Chapter 21: Spirochete Diseases

Syphilis

Most commonly acquired spirochete disease

Treponema pallidum subsp. pallidum

Causative agent of Syphilis

Treponema pallidum subsp. pertenue

Agent of YAWS (chronic nonvenereal disease of skin and bones)

Treponema pallidum subsp. endemicum

Agent of nonvereneal endemic syphilis

Treponema pallidum subsp. carateum

Agent of Pinta

Sexual transmission

Primary mode of dissemination of pathogenic treponemes

Primary

Secondary

Latent

Tertiary

Stages of Syphilis

Chancre

A painless, solitary lesion characterized by raised and well-defined borders

Develops 10-90 days after infection (Ave: 21 days)

Treponema pallidum subsp. pallidum

The Great Imitator

Gummatous syphilis

Cardiovascular disease

Neurosyphilis

Manifestations of Tertiary Syphilis

Note: This occurs 10-30 years following the secondary stage

Gummas

Localized areas of granulomatous inflammation that are most often found on bones, skin or subcutaneous tissue

Congenital Syphilis

This occrs when a woman who has early syphilis or early latent syphilis transmits treponemes to the fetus

Direct detection

Nontreponemal Serological tests

Treponemal serological tests

Three main types of laboratory tests for Syphilis

Darkfield Microscopy

Fluorescent antibody testing

Direct Detection of Spirochetes is accomplished by means of ?

Fluorescent Antibody Testing

A sensitive and highly specific alternative to dark field microscopy

Serological Tests

Key to diagnosis if patient has no active lesions in the case of Secondary and Tertiary Syphilis

Nontreponemal Tests

Traditional screening tests for Syphilis

Note: False-positive results are common because of the nonspecific nature of the antigens

Treponemal Tests

Positive results in nontreponemal tests must be confirmed by ?

August Paul von Wasserman

Developed the first nontreponemal Test

Complement Fixation

Principle of Wasserman Test

Nontreponemal Test

Tests that determine the presence of an antibody that forms against cardiolipin

Cardiolipin

A lipid materail released from damaged cells

Reagin

Antibody to Cardiolipin

0.03% Cardiolipin

0.9% Lecithin

0.21% Cholesterol

Composition of Antigen complex used in the reaction to detect the nontreponemal reagin antibodies in VDRL

Note: These abs are either IgG or IgM class

VDRL (venereal disease research laboratory)

RPR (rapid plasma reagin)

TRUST (Toluidine Red Unheated Serum Test)

RST (Reagin Screen Test)

Most widely used nontreponemal tests

Flocculation Reactions

Principle of Nontreponemal Tests

Flocculation

A specific type of precipitation that occurs over a narrow range of antigen concentrations

1-4 weeks after the appearance of primary chancre

Nontreponemal test are positive within

Prozone phenomenon

Testing the sera of patients in secondary syphilis is subject to false negative due to

Prozone phenomenon

Lack of a visible reaction in antigen-antibody combination caused by the presence of excess antibody. This may result in a false-negative reaction.

Serial dilutions

Remedy if prozone phenomenon is suspected

VDRL

Both qualitative and quantitative slide flocculation test for serum that includes a modification for use on spinal fluid

Hamilton syringe

Instrument used to deliver one drop of VDRL antigen for the slide test

Alcohol and recalibrated

If the delivery of Hamilton syringe is off by >2 drops out of 60, the syringe must be cleaned with ____________?

Nonreactive

Minimally reactive

Reactive

Three control sera for VDRL

4 minutes

180 rpm

VDRL slide is rotated for __ minutes on a rotator at ____ rpm

Reactive

VDRL result: Medium to Large clumps

Weakly reactive

VDRL result: Small clumps

Nonreactive

VDRL result: No clumps or slight roughness

1:2 to 1:32

All sera with reactive or weakly reactive VDRL results must be tested using the quantitative slide tests with two-fold dilutions of serum ranging from ________________ are initially used

VDRL

Nontreponemal test that is read microscopically

Rapid Plasma Reagin

Modified VDRL test read macroscopically

Cardiolipin

Lecithin

Cholesterol

EDTA

Thimerosal

Choline chloride

Composition of RPR

Rapid Plasma Reagin

Nontreponemal Test that does not require heat inactivation before use

EDTA

Thimerosal

Choline chloride

Components of RPR that stabilize the antigen and inactive complement

Retesting using doubling dilutions in a quantitative procedure

All positive results in RPR should be confirmed by _______?

4

Inactivated serum for VDRL should be use within ______ hours

Beef Heart

Antigen source of VDRL

Cardiolipin source

56C for 10 minutes

Reinactivation of serum for VDRL Test is done at ________ when >4hrs has elapsed

18g

Gauge used for Qualitative VDRL and requires 60 drops of Ag suspension

19g or 23g

Gauge used for Quantitative VDRL and requires 75 and 100 drops of Ag suspension

21g or 22g

Gauge used for CSF VDRL and requires 100 drops of Ag suspension

Charcoal

Component of RPR that allows visualization of flocculation macroscopically

Choline chloride

Component of RPR that stabilizes antigen. Heating is not necessary because of this.

T. pallidum immobilization test

Most specific test for syphilis

Gummas

Localized areas of granulomatous inflammation that are most often found on bones, skin or subcutaneous tissue

0.03% Cardiolipin

Main reacting component of VDRL Antigen

0.9% Cholesterol

Component of VDRL Antigen that enhances the reacting surface of cardiolipin

0.21% Lecithin

Component of VDRL Antigen that removes anti-complementary activity of cardiolipin

EDTA

Component of RPR Antigen that prevents oxidation of lipids

100 rpm for 8 minutes

Rotation and time in RPR

Indirect Fluorescent Treponemal Antibody Absorption Test

Agglutination Test

Two main types of manual treponemal tests

Reiter strain

Sorbent used in FTA-ABS used to remove antibodies that cross-react with treponemes other than T. pallidum

Borrelia burgdorferi

Agent of Lyme disease

Willy Burgdorfer

First author and discoverer of the causative agent of Lyme disease

Lyme disease

Most common vector-borne disease in the U.S

Barbour Stoenner Kelly Medium at 33C

Culture medium for Borrelia burgdorferi

Erythema migrans (EM)

Clinical Hallmark of early infection of B. burgdorferi

Facial palsy

Most common neurologic sign of Lyme disease

Facial palsy

A peripheral neuritis that usually involves one side of the face

Arthritis

Peripheral Neuropathy

Encephalomyelitis

Major manifestations of late Lyme Disease

HLA-DRB alleles

HLA associated with treatment-resistant arthritis caused by Lyme disease

Immunofluorescence assay

Enzyme Immunoassay

Patients with clinical evidence of Lyme disease be screened with?

Western Blot

Supplemental test for Lyme diseases

Note: This is done if the serology (IFA & EIA) is positive or borderline

1:256 or higher

Titer in IFA that is considered positive

B. reccurentis

T. denticola

RA

SLE

Causes biological false-positive to IFA for Lyme disease

Immunofluorescence Assay (IFA)

Serological test for Lyme disease best suited for low-volume testing

Beaded IFA pattern

IFA pattern of False positive to Lyme disease caused by biological false-positive causes

Western Blot/Immunoblotting

Confirmatory test for Lyme disease

2

Any of these; 23, 39, 41

Number of bands in Western Blot for Lyme disease to be considered positive for IgM antibody

5 of 10 proteins

Number of bands in Western Blot for Lyme disease to be considered positive for IgG antibody

Corscrew motility

Motility pattern of T. pallidum

Chancre

Specimen used in Direct Fluorescent Antibody Staining for T. pallidum

Darkfield Microscopy

DFAS

Levaditi's Silver Impregnation

Methods for Direct Microscopy of T. pallidum

Wasserman antigen

Other name of cardiolipin

Wasserman Complement Fixation Test

Oldest Test for Syphilis

0.9% Cholesterol

Component of VDRL antigen that is the center for absorption of tissue lipids to increase antigen size

0.12% Lecithin

Component of VDRL antigen that produces standard reactivity

60 +- 2 drops

Number of drops for Qualitative VDRL

Note: It uses 18 gauge

75 +- drops

Number of drops for Quantitative VDRL

Note: It uses 19 gauge

8 minutes at 100 rpm

Rotator setting for RPR

Nichols strain

T. pallidum strain seen on the slide in FTA-ABS

Green

Positive color in FTA-ABS

Serodia T. pallidum particle agglutination (TP-PA) Test

Treponemal test that uses a colored gelatin particles coated with treponemal antigens.

Note: It is more sensitive in detecting primary syphilis

Neurosyphilis

Indication of positive VDRL in CSF

Treponema pallidum-Particle Agglutination

Assay for Syphilis that is excellent in resolving inconclusive FTA-ABS results

Condyloma lata

These are flat lesions resembling warts that are seen most commonly in moist areas of the body.

It is seen in secondary syphilis

Treponemal Tests

Most sensitive tests for primary syphilis