Syphilis Testing in Northern California Kaiser

Syphilis Testing in Northern California Kaiser
Jen Shieh, MS, CLS
Test Development Scientist
Kaiser Permanente TPMG Regional Laboratory
Microbiology Department

Objectives:
Syphilis Overview
Validation of Liaison Treponema Assay
New algorithm
Guideline of Interpretation

SYPHILIS
Caused by Treponema pallidum
Transmission: sexual, maternal-fetal
Increases risk of obtaining and acquiring
HIV infection
All patients with syphilis should be HIV
tested
Lesions of syphilis resolve without
treatment although person remains
infected

STAGES OF SYPHILIS
Primary (1-3 months)
Secondary (2-6 months)
Latent
Early latent
Late latent
Late or tertiary
May involve any organ, but main parts are:
Neurosyphilis
Cardiovascular syphilis
Late benign (gumma)

PRIMARY SYPHILIS
Incubation period 9-90 days, usually ~21
days.
Develops at site of contact/inoculation.
Painless ulcer
Very infectious.
May be darkfield positive but serologically
negative.
Untreated, heals in several weeks, leaving
a faint scar.

SECONDARY SYPHILIS
Seen 6 wks to 6 mos after primary
chancre
Usually w diffuse non-pruritic, indurated
rash, including palms & soles.
May also cause:
• Fever, malaise, headache, sore throat,
myalgia, arthralgia, generalized
lymphadenopathy

LATENT SYPHILIS
Positive syphilis serology without clinical signs of
syphilis
Early latent:
• The first year after the resolution of primary or secondary
lesions, or
• A reactive serologic test for syphilis in an asymptomatic
individual who has had a negative serologic test within the
preceding year.
• Infectious.
Late latent:
• Usually not infectious, except for the pregnant woman, who
may transmit infection to her fetus.

LATE SYPHILIS
‘Tertiary Syphilis’
Lesions develop in skin, bone, & visceral
organs (any organ).
Can be crippling and life threatening
Blindness, deafness, deformity, lack of
coordination, paralysis, dementia may
occur
slowly progressive
Late syphilis is noninfectious.

Infection
The Course of Untreated Syphilis
6 wks
to
6 mo.
Primary
(Chancre)
Incubation period
9-90 days
Secondary
(Rash)
1-2 years
Approx.
18 months
Latent Syphilis
(No signs of disease)
Many years
To a lifetime
Tertiary
Benign gummatous
Cardio-vascular syphilis
Neurosyphilis
Many years
To a lifetime
Early Syphilis Late Syphilis

TREATMENT
Primary, Secondary, Early Latent
Benzathine Penicillin G, 2.4 million units IM
Penicillin Allergy
-Doxycycline 100 mg twice daily x 14 days
or
-Ceftriaxone 1 gm IM/IV daily x 8-10 days
(limited studies) or
-Azithromycin 2 gm single oral dose
(preliminary data)

TREATMENT
Late Latent Syphilis
Benzathine penicillin G 2.4 million units IM
at one week intervals x 3 doses
Penicillin allergy
-Doxycycline 100 mg orally twice daily x
28 days or
-Tetracycline 500 mg orally four times
daily x 28d

Diagnosis of Syphilis
Darkfield Microscopy
Direct Immunofluorescence
Polymerase Chain Reaction (PCR)
Serology
- Nonspecific (Cardiolipin-based)
- Specific (Treponemal)

Serological Tests for Syphilis
Non-treponemal (reagin) tests
- Complement Fixation Test
Wasserman reaction
- Flocculation Reactions
Rapid plasma reagin (RPR) test
VDRL
TRUST
Treponemal (specific) tests
- FTA-ABS
- TP-PA
- ELISA (EIA)
- Automated chemiluminescence plateforms
- Current Chromatographic (POC) tests

Antibody patterns during treponemal infection
1 Pope, Victoria. Infect. Med. 21 (B):339-404, 2004. ©Cliggott Publishing, division of
CMP Heatthcare Media
2 Mutter F, Hagedorn HI. Syphilis in: Clinical Laboratory Diagnostics, Thomas L, TH
Books Frankfurt 1998; 1203-12

3.2 million members
22 medical centers
50 MOB and clinics
Kaiser Permanente

Microbiology Laboratory
177 FTE – Micro Lab
30 FTE Immuno-Diagnostic/Virology
24/7 operation
M-F, clean up on Saturday, Sunday Maintenance
TrepAb/RPRQ/TPPA – 1.5 FTE,not including preanalytic
and post-analytic

Syphilis Testing
2008 Volume
Annually: 159,744
Monthly: 13,312
Daily: 605

170000
160000
150000
140000
130000
120000
110000
100000
Syphilis Testing
2002 2003 2004 2005 2006 2007 2008
annually 131694 133584 138793 148738 155853 156612 159744
monthly 10975 11132 11566 12395 12988 13051 13312
daily 499 506 526 563 590 593 605

Total=2,378 RPR
Validation Data
+ -
Liaison + 63 45
- *26 2244
*26- (TPPA-)
45 Excluded 1
Negative 10
RPR-Liaison+ TPPA+ 24
RPR-Liaison+ TPPA- 7
RPR+Liaison+ TPPA+ 3
45

Revised
Total=2,377 RPR
+ -
Liaison + 66 31
- *26 2254
*26- (TPPA-)
24 RPR-Liaison+ TPPA+
Age: 24-81
Gender: 9 Female -- 5 GYN -- 2 Prenatal
7 RPR-Liaison+ TPPA-
Age: 27-65
15 Male -- all MED -- 9 HIV+
Gender: 3 Female -- 2 GYN -- 1 Prenatal
4 Male -- all MED -- 2 HIV+

Total = 2,377
RPR
Sensitivity & Specificity
True
+ -
+ 66 26
- 24 2,261
LIAISON
True
+ -
+ 90 7
- 0 2,280
RPR Liaison
Sensitivity 73.3% 100%
Specificity 98.6% 99.7%
PPV 71.7% 92.8%
NPV 98.9% 100%

7 Discrepancies
# Age RPR Trep Rtrep TPPA
CDC
Trep-Sure
CDC
RPR
CDC
TPPA WB G WB M
1 60M - P P - 2.848 P - - Bord Neg
2 28F - P(1.92) P(2.1) - 1.294 P - - TND TND
3 32F - P(1.18) P(1.23) - 0.018 N - - Neg Neg
4 27M - P(1.83) P(1.78) - 0.396 P - - Neg Neg
5 55M - P P - 2.393 P - - Neg Pos
6 65F - P QNS - >3.000 P - - Bord Neg
7 54M - P(1.47) P(2.9) - >3.000 P - - Neg Neg
Cutoff (0.171)

No Syphilis
Old Algorithm
RPR
neg pos
Do RPR Q
&
TPPA
Report RPR titer
& TPPA results

Not Syphilis
New Algorithm
TrepAb
Nonreactive Reactive or Equivocal
Nonreactive
Nonreactive
TP-PA
Reactive
Further investigation
Clinical correlation required
RPR Q
Reactive
Syphilis

Treponemal
Results
negative (nonreactive)
negative (nonreactive)
positive
(reactive)
positive
(reactive)
positive
(reactive)
RPR Q TPPA Report/Interpretation for all except
neonates or infants
not
performe
d
not
performed
reactive nonreactive
nonreactive
nonreactive
No serological evidence of infection with T.
pallidum (incubating or early primary syphilis
cannot be excluded)
Current infection unlikely, probability of
biological false positive secondary to other
medical conditions (febrile diseases,
immunization, IVDU, autoimmune diseases, etc.)
reactive Probably past treated infection; additional
testing maybe necessary for clinical suspicion of
late syphilis or neurosyphilis.
nonreactive
reactive not
performed
Probably false positive Trep Antibody result
Clinical correlation required
Evidence of current infection (if low positive
RPR with history of treatment, this is serofast
state.)

U
T
U
T
Syphilis Reaction Table
Reaction of Non-Treponemal Serological Test (RPR) by Stages of Syphilis and
Influence of Successful Treatment
Negative
Negative
Becoming
Positive
Positive
Negative Negative
Positive Positive
Serofast
Positive
(rarely Negative)
Serofast
Reaction of Treponemal Serological Test (TrepAB) by Stages of Syphilis and Influence of
Successful Treatment
Negative
Positive
Remains
(If initially
Primary
Primary
Becoming
(early)
Positive
Positive)
U: Untreated
T: Successfully treated
Early Syphilis Late Syphilis
Secondary
Early Syphilis Late Syphilis
Secondary
Early Latent Late Latent Tertiary
Early Latent
Positive Positive Positive Positive
Positive Positive Positive
Late Latent Tertiary
Positive

Syphilis Serologic Testing –
Guidelines for Interpretation
• Since treponemal tests may remain active for life in
adequately treated patients, a positive T PALLIDUM
IGG + IGM [86781E] indicates exposure to syphilis
and it does not indicate untreated syphilis.
• If the RPR is also positive (especially at >1:8) and
there is no history of treatment for syphilis, a
diagnosis of syphilis is made and the patient should
receive treatment.
• Most people become negative for RPR with adequate
treatment, though some patients who present with
later stage disease may maintain a low titer RPR
(

• Initial screening may be negative in early primary syphilis. If the
history is strongly suggestive of syphilis then an RPR should be done
and/or repeat T PALLIDUM IGG + IGM [86781E] in 1 week.
• The most common cause of a false negative syphilis serologic test
is performance prior to the development of diagnostic antibodies.
• Positive T PALLIDUM IGG + IGM [86781E] with a non-reactive RPR
and non-reactive TPPA is most likely a false positive T PALLIDUM
IGG + IGM [86781E] result. If clinical history suggests a risk for
syphilis then T PALLIDUM IGG + IGM [86781E] should be repeated in
3-4 weeks.
• Positive T PALLIDUM IGG + IGM [86781E] with a non-reactive RPR
and REACTIVE TPPA is most consistent with old treated syphilis. If
there is no clear history of syphilis treatment then 3 weekly shots of 2.4
million units of benzathine penicillin should be considered. Clinical
correlation is required as in rare cases of late latent or tertiary syphilis
the RPR may be negative.
• The diagnosis of syphilis should not be made on the basis of a single
test result. Clinical history, findings and symptoms should be taken
into consideration