Syphilis is a sexually transmitted disease which is characterised by:
- minor early illness
- more serious late manifestations after a variable latent period
The infective agent is a spirochete, treponema pallidum.
Syphilis burden in the UK
- syphilis is a sexually transmitted bacterial infection caused by Treponema pallidum subspecies pallidum which can be successfully treated with antibiotics
- the burden of syphilis in the UK fell since penicillin became widely available. However, between 2013 and 2019, the number of infectious syphilis cases diagnosed increased by 140%. Following a temporary decline in diagnoses in 2020 and 2021 - corresponding to reduced testing during COVID-19 - diagnoses rebounded to 9,513 in 2023 (1)
Approximately one-third of sexual contacts of individuals with infectious syphilis will subsequently develop the disease (2) and there are an estimated 10.6 million incident cases of syphilis worldwide each year. (3)
Syphilis disease stages: (4)
There are four stages of syphilis infection: primary, secondary, latent and tertiary (late).
- the first two stages are symptomatic with sores, referred to as chancres, developing on the genital or mouth region in primary syphilis which lasts 4-12 weeks, and rash or more general symptoms such as fever and sore throat developing in the secondary stage which lasts 3-4 months. In some cases, these symptoms can be mild and overlooked or go unnoticed
- latent syphilis is typically asymptomatic, although there can be a relapse of symptoms in the early latent stage, which lasts up to 2 years
- the late latent stage, which can last a lifetime, is generally non-symptomatic
- in one-third of cases, latent syphilis develops into the tertiary stage around 10-13 years after the initial infection. This final stage can result in severe multi-organ damage, neurosyphilis and death
A single intramuscular dose of long-acting benzathine penicillin with lidocaine is recommended for people who have had syphilis for less than 1 year and longer courses for people with late latent syphilis (4) and treatment depends on the disease stage: (4)
Seek expert advice
- Primary, secondary, early latent syphilis: benzathine penicillin 2.4 mega units (intramuscular (IM), single dose)
- Late latent syphilis: benzathine penicillin weekly for three weeks is first-line, or doxycycline 100mg twice daily for 28 days
- Neurosyphilis: procaine penicillin 1.8-2.4 units once daily (IM, for 14 days) with oral probenecid 500 mg four times a day.
- Treatment in pregnancy depends upon the presenting trimester. In the first and second trimesters give single dose benzathine penicillin. In the third trimester give two doses of benzathine penicillin one week apart.
Macrolides are no longer an option for treatment due to antimicrobial resistance. Ceftriaxone is an alternative treatment and is appropriate in most cases where penicillin cannot be used. (4)
References:
- 1. UK Health Security Agency. Tracking the syphilis epidemic in England: 2013 to 2023 (Updated 12 September 2024)
- 2. How infectious is syphilis? Br J Vener Dis.1983 Aug;59(4):217-9
- 3. Tuddenham S et al. Emerging trends and persistent challenges in the management of adult syphilis. BMC Infect Dis. 2015 Aug 19:15:351
- 4. Kingston M et al. BASHHUK. Guidelines for the management of syphilis 2024. International Journal of STD & AIDS 2024, Vol. 0(0) 1–19