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 spirochaete, 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 has remained low since penicillin became widely available
- however, over the past two decades the number of new diagnoses has increased and the number of cases in women more than doubled between 1999 and 2007 [1,2]
Syphilis prevalence in pregnant women remains low. A study of syphilis screening in pregnancy in England found that one-in-2800 pregnant women required treatment for syphilis in the period 2010-2011 .
Syphilis disease stages:
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 is recommended for people who have had syphilis for less than 1 year and longer courses for people with late latent syphilis :
- treatment depends on the disease stage :
- seek expert advice
- primary, secondary, or early latent syphilis is treated with a single dose of intramuscular (IM) benzathine penicillin G 2.4 million units.
- neurosyphilis is treated with IV penicillin G aqueous 18-24 million units daily for 14 days. An alternative regimen would be procaine penicillin G 2.4 million units IM once daily AND Probenecid 500 mg orally 4 times/day for 10-14 days
- tertiary and latent syphilis and HIV-infected patients should be treated with weekly benzathine penicillin G 2.4 million units IM for three weeks
- alternative therapies include doxycycline 100 mg orally (PO) twice daily for 14 days or ceftriaxone 1 to 2 gm IM or intravenously (IV) daily for 10 to 14 days or tetracycline 100 mg PO 4 times for 14 days. Azithromycin is no longer recommended due to reports of resistance.
- Health Protection Agency. Syphilis and Lymphogranuloma venereum (LGV): resurgent sexually transmitted infections in the UK. GOV.UK. https://www.gov.uk/government/publications/syphilis-and-lymphogranuloma-venereum-lgv-resurgent-sexually-transmitted-infections-in-the-uk (accessed 13 Feb 2019).
- Public Health England. Annual review of infections in UK blood, tissue and organ donors: 2016. Health Protection Report Volume 11 Number 33. 2017. https://www.gov.uk/government/publications/safe-supplies-annual-review
- Townsend CL, Francis K, Peckham CS, et al. Syphilis screening in pregnancy in the United Kingdom, 2010-2011: a national surveillance study. BJOG Int J Obstet Gynaecol 2017;124:79–86. doi:10.1111/1471-0528.14053
- Garnett GP, Aral SO, Hoyle DV, et al. The natural history of syphilis: its implications for the transmission dynamics and control of infection. Sex Transm Dis 1997;24:185-200.
- Peeling RW et al. Syphilis. Lancet 2023; 402 (10398):336-346.
- Tudor ME, Al Aboud AM, Leslie SW, et al. Syphilis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534780/