ID Flashcards
C diff diagnosis
Enzyme immunoassay for glutamate dehydrogenase, toxins A and B
(EIA less sensitive)
And
Cell cytotoxin assay (labour intensive and expensive)
So EIA for GDH for screen then toxin EIA or cell cytotoxin assay
Treatment c diff (mild)
Watery diarrhea without systemic toxicity (<4 abn stool/d) = d/c precipitating antibiotic, follow up and reassess
C diff treatment initial episode moderate (or mild not responding to d/c abx)
Moderate (>4 abnormal stools/d) without systemic toxicity = flagyl 30 mg/kg/d divided 4 doses for 10-14 days
C diff treatment initial episode severe
Severe (evidence of systemic toxicity - rigours, high grade fever) = vanco 40mg/kg/d PO for 10-14 days
C diff treatment initial episode severe, complicated
Complicated (evidence of severe colitis, hypotension, shock, peritonitis, ileus, or megacolon) = vanco PO plus iv flagyl (same doses as above, 10-14 days. For ileus can give vanco PR.
C diff treatment for recurrence
First: Same treatment as first episode
Second: vancomycin in a tapered or pulsed regimen (40/kg/d divided 4 times daily for 10-14 days then 10 mg/kg twice daily for 7 days, the 10/kg once daily for 7 days, then every 2-3 days for 2-8 weeks)
C diff prevention
Hand hygiene
Identify and remove environmental sources of c diff
Chlorine containing sporicidal agents (alcohol doesn’t kill)
Contact precautions until 48 hours no diarrhea
Private rooms or cohorting and don’t retest stool, go based off of symptoms
Anti microbial stewardship
Toxoplasmosis classic triad + other symptoms and timing of infection
1st - most severe, fetal demise 2nd trimester - classic: - intracranial calcifications - hydrocephalus - chorioretinitis \+ jaundice, HSM, anemia, hearing loss, microcephaly, developmental delay, LAD, visual problems 3rd trimester: asyptomatic
Congenital toxo diagnosis
organism isolation from the placenta, serum, and cerebrospinal fluid (CSF)
ophthalmologic examination - chorioretinitis, CT head looking for calcifications, and
CSF - elevated protein and pleocytosis
congenital toxo treatment
pyrimethamine, sulfadiazine, and leucovorin for 1 year
Syphilis bug
gram-negative spirochete Treponema pallidum
Congenital Syphilis most common presentation:
majority of infants born with congenital syphilis are asymptomatic at birth
Congenital syphilis - early
1-2 months:
maculopapular rash, snuffles, generalized lymphadenopathy, hepatomegaly, thrombocytopenia, anemia, meningitis, chorioretinitis, pneumonia alba, and osteochondritis.
Congenital syphilis - late
Hutchinson/peg teeth (small teeth with an abnormal central groove), mulberry molars (bulbous protrusions on the molar teeth resembling mulberries), hard palate perforation, eighth nerve deafness, interstitial keratitis, bony lesions, and saber shins (due to chronic periosteitis)
Syphilis nontreponemal tests (2)
venereal disease research laboratory test and rapid plasma reagin are used for screening and monitoring treatment of the disease
Syphilis treponemal tests
fluorescent treponemal antibody absorption test or T pallidum particle agglutination are used to confirm diagnosis. Treponemal tests are not used alone due to false positives that may occur with other infections such as Lyme disease
Syphilis testing in newborn
same nontreponemal test as the mother if the mother has a nontreponemal titer that increased fourfold; had a positive treponemal test without documented treatment; had a positive treponemal test not treated with penicillin; had a positive treponemal test and was treated less than 1 month before delivery; or if the infant has signs of congenital syphilis.
If the infant’s nontreponemal titer is more than fourfold higher than the mother’s or if there is any clinical finding consistent with congenital syphilis, the infant must be treated and undergo a venereal disease research laboratory test of CSF, liver function tests, complete blood count, and long bone radiographs.
Syphilis treatment
Pen G
Mom HBsAg + treatment and tests
–> HBV vaccine and hepatitis B immune globulin within 12 hours of birth!
These infants should then complete the HBV vaccine series with two more additional immunizations per the CDC’s recommended schedule, as well as undergo HBsAg and anti-HBs testing after 9 months of age.
Mom Hep B status unknown at delivery
Test mom immediately
Baby gets Hep B vaccine within 12 hours and if mom is positive Hep B IG within 7 days
Maternal VZV
Treat baby with VZV IG if mom develops varicella 5 days before or 2 days after delivery
Maternal HIV - who gets a c/s
viral load > 1000 copies/mL
Baby to HIV + mom - when to test
HIV-1 DNA or RNA PCR should be analyzed at: 14 to 21 days after birth, 1 to 2 months of age, and 4 to 6 months of age
HIV + mom - when is baby considered uninfected?
1) two negative HIV-1 DNA or RNA assays, one obtained after 1 month of age and the other at 4 months of age or older, or
2) two negative HIV-1 antibody tests from separate specimens obtained at 6 months of age or older.
Some practitioners may follow antibodies until after 18 months of age because maternally derived antibodies rarely persist beyond this age
HIV + mom - treatment for baby
6 weeks of zidovudine. If confirmed infection then continue long term ARV
Parvo virus B19 baby risk
hydrops, pleural/pericardial effusion, IUGR, death
infection during 1st half of preg has greatest risk
Parvo virus B19 baby treatment
supportive care
IVIG may be helpful
Congenital rubella (german measles)
blueberry muffin rash (extramedullary hematopeoisis), radiolucent bone disease, IUGR, interstistial pneumonitis, LAD, HSM, thrombocytopenia, cataract
endocrinopathies - DM
Congenital rubella eye findings
cataract! also glaucoma, microphthalmos, pigmentary retinopathy
Congenital rubella cardiac findings
Pulmonic stenosis, PDA
Congenital rubella CNS s/e
developmental delay, encephalitis, SNHL
Congenital rubella diagnosis
infant rubella IgM
rising rubella IgG
virus isolated from CSF, serum, oral/nasal secretions
Most common congenital infection
CMV (0.5-1%)
CMV presentation
most are asymptomatic!
SNHL, HSM, jaundice, thrombocytopenia, periventricular calcifications, retinitis, IUGR, microcephaly
Congenital CMV diagnosis
CMV in urine or pharyngeal secretions in first 3 weeks - culture or PCR
Antibodies not helpful (IgG doesn’t tell you when mom got it, IgM not sens/specific)
Cong CMV treatment
Ganciclovir to improve SNHL and neurodevelopment
Maternal HSV highest risk
primary infection late in preg (3rd trimester)
Congenital HSV age of presentation
birth-6 weeks
How often is there a maternal Hx of HSV in infants with congenital HSV?
12.5%
HSV classification (3)
- primary skin, eyes, mucosa
- primarily CNS
- disseminated with multiple organ involvement
Best test for HSV CNS
PCR (sensitivity 75-100%)
Best test for HSV skin lesions
viral culture of skin lesion
