Is chlamydia screening and testing in Britain reaching young adults at risk of infection? Findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).
BACKGROUND
In the context of widespread opportunistic chlamydia screening among young adults, we aimed to quantify chlamydia testing and diagnosis among 16-24 year olds in Britain in relation to risk factors for prevalent chlamydia infection.


METHODS
Using data from sexually experienced (≥1 lifetime sexual partner) 16-year-old to 24-year-old participants in Britain's third National Survey of Sexual Attitudes and Lifestyles (conducted 2010-2012), we explored socio-demographic and behavioural factors associated with prevalent chlamydia infection (detected in urine; n=1832), self-reported testing and self-reported diagnosis in the last year (both n=3115).


RESULTS
Chlamydia prevalence was 3.1% (95% CI 2.2% to 4.3%) in women and 2.3% (1.5% to 3.4%) in men. A total of 12.3% of women and 5.3% men had a previous chlamydia diagnosis. Factors associated with prevalent infection were also associated with testing and diagnosis (eg, increasing numbers of sexual partners), with some exceptions. For example, chlamydia prevalence was higher in women living in more deprived areas, whereas testing was not. In men, prevalence was higher in 20-24 than 16-19 year olds but testing was lower. Thirty per cent of women and 53.7% of men with ≥2 new sexual partners in the last year had not recently tested.


CONCLUSIONS
In 2010-2012 in Britain, the proportion of young adults reporting chlamydia testing was generally higher in those reporting factors associated with chlamydia. However, many of those with risk factors had not been recently tested, leaving potential for undiagnosed infections. Greater screening and prevention efforts among individuals in deprived areas and those reporting risk factors for chlamydia may reduce undiagnosed prevalence and transmission.
Research Department of Infection and Population Health, University College London, London, UK Centre for Infectious Disease Surveillance & Control (CIDSC), Public Health England, London, UK.
Sarah C
SC
Woodhall
Centre for Infectious Disease Surveillance & Control (CIDSC), Public Health England, London, UK.
Kate
K
Soldan
Research Department of Infection and Population Health, University College London, London, UK.
Pam
P
Sonnenberg
Research Department of Infection and Population Health, University College London, London, UK.
Catherine H
CH
Mercer
Research Department of Infection and Population Health, University College London, London, UK NatCen Social Research, London, UK.
Soazig
S
Clifton
Microbiology Services, Public Health England, London, UK.
Pamela
P
Saunders
Microbiology Services, Public Health England, London, UK.
Filomeno
F
da Silva
Microbiology Services, Public Health England, London, UK.
Sarah
S
Alexander
Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, UK.
Kaye
K
Wellings
Research Department of Infection and Population Health, University College London, London, UK.
Clare
C
Tanton
Research Department of Infection and Population Health, University College London, London, UK.
Nigel
N
Field
Research Department of Infection and Population Health, University College London, London, UK.
Andrew J
AJ
Copas
Microbiology Services, Public Health England, London, UK.
Catherine A
CA
Ison
Research Department of Infection and Population Health, University College London, London, UK.
Anne M
AM
Johnson
D000293:Adolescent; D000367:Age Factors; D001290:Attitude; D001437:Bacteriuria / Q000382:microbiology; D002690:Chlamydia Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008019:Life Style; D016015:Logistic Models; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012725:Sexual Behavior; D066252:Sociological Factors; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
CHLAMYDIA TRACHOMATIS; EPIDEMIOLOGY (GENERAL); SCREENING