Lecture 30 & 31- spirochetes

Question 1

Name the spirochete organism

What does it cause?

Answer 1

Treponema Pallidum

Syphilis

Question 2

How do you grow out treponema pasllidum in lab?

Answer 2

it is a hypotrophic- it needs ti be grown on something alive (such as rabbits)

Question 3

Describe how Treponema pallidum can be transmitted

Answer 3

Need 57 spirochetes for infection
hooks into skin with it's flagellum
Gotten from contact with abrasion of skin:
sex, skin rash
Can pass through the placenta (STORCH)
CANNOT get from fomites

Question 4

What is the morbidity of Treponema pallidum?

Answer 4

80-90% don’t know they have it

40,000 reported each year in USA

Question 5

What is the mortality of Treponema pallidum?

Answer 5

100 deaths per year in USA

mixing syphilis with AIDS makes it much deadlier

Question 6

How long does it take for the symptoms of Treponema pallidum to appear?

Answer 6

3 week incubation period then phases start

Question 7

Describe the phases of Treponema pallidum

Answer 7

PRIMARY
lesions are chancres (raised nodules)
chancre is broken down into an ulcer- becomes spreadable
lesions are indolent (not painful, itchy)
chancres last for 4-6 weeks without treatment
PRIMARY LATENT
body produces antibodies
organism is systemic (in blood, spreading)
can use serology tests for detection
phase lasts from 0-6 months
SECONDARY
symptoms- flu-like syndrome, rash (indolin, contagious), lymphadenopathy (swollen lymph-nodes)
EARLY LATENT
lasts 1-4 years
breaking out in secondary phase symptoms periodically
LATE LATENT
not contagious (besides STORCH)
25% are cured due to antibodies
25% remain here for life
50% go to tertiary
TERTIARY
lesions are gumma (indolent, destructive)
organism is detected by DNA only
organism is in every tissue
worst symptoms are cardiovascular lesions (aneurisms in aorta) and neurosyphilis (blindness, dementia)

Question 8

Describe neonatal syphilis

Answer 8

TRANSMISSION
transmitted through the placenta during the 5th month of pregnancy
INCIDENCE
25% result in still-borns, miscarriage
25% result in child’s death soon after birth
50% result in neonatal syphilis
SYMPTOMS
early syphilis- rash a few weeks after birth
late syphilis- lesions similar to gummas which appear about 2 years after birth
only 40% show symptoms
SIGNS (stigmata)
hypersensitivity reaction
hutchinson’s triad:
hutchinson’s incisors- notch in front teeth
interstitial keratitis- scarring of the cornea, loss of vision
deafness (due to 8th nerve)

Question 9

List the tests for diagnosis of Treponema pallidum

Answer 9

microscopic examination of chanchre/rash with dark field microscope
x-ray to look for gummas
serological tests- looking in blood for either treponemal or non-treponemal antigens

Question 10

Describe the serological test that screens for non-trponemal antigen

Answer 10

not-specific
rapid plasma reagent test (RPR)
uses Cardilopin antigen (produced by tissue breakdown, comes from mitochondria)
Use cardiolopin with reagents, wasserman antibodies, immunoglobulin E and M
can get false positives 18% of the the time
false negatives happen 10% of the time

Question 11

Describe the serological test that screens for treponemal antigen

Answer 11

uses the organism grown out in a rabbit
fluorescent treponemal antibody absorption (FTA absorption test)- uses the REILTER strain of treponmena palidum
Hemagultination treponmena tests for syphilis- uses the NIKOL strain of treponema pallidum
very expensive, but very few false negatives and positives

Question 12

Describe the treatment of Treponema pallidum (2)

Answer 12

Benzathine (penicillin G)- 1 dose IM for patients infected for less than a year (more doses the longer you have it)
Expedited partner treatment- index patient is given enough drugs to treat their partner as well