TORCH, Spirochetes, Mono Flashcards
What does TORCH stand for?
T = toxoplasmosis
O = others perinatal infections (gonorrhea, syphilis, HIV)
R = Rubella
C = CMV
H = Herpes
What is TORCH used for?
Prenatal screening test
Toxoplasmosis - infectious agent. Modes of transmission
Toxoplasma gondii
-cannot be cultured
From cats or uncooked meats
Toxoplasmosis gold standard. Another test includes…
Sabin-Feldman Dye test
EIA
Toxoplasmosis - clinical findings
Mono-like symptoms
Hydrocephalus birth defects
Difference between EBV and CMV
EBV produces heterophile antibodies
CMV does not
CMV is a member of…
Herpes virus
-almost everyone has it
CMV - clinical findings
Neurological symptoms = mental-retardation, stillbirth
Mono-like symptoms
Cold sores, blisters
-mostly asymptomatic
Rubella - at what titer is a person considered immune? A recent infection has these findings…
1:8
4 fold increase in titer with symptoms
Rubella - clinical findings
Defects - CHF
Hepatitis
Diabetes
Rubella tests
EIA
Latex agglutination
Hemagglutination inhibition (HAI) - rubella can agglutinate chick RBCs. Mix patient serum with RBCs. Antibodies present = no agglutination
Passive hemagglutination (PHA) - human RBCs coated with Rubella antigen and serum diluted. Positive result is RBC agglutination (antigen-antibody complex)
What type of virus is the herpes virus? Which herpes virus is genital herpes?
DNA virus
HSV-I
Herpes tests
EIA
Viral culture - reference lab
Herpes - clinical findings
Fatal to infant if transmitted
Can spirochetes be gram-stained?
No
Syphilis bacterium
Treponema pallidum
- fragile, need open lesion to pass
- mother can transmit to newborn
- quickly disseminate throughout body in 30 mins
Syphilis - clinical findings
Primary (chancre)
Secondary (lymphadenopathy, skin rash, sore throat)
Latent (asymptomatic)
Tertiary (granulomatous inflammation, cardiovascular disease, neurosyphilis)
Congenital syphilis - clinical findings
Generalized lymphadenopathy, hepatosplenomegaly, jaundice, anemia, bone abnormalities, neurosyphilis
Facial deformity: Hutchinson’s teeth
Suspected Treponema infection should be screened for… Confirm with…
Non-treponemal antibodies first
- MUST be confirmed
- test is non-specific to treponema
Confirm with treponemal antibodies assay - cumbersome, expensive, lengthy
What are Reagin antibodies? What do Reagin antibodies target
Antibodies that develop targeting cholesterol-containing compounds in the cell membrane when they rupture from a syphilis infection
- seen as “foreign”
- Reagin is non-specific, seen in old people, autoimmune, cancer, TB, chickenpox, hepatitis
- diminish over time
Cardiolipin
Direct lab diagnosis of syphilis (2)
Fluorescent microscopy
Darkfield microscopy - corkscrew morphology, flexing mobility
-cannot be gram-stained
Serological tests for syphilis are divided into two categories. Which is screening and which is confirmatory?
Non-treponemal = screening
Treponemal = confirmatory
What are the 2 non-treponemal tests? Are they sensitive or specific for treponema?
VDRL and RPR
-look for flocculations = cardiolipin clumping
Both sensitive but not specific for treponema
VDRL vs RPR - which one is easier to do? Benefit of VDRL?
RPR - sensitive, faster, no microscope needed
Can be used on CSF samples
