Syphilis (Including congenital syphilis)

Clinical definition:

Multi-organ infection caused by T. pallidum. Congenital infection is acquired by vertical transmission via the transplacental route during pregnancy. Signs that may be present at birth or within the first 3 months of life include jaundice, pallor, oedema, generalised erythematous maculopapular rash that may desquamate, hepatosplenomegaly, lymphadenopathy, rhinitis, pseudoparalysis of one or more limbs. Acquired syphilis is transmitted via sexual contact including sexual abuse. For treatment of syphilis in pregnant adolescents, refer to separate guidelines.

 

Neonate

Preferred antibiotic choice
DrugFormulationDosageDuration
For patients with symptomatic infection:

Benzylpenicillin (IV)A

Powder for injection: 600 mg (= 1 million IU); 3 g (= 5 million IU) (sodium or potassium salt) in vial.o   First week of life (7 days or less): 50 000 units/kg/dose 12 hourly

o   8 – 28 days: 50 000 units/kg/dose 8 hourly

10 days
For patients with asymptomatic infection & mother seropositive or result unknown & mother has not been treated or was only partially treated during pregnancy:

Benzathine benzylpenicillin (IM)A

Powder for injection: 900 mg benzylpenicillin (= 1.2 million IU) in 5- mL vial; 1.44 g benzylpenicillin (= 2.4 million IU) in 5- mL vial.50,000 units/kgSingle dose
Alternative antibiotic choice(s)
Cefotaxime (IV)Powder for injection: 250 or 500 mg per vial (as sodium salt)o   First week of life (7 days or less): 50 mg/kg/dose 12 hourly

o   8-20 days: 50 mg/kg/dose 8 hourly

o   21 days & older: 50 mg/kg/dose 6 hourly

10 days

Infant, Child & Adolescent

Preferred antibiotic choice for delayed diagnosis of congenital syphilis
DrugFormulationDosageDuration
Benzylpenicillin (IV)APowder for injection: 600 mg (= 1 million IU); 3 g (= 5 million IU) (sodium or potassium salt) in vial.50,000 units/kg/dose 6 hourly, maximum dose 5 million IU/kg/dose 6 hourly10 days
Alternative antibiotic choice(s)
Ceftriaxone (IV)Powder for injection: 250 mg; 1 g (as sodium salt) in vial50 mg/kg/dose 12 hourly, maximum dose 2 g 12 hourly10 days
For acquired, primary, or secondary syphilis infection (not congenital syphilis)
Benzathine benzylpenicillin (IM)APowder for injection: 900 mg benzylpenicillin (= 1.2 million IU) in 5- mL vial; 1.44 g benzylpenicillin (= 2.4 million IU) in 5- mL vial.50,000 units/kg/dose, maximum dose 2.4 million units3 doses at 1-week intervals
Alternative antibiotic choice(s) or for confirmed penicillin allergy
Children/adolescents <12 years of age:

Amoxicillin (PO)

PLUS

Probenecid (PO)

Amoxicillin- Powder for oral liquid: 125 mg (as trihydrate)/5 mL, 250 mg (as trihydrate)/5 mL; solid oral dosage form: 250 mg, 500 mg (as trihydrate)1 g 8 hourlyEarly syphilis: 14 days

Late/latent syphilis:

28 days

Probenicid- Tablets: 500 mg (not included in WHO MLEM)250 mg 8 hourly
Adolescents 12 years & older:

Doxycycline (PO)

Oral liquid: 25 mg/5 mL, 50 mg/5ml (anhydrous); solid oral dosage form: 50 mg, 100 mg (as hyclate)100 mg 12 hourlyEarly syphilis: 14 days

Late/latent syphilis: 28 days

 

 

A. If benzylpenicillin (IV) or benzathine benzylpenicillin (IM) is not available, seek expert opinion on alternative therapies (The efficacy of cefotaxime/ceftriaxone is uncertain.).

 

Principles of Stewardship:

  • For congenital syphilis, a complete 10-day course is required. If treatment is interrupted by 1 day (or longer), restart the full 10-day course of treatment.
  • Infants treated for congenital syphilis should be followed-up 3-monthly after initial treatment to repeat non-treponemal serological testing until the test becomes non-reactive. If the decrease in serological titre is less than 4-fold, the course of treatment should be repeated.

Other Notes:

  • Acquired syphilis in a child (not sexually active) requires investigation for child abuse.
  • Investigate and treat both parents, if necessary and if not already diagnosed and treated.