Neonatal and childhood infections

Question 1

Congenital infection definition

Answer 1

o Babies are born with congenital infections (i.e. vertically transmitted from mother to baby)
o An infection can occur at any time during pregnancy

Question 2

Infections currently screened for during pregnancy:

Answer 2

• Hep B
• HIV
• Rubella status (NOT THE INFECTION ITSELF)
• Syphilis

Question 3

Currently NOT screened but possible:

Answer 3

• CMV (most common cause of congenital deafness in the UK)
• Toxoplasmosis
• Hep C
• Group B Streptococcus (mother is screened only if asymptomatic bacteriuria)

Question 4

Congenital infection presentation → varied/non-specific presentation (TORCH screen, but outdated)

Answer 4

Question 5

Congenital infections: common clinic features and examples

Answer 5

Question 6

Toxoplasmosis lifecycle

Answer 6

Question 7

Congenital toxoplasmosis

long-term sequelae (3)

4C’s (symptoms at birth 40% of babies)

Answer 7

Question 8

Congenital Rubella Syndrome

mechanism and classical triad

other features

Answer 8

Effect on the foetus depends on the time of infection

Mechanism: mitotic arrest of cells, antipathy, growth inhibitor effect

Triad: cataracts, CHS (PDA;ASD/VSD), deafness/SNHL

Other features:

• microphthalmia, glaucoma, retinopathy, ASD/VSD, microcephaly, meningoencelopathy, developmental delay, growth retardation, bone disease, heaptosplenomegaly, thrombocytopaenia, rash

Question 9

Herpes Simplex Virus

Answer 9

• This can spread to the neonate through the genital tract → blistering rash
• It can cause disseminated infection with liver dysfunction and meningoencephalitis

Infection control is particularly important because you don’t want this to spread

Question 10

Chlamydia trachomatis

Answer 10

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

Question 11

other congenital infections

Answer 11

• Hep B and C HIV Listeria monocytogenes GBS
• Syphilis Mycoplasma species Parvovirus

Question 12

What is the neonatal period?

Answer 12

First 4 weeks of life

If born premature, the neonatal period is longer and is adjusted for the expected birth date

Premature neonates are at INCREASED risk because:

• Less maternal IgG
• NICU care
• Exposure to micro-organisms, colonisation and infection

Question 13

Neonatal infection key points

Answer 13

• Babies can become very ill very quickly
• With neonates, it is important to treat with antibiotics at the first suspicion of infection
• Neonates have immature host defences

Question 14

Neonatal infections: early-onset and late-onset

early onset definition

3 examples

most common one

Answer 14

within 48 hours (or 3 to 5 days; definitions vary) of birth

Group B strep (MOST COMMON)

E. coli

Listeria monocytogenes

Question 15

Group B strep

Answer 15

Question 16

E.coli

Answer 16

Question 17

Listeria monocytogenes

Answer 17

Question 18

Risk factors for early-onset infection (baby and mother)

Answer 18

Question 19

Early onset infection investigations

Answer 19

Question 20

Tx for early onset neonatal sepsis

Answer 20

Question 21

• Treatment for early onset neonatal infection

Answer 21

Question 22

Late onset neonatal infection definition and causes

Answer 22

48-72 hours of birth

Question 23

Late onset neonatal infection clinical features and ix

Answer 23

Question 24

Tx of late onset neonatal infection

Answer 24

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

Question 25

Infections during childhood

Answer 25

Age is important in considering likely pathogens

• May be difficult to ascertain the site of infection from history and examination

Viral infections are very common (e.g. chickenpox, HHV6, EBV, RSV)

• Bacterial infections are important and may cause secondary infection after viral illness (e.g. invasive Group A Streptococcus (iGAS) infection after VZV

Common, non-specific symptoms → fever and abdominal pain

Question 26

Ix for childhood infections

Answer 26

• FBC CRP Blood cultures
• Urine Sputum, throat swabs

Question 27

Meningitis = most important cause of paediatric morbidity and mortality

Ix/diagnosis

LP contraindications

Answer 27

No LP if…meningococcal, raised ICP, bleeding disorder, overlying infection at site, spina bifida

CSF diagnosis in meningitis:

• if no growth, PCR may be positive (EDTA blood)
• rapid antigen tests can be useful

Question 28

CSF diagnosis in meningitis

Answer 28

Question 29

Main cause of meningitis and when do you give vaccine

Answer 29

Men B/neisseria meningitides

2m, 4m, 12m

usually given with paracetamol as it can make the child ill as the vaccine is very immunogenic

Question 30

Streptococcus pneumonia (pneumococcus) = leading cause of morbidity/mortality especially in <2 years

Answer 30

can lead to → meningitis, bacteraemia, pneumonia

features:

• More than 90 capsular serotypes (difficult to generate a vaccine)
• Increasing penicillin resistance

Question 31

When do you give pneumococcal vaccine?

Answer 31

12weeks and 12 months

Question 32

Haemophilus influenzae and causes of meningitis by age (H. I in all ages)

Answer 32

Gram-negative rod, grows glossy colonies on blood agar

Question 33

Causes of death in children <5 yo from meningitis

Answer 33

• Neonatal (0-27 days) → biggest causes: prematurity, intrapartum-related complications
• Post-neonatal (1-59 months) → biggest causes: pneumonia, congenital anomalies

Question 34

Features of RTI in children

Answer 34

Question 35

RTI: Streptococcus pneumonia

Answer 35

the most important bacterial cause:

Sensitive to amoxicillin or penicillin

Question 36

Mycoplasma pneumoniae

main feature

Answer 36

COLD AGGLUTININS

Question 37

if RTI fails to respond to tx, consider:

Answer 37

• Whooping cough (Bordatella pertussis)
• TB

Question 38

UTI = COMMON

diagnosis: what can you see on urine microscopy
organisms: what is the main one

early diagnosis and abs tx: what imaging and when abx

Answer 38

Question 39

recurrent or persistent infections

Answer 39

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

Question 40

What is the most common cause of death worldwide in children under 5 years?

Answer 40

Prematurity or pneumonia