ID Flashcards
What is the most common site of origin of osteomyelitis and common spread?
What about most common site?
Metaphysis
Hematogenous spread, therefore can spread to epiphysis bc blood supply is connected until 8-18 mo
Femur is most common site
What is the most common organism in osteo and septic arthritis?
Which organism is more common in septic arthritis?
Staph aureus followed by GRoup b strep
Neiserria gonorrhea is more commonly found with septic arthritis than osteo
What are the most common organisms in EOS vs late onset sepsis?
EOS: GBs, ecoli, listeria, nontypeable flu and enterococcus
LOS: coag neg staph, mssa, pseudomonas, then gbs ecoli and listeria
Initial treatment for osteo or septic arthritis?
Penicillinase resistant penicillins (nafcillin, oxacillin, methicillin) and aminoglycoside or cephalosporin. Narrow based on cultures. Osteo: 21-42 days vs septic arthritis if staph aureus 4-6 weeks vs group b strep 2-3 weeks
Treatment for omphalitis
Penicillinase resistant penicillins (methicillin, nafcillin, oxacillin)
Vanco if high local incidence of mrsa
Gent/cephalosporin for gram negative coverage
If umbilical region black-add anaerobic coverage
Infection with which ecoli subtype is more likely to lead to meningitis?
Ecoli with K 1 antigen
Which organisms are associated with worse outcomes in meningitis?
Gram negative, CSF WBC>500
Gbs if comatose, shock WBC<5000, ANC <1000 or CsF protein>300
Most common neonatal organisms for UTI?
Most common spread?
Ecoli (#1), klebsiella, enterobacter
Hematogenous or ascending vs old kids is ascending
What infection shows with placental micro abscesses?
Listeria
What are the clinical findings of a mother with rubella infection?
Highest risk of defects at what GA?
Fever, coryza, conjunctivitis and althralgia
50% risk 9-12 weeks
When is peak CRP as it relates to sepsis?
2-3 days after developing sepsis
Only 20% have this response
Most common cause of EOS in VLBW?
E Coli
First abnormality to manifest in xray in neonatal osteomyelitis?
Soft tissue swelling
Then bone destruction 7-10 days after
If affects adjacent joint then joint space widening
Cream colored macules on placenta, name the organism?
Candida
Wedged shaped microabscesses containing hyphae yeast and neutrophils
Incidence of EOS in VLBW
10 in 1000 live births
What is the recommended treatment for severe varicella infection prenatally?
IV acyclovir
If mild disease oral acyclovir
Intestinal microbes have nutritional roles including:
Synthesis of biotin, folate and Vit K
Full PPE is needed for Airborne organisms such as
Varicella, Covid, tuberculosis, measles
Travels long distance
90% of blood cultures are positive by how many hours?
36 hrs
Toxo transmission frequency is x with advancing gestation
Higher
But severity of disease
Closer to term is higher risk of transmission and with new infection
Which type of conjunctivitis is considered a medical emergency?
Gonococcal conjunctivitis which presents 2-5 days bc if not treated w IV cephalosporin can progress to involve cornea and ulceration/penetration
Describe the organism causing chorioretinitis findings for each:
- Salt and pepper appearance to fundus
- Yellow white exudates
- Yellow white fluffy retinal lesion
- necrotizing retinitis
- Fluffy white balls
- Early congenital syphilis or congenital rubella
- Herpes simplex
- cMV
- Toxo (seen 80-90%)
- candida
Which antibiotics do you use for following gastroenteritis
- Salmonella
- Shigella
- Campilobacter or yersenia
- c diff
- Cefotaxime
- Ampicillin
3 Erythromycin
4 Vanco
Gram positive rod associated with placental microabscesses
Listeria
Also described as chocolate colored mec staining
EOS-mother with prodromal flu like illness, zero type Ia and Ib and baby has sepsis/pneumonia
LOS-from maternal colonization, serotupe IVb, meningitis w milder
symptoms
Tx:amp/gent 14 days or 21 if meningitis
Indicate the precaution type
CMV - Standard Rubella - Contact + Droplet HSV - Contact (lesions) Toxo + HIV + Listeria - Standard TB + Varicella - Contact + Airborne HSV - Contact Parvovirus- Standard + Droplet
Name treponemal and non treponemal tests for syphilis
RPR: Initial Screen (non treponemal)
FTA - ABS: Confirmation (treponemal)
Mother with +RPR, + FTA-ABS, and received PCN <4 wk before birth. Next steps for mother and baby?
Check non-treponemal in mom and baby
Check treponemal in baby
Full eval and tx w PCN
FU non treponemal testing throughout 1st year and csf non-treponemal @6mo
Gbs E Coli and listeria penetrate blood brain barrier by which approach?
Transcellular
Listeria also uses Trojan horse mechanism
T/F Ribavirin contraindicated in pregnancy
True
Administration is orally
Most common cause of scalp osteomyelitis from electrode or after cephalohrmatoma
E Coli
Most common site of MRSA infection in a previously healthy neonate
Breast
Pustulosis<1cm
Abscess >1cm
VariZIG is recommended in which population
5 days before and 2 days after hospitalized newborn <28weeks or <1kg
Immunocompromised or non immune
How does parvovirus lead to hydrops?
Aplastic anemia, myocarditis and heart failure which in turn lead to hydrops
MCA doppler helps measure severe anemia
Most common cause of EOS in term vs preterm
Term GBS
Preterm ecoli
Which stool colonizing organism is associated with NEC?
Clostridium perfringes
Which is the first organ affected in congenital TB?
Liver
Transplacental/Hematogenous spread via umbilical vein
Treatment for infant with congenital TB?
INH, rifampim, pyrazinamide and aminoglycoside (4 drug regimen)
What is the treatment of congenital toxoplasmosis?
Pyrimethamine and sulfadiazine
Torch infections:
- Transmission increases with gestation, disease is more severe if acquired earlier in pregnancy
- Disease more severe if acquired later in pregnancy
- Transmission u shaped distribution but disease more severe if acquired early
- Disease more severe if acquired early
- Toxoplasmosis
- Treponema pallidum
- Rubella
- CMV, varicella
Early w severe disease: CMV, varicella, rubella, toxo
Later: syphilis
MCC congenital heart disease in congenital rubella
PDA and pulmonary arterial hypoplasia
Most common reason to get neonatal tetanus and management?
Improper umbilical cord handling
Tx: tetanus immunoglobulin and pen G 10-14 days
Diazepam for spasm
Still need to vaccinate bc doesn’t lead to immunity
Describe organism and Treatment of pertussis
Gram negative bacillus
Human only host
Oral erythromycin (may lead to infantile hypertrophic pyloric stenosis)
Some use azithro <1mo (not fda approved for this use)
Mechanism of action of acyclovir
Inhibits viral DNA transcription, activated specifically by thymidine kinase
Duration 14 day for SEM, 21 days for disseminated or CNS disease
Management of VTach
If stable (pulse) amiodarone, lidocaine or b blocker (may consider adenosine if reentry SVT) Unstable (pulseless) DC cardioversion
What are the greatest risks for CLABSI’s?
Low birth weight
Younger gestational age
Similar rates between UVC (9 days) and PICC (14 days)
Name non culture CSF testing that can help to identify meningitis (early on)
Latex agglutination
PCR
Microarray
Immunochromatography
Risk factors for Hepatitis C transmission
- high maternal HCV viral load
- High HCV RNA load -
- maternal coinfection to on withHIV (increased risk 3-5 fold)
- Female Neonate
Most serious side effect of ceftriaxone and MOA
Ceftriaxone can displace bilirubin from albumin leading to bilirubin toxicity
Most common site for Neonatal osteo
Metaphysis of long bones
Femur + tibia»_space;> humerus + fibula
Most common presentation of congenital syphilis
Hepatosplenomegaly (present in almost all affected
Respiratory distress
Pretern with LOS - what is Gram negative infection with highest mortality rate
Pseudomonas aeruginisa (45-70%)
Psuedomonas is responsible for 2-5% of late onset infections with ELBW pts
Determine fetal risk by maternal parvo immunoglobulin levels
Maternal IgG +
Maternal IgM -
= Past infection
No risk to fetus
Maternal IgG +
Maternal IgM +
= Infection within last 7-120 days
Possible risk to fetus
Maternal IgG -
Maternal IgM +
= Acute infection
High risk to fetus
Maternal IgG -
Maternal IgM -
= Non immune pregnant 🤰🏽
No sign of acute infection
*Consider repeating test in few weeks to assess if IgM becomes + (acute infection)
No risk to fetus unless + IgM with repeat testing
Risk of late onset sepsis on VLBW
20%
Adverse antibiotic effects with VLBW
-Alteration of micro biome
-Increased risk of candida infections (especially with 3rd generation cephalosporin in VLBW)
/increased risk for Nev
Increased risk for late onset sepsis
Inctrssed mortality
Most common risk factors for CLABSI
Young gestation age Low bw Length of hospitalization Parentéral nutrition (>21 d) Mechanical ventilation Lack of enteral feedings
Early onset GBS characteristics
Ascending infection from colonization
Prolonged ROM
EOS likely due to capsular polysaccharide serotypes 1a, 1n, 2, 3, 5
Which intestinal microbe is most associated with pseudomembranous colitis?
Clostridium difficile
Independent risk factor for gram
negative LOS
Parenteral nutrition
Which combination of markers have been shown to yield highest diagnostic sensitivity and specificity for LOS?
Interleukin 6 and crp or procalcitonin
What is the diagnostic criteria for sirs?
Physiologic and/or lab abnormalities Low or high temp Leucopenia/leukocytosis or >10% bands Low/high Hr Increases RR or need mechanical ventilation
Must meet temp and WBC criteria (2/4)
Most common organism for LOS?
CONS
Which side effect has been reported with fluconazole prophylaxis?
Transient hepatic dysfunction
If HepC is diagnosed after 18 mo and confirmed at 3 years which vaccines must be given to this child?
Hep A and HepB because a second cause of infectious hepatitis can increase cause of morbidity and mortality
Baby with HSV has been treated with acyclovir (IV) x 10 days. How do we minimize future neuro developmental disabilitues?
PO Acyclovir x 6 months
Infant with failed hearing screen, negatuve HUS, normal LFTs and paltelets, urine CMV PCR positive. Next best step?
Close audiologic followup q6 months for 3 years. If progressive hearing loss, offer early intervention. 10-15-% of asymptomatic infnats can have SNHL.
Failed hearing screen and otherwise asymptomatic wouldnt meet criteria for valgancyclovir treatment.
Only those w moderate to severe symptoms should begin treatment within 1 mo of birth
Hep B is a _____ _NA virus
Double stranded DNA
Which Hep B antigen is present when virus is rapidly replicating?
HepBeAg
Usually present before symptoms and disappears before clinical symptoms resolve
How do you distinguish HepB immunity from prior infection vs vaccine?
Prior infection
HepBsAg neg, AntiHepBc positive, AntibHepBs positive
Vaccine
HepBSAg negative, Anti-HepBc negative and AntiHepBs positive
Remember you cannot have antibody core without having had hardcore HepB infection
Where does parvovirus replicate?
Within the RBC precursors
Single stranded DNA
Celery stalking of long bone metaphysis. Which infection most likely?
Rubella
Other associations: cataracts, salt and pepper chorioretinitis
Cmv is ____Stranded __NA virus
Double stranded herpes DNA virus
Intranuclear and cytoplasmic inclusions
In patients of heterotaxy and poly/asplenia, which vaccines are recommended?
PCV 13 regular scheduke and PCV-23 after 2 years. Meningococcal vaccine 2,4,6 and 12 months as well. In addition to routine vaccines.
Zidovudine toxicity manifests as
Lactic acidosis and hepatic abnormalities
Macrocytic anemia and neutropenia are also possible effects of AZT treatment
