Neonatal and childhood infections Flashcards
Congenital infection definition
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
Infections currently screened for during pregnancy:
- Hep B
- HIV
- Rubella status (NOT THE INFECTION ITSELF)
- Syphilis
Currently NOT screened but possible:
- CMV (most common cause of congenital deafness in the UK)
- Toxoplasmosis
- Hep C
- Group B Streptococcus (mother is screened only if asymptomatic bacteriuria)
Congenital infection presentation → varied/non-specific presentation (TORCH screen, but outdated)
Congenital infections: common clinic features and examples
Toxoplasmosis lifecycle
Congenital toxoplasmosis
long-term sequelae (3)
4C’s (symptoms at birth 40% of babies)
Congenital Rubella Syndrome
mechanism and classical triad
other features
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
Herpes Simplex Virus
- 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
Chlamydia trachomatis
- Infection transmitted during delivery
- Mother may be asymptomatic
- Causes neonatal conjunctivitis or pneumonia (RARE)
- Treated with erythromycin
other congenital infections
- Hep B and C HIV Listeria monocytogenes GBS
- Syphilis Mycoplasma species Parvovirus
What is the neonatal period?
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
Neonatal infection key points
- 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
Neonatal infections: early-onset and late-onset
early onset definition
3 examples
most common one
within 48 hours (or 3 to 5 days; definitions vary) of birth
Group B strep (MOST COMMON)
E. coli
Listeria monocytogenes
Group B strep
E.coli
Listeria monocytogenes
Risk factors for early-onset infection (baby and mother)
Early onset infection investigations
Tx for early onset neonatal sepsis
- Treatment for early onset neonatal infection
Late onset neonatal infection definition and causes
48-72 hours of birth
Late onset neonatal infection clinical features and ix
Tx of late onset neonatal infection
- 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
Infections during childhood
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
Ix for childhood infections
- FBC CRP Blood cultures
- Urine Sputum, throat swabs
Meningitis = most important cause of paediatric morbidity and mortality
Ix/diagnosis
LP contraindications
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
CSF diagnosis in meningitis
Main cause of meningitis and when do you give vaccine
Men B/neisseria meningitides
2m, 4m, 12m
usually given with paracetamol as it can make the child ill as the vaccine is very immunogenic
Streptococcus pneumonia (pneumococcus) = leading cause of morbidity/mortality especially in <2 years
can lead to → meningitis, bacteraemia, pneumonia
features:
- More than 90 capsular serotypes (difficult to generate a vaccine)
- Increasing penicillin resistance
When do you give pneumococcal vaccine?
12weeks and 12 months
Haemophilus influenzae and causes of meningitis by age (H. I in all ages)
Gram-negative rod, grows glossy colonies on blood agar
Causes of death in children <5 yo from meningitis
- Neonatal (0-27 days) → biggest causes: prematurity, intrapartum-related complications
- Post-neonatal (1-59 months) → biggest causes: pneumonia, congenital anomalies
Features of RTI in children
RTI: Streptococcus pneumonia
the most important bacterial cause:
Sensitive to amoxicillin or penicillin
Mycoplasma pneumoniae
main feature
COLD AGGLUTININS
if RTI fails to respond to tx, consider:
- Whooping cough (Bordatella pertussis)
- TB
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
recurrent or persistent infections
- May be a feature of immunodeficiency – either congenital (e.g. SCID) or acquired (e.g. HIV)
- Warrants investigation by paediatric infectious diseases specialist
What is the most common cause of death worldwide in children under 5 years?
Prematurity or pneumonia
