Background

The quarterly data provide an in-year indication of trends for syphilis and gonorrhoea diagnoses in England.

These 2 infections have seen an overall increase since the early 2000s but numbers have fluctuated over the past few years. Due to this, in-year trends have been valuable to understand, monitor and plan for their control.

Both infections saw a series of impacts from the COVID-19 pandemic:

1. A marked but temporary decline in diagnoses in 2020 to 2021 mainly explained by a fall in testing during service disruption to sexual health services (SHSs).
2. A rapid return to and exceedance of pre-COVID levels first for syphilis and then gonorrhoea.
3. A subsequent tailing off to a more steady or declining number of diagnoses, but still remaining comparatively high (see Figures 1a and 1b).

The future trend for both these infections is unclear but may be impacted by new interventions such as doxyPEP (doxycycline post-exposure prophylaxis, against syphilis) and 4CMenB vaccine (4-component serogroup B meningococcal vaccine, against gonorrhoea). Detailed annual data on these and other infections are published mid-year with demographic, regional and local breakdowns to help interpret the factors behind the changes.

The provisional quarterly figures use data submitted to the GUMCAD STI Surveillance System on a 3 monthly basis, and can give a high level indication of the trajectory and scale of diagnoses before the full data set is available. They also provide useful context to the annual figures, which can mask fluctuations and emerging patterns in the epidemiology by averaging out changes occurring during the year.

For example, in 2023 the year began with gonorrhoea diagnoses at a high point and, while figures declined during the course of the year, the annual total overall was the highest recorded since records began in 1918. The decline has continued into the first part of 2024, but numbers remain at a comparatively high level (see Figure 1a). Gonorrhoea diagnoses have fluctuated over time, but there has been an overall increasing trend since 2010. Syphilis is following a similar trajectory, with diagnoses in 2023 at their highest since the 1940s (see Figure 1b). Although there has been an increased rate of sexually transmitted infection (STI) testing over this period, the rate of increased diagnosis of STIs has been steeper, suggesting that increased transmission of STIs is playing a role in this rise.

Figure 1a. Long-term trends in gonorrhoea diagnoses, England, 1918 to 2023

Figure 1b. Long-term trends in syphilis diagnoses, England, 1918 to 2023

Sources: Sexual Health Surveillance, England (includes GUMCAD data from 2009). Figures are reproduced from the STI Prioritisation Framework Appendix 3.

Interpretive note on the graphs

Population, societal and healthcare changes have occurred over the timespan (1918 to 2023) covered by these graphs.

The overall population has increased by more than 25 million and is on average older and more urbanised. Factors that influence the epidemiology of STIs include: 

• periods of significant upheaval and mass movement during 2 World Wars
• the advent of the antibiotic era, particularly penicillin introduction in 1948, followed soon after by antibiotic resistance in gonorrhoea
• changes in societal attitudes to sex, sexual orientation and gender identity; women’s liberation movement and decriminalisation of same sex sexual activity
• availability and more widespread use of non-barrier contraception ‘the Pill’ since the 1960s and latterly methods of long-acting reversible contraception
• the emergence of acquired immune deficiency syndrome (AIDS) and the HIV pandemic in the early 1980s; the advent of effective HIV antiretroviral treatment from the mid-1990s
• invention of the internet leading to new ways to meet and arrange social and sexual contacts using social media and apps
• wider access to and recommendations for STI testing; as well as the use of more sensitive diagnostic methods with improved detection of asymptomatic infections and which work well with self-taken samples, increasing their reach

Effect of reporting delays

Figures for quarters 1 to 3 (January to September) are likely to increase as further data submissions from SHSs are received and are indicated by a shaded portion on the graphs. The full year including quarter 4 (October to December) use the same dataset that is used to produce the annual data and represent the final figures for the year.

Publication timeline

Publication month	Quarter(s) and data included (months)
End March	Previous year quarter 1 to 3 (data from January to September)
End June (following publication of the annual STI official statistics)	Previous year quarter 1 to 4 (data from January to December)
End September	Current year quarter 1 (data from January to March)
December	Current year quarter 1 and 2 (data from January to June)