The WHO recently released new treatment guidelines for the treatment of common Sexually Transmitted Infections (STIs)- Gonorrhea, chlamydia and syphilis. In this third and last part of a three part series, I describe the guidelines for treatment of syphilis.
Background Information:
Syphilis
Syphilis is a bacterial STI caused by Treponema pallidum that results in substantial morbidity and mortality.
Syphilis is transmitted through
- sexual contact with infectious lesions of the mucous membranes or abraded skin,
- via blood transfusion, or
- transplacentally from a pregnant woman to her fetus.
Untreated, the disease lasts many years and is divided into stages.
Early syphilis consists of
- primary syphilis,
- secondary syphilis and
- early latent syphilis,
while late syphilis consists of
- late latent syphilis and
- tertiary syphilis (neurosyphilis, cardiosyphilis and gumma).
Mother-to-child transmission of syphilis (congenital syphilis) is usually devastating to the fetus if maternal infection is not detected and treated sufficiently early in pregnancy.
The burden of morbidity and mortality due to congenital syphilis is high. In 2012, an estimated 350 000 adverse pregnancy outcomes worldwide were attributed to syphilis, including
- 143 000 early fetal deaths/stillbirths,
- 62 000 neonatal deaths,
- 44 000 preterm/low-birth-weight babies and
- 102 000 infected infants.
Most untreated primary and secondary syphilis infections in pregnancy result in severe adverse pregnancy outcomes. Latent (asymptomatic) syphilis infections in pregnancy also cause serious adverse pregnancy outcomes in more than half of cases.
Key Messages:
The objectives of these guidelines are:
- to provide evidence-based guidance on treatment of Treponema pallidum; and
- to support countries to update their national guidelines for treatment of Treponema pallidum.
The Recommendations
A. Early syphilis (primary, secondary and early latent syphilis of not more than two years’ duration)
I. Adults and adolescents
Recommendation 1
In adults and adolescents with early syphilis, the WHO STI guideline recommends benzathine penicillin G 2.4 million units once intramuscularly over no treatment.
Recommendation 2
In adults and adolescents with early syphilis, the WHO STI guideline suggests using benzathine penicillin G 2.4 million units once intramuscularly over procaine penicillin G 1.2 million units 10–14 days intramuscularly.
When benzathine or procaine penicillin cannot be used (e.g. due to penicillin allergy) or are not available (e.g. due to stock-outs), the WHO STI guideline suggests using
- doxycycline 100 mg twice daily orally for 14 days or
- ceftriaxone 1 g intramuscularly once daily for 10–14 days, or, in special circumstances,
- azithromycin 2 g once orally.
II. Pregnant women
Recommendation 3
In pregnant women with early syphilis, the WHO STI guideline recommends benzathine penicillin G 2.4 million units once intramuscularly over no treatment.
Recommendation 4
In pregnant women with early syphilis, the WHO STI guideline suggests using benzathine penicillin G 2.4 million units once intramuscularly over procaine penicillin 1.2 million units intramuscularly once daily for 10 days.
When benzathine or procaine penicillin cannot be used (e.g. due to penicillin allergy where penicillin desensitization is not possible) or are not available (e.g. due to stock-outs), the WHO STI guideline suggests using, with caution,
- erythromycin 500 mg orally four times daily for 14 days or
- ceftriaxone 1 g intramuscularly once daily for 10–14 days or
- azithromycin 2 g once orally.
B. Late syphilis (infection of more than two years’ duration without evidence of treponemal infection)
I. Adults and adolescents
Recommendation 5
In adults and adolescents with late syphilis or unknown stage of syphilis, the WHO STI guideline recommends benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks over no treatment.
Recommendation 6
In adults and adolescents with late syphilis or unknown stage of syphilis, the WHO STI guideline suggests benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks over procaine penicillin 1.2 million units once daily for 20 days.
When benzathine or procaine penicillin cannot be used (e.g. due to penicillin allergy where penicillin desensitization is not possible) or are not available (e.g. due to stock-outs), the WHO STI guideline suggests using doxycycline 100 mg twice daily orally for 30 days.
II. Pregnant women
Recommendation 7
In pregnant women with late syphilis or unknown stage of syphilis, the WHO STI guideline recommends benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks over no treatment.
Recommendation 8
In pregnant women with late syphilis or unknown stage of syphilis, the WHO STI guideline suggests benzathine penicillin G 2.4 million units intramuscularly once weekly for three consecutive weeks over procaine penicillin 1.2 million units intramuscularly once a day for 20 days.
When benzathine or procaine penicillin cannot be used (e.g. due to penicillin allergy where penicillin desensitization is not possible) or are not available (e.g. due to stock-outs), the WHO STI guideline suggests using, with caution, erythromycin 500 mg orally four times daily for 30 days.
C. Congenital syphilis
Infants
Recommendation 9
In infants with confirmed congenital syphilis or infants who are clinically normal, but whose mothers had untreated syphilis, inadequately treated syphilis (including treatment within 30 days of delivery) or syphilis that was treated with non-penicillin regimens, the WHO STI guideline suggests aqueous benzyl penicillin or procaine penicillin.
Dosages:
- Aqueous benzyl penicillin 100 000–150 000 U/kg/day intravenously for 10–15 days
- Procaine penicillin 50 000 U/kg/day single dose intramuscularly for 10–15 days
Recommendation 10
In infants who are clinically normal and whose mothers had syphilis that was adequately treated with no signs of reinfection, the WHO STI guideline suggests close monitoring of the infants.
Useful Links:
Link to the WHO treatment guideline for syphilis (English) [PDF]:
Click to access 9789241549806-eng.pdf
Link to Annex D: Evidence profiles and evidence-to-decision frameworks (English)[PDF]:
Click to access 9789241549806-webannexD-eng.pdf
Link to the first article in this series (on Gonorrhea):
Link to the second article in this series (on chlamydia):
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