IID & Immuno Flashcards
Congenital syphilis skeletal abnormalities
- demineralization of proximal medial tibia (Wimberger sign)
- sawtooth metaphyseal serration (Wegener sign)
- diaphyseal periosteal reaction with new bone formation
- Irregular areas of rarefaction and increased density (moth-eaten appearance)
Small stippled epiphyses and cortical thickening
congenital hypothyroidism
osteopenia with callus formation and pseudo paralysis
osteogenesis imperfecta
extensive bone resorption and generalized bone radiolucency.
Hyperparathyroidism
umbilical cord with blue and red stripes interspersed with white areas
subacute necrotizing funiculitis; congenital syphilis
HIV viral loads checkpoints for baby born to mother with well controlled HIV
<48 hours
14 to 21 days after birth
1 to 2 months of age
4 to 6 months of age.
GBS facts
- encapsulated by a polysaccharide layer rich in sialic acid
- catalase-negative, bacitracin resistant, and forms beta-hemolysin, a pore-forming toxin that destroys the host’s red blood cells resulting in hemolysis
Hutchinson triad
- Hutchinson teeth
- interstitial keratitis
- SNHL
common microbes isolated from peritoneal cultures in cases of spontaneous intestinal perforation.
Candida and coagulase-negative staphylococcus epidermidis
XR findings and timing of signs in osteomyelitis
Diagnosis may be apparent on XR by 7 to 10 days post-infection as evidenced by bony destruction, focal area of metaphyseal necrosis, and soft tissue swelling.
do skeletal survey to assess other bone invovement
Cytomegalovirus virus type
double-stranded herpes DNA virus passed via secretions, sexual
intercourse, blood products, transplacental, intrapartum or via breastmilk→ standard
Rubella type and precautions
RNA virus passed via respiratory secretions→ contact and respiratory
droplet
Listeria: type and precautions
gram-positive rod passed via unpasteurized milk and soft cheeses, uncooked meat
and unwashed raw vegetables→ standard
ParvoB19: type and precautions
single-stranded DNA passed via respiratory secretions, transplacental→
droplet
HSV type and precautions
double-stranded herpes DNA virus passed via contact with lesions, or
rarely transplacental→ contact
Toxo type and precautions
intracellular parasite passed by poorly cooked meat, cat feces or
transplacental→ standard
RSV type and precautions
RNA paramyxovirus passed by direct contact with secretions,
highly contagious→ contact
Varicella type and precautions
DNA herpes virus passed via respiratory droplets, contact with rash or transplacental→ airborne and contact
HIV type and precautions
RNA retrovirus passed via blood, sexual contact,
transplacental or via breastmilk→standard
TB type and precautions
slow-growing acid-fast bacillus
respiratory secretions
mucous membranes or skin
rarely hematogenous spread from an infected placenta or aspiration of infected amniotic fluid
airborne and contact
Risk of stillbirth
Listeria, Parvovirus B19, Syphilis, Malaria
CMV transmission via BM
- CMV transmission via breast milk is more likely to occur among preterm infants
- Freezing and pasteurization reduces CMV transmission
Toxoplasmosis Transmission and Severity
Transmission increases with GA
Severity decreases with GA
Treponema pallidum transmission and severity
Transmission can occur at any time
Severity increases with GA
Rubella transmission and severity
Transmission most likely in early and late pregnancy (U-shaped
distribution)
Severity decreases with GA
CMV transmission and severity
Transmission any time
Severity decreases with GA
Timing of HSV surface cultures in asymptomatic exposued in infant
12-24 hours after birth
When does IgG disappear?
9 months
When does IgG decrease
6 months
HIV positive mom breastfeeding concerns
Antiretroviral drugs have differential penetration in human milk, raising concerns about toxicity
to infants receiving breastmilk
Definitive rule out of HIV in infant born to HIV positive mother
1) 2+ negative HIV RNA or DNA ≥1 months age (1 ≥4 months)
2) 2+ negative HIV Ab test ≥6 months
When does IgA production begin in neonate
After birth
Osteomyelitis MC sites
METAPHYSIS
femur > humerus > tibia > radius > maxilla
Osteo treatment
21-42 days PCNase resistent penicillin, aminoglycoside or cephalosporin
septic arthritis treatment
2-6 weeks PCNase resistent penicillin and aminoglycoside
osteo prognosis
joint deformities if epiphyseal plate damage
septic arthritis prognosis
greater risk than osteo of permanent abnormality
omphalitis treatment
PCNase resistant - use methicillin/nafcillin/oxacillin
vanco if MRSA
gentamicin or cephalosporin
+ anaerobic if black periumbilical region
Meningitis spread
hematogenous
Duration of treatment for meningitis
10-14 days GBS
14-21 days Listeria
21+ days for GNR
if E.coli UTI consider what other disease
galactosemia
acute purulent conjunctivitis
s. aureus
N.gonorrhea conjunctivitis prevention and treatment
0.5% erythro preventino
treat with 3rd gen cephalosporin
Chlamydia treatment
no prevention
treat with 14 days PO erythromycin 20% require 2nd course
which is MCC conjunctivitis
chlamydiae
which conjunctivitis is more puruluent
gonorrhea
Chorioretinitis causes and differences
salt and pepper: syphillis, Rubella
yellow + white lesions: HSV, CMV
atrophic: toxo
fluffy white: candida
MCC serotype GBS
III
IAP effect on late onset GBS
none
GBS mortality EOS and LOS
5-10% and 2-6%
MCC serotype listeria EOS
serotype Ia and Ib
AF in listeria
chocolate colored
LOS
IVB
mortality of listeria
EOS 25% and late 15%
Syphillis placenta
large
Syphilis % symptomatic
33%
Nontreponemal screening tests
VDRL and RPR
Treponemal confirmatory tests
FTA-ABS, particle agglutination or enzyme immunoassay
how long do treponemal tests stay reactive
for life even after treatment
What disease leads to false positive treponemal test
Lyme disease with ANA positive; VDRL will show true negative
False positive non-treponemal tests
AI, TB, viral, endocarditis, passive maternal IgG
False negative non-treponemal tests
early primary, latent, late congenital or if prozone phenomenon (excess Abs prevent complexing - so dilute the sera)
when do you repeat a negative treponemal test if non-treponemal screening was positive
2-4 weeks
when to retreat infant with syphillis
if titers (obtained 2,4,6,12 mos) are increasing or persistent - LP and treat with PCN 10 days
Diagnosis media for gonorrhea
Thayer-Martin (rapid plating)
GC conjunctivitis requires emergent treatment bc
corneal ulceration or perforation
what is not seen on gram stain
chlamydia trachomatis
C.trach treatment
14 days PO erythromycin base or ethylsuccinate
untreated maternal chlamydia ppx for infant
none
untreated maternal gonorrhea ppx for infant
1 dose ceftriaxone
TB transmission congenital and postnatal
congenital:hematogenous and infected AF
postnatal: resp secretions or traumatized MM or skin
asymptomatic baby, active TB mom
what is testing plan?
inh for 3-4 months then ppd
positive > reassess for TB
if no disease INH 9 months (12 if HIV)
negative > dc INH
repeat PPD q2-3mos for 1 year then yearly
isolate baby if mother noncompliant, respiratory symptoms or MDR
congenital TB treatment
what do you add if meningitis?
INH, RIF, pyrazinamide + aminoglycoside
+ CTX if meningitis
typically 9-12 months
C.botulinum affects what neurotransmitter
ACh release –> descending paralysis, ocular palsy, poor feeding
Dx botulinism
Stool toxin
EMG: incremental response at high fx, abnormal spontaneous activity, abundant & brief small amplitude AP
TX botulinism
human derived IV botulism Ig
NOT abx - aminoglycosides can increase NM blockade
C.tetani affects what neurotransmitter
blocks GABA and NMJ –> difficulty swallowing, rigidity, muscle spasms, fever, continuous crying, seizure, lockjaw
Tx C.tetani
tetanus Ig : neutralize circulating unbound toxin
PCN G 10-14 days
diazepam for muscle spasms
still need vaccine because disease does not confer immunity
Use of dexamethasone in H.influenzae
to prevent hearing loss in meningitis - give with or before first dose of antibiotics
most common strain of RSV
A
Infant > 2000 g what to do based on maternal hep B status
negative - hep B after birth
unknown - test mom ASAP, hep B to baby < 12 hours; 7 days await moms results
positive - hep B vax + HBIg < 12 hours
+2 more doses for all
Breastfeeding does not increase risk
Infant < 2000 g what to do based on maternal hep B status
negative - hep B when > 2000 g, 30 days or at dc whichever first
unknown - test mom ASAP, hep B vax < 12 hours; 12 hours to await moms results
positive - hep B vax + HBIg < 12 hours
+3 more doses (unless first given > 2000g then only 2 more)
Breastfeeding does not increase risk
maternal hep C positive
test neonate, NAAT at 1-2 months
ToRCH highest risk LBW
CMV
ToRCH highest risk HSM
CMV
ToRCH highest risk jaundice
CMV
ToRCH highest risk petechiae
CMV
ToRCH highest risk CHD
Rubella (esp if <10 wk GA
ToRCH highest risk cataracts
rubella
ToRCH highest risk chorioretinitis
toxo
ToRCH highest risk microcephaly
CMV
ToRCH highest risk cerebral calcifications and locations
toxo cortical > CMV periventricular
HIV subtypes
HIV 1: M (major), O (outlier), N (new)
HIV 2 milder
PCP infection in HIV infants
at 3-6 months; radiographic diffuse alveolar infiltrative pneumonia
Preferred test to diagnose HIV1 and what does timing of positivity tell us about method of transmission?
HIV1 DNA PCR
Positive < 2 days - in utero infection
Positive day 2-6 - intrapartum infection
HIV positive mom when to test baby
< 48 hours
14-21 days
1-2 months
4-6 months
a nonbreastfeeding baby is considered presumptive negative if
2 negative PCR > 2 weeks and > 4 weeks
1 negative PCR > 8 weeks
1 negative Ab > 6 months
Zidovudine is what type of drug
nucleoside analogue reverse transcriptase inhibitor
Neviripine is what type of drug
non-nucleoside reverse transcriptase inhibitor
How long should HIV exposed babies get bactrim?
start at 4-6 weeks and if determined negative can stop
continue 1 year if positive, longer if abnormal CD4 count
Enterovirus diagnosis and management
reverse transcriptase PCR and culture of any body fluid
Tx IVIg if life threatening disease; pleconaril but not currently available
difference betweem ampho b and liposomal ampho b
liposomal is less nephrotoxix
candida may have resistance to which antifungal
fluconazole
how does ampho b and fluconazole work
-ampho B binds sterols disrupting fungal cell wall synthesis
- fluconazole inhibits production of major component of fungal cell wall
what is flucytosine used for?
second agent to ampho b in fungal meningitis
which fungal infection has an association with intralipid administration
malassezia; requires exogenous long chain fatty acids for growth
what medication given to moms decreases transmission of toxo
spiromycin
treatment of toxo in infants and duration
pyrimethamine and sulfadiazine for 1 year
folinic acid to prevent neutropenia from pyrimethamine
vaccines contraindicated during pregnancy
live: MMR and varicella
vaccines contraindicated in HIV babies
oral polio, bCG, MMR-varicella relatively
components of breastmilk that are antibacterial
lactoferrin high; bacteriostatic
lactoperoxidase: low; requires hydrogen peroxide and thiocyanate for antibacterial effect
contraindications to breastfeeding
HIV, TB, active abscess, HSV lesion on breast
relative: CMV, hep C
Diagnosis medium for chlamydia
Giemsa stain
Diagnosis medium for pertussis
Bordet-Gengou
Diagnosis medium for pseudomonas
Oxidase-positive, catalase-positive
Diagnosis medium for rubella
hemagglutination inhibition
SE of amikacin
ototoxicity, nephrotoxicity, NMJ blockade
Consequence of clindamycin in NEC
post NEC stricture formation
Erythromycin effect on other meds
aminophylline. : interferes with hepatic metabolism
carbamazepine, digoxin : increase effect
midazolam : decrease clearance
What makes NMJ blockade by gentamicin worse?
hypermagnesemia
Which antibiotics are bactericidal?
PCN/cephalosporins - PCN binding proteins needed for peptidoglycan of cell wall
aminoglycosides : 30S subunit of ribosomes to inhibit protein synthesis
vancomycin : inhibit peptidoglycan synthesis
Quinolones - inhibit DNA gyrase
Which are bacteriostatic?
erythromycin/clindamycin - reversibly bind 50S of ribosomes
chloramphenicol
tetracycline - bind reversibly 30s of ribosomes
sulfonamides - inhibit folate synthesis
T cell lymphopoeisis in utero timeline
8.5 wk: precursors in fetal liver
10 wk: thymus becomes lymphoid
11-12 wk: t cells from thymus to spleen/nodes
16-18 wk: hasalls bodies in thymus
B cell lymphopoeisis embryology
8 wk: pre B cells in fetal liver
8-10wk: fetal bone marrow
18-22wk: liver, lung, kidney
30+ bone marrow only
neutrophil functions
chemotaxis
phagocytosis
bacterial killing
neonatal neutrophils
decreased migration
normal bacterial killing
longer neutrophilia after infection 3-4 hrs (compared to 1 hr adults)
disorders of neutrophil chemotaxis
hyper-IgE (Job’s) - coarse facies, eczema, recurrent infections
disorders of neutrophil adhesion
LAD (defect in B2 integrin), no pus, omphalitis
disorders of neutrophil intracellular killing
myeloperoxidase deficiency - fungal infections
chediak-higashi - wbc inclusions, partial oculocutaneous albanism, abnormal degranulation
chronic granulomatous disease (XL) dysfunctional NADPH oxidase/phagocytosis impaired, abscesses and poor wound healing and granuloma formation
disorders of decreased neutrophil production
Shwachmann-Diamond - AR, BM dysfunction, malabsorption with steatorrhea and FTT, myelodysplastic syndromes
Kostmann - AR, risk myelodysplastic
Reticular dysgenesis - lymphopenia, also with SNHL
disorders of excessive neutrophil margination
pseudoneutropenia
endotoxemia
meds
disorders of accelerated neutrophil usage or destruction
sepsis
chronic benign neutropenia
autoimmune or alloimmune neutropenia
Chediak higashi
Functions of monocytes
chemotaxis
phagocytosis
bacterial killing
wound repair
monocytes in neonates
decreased migration
disorders of monocytes
LAD
histiocytosis
chediak higashi - defective chemotaxis
Wiskott-Aldrich
CGD
Function of complement
opsonization
chemoattraction
inflammation
complement (Ag-Ab)
alternative (without Ab)
Complement levels in neonates
when are they normal?
decreased especially in preterm
normal levels at 3-6 months
Disorders of complements
early components C1-C4 deficiency (C2 most common) –> risk of pneumococcal infections and collagen vascular disease
late C5-C9 –> risk of neisseria
hereditary angioedema (AD) absence of esterase inhibitor, recurrent swelling
leiner syndrome - generalized erythematous desquamative dermatitis, FTT, diarrhea, C5 abnormality
mediators of vasodilation
histamine, prostaglandin, NO, bradykinin
mediators of vascular permeability
histamine, complement, bradykinin, leukotrienes, NO
mediators of leukocyte adhesion
cytokines (IL1, TNFa)
complement
eicosanoids (Pgs, leukotrienes)
selectins
mediators of chemotaxis
- chemokines
- complement
- eicosanoids (PG, leukotriene)
mediators of fever
IL1, TNFa, PGs
Mediators of tissue necrosis
neutrophillic granules, free radicals
Mediators of platelet aggregation
eicosanoids (PGs, leukotrienes)
T cells in neonates
decreased T cell function
»decreased cytotoxicity
»decreased participation in delayed type hypersensitivity and B cell differentiation
Disorders of T cells
SCID
ADA deficiency
Ataxia - telangiectasia
DiGeorge
Wiskott Aldrich - XL, thromboycytopenia, eczema, recurrent infections
chronic mucocutaneous candidiasis
B cells in neonates
poor antibody response to infection
Disorders of B cells
XL agammaglobulinemia
XL hyper IgM- perirectal or oral abscesses
Selective IgA or IgG deficiency
Job’s syndrome - IgE
CVID
when does infant start producing IgG
6 months
when does neonatal reach 75% of adult level IgM
1 year
when does neonate start making IgA
after birth
when does neonate start making IgM
in utero - fetal 6 months
disadvantages of umbilical cord stem cells
limited cell number
slower neutrophil engraftment –> longer hospitalization
slower immune reconstitution –> increased risk of viral infections
test for Ab mediated immunity
quantitative Ig levels
isohemagglutanin titers
Ab response to vaccines
test for cell mediated immunity
total t cells and subset cd4/cd8
delayed type hypersensitivity skin tests (mumps, candida, tetanus)
test for phagocytosis
quantitative nitroblue tetrazolium test (NBT)
test for complement
total hemolytic complement (CH50)
quantitative complement levels
test for CGD
NBT - cannot produce superoxide; normally turns colorless liquid blue but will remain clear in CGD
test for t cell receptor excision circles
SCID or DiGeorge
Role of spleen
- synthesis Ab against carb
- clears microbes
- site of IgM & complement production
- maturation of Abs
- support T cell proliferation
- scavenges damaged or senescent RBCs & platelets
- recycles iron from hemoglobin for hematopoeisis
asymptomatic negative testing baby but HSV exposure management
acylovir IV 10 days
encapsulated bacteria
H. flu, N. men, S. typhi, S.pneumo
Disorders of asplenia
Ivermark - AR, dextrocardia or a right-sided aortic arch
Pearson BM failure
Stormorken STIM1 gene, AD, thyrombocytopenia, dyslexia, myosis, myopathy
Smith-Meyers-Fineman (XL), cryptorchidism, and severe NDI
Treatment for SNHL CMV
6 months valganciclovir
MCC EOS order
Group B Streptococcus, Staphylococcus Aureus, Escherichia Coli, Listeria
MCC complication of toxo
chorioretinitis
White spots on the umbilical cord and amniotic membranes
candidal chorioamnionitis
Vesiculobullous mucocutaneous lesions
syphillis
highest risk GA for congenital VZV aquisition
16-20
mevalonate kinase gene mutation chr 12q24
hyperIg D syndrome
what do antibodies bind to in alloimmune neonatal neutropenia
HNA1a MCC, HNA1b or HNA2a
What does deficiency in adenosine deaminase lead to?
excess toxic metabolites in lymphoid cells leading to apoptosis in BM and thymus precursors
What does defect in Jak3 do?
failure of development and differentiation of T cells in thymus
What does defect in Rag1 or 2 lead to?
failure of Tcell receptor development
How do defects in DNA repair enzymes effect Tcell function?
failure of receptor development
How do defects in MHCII effect Tcell function?
inappropriate survival signals leading to death
22q11.2 deletion effect on t cellls
lymphopenia secondary to abnormal thymus development
Forkhead box N1 deletion effect on t cells
lymphopenia secondary to abnormal thymus development
symptoms of primary infantile lupus
MC glomerulonephritis
others pneumonitis, pulmonary hemorrhage, nephrotic syndrome
How does maternal ANA lead to fetal heart block?
maternal Abs bind to fetal cardiomyocytes leading to macrophage attraction and fibrosis
symptoms of neonatal lupus
rash
thrombocytopenia
cholestasis
causes of drug induced neutropenia
decreased production, increased destruction, increased margination
lab findings in mevalonic aciduria
elevated CRP
subsets of B-cell subtypes and function
Follicular B2 adaptive response against thymus dependent antigens; create high affinity antibodies
B1 peritoneal and pleural; thymus independent: low affinity antibodies predominant in fetus, esp CD5+
marginal zone B spleen, thymus independent and low affinity
meds that decrease chemotaxis
theophylline, magnesium, indomethacin
meds that increase chemotaxis
GCSF, GM-CSF
rate of mortality with invasive Candida
20%
rate of NDI in invasive Candida <1000g
60%
first abnormality on XR with osteomyelitis
soft tissue swelling
rate of EOS in VLBW
10/1000
route of HCV acquisition
intrauterine and intrapartum
treatment for routine varicella and severe varicella in pregnant mothers
PO in routine and IV in severe; acyclovir
nutritional roles of intestinal micobes
increase genes:
absorb carbs and lipids
synthesize biotin, folate, vit K
fermentation
which common bacteria penetrate BBB the transcellar route?
GBS, e.coli, listeria
skull osteomyelitis MCC
e coli
SIRS
Sense abnormal temps
eIther increased or decreased HR
Respiration abnormal
Some abnormal cells
MC symptom congenital syphillis
hepatomegaly
MC symptom congenital TB
HSM
risk of the different types of maternally acquire HCV
20% acute resolving
50% chronic asymptomatic
30% chronic active infection
infection with highest mortality
pseudomonas
food most related to listeria outbreaks
soft cheese
risk of LOS in VLBW
20%
bacterial vs viral meningitis CSF markers
bacteria has higher lipocalin2, lactate, CRP in CSF
neonatal TB acquisition
fetal rare bc hard to cross placenta
acquired from household contacts
MC presentation of invasive candida infection
endocarditis (15%)
MCC neonatal neutropenia
pregnancy induced hypertension
MC manifestation neonatal SLE
thrombocytopenia
incidence of invasive candidiasis in 24 week GA
20%
highest sensitivity and specificity for LOS
IL6 +/- CRP/procal
time to total intestinal reconstitution
5days
MC manifestation of LOS from listeria
meningitis
