Infectious Disease and Immunology Flashcards
I/T Ratio
%Bands + %Immature Forms
%Neutrophils + %Bands + %Immature Forms
Normal <0.2
most predictive if measured between 1-4 hours after birth
ANC
ANC <1000 - predictive of infection
%WBCs X ( %Immature Neutrophils + %Mature Neutrophils) x 0.01
Early Onset Sepsis Organisms
Most common: Group B Strep, E. Coli, Listeria
Late onset sepsis organisms
50% of cases caused by coagulase negative staph , GBS, E. Coli, Klebsiella common
E.Coli frequent cause of urosepsis
CRP levels’ sensitivity increases with serial values ______ to ______ after onset of symptoms
24 to 48 hours
CRP normal
<7-9
Procalcitonin levels peak ______ hours after infection; Compared to CRP, procalitonin is more ________ but less _________.
more sensitive, but less specific
Immature forms for Neutrophils
Bands, metamyelocytes, myelocytes
Other names for neutrophils
segs, polys, PMNS (polymorphonuclear luekocytes)
E. Coli Bacteria
gram negative rods
organism most commonly indicated in neonatal UTI
GBS
gram positive diplococci
Klebsiella
gram negative rod
Gram negative organisms such as klebsiella and E.coli are leading cause of LOS
3.5x higher risk of death than gram positive organisms; also common cause of EOS neonatal pneumonia
Coagulate Negative Staphylococci
gram positive organisms frequently found in resp. tract and on skin,
s. epidermis is the most common CONS recovered from skin and mucous membranes,
most common source of LOS
commonly associated with catheter lines
S. Aureus
an encapsulated gram + bacteria; symptoms begin after DOL 7
Treatment requires Vanc (preferred), clinda, linezolid
often associated with skin and soft tissue infections / omphalitis
MRSA Treatment
vancomycin
Chlamydia symptoms
can cause opthalmia neonatorum (conjunctivitis) or pneumonia
usually presents between 5-14 days of life ranging from mild eyelid edema to mucopurulent drainage with significant swelling
c. trachomatis pneumonia presents between 2-4 weeks of life
persistant staccato cough, tachypnea, nasal congestion without fever
symptoms occur from
Gonorrhea
most common presentation is conjunctivitis with rare dissemination to bacteremia
usually presents between DOL 1-5 w/ profuse purulent drainage, bilateral eyelid edema
Syphillis
50% of infants will be asymptomatic at birth
most common symptoms include:
- hepatitis
- hepatosplenomegaly
- radiographic bone changes (periostitis, osteochondritis)
- rash involving palms and soles of feet
- mucocutaneous lesions
- jaundice (both direct and indirect hyperbilirubinemia)
- bone marrow failure (thrombocytopenia, anemia)
- petechiae
- purpura
- snuffles (Rare)
Interpretation of NTA syphilis titers
probable - NTA 4 fold maternal result (abnormal exam + positive darkfield test or PCR of lesions/fluids)
possible - NTA less than or equal to four fold maternal result (normal exam and either inadequate maternal treatment or no record OR mother treated less than 4 weeks prior to delivery)
less likely - NTA less than or equal fourfold maternal result (normal exam and both true 1. maternal tx >4 weeks bfeore delivery, 2. no evidence of maternal relapse
unlikely - NTA less than or equal to 4-fold higher than maternal result and normal exam and both true (mother treated adequately, maternal NTA low )
Syphillis Treatment
for proven or probable disease
- Aqueous crystalline pcn G 50,000 units/kg/dose IV q12 for 7 days, then q8h for 3 more days
- OR Penicillin p procaine 50,000 units/kg/dose IM once daily for 10 days
for possible
- above options
- if evaluation completely normal - pencillin G benzathine 50,000 units/kg/dose IM x 1 dose
Toxoplasmosis
caused by protozoan T. gondii
risk factors include low socioeconomic status, lower levels of education, and having 3+ kittens
3 presentations: subclinical/asymptomatic (79-90% of cases)
neonatal symptomatic disease
Delated onset → occurs w/i first 3 months - behaves like symptomatic disease
Toxoplasmosis prenatal presentation on ultrasound
prenatal presentation - intracranial hyperechogenic foci, venticular dilation, anemia, hydrops, ascites, brain, splenic, and hepatic calcification
Toxoplasmosis postnatal presentation
MANY HAVE NO SYMPTOMS AT ALL
⅓ present with generalized symptoms
⅔ present mostly with CNS symptoms: classic triad of congenital toxoplasmosis ( 1. chorioretinitis 2.diffuse intracranial calcifications 3. obstructive hydrocephalus)
other symptoms include: pleocytosis (WBCs in CSF), elevated protein count in CSF, microcephaly, seizures, direct hyperbilirubinemia, meningoencephalitis
CSF White blood count indicative of meningitis
>1000 / mcl with predominately neutrophils
CSF Blood glucose indicative of meningitis
CSF glucose <30 mg/dL in term infants and <20 mg/dL in preterm infants
CSF Protein indicative of meningitis
Elevated CSF protein >100mg/dL in term or >150mg/dL in preterm
Meningitis treatment for organism suspected to be gram-negative bacilli
Amp + Gent + cefotaxime for csf penetration
Cefoxatime
added for treatment of meningitis for extended gram-negative coverage
Rubella Symptoms
Cataracts, Glaucoma, SNHL, PDA, Peripheral Pulmonary Stenosis, Radioleucent Bone disease, Blueberry muffin rash, Mental Retardation
CMV
Periventricular Calcifications, Retinitis, SNHL, Purpura
Syphillis
Meningitis, osteochondritis, snuffles
