Spirochetes-Treponemes

Question 1

What features do the Spirochetes share in common?

Answer 1

Flexible, spiral peptidoglycan cell well

One or more axial fibrils (“internal flagellum”) that assists in maintaining coiled shape

Question 2

Three major genera of Spirochetes responsible for human disease:

Answer 2

Treponema, Borrelia, Leptospira

Question 3

Structural characteristics of Treponema pallidum

Answer 3

Outer membrane does not contain lipopolysaccharide

Thin, tightly coiled

Question 4

How is Treponema pallidum visualized?

Answer 4

Must use Darkfield microscopy or immunofluorescence for visualization

Question 5

Describe Treponema pallidum culture and growth.

Answer 5

Can only be cultured few generations on media with rabbit epithelial cells

Very sensitive to drying and heat

Microaerophilic (only 3-5% oxygen)

Question 6

___________________ is the 3rd most common sexually transmitted infection in U.S.

Answer 6

Treponema pallidum (syphilis) is the 3rd most common sexually transmitted infection in U.S.

Question 7

Incidence of syphilis is particularly rising among what demographic?

Answer 7

MSM

Question 8

Treponema pallidum is found only in ____.

Answer 8

humans

Question 9

How is syphilis transmitted?

Answer 9

via direct sexual contact with an infective primary or secondary mucosal lesion on the genitals, anus, or lips.

Question 10

When and how does congenital infection with syphilis occur?

Answer 10

Congenital infection occurs in utero

by transmission across the placenta

Question 11

Clinical hallmarks of primary stage syphilis:

Answer 11

Painless ulcer (chancre) at the site of inoculation

Painless inguinal lymphadenopathy

No systemic manifestations (no fever, rash, or fatigue)

Darkfield positive - teeming with spirochetes

Question 12

Clinical hallmarks of secondary stage syphilis:

Answer 12

Flu-like syndrome

Fever and diffuse lymphadenopathy

Generalized mucocutaneous rash (involves the palms/soles)

Condylomata lata (papules coalesce into large lesions)

Question 13

Clinical hallmarks of latent stage syphilis:

Answer 13

Asymptomatic

Question 14

Clinical hallmarks of tertiary stage syphilis:

Answer 14

Granulomatous lesions of skin/organs/bone (gummas)

Neurosyphilis

Cardiovascular syphilis

Question 15

Timeframe of primary stage syphilis:

Answer 15

10-90 days after infection

Question 16

Timeframe of secondary stage syphilis:

Answer 16

2-10 weeks after chancre

Peaks 3-4 months after infection

Question 17

Timeframe of latent stage syphilis:

Answer 17

A few years to as many as 25 years

Progresses to tertiary syphilis if untreated

Question 18

Timeframe of tertiary stage syphilis:

Answer 18

Generally at least 5-10 years since infection

Question 19

Describe the syphilis chancre:

Answer 19

smooth margins and crusted base

Question 20

Describe Cardiovascular Syphilis:

Answer 20

Cardiovascular Syphilis – chronic large vessel vasculitis that involves the wall of the aorta, causing aortic aneurysms/dissection

Question 21

Name the stage of Neurosyphilis:

CSF inflammatory changes: pleocytosis and elevated protein

Answer 21

Early (Secondary) - Asymptomatic

Question 22

Name the stage of Neurosyphilis:

No symptoms

Answer 22

Early (Secondary) - Asymptomatic

Question 23

Name the stage of Neurosyphilis:

Meningitis and Vasculitis

Answer 23

Early (Secondary) - Symptomatic Meningovascular

Question 24

Name the stage of Neurosyphilis:

Headache, neck stiffness, fever, cranial neuropathy, stroke

Answer 24

Early (Secondary) - Symptomatic Meningovascular

Question 25

Name the stage of Neurosyphilis: | Dementia, aphasia, muscle weakness, hallucinations

Answer 25

Late (Tertiary) - General paresis

Question 26

Name the stage of Neurosyphilis: | Chronic meningoencephalitis leading to brain atrophy

Answer 26

Late (Tertiary) - General paresis

Question 27

Name the stage of Neurosyphilis: Infection/inflammation of the spinal cord Demyelination of spinal cord posterior columns and dorsal roots

Answer 27

Late (Tertiary) - Tabes dorsalis

Question 28

Name the stage of Neurosyphilis: Imbalance and Ataxia Loss of pain and temperature sensation

Answer 28

Late (Tertiary) - Tabes dorsalis

Question 29

Symptoms of congenital syphilis:

Answer 29

Rhinitis (‘snuffles’ - heavy nasal discharge) Widespread rash, hepatomegaly

Question 30

Long-term effects of congenital syphilis:

Answer 30

Bone and teeth malformation – frontal ‘bossing’ Facial abnormalities – ‘saddle nose’ Blindness, deafness, cardiovascular disease

Question 31

Methods of non-serological diagnosis of Treponema pallidum:

Answer 31

Darkfield microscopy Direct fluorescent antibody PCR

Question 32

Unique qualities of non-treponemal tests:

Answer 32

Measures reaginic (lipid) antibodies - NOT directed specifically against T. pallidum Patients revert to negative results with treatment or enough time Can be used to follow treatment

Question 33

Unique qualities of treponemal tests:

Answer 33

Tests remain positive for life, regardless of treatment Cannot be used to monitor response to treatment

Question 34

3 types of serologic specific treponemal tests:

Answer 34

Fluorescent treponemal antibody absorption Tests (FTAAbs) T. pallidum particle agglutination (TP-PA or TP-HA) T. pallidum enzyme immunoassay (EIA) or chemiluminescence immunoassay (CIA)

Question 35

2 types of serologic non-treponemal tests:

Answer 35

VDRL (serum & CSF) – Venereal Disease Research Laboratory RPR (serum) – Rapid Plasma Reagin

Question 36

True or False: A positive non-treponemal test is always confirmed with a specific treponemal test

Answer 36

True

Question 37

When are non-treponemal tests likely to be negative?

Answer 37

Early primary stage, late-latent and tertiary syphilis, following treatment, or after many years

Question 38

What is unique about a reverse sequence diagnostic algorithm for syphilis?

Answer 38

Begins with a specific treponemal test (EIA or CIA)

Question 39

Best treatment of treponema pallidum? Alternatives?

Answer 39

IM injection of Benzathine penicillin G (long acting) Doxycycline is an alternative, but is not as effective

Question 40

Treatment for neurosyphilis:

Answer 40

IV penicillin G

Question 41

What is the Jarisch-Herxheimer reaction?

Answer 41

Reaction related to the release of toxic products from dying spirochetes due to Abx.

Question 42

When are both non-treponemal and treponemal tests likely to be positive?

Answer 42

Secondary stage

Question 43

Describe transmission of Borrelia.

Answer 43

Larger spirochete that is spread from a mammalian reservoir to humans by tick or louse vectors

Question 44

Name the 2 clinical infections caused by Borrelia species.

Answer 44

Causes Relapsing fever and Lyme borreliosis (Lyme disease)

Question 45

Is Borrelia gram-positive or gram-negative?

Answer 45

Neither

Question 46

How are Borrelia species visualized?

Answer 46

Stain with Giemsa or Wright’s stain

Question 47

Why is little know about pathogenesis of diseases caused by spirochetes?

Answer 47

They are very difficult to culture due to complex nutritional needs.

Question 48

How does B. recurrentis escapes immune recognition?

Answer 48

By altering antigenic structure during infection: Gene switch from silent to expression locus on plasmid Relapses are caused by emergence and multiplication of antigenic variants

Question 49

2 most common geographic areas for Borrelia burgdorferi cases :

Answer 49

Northeast and Mid-Atlantic states (Maine to Virginia) Upper Midwest (Minnesota and WI)

Question 50

Primary Animal reservoirs of Borrelia burgdorferi:

Answer 50

White-tailed deer and white-footed mouse

Question 51

Name the hard tick that transmits Borrelia burgdorferi in the NE and Midwestern U.S.

Answer 51

Ixodes scapularis

Question 52

Name the hard tick that transmits Borrelia burgdorferi in the Western U.S.

Answer 52

Ixodes pacificus

Question 53

Most lyme disease is transmitted by the bite of a ________.

Answer 53

Most lyme disease is transmitted by the bite of a nymph

Question 54

Risk of human infection by Lyme disease is greatest in _________ and __________.

Answer 54

Risk of human infection is greatest in late spring and early summer

Question 55

Clinical Manifestations of Early Stage (3-30 days post bite) Lyme Disease:

Answer 55

Erythema migrans: expanding erythematous target-shaped lesion at site of tick bite Flu-like illness: fever, chills, malaise, myalgias

Question 56

Clinical Manifestations of Early Disseminated (weeks days post bite) Lyme Disease:

Answer 56

Arthritis and arthralgia Cardiac dysfunction (conduction block) Facial nerve paralysis or other cranial neuropathies

Question 57

Clinical Manifestations of late-stage Lyme Disease:

Answer 57

Recurrent/relapsing arthritis in large joints Acrodermatitis chronica atrophicans -hyperpigmented rash on the dorsal surface of the hands

Question 58

Describe the two-tiered testing system for Lyme disease:

Answer 58

Initial screening immunofluorescence assay (EIA, ELISA, IFA) - must allow time for Abx to be present Confirmed with a second, more specific Western Blot test - Detects specific IgG and IgM antibodies against Borrelia burgdorferi

Question 59

What evidence would suggest the Borrelia burgdorferi infection of the CNS?

Answer 59

Elevated lymphocytic pleocytosis and elevated protein in CSF Specific serology testing (IgG and IgM) from CSF PCR from CSF (reference laboratory)