Sexually transmitted infections and risky sex still an issue in the UK

In the decade since the last Natsal survey, of several strategies aimed at improving sexual health in Britain, three have been STI-specific interventions: the English National Chlamydia Screening Programme (NCSP); the UK HPV immunisation programme; and increasing HIV testing in target groups [1].

Researchers from UCL (University College London), the London School of Hygiene & Tropical Medicine, NatCen Social Research, and Public Health England interviewed nearly 9,000 participants aged 16-44 about their sexual lifestyles and uptake of STI services and interventions. They collected urine samples from over 4,500 16-to-44-year-olds, and tested these for chlamydia, gonorrhoea, high-risk human papillomavirus (HR-HPV), and HIV.

HR-HPV (the virus that causes cervical and other cancers) was the most prevalent infection, detected in 16% of women overall. Around one in a hundred people aged 16-44 had chlamydia, but this was higher in those aged 16-24 (3.1% of women and 2.3% of men). Both chlamydia and HPV prevalence were higher in people who had sex with more partners without a condom, but these STIs were also found in people with only one partner in the last year.

The population prevalence of gonorrhoea in those aged 16-44 was less than 1 in 1,000 (<0.1%) and for HIV it was slightly higher (0.1% in women; 0.2% in men). While both these infections were restricted to those with known high risk factors, they have different implications for individuals, partners, control measures, and service provision.

Exploring the reach of the HPV catch-up immunisation programme, the survey found over 60% of eligible women said that they completed the vaccination course. Encouragingly, the study found that prevalence of HR-HPV in women aged 18-20 years has fallen since the previous survey – down to 5.8% from 11.3%, an early effect of the immunisation programme.

Among 16-to-24-year-olds, 54% of women and 35% of men had been tested for chlamydia in the past year. Testing rates were higher in England than in Scotland or Wales. Those with more partners in the past year were more likely to have been tested for chlamydia.

The proportion of participants reporting an HIV test in the past five years has increased significantly to 28% in women and 17% in men, up from 8.7% in women and 9.2% in men for the previous survey. Appropriately, HIV testing was higher in those with more partners and in those targeted for testing, including men who have sex with men.

Attendance at sexual health clinics has also increased since the previous survey, rising from 6.7% to 21% in women, and from 7.7% to 20% in men. Clinic attendance is highest in younger people, those with higher numbers of partners and in women from the most deprived areas.

Dr Pam Sonnenberg from University College London (UCL), UK, one of the study authors, says: “Although there is more to do to tackle sexually transmitted infections, things are moving in the right direction. Sexual health clinic attendance has risen, more young adults are being tested for chlamydia, more people are taking up HIV testing, particularly in high risk groups, and the HPV immunisation programme has made a good start at reducing HPV infections.”

Professor Dame Anne Johnson, also from UCL, and Natsal Principal Investigator, adds: “Twenty years on from our first findings, the Natsal surveys continue to provide vital insights to shape future sexual health services and interventions, with the aim to improve sexual and reproductive health in Britain.”

The results are part of the third National Survey of Sexual Attitudes and Lifestyles (Natsal), led by Professor Dame Anne Johnson of University College London (UCL, which provided institutional leadership on the study’s management and statistical analysis), and Professor Kaye Wellings, of the London School of Hygiene and Tropical Medicine. Over 15,000 adults aged 16-74 years participated in interviews between September 2010 and August 2012, producing data on sexual behaviour, attitudes, health, and wellbeing. Two previous Natsal surveys have taken place, in 1990 and 2000, making it one of the largest ever studies of sexual behaviour undertaken in a single country. The study was funded by the Medical Research Council and The Wellcome Trust, with additional funding from the Economic & Social Research Council and the Department of Health, and is published in a special issue of The Lancet.