2nd Lecture: Pediculosis & The Treponema (Syphilis, Yaws, Pinta) Flashcards
1
Q
What are the 4 learning objectives of this lecture?
A
- Cite the presentation, diagnosis, and treatment of lice infestation.
- Explain the limitations of the “culture & Gram Stain” approach when applied to spirochete infections
- Cite the unique structural and motile properties of spirochetes
- Describe the three disease stages, transmission, treatment, and prevention of syphilis.
2
Q
What are the 5 characteristics of the bacteriology of Treponema pallidum (Syphilis)?
A
- Motile: flagellar corkscrew motion
- Not culturable
- Very slow growing
- Trepenoma are too slender to Gram stain
- Too delicate to survive outside a host
3
Q
What are the three modes of transmission of Syphilis?
A
- Sexually
- Transplacentally
- Blood-blood
4
Q
What does Syphilis infect?
A
Infects endothelium of small blood vessels
5
Q
What are the triphasic infection phases of Syphilis?
A
- Primary syphilis (weeks)
- Secondary syphilis (months)
- Tertiary syphilis (1/3 enters the tertiary)
6
Q
Discuss the primary syphilis. What are the characteristics?
A
Initial replication at site of infection forms an ulcer called chancre, which is painless
7
Q
Discuss the secondary syphilis. What are the characteristics?
A
- Macropapular rash on palms and soles
- Moist papules on skin and mucous membrane
- Condylomata lata: highly infectious moist lesions on genital
- Patchy alopecia, symptoms of fever, malaise, anorexia, weight loss, headache, myalgia, lymphadenopathy
8
Q
What happens to patients with secondary syphilis?
A
1/3 resolve, 1/3 enter latency (years), the remaining 1/3 enter tertiary syphilis
9
Q
1’ syphilis can be considered as localized or disseminated?
A
Localized
10
Q
2’ syphilis is different from 1’ how?
A
Secondary syphilis is disseminated disease with constitutional symptoms such as maculopapular rash (palms and soles), condylomata lata.
11
Q
How can 1’ and 2’ syphilis be visualized?
A
Using darkfield microscopy
12
Q
Discuss the tertiary syphlis. What are some important characteristics?
A
- 1/3 of syphilis patients enter into syphilis
- Characterized as granulomas “gummas”
- CNS involvement
13
Q
What are the two types of CNS involvement of 3’ syphilis?
A
- Early meningitis (less than 6 months): low-inflammation
2. Late neurosyphilis
14
Q
Discuss late neurosyphilis
A
- Meningovascular syphilis
- Parenchymal neurosyphilis
1) Tabes dorsalis
2) General paresis
15
Q
What is Gummas?
A
chronic granulomas characteristics of 3’ syphilis
16
Q
(First Aid) What are the 4 important characteristics of 3’ syphilis?
A
- Gummas (chronic granulomas)
- aortitis (vasa vasorum destruction)
- Neurosyphilis (tabes dorsalis)
- Argyll Robertson pupil
17
Q
(First Aid) What is Argyll Robertson pupil?
A
Argyll Robertson pupil constricts with accommodation but is not reactive to light. Associated with 3’ syphilis. Also, called “Prostitute’s pupil”
18
Q
(First Aid) What is Tabes dorsalis?
A
Degeneration of dorsal roots and dorsal columns, which leads to impaired proprioception and locomotor ataxia
19
Q
What are the characteristics of 3’ syphilis?
A
- Gummas (chronic granulomas)
- Aortitis (vasa vasorum destruction)
- Neurosyphilis (tabes dorsalis)
- Argyll Robertson pupil
20
Q
(First Aid) What are the clinical signs of 3’ syphilis?
A
- Broad-based ataxia
- Positive Romberg
- Charot joint
- Stroke w/o HTN
21
Q
(First Aid) How can 3’ syphilis be diagnosed?
A
- Screen with VDRL
2. Then confirm with FTA-ABS
22
Q
Can spirochetes easily cross placenta?
A
yes
23
Q
What is the clinical consequence of spirochetes crossing the placenta?
A
- 40-50% miscarriage/stillbirth/neonatal death
2. Congenital Syphilis: survivors develop severe secondary syphilis and physical abnormalities
24
Q
What is the characteristics of the immunity of syphilis?
A
Immunity is incomplete and late latency has some protection from reinfection
25
What is the characteristics of pathogenesis of syphilis?
Pathogenesis does not seem to involve toxins, primarily immune evasion.
26
What are the lesions you are looking for to diagnosis syphilis?
Chancre, rash, condylomata lata, patchy alopecia, CNS symptoms
27
What are the CNS symptoms observed in syphilis pts?
1. Meningitis
2. Gummas
3. Cardiovascular symptoms
4. Argyll-Robertson pupil
28
Why is it important to obtain complete history of symptoms to diagnose syphilis?
B/c it may extend over years with varied symptoms arriving and departing.
29
What are the two types of lab test that can be done to diagnose syphilis?
1. Microscopy
| 2. Serology
30
Discuss how you can diagnose syphilis using microscopy.
1. Swab lesions for darkfield microscopy or IF
| 2. Biobsy gummas for histology with silver or IF
31
Discuss how you can diagnose syphilis using serology
It could be either done by reagin which are nonspecific antibodies or specific antibodies
32
Discuss how reagin (nonspecific antibodies) can be used to diagnose syphilis
1. Use nonspecific antibodies detectable by flocculation tests with cardiolipin (VDRL or RPR).
2. Positivity decreases with treatment
3. False positives and negatives (prozone phenomenon) may occur
4. Positives may be confirmed by specific tests.
33
Discuss how specific antibodies can be used to diagnose syphilis
Specific antibodies are detectable by IF or hemagglutination, remain positive for life
34
What is the treatment for syphilis?
1. Penicillin: single injection of benzathine penicillin G for primary or secondary syphilis
2. Slow release enhances effectiveness
3. No known resistance
35
What is the alternate treatment for syphilis?
1. long-term doxycycline, erythromycin, ceftriazone, much less effective
2. Need to be followed up with repeat reagin tests
36
What is the flulike symptoms for 24 hours after the syphilis treatment?
Jarisch-Herxheimer rxn
37
What are the 5 characteristics of congenital syphilis?
1. Saber shins
2. Saddle nose
3. CN VIII deafness
4. Hutchinson's teeth
5. Mulberry molars
38
(First Aid) What is VDRL false positive?
VDRL detects nonspecific antibody that reacts with beef cardiolipin. It is used for diagnosis of syphilis, but it often gives false positive
39
(First Aid) What are the most common causes for VDRL false positive?
VDRL
1. Viruses (mono, hepatitis)
2. Drugs
3. Rheumatic fever
4. Lupus and leprosy
40
(Goljan) Having what antibody will give you a false positive syphilis serology?
Anti-cardiolipin antibodies
41
(Goljan) If you have a pt who is positive for VDRL and RPR, to confirm that the pt does not have any syphilis, what needs to be done?
FT ABS needs to be negative
42
(Goljan) So explain why you could end up having a positive RPR when you don't have syphilis?
Syphilis antibodies react to against beef cardiolipin so does the anti-cardiolipin antibodies.
43
(Goljan) If you have a woman with a biological false positive syphilis serology, what is the first test you should do?
Serum anti ANA antibody, b/c she can develop lupus.
44
(Goljan) True or False?
| Is anti-cardiolipin antiboides very common feature of lupus?
True. A biological false positive with a syphilis serology is a criteria for lupus diagnosis.
45
(Goljan) What is the most common cause for aneurysm of the arch of the aorta?
Tertiary syphilis
46
(Goljan) Discuss the pathology of syphilis.
1. Vasculitis of arterioles
2. Painless chancre (painless b/c if you section it, you will see little arterioles surrounded by plasma cells and the lumen of the vessel is completely shut, so it is ischemic necrosis) --> It is ischemia of the overlying tissue undergoing necrosis. B/c nerves are next to vessels, they are knocked off too, thus it is painless.
3. All of syphilis is a vasculitis.
47
What is a classic presentation of pediculus humanus capitis?
1. Schoolgirls sharing hair accessories
48
What is the treatment of pediculus humanus capitis?
insecticidal shampoo twice 10D apart ;plus nit combing
49
What are the special considerations of the infection of pediculus humanus capitis?
Marker for other STDs, condoms are NOT protective
50
Is T. pallidum stained with gram negative?
no, dark-field microscopy needs to be performed
51
What are some characteristics of T. pallidum
1. very delicate, can't survive outside of cell
2. flagellar "corkscrew" motion
3. human restricted in nature
4. cannot be grown in culture
5. extremely infectious sexually
6. virulence based on immune evasion
52
Syphilis can be transmitted via
1. blood
2. transplacentally (congenital)
3. transmitted by sexual contact (acquired)
53
T. pallidum penetrates
mucous membranes or small abrasions, grows in blood vessel endothelium, enters lymphtics and bloodstream
54
Surface of spirochete is
nonimmunogenic
55
Spirochete down-regulates
TH1 cells
56
CNS is invaded relatively
early
57
Primary syphilis
1. Painless chancre (heals by itself)
2. Chancre is highly infections
3. 2-3 weeks
58
Secondary syphilis
4-10 weeks, fever, malaise, a lot cutaneous lesions, condolymata lata (caused by syphilis)
59
2/3 of the pts with syphilis go into
latent syphilis
60
1/3 of the pts who do not go into the latent syphilis, go into
3' syphilis
61
3' syphilis
1. gummatous syphilis--> granulomatous lesions (gummas)
2. neurosyphilis
- syphilitic meningitis: early (6mo)
- Parenchymal neurosyphilis
62
Congenital syphilis
1. treponemes readily cross placenta and infect feuts
| 2. half of the pregnancy lose the fetus
63
Syphilis is associated with
1. HIV (ulcerations of syphilis facilitate HIV infeciton)
| 2. HIV immunosuppression accelerates syphilis course, and reduces effecay of treatement
64
Syphilis diagnosis: exam
1. primary is the easiest, most likely to reversed --> look for chancres (raised, red, firm , buttonlike structure up to several cm, heal in 4-8 wks, not painful unless superinfected), site many be genital
2. 2' syphilis begins 4-10 weeks after primary, may be subtle, first round rash is bilaterally symmetrical with generalized nontender, lymphadenopahty
65
What is the defining lesion of the 2ndary syphilis
condylomata lata (reddish brown papular lesions on the penis or anogential area, gun metal grey color, sometimes confused with what?
66
3' syphilis
1. 3-10 yrs after infection
2. Gumma (bone), Liver, Cardiovascular syphlis (aorta or other major arterial scarring, diastolic murmur with a tambour quality)
67
Meningovascular syphilis
1. 5-10 yrs after infection
| 2. CNS vascular insufficiency or stroke
68
Tabes dorsalis
Paranchymal shpyphilis
69
Argyll-Robertson puil
hallmark of neurosyphilis (one or both pupils fails to constrict in response to light but does constrict to focus on a near object (accomodation)
70
Lumbar puncture for
neurosyphilis for VDRL
71
Lab for syphilis
1. won't culture, too small to gram stain
2. serology --> nontreponemal serolgy screening using Venereal Dz Research Laboratory (VDRL), rapid plasma reagin (RPR), or ICE Syphilis recombinant
72
VDRL/RPR Flocculation (응집) assay
cheap, easy, titer decreases with successful treatment
73
Confirm positive/equivocal results with treponeme-specific tests
FTA-ABS
74
What stage is best to diagnose using RPR and VDRL?
2'
75
Will RPR/VDRL give positive for 3' syphilis
yes and no (only specific test FTA will be positive at 3')
76
What is endarteritis
hardening of the heart caused by binding of spirochetes to endothelial cells meditated by host fibronectin
77
Jarish -Herxheimer rxn
after 8-24 hours after start of treatment, many pts have flulike symptoms
78
(Symmary) Pediculosis is caused by
three types of lice
1. Head: schoolkids, itchy behind ears
2. Body: homeless, itchy at night
3. Pubic: promiscuous, itchy groin
79
How is the diagnosis of pediculosis made?
by eye, magnifying glass, microscope
80
Head and pubic nits
are on hair
81
Body nits are on
clothes
82
Head & Body lice are
elongated
83
Pubic lice are
wide (crabs)
84
How do we treat pediculosis?
two rounds of insecticide and nit combing and hot laundering
85
Do we need to perform full STD panel for pediculosis?
yes
86
Treponema
1. Too small to see by standard microscopy, use darkfield (no Gram stain!)
2. Can’t be cultured
3, Invade lymphatics and bloodstream right away (no build-up)
4, Virulence based on immune evasion – low inflammation
87
T. pallidum transmitted
sexually or congenitally, yaws&pinta by direct contact
88
Syphilis has four-stage disease
primary chancre, secondary body-wide rashes, condylomata lata, and patchy alopecia, latent period, tertiary gummas, neurosyphilis, cardiac involvement
89
Neurosyphilis may be
meningitis, tabes dorsalis, general paresis, check for Argyll-Robertson pupil
90
Congential syphilis kills
50% fetus/newborn, survivors are infected, bone deformities, interstitial keratitis, progress rapidly to symptoms of secondary&tertiary syphilis if untreated
91
Diagnosis of syphilis depends on
assembling accurate timecourse of the many varied symptoms: patient may have ignored early ones that appeared to resolve spontaneously
92
Labs for syphilis:
Syphilis serology for reagin (VDRL, RPR) is best test for disease-in-progress and for efficacy of treatment; confirm exposure with tests for treponeme-specific antibodies; histo of lesions shows infiltrate rich in plasma cells
93
Treat syphilis with
Penicillin G
