Neonatal and childhood infections 101121

Question 1

TORCH infections

Answer 1

o	T	Toxoplasmosis
o	O	Other – Syphilis, HIV, HBV, HCV
o	R	Rubella
o	C	CMV
o	H	HSV

Question 2

Common clinical features in congenital infections

Answer 2

o Mild/no apparent maternal infection Low platelets, rash
o Wide range of severity in the baby Cerebral abnormalities
o Similar clinical presentation Hepatosplenomegaly/hepatitis/jaundice
o Serological diagnosis
o Long term sequelae if untreated

Question 3

Toxoplasmosis

Answer 3

 May be asymptomatic (60%) at birth but may still go on to have long-term sequelae such as:
• Deafness Low IQ Microcephaly
 40% of babies are symptomatic at birth (4 C’s)
• Choroidoretinitis Microcephaly/hydrocephalus
• Intracranial calcifications Seizures / convulsions
• Hepatosplenomegaly/jaundice

Question 4

Congenital HSV symptoms

Answer 4

o This can spread to the neonate through the genital tract  blistering rash
o It can cause disseminated infection with liver dysfunction and meningoencephalitis
o Infection control is particularly important because you don’t want this to spread

Question 5

congenital Clamydia symptoms

Answer 5

o Infection transmitted during delivery
o Mother may be asymptomatic
o Causes neonatal conjunctivitis or pneumonia (RARE)
o Treated with erythromycin

Question 6

congenital Rubella symptoms

Answer 6

o Effect on the foetus depends on the time of infection
o Mechanism: mitotic arrest of cells, angiopathy, growth inhibitor effect
o Classical Triad:
 Cataracts Congenital heart disease (PDA; ASD/VSD) Deafness/SNHL
o Other features:
 Microphthalmia Glaucoma Retinopathy ASD/VSD
 Microcephaly Meningoencephalopathy Developmental delay Growth retardation
 Bone disease Hepatosplenomegaly Thrombocytopaenia Rash

Question 7

Why are premature babies more at risk

Answer 7

o Premature neonates are at INCREASED risk because:
 Less maternal IgG
 NICU care
 Exposure to micro-organisms, colonisation and infection

Question 8

Group B strep

Answer 8

• Features:
o Gram +ve coccus Catalase -ve
o Beta haemolytic Lancefield Group B
o 33% of women have GBS commensal
• In neonates, causes…
o Bacteraemia Meningitis
o Disseminated infection (i.e. joint infection)

Question 9

E. coli

Answer 9

•	Features:
o	Gram -ve rod 
o	The K1 antigen is particularly problematic
•	In neonates, causes:
o	Bacteraemia					Meningitis
o	UTI

Question 10

risk factors for early onset sepsis

Answer 10

•	Baby:					Mother:
o	Birth asphyxia				PROM/PPROM
o	Resp. distress				Fever
o	Low BP					Foetal distress
o	Acidosis					Meconium staining
o	Hypoglycaemia				Previous history GBS
o	Neutropenia
o	Rash
o	Hepatosplenomegaly
o	Jaundice

Question 11

Listeria monocytogenes

Answer 11

	Listeria monocytogenes:
•	Features:
o	Gram +ve rod
•	In neonates, causes:
o	Sepsis in both the mother and baby

Question 12

early onset sepsis investigations

Answer 12

• FBC CRP Blood culture
• Deep ear swab LP Surface swabs
• CXR (full body)

Question 13

Treatment for early onset sepsis

Answer 13

• Supportive – ventilation, circulation, nutrition
• Antibiotics (e.g. benzylpenicillin (GBS) & gentamicin (e.coli)  used in combination because…
o GBS is treated by benzylpenicillin
o E. coli is treated by gentamicin
o +amoxicillin if listeria

Question 14

Late onset sepsis treatment

Answer 14

• Treat early – low threshold for starting therapy
• Review and stop antibiotics if cultures are negative and clinically stable
• Antibiotics (guidelines do vary):
o 1st line: cefotaxime + vancomycin
o 2nd line: meropenem
o Community-acquired: cefotaxime, amoxicillin ± gentamicin

Question 15

Men B/neisseria neningitis

Answer 15

main cause of meningitis. Men B / Neisseria meningitidis
 The meningococcal disease can be fulminant to the point where limb amputation is necessary
 Given: 2m, 4m and 12m
 The vaccine is very immunogenic and is usually given with paracetamol because it can make the child ill

Question 16

Streptococcus pneumoniae

Answer 16

(Pneumococcus) – leading cause of morbidity/mortality especially in <2 years
 Gram-positive diplococcus, Alpha-haemolytic, Optochin-sensitive
 Can lead to  Meningitis, Bacteraemia, Pneumonia Given: 12w, 12m
 Features:
• More than 90 capsular serotypes (difficult to generate a vaccine)
• Increasing penicillin resistance

Question 17

Pneumococcal conjugate vaccine

Answer 17

• Previously there was a polysaccharide vaccine with 23 capsular types of pneumococcus
• Children <2 showed a poor response to this vaccine  antibody response was improved by conjugating the polysaccharide with proteins such as CRM
o The conjugate vaccine is immunogenic in children from 2 months
o This conjugate vaccine was called Prevenar 7 which targeted 7 serotypes
o These serotypes were almost eradicated  however, we are still seeing a lot of cases of invasive pneumococcal disease (may be due to serotype replacement)
 This could lead to a change in phenotype
o More serotypes were added to create Prevenar 13

Question 18

respiratory tract infections

Answer 18

strep pneumonia, mycoplasma pneumonia, whooping cough,

Question 19

strep pneumoniae

Answer 19

o Streptococcus pneumoniae – the most important bacterial cause:
 Sensitive to amoxicillin or penicillin

Question 20

Respiratory tract infections

Answer 20

o Features:
 1/3 of all childhood illnesses Mostly URTIs
 Mostly viral Age is important
 Sputum is difficult to obtain Often need to give empirical antibiotics

o Streptococcus pneumoniae – the most important bacterial cause:
 Sensitive to amoxicillin or penicillin

o Mycoplasma pneumoniae – cold agglutinins:
 Features:
• Tends to affect older children (> 4 years) Person-to-person droplet transmission
• Incubation period 2-3 weeks Epidemics evert 3-4 years
• Occurs in school children / young adults Mainly asymptomatic
 Clinical features (if not asymptomatic):
• Fever Headache
• Myalgia Pharyngitis
• Dry cough
 Extrapulmonary Manifestations
• Haemolysis
o IgM antibodies to the I antigen on erythrocytes
o Cold agglutinins in 60%
• Neurological
o Encephalitis Aseptic meningitis
o Peripheral neuropathy Transverse myelitis
o Cerebellar ataxia
• Cardiac
• Polyarthralgia, myalgia, arthritis
• Otitis media
• Bullous myringitis (vesicles on tympanic membrane – pathognomonic of mycoplasma disease)
 Treated with macrolides (azithromycin)

o If a respiratory tract infection fails to respond to treatment, consider:
 Whooping cough (Bordatella pertussis)
 TB

Question 21

Recurrent or persistent infections

Answer 21

• May be a feature of immunodeficiency – either congenital (e.g. SCID) or acquired (e.g. HIV)
• Warrants investigation by paediatric infectious diseases specialist

Question 22

UTI

Answer 22

o Diagnosis
 Symptoms – If child can give a history
 Pure growth of >105 CFU/mL
 Pyuria – pus cells on urine microscopy

o Organisms
 Escherichia coli – MAIN ORGANISM
 Other coliforms (Proteus, Klebsiella, Enterococcus sp.)
 Coagulase-negative Staphylococcus (Staphylococcus saprophyticus)

o Early diagnosis and antibiotic treatment is important
 Obtain sample before starting treatment
 Renal tract imaging may be required to check for congenital anomalies
 Antibiotic prophylaxis may be given after treatment of the infection