MI: Neonatal and Childhood Infections Pt.1

Question 1

Which infections are screened for in pregnancy?

Answer 1

• HIV
• Hepatitis B
• Syphilis

Question 2

Which other congenital infections are known to cause issues in pregnancy/delivery?

Answer 2

• TORCH
  
  • Toxoplasmosis
  • Other (varicella, parvovirus)
  • Rubella
  • CMV
  • Herpes
• Group B Streptococcus
• Hepatitis C

Question 3

What is the source of toxoplasmosis?

Answer 3

Cat faeces

Question 4

What are the possible outcomes for neonates with congenital toxoplasmosis?

Answer 4

Asymptomatic (60%) at birth but go on to develop long-term sequelae such as deafness, low IQ and microcephaly

Symptomatic (40%) at birth

• Triad
  
  • Chorioretinitis
  • Hydrocephalus
  • Intracranial calcifications
• Other features: seizures, hepatosplenomegaly/jaundice

Question 5

What is the triad of features in congenital rubella syndrome?

Answer 5

• Cataracts
• Congenital heart disease (PDA is most common)
• Sensorineuronal deafness
• Other features: microphthalmia, glaucoma, retinopathy, ASD/VSD, microcephaly, meningoencephalopathy, developmental delay

Question 6

How is herpes simplex virus transmitted to the neonate? What are the presenting features?

Answer 6

• In utero/congenital - rare (5%)
  
  • Triad of cutaneous, ophthalmic, and CNS manifestations
• Exposure to virus in the around time of delivery (mainly intrapartum) - most common (95%)
  
  • Predominantly skin, eye and mouth (SEM) infections - vesicular lesions in these places
  • Can also cause CNS and disseminated disease - meningoencephalitis, liver dysfunction

Question 7

How is Chlamydia trachomatis transmitted to the neonate and what disease does it cause in the neonate?

Answer 7

• During delivery
• Causes neonatal conjunctivitis or pneumonia

NOTE: it is treated with erythromycin

Question 8

Which mycoplasma species can cause neonatal infection?

Answer 8

• Mycoplasma hominis*
• Ureaplasma urealyticum*

Question 9

Why are premature infants at increased risk of infection?

Answer 9

• Immune system less developed
• Less maternal IgG
• NICU care (exposure to microorganisms)

Question 10

What is the definition of ‘early-onset’ infection?

Answer 10

Infection that occurs within 72 hours of birth

Question 11

What are the three main organisms that cause early-onset infection?

Answer 11

• Group B Streptococcus
• E. coli
• Listeria monocytogenes

Question 12

What type of bacterium is Group B Streptococcus?

Answer 12

Streptococcus agalactiae

• Gram-positive coccus
• Catalase negative
• Beta-haemolytic

Question 13

What can GBS cause in neonates?

Answer 13

Most common causes of neonatal infection

• Sepsis
• Meningtits
• Pneumonia

Question 14

What type of organism is E. coli and which diseases can it cause in the neonate?

Answer 14

• Gram-negative rods
• Can cause bacteraemia, meningitis and UTI

NOTE: the K1 antigen is particularly problematic

Question 15

What type of organism is Listeria monocytogenes and what disease can it cause?

Answer 15

• Gram-positive rods
• Causes sepsis in the mother and the newborn

Question 16

List some risk factors for early-onset sepsis.

Answer 16

• Prematurity
• Prolonged rupture of membranes
• Maternal pyrexia
• Previous history of neonatal GBS infection
• Maternal bacturia
• Foetal distress

Question 17

List some investigations that may be useful in early-onset sepsis.

Answer 17

• Bloods
  
  • Blood culture
  • FBC, CRP
  • Blood gases
• LP (meningitis)
• CXR (pneumonia)

Question 18

Outline the treatment of early-onset sepsis.

Answer 18

• ABCDE
• Antibiotics - benzylpenicillin and gentamicin
  
  • Benzylpencillin covers GBS and gentamicin covers E coli

Question 19

What is late-onset sepsis?

Answer 19

Sepsis that occurs more than 72 hours after birth

Question 20

What are the main causes of late-onset sepsis?

Answer 20

• Coagulase negative staphylococci (e.g. S. epidermidis)
• GBS
• E. coli
• Listeria monocytogenes
• S. aureus
• Enteroccocus sp.
• Gram-negatives (e.g. Klebsiella, Enterobacter, Pseudomonas)

Question 21

List some clinical features of neonatal sepsis.

Answer 21

Non-specific

• Respiratory
  
  • Distress: grunting, nasal flaring, recessions
  • Apnoea
• Cardiovascular: tachycardia, hypotension, cool peripheries, increased CRT
• Irritability, poor feeding, lethargy
• Skin changes: jaundice, blue/mottled
• Temperature: can be high or low
• Seizures (meningitis)

Question 22

List some investigations that may be used in late-onset sepsis in addition to the ones used in early-onset sepsis

Answer 22

• Urine MCS
• Swabs from an infected site
• ET swabs if ventilated