Microbiology 20 - Neonatal and Childhood infection

Question 1

What infections are currently screened for in pregnancy in the UK?

Answer 1

Hep B
HIV
Syphilis

Question 2

What does TORCH stand for?

Answer 2

Toxoplasmosis
Other (syphilis, HIV, Hep B/C)
Rubella
CMV
HSV

Question 3

What long term effects can toxoplasmosis have on the neonate?

Answer 3

Deafness, low IQ and microcephaly

Question 4

How can txoplasmosis be transmitted?

Answer 4

cat faeces contain oocysts

oocysts may be ingested if cat pet

Question 5

What are the clinical features of toxoplasmosis?

Answer 5

4 C’s

1. Choroidoretinitis
2. Microcephaly/hydrocephalus
3. Intracranial calcifications
4. Seizures / convulsions

Hepatosplenomegaly/jaundice

Question 6

Recall the symptoms of congenital rubella syndrome

Answer 6

Classical Triad:

1. Cataracts
2. Congenital heart disease (PDA; ASD/VSD)
3. Deafness/SNHL

Brain pathology
BLUEBERRY MUFFIN RASH

Question 7

What is the cause of a ‘blueberry muffin rash’ and in which infection is it seen?

Answer 7

Extramedullary haematopoiesis
Congenital rubella syndrome

Question 8

Recall the symptoms of congenital HSV infection

Answer 8

speads to neonate through genital tract

Nasty disseminated infection, causing:

• Meningoencephalitis
• Ulcers and skin problems
• High mortality

Question 9

How does chlamydia present in the neonate?

Answer 9

Infection transmitted during delivery

Mother may be asymptomatic

Causes neonatal conjunctivitis or pneumonia (RARE)

Question 10

How would you treat congenital chlamydia?

Answer 10

erythromycin

Question 11

What are the ‘big 3’ neonatal infections?

Answer 11

Listeria
E coli
Group B strep

Question 12

How do neonatal infections present?

Answer 12

bacteraemia

meningitis

sepsis

UTI - E coli

Question 13

Describe the microbiology for group B streptococcua

Answer 13

gram +ve coccus (purple cocci)

catalase -ve

beta-haemolytic (whiteness around colonies)

Lancefield group B

Question 14

Describe the microbiology of E. coli

Answer 14

Gram -ve rod

Question 15

Describe the microbiology of Listeria monocytogenes

Answer 15

Gram +ve rod

Question 16

What is the treatment for early onset neonatal sepsis

Answer 16

benzylpenicillin (GBS)

gentamicin (E coli)

additional meningitis - amoxicillin (Listeria)

Question 17

What is the most common cause of late-onset sepsis in neonates?

Answer 17

Coagulase negative staph

Question 18

What is the first line treatment for late-onset neonatal sepsis?

Answer 18

Cefotaxime (this is brain-penetrative) and vancomycin (this is good for staph)

2nd lin e- meropenem

Community-acquired: cefotaxime, amoxicillin ± gentamicin

Question 19

What secondary infection is common after chickenpox?

Answer 19

Group A streptococcus

Question 20

When is lumbar puncture contraindicated in meningitis?

Answer 20

meningococcal, ↑ ICP, bleeding disorder

Question 21

Describe the CSF characteristics for bacterial viral and fungal/TB meningitis

Answer 21

Question 22

Describe the microbiology of Neisseria meningitidis

Answer 22

gram -ve coccus

Question 23

Describe the microbiology of streptococcus pneumoniae

Answer 23

Gram-positive diplococcus, Alpha-haemolytic, Optochin-sensitive (donut colonies)

Question 24

Describe the microbiology of Haemophilus influenzae

Answer 24

Gram-negative rod, grows glossy colonies on blood agar (needs chocolate agar)

Question 25

What is the most common cause of respiratory tract infections in children?

Answer 25

Streptococcus pneumoniae – the most important bacterial cause:

Question 26

How would you treat streptococcus pneumoniae pneumonia in children?

Answer 26

amoxicillin or penicillin

Question 27

What are some extrapulmonary manifestations of mycoplasma pneumonia?

Answer 27

**Haemolysis** **Neurological -** encephalitis, aseptic meningitis Cardiac Polyarthralgia, myalgia, arthritis Otitis media Bullous myringitis (vesicles on tympanic membrane – pathognomonic of mycoplasma disease)

Question 28

What is the mechanism of haemolysis in Mycoplasma pneumoniae?

Answer 28

IgM Abs → I antigen on erythrocytes Cold agglutinins in 60%

Question 29

What is the treatment for Mycoplasma pneumoniae?

Answer 29

macrolide s- azithromycin

Question 30

How would you diagnose UTIs in children?

Answer 30

Pure growth of \>10^5 CFU/mL Pyuria – pus cells on urine microscopy Renal tract imaging may be required to check for congenital anomalies

Question 31

What are some common organisms that cause UTIs?

Answer 31

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