Syphilis Flashcards
What causes syphilis?
T pallidium
What are the features of primary syphilis?
🚩1-3 week of T pallidium lands on skin
🚩local destroy of tissue 👉 syphilitic CHANCRE: painless / hard base / raised borders / covered with a fluid rich in spirochetes
🚩chancre:spontaneous heal( 3-8w)
🚩 spirochetes 👉 lymph nodes 👉lymphadenopathy👉 blood
What are the features of secondary syphilis ( disseminated stage)?
🚩6 - 12 weeks after the infection
MOST INFECTIOUS STAGE
🚩 flu like symptoms
🚩spirochetemia 👉 generalized lymphadenopathy
🚩spirochetes destroy endothelium of small capillaries 👉 non itchy maculopapular rash on the trunk, arms , legs , palms & soles & mucosa
🚩 condyloma lata : smooth,warty, white painless lesions, highly infectious on : ( genitals,anal,armpits)
What are the features of latent stage of syphilis?
📌Early phase: within a year of infection: spirochetes can reenter the blood 👉symptoms of secondary syphilis
📌late phase: after a year of infection: spirochetes stay in organs & tissues
What are the features of tertiary stage of syphilis?
IMMUNE RESPONSE STAGE
🚩Granulomatous lesions ( GUMMA)
[ are immune cells surrounded by fibroblasts with central necrosis]
🚩organ damage: heart , brain, liver , joints , eye
How is syphilis diagnosed?
1- identify spirochetes in chancres by dark field microscopy
2- non treponemal tests (nonspecific to syphilis):
* RPR
*VDRL( detect anti-cardiolipin)
3- trepenemal tests :
* TPPA
* FTA-ABS
What is Jarisch - Herxheimer reaction?
📌Complicate 45% of syphilis treatment in pregnancy by penicillin
📌 spirochetes die👉 releasing lots of antigens 👉
📌 within 24 h of treatment:
1- fever / sweating
2- muscles & joints pain
3- skin rash
4- uterine contractions
resolve in few hours to few days
What is the most congenital infection worldwide?
T pallidium
According to routine antenatal screening for syphilis in UK, what is the percentage of women screened positive for syphilis annually?
1/700 - 1/7000
1/4 had new infections in pregnancy
What is the occurrence rate of syphilis co-infection with HIV ?
40% of the patients
How many pregnancies are affected by syphilis each year ?
1,5 million
How is the fetal infection with syphilis characterized?
By : placental involvement + hepatic dysfunction which results in:
1- FGR
2- hepatomegaly : thrombocytopenia- anaemia- ascites
3- preterm birth
4- stillbirth - neonatal birth
How many individuals exposed to T pallidium will become infected?
1/3
Transmission of syphilis transplacentally is dependent on which factors?
1- stage of maternal infection
2- duration of fetal exposure
*at any time of pregnancy
At what age of pregnancy T pallidium can cross the placenta & cause fetal infection?
14 weeks
The risk increase as the pregnancy progresses towards term
What is the percentage of fetal loss caused by syphilis infection during pregnancy?
30 - 40 %
Caused by placental infection or compromised blood flow to the fetus
Among survived fetus from maternal syphilis in pregnancy, how many of them will have congenital syphilis?
1/3 of them
According to the stage of syphilis in the mother, what is the risk of transmission at each stage?
Primary 👉 100%
Early latent 👉 40 %
Late latent 👉 10 %
What are the fetal ultrasonic features of syphilis infection?
General hallmarks of infection
Nonspecific
( fetal hydrops/ Intrahepatic calcification)
What are the recommendations on testing for syphilis according to NICE?
1- serological:
*TPPA ( T pallidium particle agglutination )
* EIA : enzyme immunoassay ( detect IgG)
2- swab from lesions: syphilis PCR
Also to test for herpes as DDx
3- screen for other STDs
What is the suggested screening algorithm for syphilis?
Detect IgG+IgM : EIA / TPPA / CLIA
👉 POSITIVE
⬇️
confirmatory test
⬇️
1- original sample for a different serological test e.g.: TPPA / TPHA
2- second sample for treponemal serology: EIA / CLIA
⬇️
1- Qualitative RPR or VDRL
( to elicit titres for monitoring )
Then repeat every 3 months
2- refer to GUM + neonatal care
What is the standard antibiotic treatment for syphilis in primary or latent < 2 years ?
🍀 1st & 2nd trimester: penicillin
2.4 MU/IM single dose
🍀 3rd trimester: penicillin
2.4MU/IM weekly for 2 weeks
What is the standard antibiotic treatment for syphilis in latent >2 years or unknown duration?
At any stage of pregnancy;
Bezathine penicillin 2.4 MU/IM
Weekly for 3 weeks
What is the period of gestation that treatment of syphilis should be commenced before to lower the risk of congenital infection?
30 days before delivery
