treponema pallidum: syphilis

Question 1

Sprirochete genera

Answer 1

Treponema – syphilis, yaws, bejel, pinta, and part of the NF on mucosal surfaces.
Borrelia – Lyme disease and relapsing fever.
Leptospira – causing leptospirosis.

Question 2

Nonpathogenic Treponema are ?? and are present in ??
(e.g. T. denticola) and on virtually all mucosal surfaces.
where??
Diagnosis of syphilis requires ??

Answer 2

normal flora of humans
oral cavity

These are the same places where the primary chancre of syphilis occurs.

differentiating between the Treponema normal flora versus T. pallidum.

Question 3

Pathogenic Treponema: Human:

Answer 3

T. pallidum var. pallidum (syphilis).

Question 4

Characteristics of T. pallidum, etiologic agent of syphilis (hard chancre), a genital ulcer disease (GUD).

Answer 4

unicellular, G-, motile, “delicate” very thin, elongated spirochete
(coiled/helical) with a very small genome relative to the pathogen’s size.

Question 5

T. pallidum G- cell wall architecture

Answer 5

• Phospholipid outer membrane - a paucity of proteins and no LPS (It is postulated that the lack of outer membrane proteins [OMP] causes the organism to have a “low profile”, immunologically).
• Lipoprotein - induce similar responses as endotoxin, a potent immunomodulator (important in Jarisch-Herxheimer reactions).

Question 6

T. pallidum: motile or non-motile?

visible or not visible on Gs??

Answer 6

Highly motile by means of an “endoflagella/periplasmic flagella”.

Cells are not visible on gram-stained smears (too thin), but cells are visible by darkfield microscopy

Question 7

T. pallidum: slow or fast growing?

Answer 7

slow growth rate & cannot be cultured in vitro. The only known way to predictably grow or expand a syphilis isolate is to inject lesion material into rabbit testicles on a living rabbit.

Question 8

T. pallidum sensitivity to ??

Answer 8

various environmental factors is great (e.g. high (>42°C) and low
temperature (4°C), desiccation, soap & water, etc. are lethal to T. pallidum).

Question 9

T. palladium host/reservoir?

mode of transmission??

Answer 9

Humans are the sole host and reservoir.

-Direct Contact - Sexual transmission is the primary mechanism of spread via
microscopic creaks/breaks in the mucous membranes and skin.
-Transplacentally (in utero): congenital infections–> to congenital syphilis.
-Lab workers have been infected accidentally.
-Blood and blood transfusions is a potential source of infection.

Question 10

Syphilis is a systemic disease involving the ??, which can result in pathology in various organs during stages of the full course of the disease.

Answer 10

inflammatory response

Question 11

T. pallidum Vascular pathology:

Answer 11

• Endarteritis/ Endarteritis obliterates: proliferative concentric thickening of small BVsby endothelial & fibroblastic cells–> reduction in the caliber of the vessel lumen or even blocking the vessels. Partially responsible for 1o/2o lesions and manifestations of tertiary (3o) syphilis.
• Periarteritis: proliferation of the adventitial cells and cuffing of the vessel by inflammatory cells consisting of monocytes, plasma cells, lymphocytes.

Question 12

?? are prone to develop more severe syphilitic disease.

Answer 12

Immunosuppressed patients

Question 13

immune response to syphilis: T. pallidum-specific Antibodies: IgM titer peak during ?? and then rapidly decline. IgG titer peak when?? but declines very slowly over time.
?? are present when clinical signs appear.

Answer 13

secondary syphilis

at end of secondary syphilis after the IgM peak

Both IgM, IgG antibodies

Question 14

immune response to syphilis: ?? response appears to dominate in primary syphilis, the agent drives a conversion to ??response in secondary syphilis.

Answer 14

Th1

Th2

Question 15

Primary syphilis: incubation period ?? during which the
organisms multiply locally, and at the same time or some time later, enter and disseminate the ??. As the spirochetes multiply locally, an immune response slowly evolves that induces ??

Answer 15

an average of 21 days (range is 3 to 90 days)

draining lymphatics and/or bloodstream

chancre formation

Question 16

Hard single chancre/genital ulcer develops at the ??

what is it??

Answer 16

POE
-is a button-like induration (i.e., firm-hard), sharply demarcated, clean based, lesion with an eroded center and serous discharge, usually painless and is highly infectious

Question 17

can there be multiple chancres??

when/how do they heal??

Answer 17

YES. Occasionally, there may be multiple chancres. Chancre heals spontaneously in 26w, except in the immunocompromised patient.

Question 18

how can chancres go unnoticed??

what can alter its appearance??

Answer 18

Besides being painless, the chancre may be so small or anatomically located so as to go unnoticed and is especially difficult to find in females and tends to be more conspicuous in males. Many (60% of all) patients do not recall lesions of any sort.

-Secondary bacterial or viral infections (e.g., herpes) of the chancre

Question 19

Syphilis should be included in the ddx of ??

Answer 19

any lesion or ulcer of the genitalia, rectum, anus, lip, or hand of sexually active patients.

Question 20

There may be accompanying ?? which appears 7-10 days after the chancre develops.

Answer 20

painless, regional and generalized lymphadenopathy

regional: bilateral inguinal – A chain of discrete, firm, freely movable, nonsupprative nodes

Question 21

Secondary syphilis is a disseminated infection involving ??
which occurs about ?? after exposure
Duration is ?? if untreated.
Several relapses are possible mostly within ??

Answer 21

virtually every organ system

6wks (range is 2wks-6 months)

1 to 2 months

the first year

Question 22

Syphilis manifestations are protean (assuming different forms) and each time a patient manifests with S&S of secondary syphilis, the patient is ??

Answer 22

infectious to his/her partner(s)

Question 23

syphilis s/s: rash

Answer 23

A bilaterally symmetrical, non-pruritic, infectious

• usually starts on the palms of the hands and the soles of the feet, the mouth, anus and spreads throughout the body. (centripetal spread?)
• can be macular, maculopapular, pustular, annular, scaling. All forms may be present at one time and may be widely distributed over the whole body.

Question 24

syphilis s/s: mucous patches AKA condylomata lata

Answer 24

highly infectious raised, painless, with a central erosion and covered with a thin membrane and are found on the genital, oral, and/or rectal mucosa (warm moist tissue)

Question 25

syphilis s/s: Alopecia

Answer 25

patchy hair-loss with a “moth-eaten” appearance of scalp & eyebrows.

Question 26

syphilis Constitutional s/s

Answer 26

Low-grade fever, malaise, headache, arthralgais,

generalized lymphadenopathy.

Question 27

syphilis can invade any organ, but commonly ??

Answer 27

liver (hepatitis); kidney (immune-complex glomerulonephritis); eye, CNS (meningitis/encephalitis), arthritis, GI tract.

The manifestations are protean and why syphilis is called “the great imitator”.

Question 28

T. pallidum has a propensity for invading the ??

Answer 28

CNS.

Pts with 1o and especially 2o syphilis have a more than 40% chance of CNS invasion. -typ. asymptomatic.”

Question 29

Secondary syphilis resolves ??.

If untreated or inadequate therapy is used, ?? is initiated.

Answer 29

with or without treatment

a latent stage of infection

Question 30

Latent syphilis is an asymptomatic phase-post-primary syphilis with no ?? but with ?? which can persist for variable periods of time ??
Latent syphilis terminates after ?? or ??

Answer 30

clinical S/S
positive serology
(2 months or for life of patient; average is 4 years).

therapeutic cure occurs or tertiary manifestations develop.

Question 31

Latent syphilis is arbitrarily divided into ??

Answer 31

early- and late-latent syphilis based on the ability to relapse into secondary disease.

Question 32

Early latent syphilis occurs when ??
the patient is in latent syphilis anytime ??

Patient is infectious to sex partners due to relapses into ??

Answer 32

the first year of infection – 365 days from day of
exposure to agent to the end of year

post 1o syphilis, that the patient is asymptomatic in that first year

2o syphilis: Nearly all 2o syphilis relapses occur during early latent syphilis (90%), the remainder in late latent syphilis.

Question 33

Late latent syphilis occurs when ??.

Patient is NOT considered infectious to sex partners because ??

Answer 33

from the end of 1st yr–>4y

there is a very low rate of relapse to secondary syphilis (less than 10%)

Question 34

A person is considered infectious during all relapses into secondary syphilis regardless of ??

Answer 34

when they occur.

Question 35

T. pallidum may be transmitted ?? any time during latent syphilis.

Answer 35

via blood transfusion and a pregnant woman can infect her fetus in utero

Question 36

Tertiary (Late) syphilis: 1/3 of untreated 2o syphilis pts will undergo a ?? and 1/3 remain ?? Another 1/3 advances to ??

Answer 36

spontaneous cure
persistently infected but asymptomatic
tertiary syphilis

Question 37

tertiary syphilis is ??

Usually occurs ?? after initial exposure

Answer 37

is a slow, degenerative progressive inflammatory disease affecting any organ system that is refractory to antibiotic treatment and is fatal
10y (range 2 to 30y)

Question 38

3 tertiary syphilis manifestations

Answer 38

Cardiovascular syphilis/Syphilitic aortitis
Neurosyphilis
Gumma (late, benign syphilis)

• “These divisions of late syphilis are not mutually exclusive. A patient may have more than one type of late involvement.”

Question 39

Cardiovascular syphilis/Syphilitic aortitis:

Answer 39

Vasculitis/Endarteritis obliterans of vasa vasorum blocks the vessels especially those associated with the aortic arch–>aortic stenosis, aortic regurgitation, coronary artery ostial stenosis, aortic aneurysm

Question 40

Early Neurosyphilis:
how to dx if asymptomatic??
complications if symptomatic??

Answer 40

• Asymptomatic: dx by a + CSF serology (reactive VDRL), increases in WBC cells present and total protein.
• Symptomatic syphilitic meningitis–acute
• Meningovascular: obliterative endarteritis of meninges, brain, spinal chord, there is CNS damage from cerebral vascular occlusion and infarction–>focal neurologic signs corresponding to the size and location of the lesion.

Question 41

Late neurosyphilis - Parenchymatous Neurosyphilis: General paresis (also known as general paralysis of the insane, paretic
neurosyphilis, or dementia paralytica)

Answer 41

a progressive dementing illness. In the early stage of disease, general paresis is associated with symptoms of forgetfulness and personality change with progression to severe dementia (Paresis mnemonic: Personality, Affect, Reflexes, Eyes, Sensorium, Intellect, Speech)

Question 42

Late neurosyphilis - Parenchymatous Neurosyphilis: Tabes dorsalis (also called locomotor ataxia)

Answer 42

a disease of the posterior columns of the SC and of the DRs and DRG–>Ataxia (gait changes, foot slap, etc), areflexia, paraesthesias (lancinating pain)

Question 43

Tabes dorsalis: Posterior column impairment results in ??

Disruption of the dorsal roots leads to ??

Answer 43

impaired vibration and
proprioceptive sensation, leading to a wide-based gait.

loss of pain and temperature sensation and areflexia.

Question 44

Tabes dorsalis: Pillary irregularities are among the most common signs and the ?? accounts for approximately one-half of these pillary irregularities.

Answer 44

Argyll-Robertson pupil:
-is smaller than normal.
-does not respond to light but contracts normally to
accommodation and convergence.
-Dilates imperfectly to mydriatics
-Does not dilate in response to painful stimuli).

Question 45

Gumma (late, benign syphilis) may be result of ??

what is it ??

Answer 45

DTH response to antigens, not viable T. pallidum cells.
A non-specific granulomatous-like lesion in the skin, liver, testes, and bones, etc.
-may be benign but when occurring in the brain or heart–>serious complications
Gummas produce a wide variety of symptoms that are similar to many chronic diseases and this has also led to syphilis being termed “the great imitator”