Congenital Syphillis

Question 1

What population/demographic accounts for most cases of syphilis in Canada?
What 2 provinces have highest incidence?

Answer 1

Heterosexual transmission in inner city populations
(previously men who have sex with men)

Highest incidence in BC & Alberta

Question 2

Most recent incidence of congenital syph in Canada?

Answer 2

10 cases per year

Question 3

How is syphilis usually transmitted? What are rarer mechanisms of transmission?

Answer 3

Usually - sex with person infected with syphilis within the past year

Rarely - blood transfusion, oral secretions, needle sharing, direct contact with infected lesion

Question 4

Why are all pregnant women assumed to be at risk?

Answer 4

Many infected pts are asymptomatic

Question 5

What is the risk of vertical transmission if:

(1) Untreated primary or secondary syph during pregnancy
(2) Early latent syph
(3) Late latent syph

Answer 5

(1) Untreated primary/secondary - 70-100%
(2) Early latent - 40% (at risk for reactivation)
(3) Late latent - 10%

Question 6

When are fetuses infected with syphilis?

Answer 6

In utero, after 4 months gestation

but can occur as early as 9 weeks OR with during birth with active lesion

Question 7

When should syphilis serology be done on pregnant patients?

When should rescreening be done and what population?

Answer 7

• Syph serology at first prenatal visit

- Rescreen at 28-32 weeks + at delivery for high risk women (i.e. high incidence of syph in country of origin)

Question 8

What if maternal serologies not done before delivery?

Answer 8

Do not discharge newborn until maternal serologies drawn and f/u arranged

Question 9

What are the different types of syphilis serology tests for screening vs confirmation?

Answer 9

Nontreponemal tests for screening:

• RPR (rapid plasma reagin)
• VDRL (venereal disease research lab)

Treponemal test for screening:
- EIA (enzyme immunoassay)

Treponemal test for confirmation:

• florescent treponemal antibody absorption (FTA-ABS)
• T pallidum particle agglutination (TP-PA)
• Line blot immunoassay (INNO-LIA)

Question 10

If RPR negative, TP-PA negative, FTA positive – what is the most likely condition?

Answer 10

Primary syphilis

Question 11

If RPR positive, TP-PA positive, FTA-ABS positive – what is the most likely condition?

Answer 11

Any of:

• Any stage of syphilis
• Old treated syphilis/being treated
• Pt from endemic country
• Lyme disease/yaws/pinta

**If both confirmatory tests+ and RPR+, CAN be active syphilis (along with other possibilities). RPR- means not most active syphilis.

Question 12

If RPR negative but TP-PA/FTA positive – what is the most likely condition?

Answer 12

Any of:

• Old treated syphilis
• Early infection (early primary)
• Late latent/tertiary syphilis
• Persons from endemic countries
• Lyme disease/yaws/pinta

Question 13

If RPR positive, TP-PA/FTA negative – what is the most likely condition?

Answer 13

False positive

Some reasons for this:

• collagen vascular diseases
• pregnancy
• IVDU
• Lyme disease
• Test technique

Question 14

If RPR negative (and conf tests not performed) – what is the most likely condition?

Answer 14

Not syphilis!

Repeat serology if at risk

Question 15

EIA indeterminate
RPR negative
Confirmation test neg/indeterminate

What is the most likely condition?

Answer 15

May be in early serovonversion
Needs repeat serology
(if repeat same, not syphilis!)

Question 16

EIA indeterminate
RPR negative
Confirmation test positive

What is the most likely condition?

Answer 16

Any of:

• Early primary
• Late latent
• Previously treated
• Endemic country
• Lyme disease

Question 17

EIA positive
(RPR positive OR negative)
Confirmation test negative

Answer 17

False positive

Question 18

EIA positive + RPR positive

Confirmation test indeterminate

Answer 18

Repeat serology
(if conf test + – any stage of syphilis or treated syphilis or endemic person)
(if unchanged - false positive)

Question 19

EIA positive
RPR negative
Confirmation test indeterminate

Answer 19

Repeat serology
(if conf test + – any stage of syphilis or treated syphilis or endemic person)
(if unchanged - false positive)

Question 20

EIA positive
RPR negative
Conf test positive

Answer 20

Early primary, late latent, or previously treated; endemic person, Lyme disease
- just not the most active syph*

Question 21

EIA positive
RPR positive
Conf test positive

Answer 21

Any stage of syphilis
(more likely to be infectious if RPR titre 32 dilutions+)

• Includes old treated syphilis, being treated
• Endemic persons
• Lyme/yaws/pinta/bejel

Question 22

What is the usual screening approach for syphilis in Canada?

Answer 22

RPR initial screen
Treponemal test to confirm

• Others use EIA as initial screen (more sens and spec than RPR)
• Still need to obtain RPR titres if EIA positive – RPR used for staging of infection

Question 23

How long with treponemal tests remain reactive for after treatment?

Answer 23

Usually for life, unless tx started v early in course of infection

Question 24

How do you monitor for adequacy of maternal syphilis tx?

Answer 24

Decline in RPR titres!

Question 25

What is the expected RPR titre decline in tx of maternal syphilis (primary) at:

• 6 months
• 12 months
• 24 months

Answer 25

6 months - 4-fold drop
12 months - 8-fold drop
24 months - 16-fold drop

Question 26

What is the expected RPR titre decline with tx of maternal syphilis (secondary) at:

• 6 months
• 12 months

Answer 26

6 months - 8 fold drop

12 months - 16 fold drop

Question 27

What is the expected RPR titre decline with tx of maternal syphilis (early latent) at:
- 6 months

Answer 27

6 months - 4 fold drop

Question 28

If RPR serofasts (reverts to nonreactive) after tx, what next?

Answer 28

Still need to repeat RPR at regular intervals is reinfection thought to be a risk

Question 29

If treponemal test reactive (and RPR nonreactive) during pregnancy – no history of treatment and no evidence of early primary syphilis… what should be done?

Answer 29

Treat as late latent syphilis

Assume there is some risk of vertical transmission

Question 30

How do you manage a neonate with maternal treponemal test+ but inadequately treated?

What is the definition of early congenital syphilis?

Answer 30

Infant at risk for congenital syphilis!

Early congenital syphilis = diagnosis within first 2 years of life

Question 31

What are the H+N manifestations of congenital syphilis?

Answer 31

Rhinitis - in 40% of cases; often first manifestation at birth

Hutchison’s teeth - upper central and lateral incisors widely spaced, look like screwdrivers

Mulberry molars - first molars have dwarfing of cusps; hypertrophy of enamel around cusp (looks like a berry)

Question 32

Neurologic and MSK manifestations of congenital syphilis?

Answer 32

Neurosyphilis - present at birth or delayed; in 50% of cases (but usually asymptomatic)

CN8 impairment - onset 10-40 years, SNHL

Osteochondritis or perichondritis

• 25% seen initially on XR within 2 weeks
• pseudoparalysis can occur
• later changes: frontal bossing, poorly developed maxilla, saddle nose, winged scapula, sabre shins

Recurrent arthropathy/painless knee effusions (Clutton’s joints)
- occurs after 2 yo

Question 33

Abdominal and skin manifestations of congenital syphilis?

Answer 33

HSM - onset in first 8 weeks; occurs in 20% of cases; may persist for many years

Rash - onset in first 8 weeks; 50% of cases; diffuse MP rash typically
(can also have just desquamation or vesicles or bullae or mucosal lesions)

Necrotizing funisitis - present at birth; umb cord looks like barbershop pole (rare by pathognomonic!)

Question 34

% of congenital syph cases presenting as SA/stillbirth/hydrops fetalis?

Answer 34

40% if syphilis acquired during pregnancy – highest risk if first trimester infection