Research and analysis

Tracking the syphilis epidemic in England: 2013 to 2023

Updated 12 September 2024

Applies to England

Introduction

This report updates the Tracking the syphilis epidemic in England report published in 2019. It provides a descriptive analysis of the epidemiology of syphilis in England including the years most impacted by the COVID-19 pandemic response and the period afterwards. It illustrates differences in the epidemiology of syphilis between gay, bisexual and other men who have sex with men (GBMSM), men who have sex with women (MSW) and women who have sex with men (WSM) across the country.

Trends are presented for the period 2013 to 2023 using annual data from the GUMCAD STI Surveillance System by demographic characteristics to illustrate groups disproportionately affected by syphilis. The report also provides an update on diagnoses of congenital syphilis, syphilis in pregnancy and among blood donors. For information on other sexually transmitted infections (STIs), please refer to the ‘Sexually transmitted infections and screening for chlamydia in England: 2023 report’.

Main points from these analyses include:

• in 2023, diagnoses of infectious syphilis increased to 9,513, up 9.4% compared to 2022 (8,693)
• there were a further 3,075 new diagnoses of other acquired syphilis: 2,777 late latent infections (asymptomatic, non-infectious but requiring treatment) and 298 syphilis complications (such as neurosyphilis or cardiovascular syphilis)
• the number of infectious syphilis diagnoses remained greatest among GBMSM, and people aged 25 to 34 years
• recent increases have been relatively higher among heterosexual people; between 2022 and 2023 infectious syphilis diagnoses increased by 29% (641 to 825) among WSM and 17% (967 to 1,133) among MSW, compared to 7% for GBMSM (6,081 to 6,527)
• diagnoses were highest in London and other major urban areas
• in 2023, the number of syphilis tests in sexual health services increased to 1,587,509, up 11% compared to 2022 (1,430,172) and slightly higher compared to 2019 (pre-pandemic) levels (1,533,560), although there were differences seen across population groups
• the rate of women who screened positive for syphilis during antenatal care increased by 18% from 1.39 per 1,000 women tested in the screening year 2017 to 2018, to 1.64 per 1,000 women tested in the screening year 2021 to 2022
• between 2013 and 2022, the rates of confirmed positive syphilis cases in blood donors increased for early (218%, 2.1 to 6.6 per 100,000 donors) and late syphilis (97%, 6.0 to 11.8 per 100,000 donors) among men, and for early syphilis among women (374%, 0.4 to 1.8 per 100,000 donors)

Overview of syphilis epidemiology in England

In 2023, 12,588 new diagnoses of syphilis (all stages) were made in sexual health services (SHSs) in England, 76% (9,513) of which were classified as infectious syphilis, comprising primary, secondary and early latent clinical stages (see ‘Technical notes’ for definitions). The remaining 3,075 diagnoses were ‘other acquired syphilis’ including cardiovascular, neurosyphilis or any other late or latent syphilis (asymptomatic and non-infectious but requiring treatment). These figures will underestimate the extent of syphilis complications in England as diagnoses from other clinical settings are not included.

This report reviews syphilis data from 2013, to show a longer-term trend, as well as comparing 2023 data with data from 2019, before the disruption of the COVID-19 pandemic. Between 2013 and 2019, infectious syphilis diagnoses increased by 140% (3,345 to 8,040). Following a temporary decline in diagnoses in 2020 and 2021, corresponding to reduced testing during COVID-19 related disruption to SHSs, diagnoses rebounded to 9,513 in 2023 (Figure 1a). This was the highest number of diagnoses reported since the 1940s (although comparisons of syphilis trends over several decades should be made with caution given increases in the population size and access to and use of more sensitive diagnostic tests over time).

Compared to diagnoses, syphilis tests increased to a lesser extent, 38% between 2013 and 2019 (from 1,111,606 to 1,533,560). Following the COVID-19-related decrease, total testing rates recovered to pre-pandemic levels by the end of 2023 (1,587,509, 3.5% increase) (Figure 1b).

Positivity increased, from 0.3% (3 in 1,000 tests) in 2013 to 0.5% in 2019. The rise in positivity to 0.7% in 2020 was likely because of changes in testing prioritisation within SHSs in response to COVID-19. Although positivity declined to 0.6% in 2023 it remained above pre-pandemic levels (data not shown).

Figure 1a. Number of infectious syphilis diagnoses, England, 2013 to 2023 [note 1]

Figure 1b. Number of syphilis tests, England, 2013 to 2023 [note 1]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 1: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Syphilis diagnoses by gender and sexual orientation

Most diagnoses of infectious syphilis continue to be among GBMSM (76% in 2023) (Figure 2). However, the proportional increase between 2013 and 2023 was most pronounced for WSM (203%; 272 to 825), followed by GBMSM (173%; 2,390 to 6,527) and MSW (126%; 502 to 1,133). In 2023, infectious syphilis diagnoses among GBMSM, WSM and MSW surpassed pre-pandemic 2019 levels (11%, 36% and 13% increase between 2019 and 2023 respectively).

The number of infectious syphilis diagnoses among women who have sex with women (WSW) are small, ranging from 12 in 2013 to 58 in 2023 (accounting for less than 1% of diagnoses in 2023; 58 of 9,513, 0.6%). Due to small numbers, figures for WSW are not broken down further in this report.

Figure 2. Number of infectious syphilis diagnoses by gender and sexual orientation, England, 2013 to 2023 [note 2][note 3]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 2: The abbreviations used in the legend in the chart are defined as the following: GBMSM: Gay, bisexual and other men who have sex with men. MSW: Men who have sex with women. WSM: Women who have sex with men. WSW: Women who have sex with women.

Note 3: Figures reported in 2020 and 2021 are lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

The age distribution of infectious syphilis diagnoses in 2023 varied by gender and sexual orientation. Overall, the highest proportion of diagnoses occurred in those aged 25 to 34 years. However, diagnoses among WSM were skewed towards the younger age groups; 29% of diagnoses among WSM occurred in those aged 24 and under compared to 8.8% and 12% among GBMSM and MSW respectively (Figure 3).

Figure 3. Diagnoses of infectious syphilis by sexual orientation and age group, England, 2023 [note 4]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 4: The abbreviations used in the legend in the chart are defined as the following: GBMSM: Gay, bisexual and other men who have sex with men. MSW: Men who have sex with women. WSM: Women who have sex with men. WSW: Women who have sex with women.

Trends in GBMSM

Trends of infectious syphilis diagnoses, syphilis tests and positivity

Among GBMSM, diagnoses of infectious syphilis increased by 146% from 2,390 in 2013 to 5,875 in 2019, before declining temporarily in 2020 and 2021. In 2023, the number of diagnoses rose to 6,527, a slightly larger annual increase than in the years immediately prior to the pandemic (Figure 4a).

Syphilis testing among GBMSM also increased, from 95,771 in 2013 to 246,541 in 2019 (157%). Whilst tests decreased in 2020, numbers recovered in subsequent years reaching 346,373 by 2023 (Figure 4b). In 2023, testing amongst GBMSM was 40% greater compared to 2019, whereas diagnoses were 11% greater.

The increase in testing led to a decrease in positivity, from 2.5% in 2013 to 1.9% in 2023. This suggests that the post-COVID-19 rebound in syphilis diagnoses among GBMSM was likely to be explained, at least in part, by an increase in testing, rather than an increase in the incidence of infection in the community.

Figure 4a. Number of infectious syphilis diagnoses among GBMSM accessing SHSs, England, 2013 to 2023 [note 5]

Figure 4b. Number of syphilis tests among GBMSM accessing SHSs, England, 2013 to 2023 [note 5]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 5: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

There was an increase in syphilis tests accessed online during and following the pandemic; between 2019 and 2020 the number doubled (from 40,831 to 84,649), and by 2023, 39% of tests among GBMSM were accessed online (Figure 5). When considered by age group, the proportion of tests that were online was higher among younger GBMSM (aged 15 to 24 years), where 46% of tests were online in 2023 (data not shown).

Figure 5. Number of syphilis tests by consultation type [note 6] among GBMSM accessing SHSs, England, 2013 to 2023 [note 7]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 6: See ‘Technical notes’ for further description of developments in the collection of online test data.

Note 7: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Syphilis diagnoses by clinical stage

Infectious syphilis (primary, secondary and early latent stages) comprised the majority of syphilis diagnoses among GBMSM, accounting for 86% (6,527 of 7,615) in 2023 (Figure 6). Between 2013 and 2023, the overall proportion of syphilis that was infectious remained steady but the proportion that was diagnosed as early latent (asymptomatic infection acquired within the previous 2 years) increased from 24% to 35%.

In the early latent stage, approximately 25% of patients can develop recurrence of secondary disease (1). Consequently, just over a third of all syphilis diagnoses among GBMSM in 2023 were asymptomatic but may be infectious. There are a number of possible explanations that could account for the increase in early latent infections, including increased frequency of asymptomatic testing, increased re-infections (which are less likely to show overt symptoms), or a signal of difficulty or delay in accessing services. Further work is needed to explore these hypotheses.

For other acquired syphilis, the proportion of late latent syphilis diagnoses (longstanding infections acquired more than 2 years earlier) has remained consistent over time. In 2023, late latent diagnoses accounted for 12% (917 of 7,615) of all syphilis cases among GBMSM.

Diagnoses of syphilis complications (such as neurosyphilis and cardiovascular syphilis) increased between 2013 and 2023, in line with the overall increase in syphilis, and accounted for 2.2% (171 of 7,615) of diagnoses in SHSs in 2023. Most (97%) of these presentations were neurosyphilis. These figures will underestimate the extent of syphilis complications in England as diagnoses from other clinical settings are not included.

Figure 6. Diagnoses of syphilis by stage of infection among GBMSM accessing SHSs, England, 2013 to 2023 [note 8][note 9]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 8: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Note 9: Infectious syphilis is defined as primary, secondary, and early latent syphilis. Other acquired syphilis includes late latent syphilis and syphilis complications such as cardiovascular and neurosyphilis.

Infectious syphilis diagnoses by

HIV status

Although rates of syphilis diagnoses remain higher among GBMSM living with HIV, between 2013 and 2023, the proportion of infectious syphilis diagnoses among GBMSM living with HIV decreased from 39% (924 of 2,390) to 26% (1,670 of 6,527) (Figure 7).

Pre-exposure prophylaxis (PrEP) for HIV prevention was made routinely available in England from the end of 2020. In 2023, 42% of infectious syphilis diagnoses among GBMSM who were HIV negative or undiagnosed were classified as using PrEP (having had an indication for PrEP use in the previous 6 months). The demographics of those using and not using PrEP were the same; the highest proportions were seen amongst those aged 25 to 34 years (39%) and people of white ethnicity (70%). As syphilis is a strong predictor for HIV acquisition (2), this suggests that there are further individuals who could benefit from the protection offered by HIV PrEP.

Figure 7. Number of infectious syphilis diagnoses among GBMSM accessing SHSs by HIV and PrEP use status, England, 2013 to 2023 [note 10]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 10: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Ethnicity

In 2023, the number of infectious syphilis diagnoses among GBMSM was highest among those of white ethnicity (70%, 4,538 of 6,527), compared to other ethnic groups (Figure 8).

Figure 8. Diagnoses of infectious syphilis among GBMSM accessing SHSs by ethnic group, England, 2023 [note 11]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 11: The ethnic categories above are as specified by the Office for National Statistics (ONS).

Geographical distribution

Infectious syphilis diagnoses among GBMSM are unevenly distributed geographically with London residents accounting for 53% (3,468 of 6,527) in 2023. Outside London, diagnoses were concentrated in the South East and in urban areas in the Midlands and North of England (Figure 9). In 2023, 50% of all diagnoses were made in those residing in 13% (20 of 153) of upper tier local authorities (Figure 10). The geographical distribution of syphilis and comparisons by upper tier local authority can be explored further in the Sexual and Reproductive Health Profiles.

Syphilis continues to disproportionately affect GBMSM living in more socioeconomically deprived areas (see ‘Technical notes’ for details on how deprivation is measured). In 2023, 61% of infectious syphilis diagnoses among GBMSM were in those living in the 2 most deprived quintile areas; whilst only 8% were made among those living in the least deprived quintile (Figure 11). The distribution of diagnoses by Index of Multiple Deprivation (IMD) quintile remained stable between 2013 and 2023.

Figure 9. Map of number of infectious syphilis diagnoses among GBMSM accessing SHSs by upper tier local authority of residence, England, 2023

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Figure 10. Number of infectious syphilis diagnoses among GBMSM accessing SHSs by upper tier local authority of residence, England, 2023

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Figure 11. Number of infectious syphilis diagnoses among GBMSM accessing SHSs by Index of Multiple Deprivation quintile [note 12], England, 2023

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 12: See ‘Technical notes’ for detail on Index of Multiple Deprivation.

Trends in heterosexual men and women

Trends of infectious syphilis diagnoses, syphilis tests and positivity

In 2023, 23% of all infectious syphilis diagnoses were reported among heterosexual people. Diagnoses among MSW and WSM approximately doubled between 2013 and 2019, by 99% (502 to 1,001) among MSW and 122% (272 to 605) among WSM (Figure 12a). In 2023, the number of infectious syphilis diagnoses increased to 1,133 (MSW) and 825 (WSM).

Syphilis testing dropped steeply in 2020 and has not recovered to pre-pandemic levels (Figure 12b). Consequently, positivity has increased over the decade from 0.12% in 2013 to 0.30% in 2023 for MSW, and from 0.05% to 0.12% for WSM (data not shown).

Figure 12a. Number of infectious syphilis diagnoses among MSW and WSM accessing SHSs, England, 2013 to 2023 [note 13]

Figure 12b. Number of syphilis tests among MSW and WSM accessing SHSs, England, 2013 to 2023 [note 13]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 13: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Between 2019 and 2020 the number of syphilis tests accessed online increased. By the end of 2023 these accounted for 47% of tests in MSW and 56% in WSM, more than double the proportions seen in 2019 (Figure 13a and 13b).

Figure 13a. Number of syphilis tests by consultation type [note 14] among MSW accessing SHSs, England, 2013 to 2023 [note 15]

Figure 13b. Number of syphilis tests by consultation type [note 14] among WSM accessing SHSs, England, 2013 to 2023 [note 15]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 14: See ‘Technical notes’ for further description of developments in the collection of online test data.

Note 15: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Syphilis diagnoses by clinical stage

The proportion of diagnoses classified as late latent is higher for heterosexual men and women than GBMSM. Between 2013 and 2023, the proportion of syphilis diagnoses that were infectious (primary, secondary of early latent) increased from 43% to 61% among MSW and from 31% to 55% among WSM (Figure 14a and 14b). The proportional increase in diagnoses of infectious syphilis among heterosexual people may indicate that infections are being diagnosed at an earlier stage. Conversely, it could also result from late latent infections not being diagnosed due to the reduction in face-to-face attendance at specialist SHSs, where these asymptomatic infections may be more likely to be detected.

Figure 14a. Diagnoses of syphilis by stage of infection among MSW accessing SHSs, England, 2013 to 2023 [note 16][note 17]

Figure 14b. Diagnoses of syphilis by stage of infection among WSM accessing SHSs, England, 2013 to 2023 [note 16][note 17]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 16: Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Note 17: Infectious syphilis is defined as primary, secondary, and early latent syphilis. Other acquired syphilis includes late latent syphilis and syphilis complications such as cardiovascular and neurosyphilis.

Infectious syphilis diagnoses by:

Ethnicity

In 2023, most infectious syphilis diagnoses were made among heterosexual people of white ethnic background, 693 (61%) in MSW and 583 (71%) in WSM (Figure 15a and 15b).

Figure 15a. Diagnoses of infectious syphilis diagnoses among MSW accessing SHSs by ethnic group, England, 2023 [note 18]

Figure 15b. Diagnoses of infectious syphilis diagnoses among WSM accessing SHSs by ethnic group, England, 2023 [note 18]

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 18: The ethnic categories above are as specified by the ONS.

Geographical distribution

With overall lower numbers of syphilis diagnoses in MSW and WSM the focus on London is less pronounced, with only 28% of diagnoses among heterosexual people in 2023 (556 of 1,958), followed by 14% in the West Midlands (282 of 1,958) and 14% in the North East (271 of 1,958) (Figure 16). While the geographical distribution is uneven across the country, this pattern is slightly less extreme compared to GBMSM, with 50% of cases seen across 22% (33 of 153) of upper tier local authorities (Figure 17). The geographical distribution of syphilis and comparisons by upper tier local authority can be explored further in the Sexual and Reproductive Health Profiles.

Syphilis continues to disproportionately affect heterosexual people living in the most socioeconomically deprived areas. In 2023, the highest number of syphilis diagnoses were seen in the most deprived quintile, which accounted for 41% of diagnoses among MSW and 40% among WSM in 2023 (Figure 18).

Figure 16. Map of number of infectious syphilis diagnoses among heterosexual people accessing SHSs by upper tier local authority of residence, England, 2023

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Figure 17. Number of infectious syphilis diagnoses among heterosexual people accessing SHSs by upper tier local authority of residence, England, 2023

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Figure 18. Number of infectious syphilis diagnoses among heterosexual people accessing SHSs by Index of Multiple Deprivation quintile [note 19], England, 2023

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Note 19: See ‘Technical notes’ for detail on Index of Multiple Deprivation.

Syphilis in pregnancy

The Integrated Screening Outcomes Surveillance Service (ISOSS) syphilis report 2023 outlined that in the screening year 2021 to 2022 in England, coverage for antenatal HIV, hepatitis B and syphilis screening was 99.8%. The rate of women who screened positive for syphilis during antenatal care increased by 18% from 1.39 per 1,000 women tested in the screening year 2017 to 2018, to 1.64 per 1,000 women tested in the screening year 2021 to 2022 (Figure 19). Among women who screened positive, the rate of women requiring treatment also increased from 0.53 per 1,000 women tested in the screening year 2017 to 2018, to 0.66 per women tested in the screening year 2021 to 2022 (25% increase).

Figure 19. Screen positive rates for syphilis in pregnant women, England, screening financial year 2017 to 2018, to screening year 2021 to 2022

Source: Data from ISOSS syphilis report 2023.

In the screening year 2021 to 2022, there were 934 pregnancies to 928 women who screened positive for syphilis in pregnancy, of whom 386 (41%) required treatment (defined as current untreated infections that, following SHSs review and tests, require treatment). There were 4 infants with confirmed congenital syphilis born to women with screen positive syphilis requiring treatment.

There were 55 infants with congenital syphilis in England reported to ISOSS from January 2015 to September 2023, 16 of which were reported since January 2022.

Syphilis among blood donors

Confirmed cases of syphilis in blood donors gives insight into underlying infection trends in the general population. Donors in England are voluntary unpaid individuals aged 17 and over and selected to be at low risk of blood-borne infections. NHS Blood and Transplant (NHSBT) screens all blood donations made in England for treponemal antibodies indicating syphilis. Reactive (screen positive) donations are discarded and undergo further confirmatory testing including immunoglobulin M (IgM) and rapid plasma reagin (RPR) test.

Since 2016, people wishing to donate in England have been advised not to give blood if they have a history of syphilis to avoid people making unusable donations. There have been no reported cases of syphilis transfusion transmissions in the UK since reporting began in 1996.

When donations are confirmed antibody positive, donors are invited for a post-test telephone discussion to obtain a history and refer for follow up. Donors disclosing a history of treatment at their post-test discussion were excluded from these data (n = 202). Those donors with unknown infection status were assigned to the late category (n = 28). Consequently, this may over-estimate the rate of untreated late infection.

In 2022, 8 women and 24 men who donated blood were antibody positive and classified as likely to have early syphilis (acquired within 2 years and untreated), while 8 women and 43 men were likely to have late syphilis (acquired more than 2 years prior and untreated). The rates of confirmed positive syphilis cases in blood donors increased for early and late syphilis among men, and for early syphilis among women, between 2013 and 2022 (Figure 20). The substantial increase in late syphilis among men should be considered in the context of the Department of Health and Social Care announcing a policy change to more individualised risk-based assessments for blood donation. Implemented from June 2021, the eligibility rules changed to allow some GBMSM with one regular partner to donate blood, resulting in an increase in men reporting sex with men donating blood.

Figure 20. Rate of confirmed positive syphilis cases in blood donors per 100,000 donors by gender and early or late stage, England, 2013 to 2022 [note 20]

Source: Blood donor data for NHS Blood and Transplant (NHSBT) provided by the NHSBT and UKHSA Epidemiology unit.

Note 20: Confirmed positives have been separated into under 2 years and over 2 years to increase comparability with the coding ‘infectious’ and ‘late latent’ syphilis used elsewhere in this report. Over 2 years refers to syphilis acquired more than 2 years prior to detection and left untreated.

Conclusions

Over the past decade diagnoses of infectious syphilis have increased and, despite the reduction seen consequent to the COVID-19 pandemic, by 2023 were at their highest level recorded since the 1940s. In 2019, in response to the increasing burden of syphilis infection in England, Public Health England (now UKHSA), published a Syphilis Action Plan. The Action Plan highlighted that a wide range of measures to control transmission already exists, but the continued increase in diagnoses suggested that these are either not being applied consistently or that new, additional measures should be considered. Specifically, the Action Plan highlighted that a successful response to the increasing incidence was dependent upon the optimisation of the following 4 prevention pillars:

1. Increase testing frequency of high-risk men who have sex with men and re-testing of syphilis cases after treatment.
2. Deliver partner notification to British Association for Sexual Health and HIV (BASHH) standards.
3. Maintain high antenatal screening coverage and vigilance for syphilis throughout antenatal care.
4. Sustain targeted health promotion.

In 2023, syphilis testing among GBMSM had continued to increase compared with previous years and was 40% higher than that seen in 2019 (pre-pandemic). Infectious syphilis diagnoses had only increased by 11% in the same period. In contrast, after the fall in testing in 2020, testing in 2023 amongst MSW and WSM remained below the pre-pandemic levels seen in 2019. This could indicate the presence of barriers that have reduced service access or a lack of awareness to the importance of testing for syphilis among the heterosexual population. These potential barriers are being explored in a qualitative National Institute for Health and Care Research Health Protection Research Unit funded research project called the NEXUS study, which is being conducted at 3 sexual health services in England.

A theme highlighted in this report is the inequality in the distribution of syphilis (3 to 5). The burden of infectious syphilis diagnoses remained in those living in the most deprived areas, which is evident for GBMSM and heterosexual people.

There has been an increase in the rate of women who have screened positive for syphilis during antenatal care and those that require treatment, and while antenatal screening coverage has remained high, there has been an increase in cases of congenital syphilis.

This report highlights the continued increases in syphilis diagnoses and positivity. Further insight is needed to help inform existing prevention, testing and treatment strategies, and the potential for new approaches, such as doxycycline post-exposure prophylaxis, to support syphilis control.

References

1. O’Byrne P and MacPherson P. ‘Syphilis’. The BMJ 2019: volume 365, page I4159 (date accessed: 16 May 2024)

2. Desai S and others. ‘HIV incidence in an open national cohort of men who have sex with men attending sexually transmitted infection clinics in England’. HIV Medicine 2017: volume 18 issue 9, pages 615 to 622 (date accessed: 16 May 2024)

3. Bardsley M and others. ‘Improving our understanding of the disproportionate incidence of STIs in heterosexual-identifying people of black Caribbean heritage: findings from a longitudinal study of sexual health clinic attendees in England’. Sexually Transmitted Infections 2022: volume 98, pages 23 to 31 (date accessed: 11 October 2023)

4. Petersen J and others. ‘Identifying and interpreting spatiotemporal variation in diagnoses of infectious syphilis among men, England: 2009 to 2013’. Sexually Transmitted Infections 2016: volume 92 issue 5, pages 380 to 386 (date accessed: 11 October 2023)

5. Acheson P and others. ‘An ongoing outbreak of heterosexually-acquired syphilis across Teesside, UK’. International Journal of STD and AIDS 2011: volume 22 issue 9, pages 514 to 516 (date accessed: 11 October 2023)

Technical notes

Data

1. All data presented is sourced from the GUMCAD STI Surveillance System, which collects data on STI testing and diagnoses provided at all sexual health services in England, except where otherwise stated in ‘Syphilis in pregnancy’ and ‘Syphilis among blood donors’ sections.
2. Data represent the number of diagnoses or tests reported, not the number of people diagnosed or tested.
3. Data reported with an unknown gender and/or sexual orientation are included in the data total.
4. Sexual orientation data reflect the sexual orientation of attendees reported at the date of STI diagnosis.
5. GBMSM refers to gay, bisexual and other men who have sex with men. WSW refers to lesbians and other women who have sex with women exclusively. WSM refers to heterosexual and bisexual women who have sex with men.
6. Syphilis test positivity is defined as the number of infectious syphilis (primary, secondary, and early latent stage) diagnoses divided by all syphilis tests.
7. Complications of syphilis may be underreported as cases with cardiovascular and neurosyphilis may present in clinical settings other than SHSs and therefore will not be recorded in the GUMCAD STI Surveillance System.
8. Data for GBMSM was under-reported in London for 2021 (also affecting the GBMSM total in England for 2021). Therefore, the associated trends in diagnoses among GBMSM are also likely to be an underestimate. Please refer to the ‘Technical notes’ in the ‘Sexually transmitted infections and screening for chlamydia in England: 2023 report’ for further information.
9. The UKHSA regions shown may not match the Government Office Regions (GOR) shown in Sexual and Reproductive Health Profiles.

Sexual health services

Sexual health services (SHSs) refer to services offering specialist (Level 3) STI-related care such as genitourinary medicine (GUM) and integrated GUM and sexual and reproductive health (SRH services). They also include other services offering non-specialist (Level 2) STI-related care and community-based settings. Further details on levels of sexual healthcare provision are provided in the BASHH Standards for the Management of STIs (Appendix B).

Residence data represent data from patients accessing services located in England who are also residents in England and those reported with an unknown residence (data for those outside of England is not included).

Sexual health services may be provided via face-to-face, telephone or internet consultations.

Syphilis clinical stages

Early stages of syphilis include primary, secondary and early latent syphilis. Early stages are referred to collectively as ‘infectious syphilis’. Primary syphilis is the initial presentation of the disease, characterised by a chancre. Secondary syphilis has systemic involvement and can present with a wide range of clinical features, most commonly a rash. Early latent syphilis is defined as asymptomatic positivity to a syphilis diagnostic test within 2 years of acquisition.

Late latent syphilis is defined as asymptomatic positivity to a syphilis diagnostic test after 2 years of transmission. Due to the need for prior negative test results to ascertain whether latent syphilis is early or late, clinical judgement determines if patients with no treatment history are managed and treated as having early or late latent syphilis. Other syphilis includes neurosyphilis and cardiovascular syphilis.

Internet and online data sources

In this report, online or internet data is sourced from dedicated (standalone) online services reporting to the GUMCAD STI Surveillance System and satellite online services provided by face-to-face SHSs.

Deprivation measure

Deprivation is measured using the IMD, a residential area-level measure of socioeconomic status. The first quintile represents the most deprived 20% of Lower layer Super Output Areas (LSOAs) (small geographical areas with 1,000 to 3,000 residents) and the fifth quintile the least deprived 20% of LSOAs.

Appendix

A comparison between the number of diagnoses of infectious and late latent syphilis by upper tier local authority is given in Appendix Figures A1 and Figure A2. The number of diagnoses of late latent syphilis is lower than that of infectious syphilis. However, late latent diagnoses follow a similar geographical pattern, cases being seen in larger urban areas of the country.

Figure A1. Number of infectious syphilis diagnoses by upper tier local authority, England, 2023

Figure A2. Number of late latent syphilis diagnoses by upper tier local authority, England, 2023

Source: Data from routine sexual health service returns to GUMCAD STI Surveillance System.

Acknowledgements

Contributors (listed alphabetically)

Hannah Charles, Helen Fifer, Holly Fountain, Giulia Habib Meriggi, Tobi Kolawole, Sema Mandal, Stephanie J Migchelsen, Hamish Mohammed, Debbie Mou, Norah O’Brien, Natasha Ratna, John Saunders, Deborah Shaw, Ian Simms, Katy Sinka, Megan Walsh

Thank you to all sexual health services, GUMCAD reporters, NHSBT and UKHSA Epidemiology Unit, NHSE Infectious Diseases in Pregnancy Screening Programme (IDPS) and Integrated Screening Outcomes Surveillance Service (ISOSS) for providing data.

Suggested citation

Holly Fountain, Hannah Charles, Ian Simms, Stephanie J Migchelsen, Hamish Mohammed, Katy Sinka and contributors. Tracking the syphilis epidemic in England: 2013 to 2023. June 2024, UK Health Security Agency, London