Paediatric ID Flashcards
Name encapsulated bacteria:
- Streptococcus pneumoniae
- Staphylococcus aureus
- Haemophilus influenzae
- Neisseria meningitidis
Name viruses in the enterovirus family:
- Enterovirus
- Coxsackievirus
- Echovirus
- Poliovirus
- RSV
Name catalase-positive microorganisms:
- Nocardia
- Pseudomonas
- Listeria
- Aspergillus
- Candida
- E. coli
- Staphylococcus
- Serratia
- Burkholderia cepacia
- H. pylori
What renal issue is associated with congenital syphilis?
Membranous nephropathy
How does parvovirus cause anaemia?
- Cytotoxic to erythroid progenitor cells - binds to red cell P antigen
- reticulocytopenic anaemia
- Generally mild unless pre-existing immunocompromise/haemolytic disease
What is hepcidin?
- Decreases extracellular iron
- Synthesized in liver
- Reduces ferroportin which causes:
1. decreased iron absorption by decreased transport across enterocytes
2. less iron exit from macrophages
3. reduced iron exit from the liver
Which drugs impair folate ABSORPTION?
- phenytoin
- primidone (barbiturate)
- phenobarbitone (barbiturate)
Which drugs have ANTI-folic acid actions?
- methotrexate ( binds to dihydrofolate reductase)
- Pyrimethamine (treats toxoplasmosis)
- trimethoprim
Which non-polio enterovirus is associated with paralytic disease?
Enterovirus 71
What is the risk of congenital varicella if mother gets infection during 1st/2nd trimester
- 0.4% if maternal infection < 12/40
- 2% if maternal infection 13-20/40
Which bacteria are urease-producing?
mnemonic PUNCH
- Proteus, Klebsiella - predispose to struvite stone production (UTI)
- Ureaplasma urealyticum
- Nocardia
- Cryptococcus
- Helicobacter pylori
What infection causes fatty acid crystals on faecal microscopy?
Giardia (also celiac)
Underlying: digestion/breakdown of fat OK but not being absorbed due to physical defect/metabolic cause e.g. celiac disease or infection
Name first-generation cephalosporins and what they are used for:
- Cefazolin, cefalexin
- skin and soft tissue infections
- staph. aureus, group A strep
- minimal gram -ve cover (e.coli and klebsiella if sensitive)
Name second-generation cephalosporins and what they are used for:
- cefuroxime, cefoxitin, cefaclor
- gram positive and gram negative cover, less cover for staph
- chest, urinary tract, skin and soft tissue
Name third-generation cephalosporins and what they are used for:
- ceftazidime, ceftriaxone, cefotaxime
- meningitis and sepsis
- won’t cover listeria, enterococcus, staph (except ceftaz)
- ceftaz - antipseudomonal, anti-staph
- ceftri - jaundice in neonates as displaces bilirubin from glucuronidation
Name fourth-generation cephalosporins and what they are used for:
- cefipime
- gram negative cover and can cover staph, strep
- won’t cover listeria, enterococcus
Which antifungals are best for CNS infection?
- Azoles are good for brain
- Fluconazole has good brain and CSF concentration
- Anidulafungin has good CSF but low brain concentration
Super-itchy migratory rash, “serpiginous”, may have been in contact with animal faeces:
- cutaneous larva migrans, associated with cat/dog hookworms
- ancylostoma braziliense (cat)/caninum
- albendazole or ivermectin
- majority self limiting
- complications are impetigo, local and generalised allergic reactions, hypereosinophilia
How does staph become MRSA?
- Production of altered penicillin-binding proteins (PBPs) in the bacterial cell wall
- PBP-2A is responsible for the methicillin resistance of MRSA isolates.
What is the exclusion period for chicken pox?
Until all lesions are crusted - 6-7 days after onset of rash
Which immunisations are T-lymphocyte independent and what are the clinical implications?
- Polysaccharide immunisations (Pneumovax 23)
- Poor response after age 2
- Antibodies last around 3–5 years in children
When do you see antibody response to immunisation?
- 7 to 10 days later
- IgM then IgG
Which immunisations cannot be frozen?
- DTaP/anything with DTaP components
- Hepatitis A, B
- HPV
- Pneumococcal (conjugate)
- Influenza (inactivated, split) Hib (liquid)
- Meningitis C (polysaccharide-protein conjugate)
- Cholera (inactivated)
- Inactivated poliovirus
- Typhoid polysaccharide
- Rotavirus (liquid)
Which immunisations can be frozen?
- Hib (freeze dried prior to reconstitution)
- Measles, mumps, rubella
- Rotavirus (theoretically)
- Varicella-zoster virus
- Oral poliovirus
- Rabies
- Meningitis A (polysaccharide-protein conjugate)
- Yellow fever
- BCG
If you see villous atrophy with infectious diarrhoea…
…think rotavirus, giardia
Osteomyelitis in sickle cell disease…
…think salmonella (up to 70%)
India ink stain with halo is classical for which organism?
Cryptococcus neoformans
Congenital infections causing hearing loss:
Rubella, CMV (10% if asymptomatic), toxo (less likely)
How do aminoglycosides work?
- Inhibit bacterial protein synthesis
- All bind to sites on the 30S subunit of the bacterial ribosome, causing an alteration in codon:anticodon recognition
Don’t give which antibiotic for pseudomonas?
Cefotaxime
Enterococcus is intrinsically resistant to…
Cephalosporins
Aztreonam is useful because…
It is not cross reactive for people allergic to penicillin/cephalosporin
Imipenem important side effect…
Decreases seizure threshold/neurotoxicity
What is the most likely mechanism of resistance to penicillin in strep pneumoniae?
PBP affinity alteration
What vaccine do you avoid in HIV?
BCG
No herd immunity from which type of immunisation?
Polysaccharide
Non human-human spread
Contraindications to rotavirus immunisation:
Previous intussusception
Anaphylaxis
GI surgery, anatomical malformation, NEC are actually relative contraindications
First line for aspergillus…
Voriconazole
Which viruses are associated with Karposi Sarcoma?
HHV8
HIV
Which viruses cause haemorrhagic cystitis?
BK/JC if immunosuppressed
Adenovirus
What is recommended varicella prophylaxis if exposed/not previously infected?
Immune compromised ‐ Give VZIG / IVIG ASAP up to 10/7
Immune competent:
• vaccine within 3/7 may prevent chicken pox
• within 5/7 lessens severity of illness
For all:
• aciclovir if symptomatic
What is the maternal/neonatal treatment for toxoplasmosis?
- Maternal to prevent transmission is spiramycin
- Maternal if foetal infection is pyrimethamine + sulphadiazine + folinic acid
- neonatal if infected is 12/12 treatment
Pyrimethamine, sulfadiazine and leucovorin 5‐10mg 3x weekly
What is the most infective of the diseases we vaccinate against? (Highest R0)
Measles
maybe rotavirus as well…
What is the risk of catching chlamydia if Mum has it?
50% overall - 30%-50% conjunctivitis, 10-20% pneumonia
What type of ART is zidovudine?
Nucleotide reverse transcriptase inhibitor
What is Gianotti-Crosti Syndrome?
- a.k.a. infantile papular acrodermatitis
- viral infections and immunizations of all types
- typically 3-4/7 hx of non itchy 5-10mm dull/dark red spots (first on thighs/bum, then outer arms, then face)
- evolve from deep red -> purple and become vesicular
- well/mild fever and mild lymphadenopathy
- fades in 2–8 weeks with mild scaling.
What infections are associated with Gianotti-Crosti Syndrome?
Hepatitis B infection EBV CMV Enterovirus infections Echo viruses RSV
What type of vaccination is HPV-9?
Recombinant subunit vaccine containing virus-like particles
What are the HACEK organisms and what is their significance?
H – Haemophilus A – Aggregatibacter (previously Actinobacilus) C – Cardiobacterium E – Eikenella K - Kingella
Fastidious gram-negatives which cause 5-10% of IE
What is the most common viral cause of myocarditis?
Cocksackie B
