MI: Neonatal and Childhood Infections Flashcards
Which infections are screened for in pregnancy?
- HIV
- Hepatitis B
- Syphilis
Which other congenital infections are known to cause issues in pregnancy/delivery?
- TORCH
- Toxoplasmosis
- Other (varicella, parvovirus)
- Rubella
- CMV
- Herpes
- Group B Streptococcus
- Hepatitis C
What is the source of toxoplasmosis?
Cat faeces
What are the possible outcomes for neonates with congenital toxoplasmosis?
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
What is the triad of features in congenital rubella syndrome?
- Cataracts
- Congenital heart disease (PDA is most common)
- Sensorineuronal deafness
- Other features: microphthalmia, glaucoma, retinopathy, ASD/VSD, microcephaly, meningoencephalopathy, developmental delay
How is herpes simplex virus transmitted to the neonate?
- 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
How is Chlamydia trachomatis transmitted to the neonate and what disease does it cause in the neonate?
- During delivery
- Causes neonatal conjunctivitis or pneumonia
NOTE: it is treated with erythromycin
Which mycoplasma species can cause neonatal infection?
- Mycoplasma hominis*
- Ureaplasma urealyticum*
Why are premature infants at increased risk of infection?
- Immune system less developed
- Less maternal IgG
- NICU care (exposure to microorganisms)
What is the definition of ‘early-onset’ infection?
Infection that occurs within 72 hours of birth
What are the three main organisms that cause early-onset infection?
- Group B Streptococcus
- E. coli
- Listeria monocytogenes
What type of bacterium is Group B Streptococcus?
Streptococcus agalactiae
- Gram-positive coccus
- Catalase negative
- Beta-haemolytic
What can GBS cause in neonates?
Most common causes of neonatal infection
- Sepsis
- Meningtits
- Pneumonia
What type of organism is E. coli and which diseases can it cause in the neonate?
- Gram-negative rods
- Can cause bacteraemia, meningitis and UTI
NOTE: the K1 antigen is particularly problematic
What type of organism is Listeria monocytogenes and what disease can it cause?
- Gram-positive rods
- Causes sepsis in the mother and the newborn
List some risk factors for early-onset sepsis.
- Prematurity
- Prolonged rupture of membranes
- Maternal pyrexia
- Previous history of neonatal GBS infection
- Maternal bacturia
- Foetal distress
List some investigations that may be useful in early-onset sepsis.
- Bloods
- Blood culture
- FBC, CRP
- Blood gases
- LP (meningitis)
- CXR (pneumonia)
Outline the treatment of early-onset sepsis.
- ABCDE
- Antibiotics - benzylpenicillin and gentamicin
- Benzylpencillin covers GBS and gentamicin covers E coli
What is late-onset sepsis?
Sepsis that occurs more than 72 hours after birth
What are the main causes of late-onset sepsis?
- Coagulase negative staphylococci (e.g. S. epidermidis)
- GBS
- E. coli
- Listeria monocytogenes
- S. aureus
- Enteroccocus sp.
- Gram-negatives (e.g. Klebsiella, Enterobacter, Pseudomonas)
List some clinical features of neonatal sepsis.
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)
List some investigations that may be used in late-onset sepsis in addition to the ones used in early-onset sepsis
- Urine MCS
- Swabs from an infected site
- ET swabs if ventilated
Outline the treatment of late-onset sepsis.
- Check local guidelines
- Example antibiotic regimen: 1st line = flucloxacillin + gentamicin; 2nd line = meropenem
- If community acquired = ceftriaxone or cefotaxime with calcium infusion
What are some common non-specific symptoms of infections in childhood?
- Fever
- Abdominal pain
List some investigations for meningitis in children.
- Blood cultures
- LP
- Rapid antigen screen
- Blood PCR
- Serology
Why is it dangerous to perform an LP in meningococcal septicaemia?
They may be coagulopathic
The incidence of meningitis caused by which three agents has decreased in incidence since the introduction of vaccination programmes?
- Meningitis C
- Haemophilus influenzae type B
- Pneumococcus
What is the main bacterial cause of meningitis at the moment?
S. pneumoniae
What type of organism is Streptococcus pneumoniae?
- Gram-positive diplococcus
- Alpha-haemolytic
Which diseases can S. pneumoniae cause?
- Meningitis
- Pneumonia
- Sepsis
What type of vaccine is the S. pneumoniae vaccine?
- Conjugate vaccine
- Old version was called Prevenar 7 (7 serotypes), but a new version has been created call Prevenar 13
What type of organism is Haemophilus influenzae?
- Gram-negative cocco-bacilli
What are the typical causes of meningitis for the following age groups:
- Under 3 months
- 3 months to 5 years
- Over 6 years
Under 3 months:
- Group B Streptococcus
- Escherichia coli
- Listeria monocytogenes
- Neisseria meningitidis
- Streptococcus pneumoniae
- Haemophilus influenzae
3 months to 5 years:
- Neisseria meningitis
- Streptococcus pneumoniae
- Haemophilus influenzae
Over 6 years:
- Neisseria meningitis
- Streptococcus pneumoniae
What is the most common cause of death in:
- Children (1-9 years)
- Neonates
Children (1-9 years)
- Cancer (UK)
- Infections e.g. pneumonia, diarrhoea (worldwide)
Neonates:
- Prematurity
- Followed by intra-partum complications
What is the most important bacterial cause of respiratory tract infection in children?
Streptococcus pneumoniae
Which children are mainly affected by Mycoplasma pneumoniae?
Older children (> 4 years)
Which group of antibiotics are used to treat Mycoplasma pneumoniae?
Macrolides
Describe the classical presentation of Mycoplasma pneumoniae.
Atypical
- Fever
- Dry cough
- Headache
- Myalgia
- Pharyngitis
List some extra-pulmonary manisfestations of Mycoplasma pneumoniae.
- Haemolysis - IgM antibodies to I antigen on erythrocytes, cold agglutinins
- Neurological - encephalitis, aseptic meningitis, peripheral neuropathy, transverse myelitis
- Polyarthralgia
- Cardiac
- Otitis media
- Bullous myringitis (vesicles on the tympanic membrane)
If a respiratory tract infection fails to respond to conventional treatment, which diagnoses should be considered?
- Whooping cough
- TB
How is UTI diagnosed in children?
- Clinically + urine dip
- MCS - pure growth of > 105 CFU/mL
- Pyuria
What are the main organisms responsible for UTI in children?
- E. coli (most common)
- Other coliforms (Proteus, Klebsiella, Enterococcus)
- Coagulase-negative Staphylococcus (S. saprophyticus)
Why might renal tract imaging be useful in children who experience UTIs?
To check for congenital anomalies e.g. MCUG for vesico-ureteric reflux in children with recurrent UTI
What might recurrent childhood infections suggest?
Immunodeficiency
