIG * Avoid NSAIDs * Surgical debridement

Question 58

Staphylococcal & Streptococcal Infection Recap: * Predominant cause of skin & ____ \_\_\_\_\_\_\_ infection in children * Cause very similar patterns of _______ - except Scarlet Fever (exclusively GAS) & SSSS * \_\_\_\_\_\_ are major virulence factors * Can cause significant morbidity and \_\_\_\_\_\_\_

Answer 58

soft tissue infection Toxins mortality