Skills Lab Flashcards
(45 cards)
SYPHILIS
A sexually transmitted disease caused by the bacterium_______
Treponema pallidum, subspecies pallidum.
Other Treponema:
causes yaws
causes endemic syphilis.
causes pinta.
Treponema pallidum subspecies pertenue
Treponema pallidum subspecies endemicum
Treponema carateum
• Presents with a painless ulcer called a chancre at the site of infection.
• Nontreponemal tests typically become positive 1 to 4 weeks after the primary chancre appears, but 13% to 41% of individuals with primary syphilis may have nonreactive results.
Primary syphilis
• Is marked by a generalized illness with symptoms like headache, sore throat, low-grade fever, and rash.
• Characteristic lesion: Condyloma lata
Secondary syphilis
• An asymptomatic stage where the infection lies dormant.
• While not infectious through contact, pregnant women can still transmit the disease to their tetus during this stage.
• Nontreponemal tests gradually become nonreactive, although about one-third of patients remain seroreactive.
Latent syphilis
• The most destructive stage, developing in about one-third of untreated individuals, often years after the initial infection.
It manifests in three main forms: what are those?
Tertiary syphilis
Gummatous syphilis
Cardiovascular syphilis
Neurosyphilis
T pallidum
DIRECT MICROSCOPY
Darkfield Microscopy = “_____” motility
Requires active lesions to obtain a suitable sample.
Direct Fluorescent Antibody Staining = specimen:______
Levaditi’s Silver Impregnation = silver reagent; positive is black
corkscrew
chancre
NON-TREPONEMAL TESTS
These tests detect antibodies (Reagin) to cardiolipin.
________ antigen
• A.k.a._____ antigen
• A lipid released from damaged cells during inflammation.
_________
• A.k.a. anti-lipoidal antibodies
• Is not a specific antibody against Treponema pallidum
Cardiolipin (antigen)/ Wasserman
Reagin (Anti-cardiolipin)
Non treponemal tests (2)
Venereal Disease Research Laboratory (VDRL) and
rapid plasma reagin (RPR) tests.
Non treponemal test principle
Principle:_______
The formation of downy masses of precipitate that occurs over a narrow range of antigen concentration.
Where a positive reaction involves visible clumping of fine antigen particles.
Flocculation
These tests detect antibodies directly against Treponema pallidum antigens
TREPONEMAL TESTS
One of the earliest confirmatory tests.
Label used: FITC-AHG
Uses killed T. pallidum (Nichols strain) fixed to a slide as the antigen.
Patient serum is first absorbed with non-pathogenic treponemes (Reiter strain) to remove cross-reacting antibodies.
Fluorescent treponemal antibody absorption (FTA-Abs) test
VDRL vs RPR
Detects
Reagin
VDRL antigen (C-L-C):
Cardiolipin
Lecithin
Cholesterol
RPR
Modified VDRL antigen:
C-L-C plus:
= makes the reaction easy to read
= prevents lipid oxidation
= inactivates complement;
stabilizes antigen
= preservative
Charcoal
EDTA
Choline chloride
Thimerosal
HUMAN IMMUNODEFICIENCY VIRUS (HIV)
A retrovirus that infects (3)
CD4+ T cells,
macrophages, and
dendritic cells
HIV uses an envelope protein (_____) to bind to CD4+ T cells and chemokine receptors (co-receptors: CXCR4 and CCR5).
GP120
The most prevalent type, responsible for the main AIDS epidemic
Mainly found in West Africa
HIV 1
HIV 2
HIV confirmatory test
Western blot
HIV
Gold standard:
Immunophenotyping with Flow Cytometry
: new confirmatory test only in PH; follows 4th gen. ELISA;
can detect Ab and Ag
rHIVda (rapid HIV diagnostic algorithm)
HIV
•________ : rises throughout the infection;
first detectable antibody
•_______: exhibits poor prognosis
Anti-gp41
Anti-p24
Current medicine (pampa lessen lang sa effect) for HIV
antiretroviral therapy/drug (ARD/ART)
Short-Incubation Hepatitis
Primarily fecal-oral
Close person-to-person contact.
HAV
