Screening for Chlamydia trachomatis infection CLaSS project (Chlamydia Screening Studies) Low N, McCarthy A, Macleod J, Salisbury C, Campbell R, Roberts TE, et al. Epidemiological, social, diagnostic and economical evaluation of population screening

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Screening for Chlamydia trachomatis infection
CLaSS project (Chlamydia Screening Studies)Low
N, McCarthy A, Macleod J, Salisbury C, Campbell
R, Roberts TE, et al. Epidemiological, social,
diagnostic and economical evaluation of
population screening for genital chlamydial
infectionHealth Technol Assess 200711(8)

• Adam Hardie
• ST1

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Chlamydia trachomatis

• 166 increase since 1997 (gt100,000 cases/yr)
• Can cause PID and increase risk of ectopics,
  tubal infertility, chronic pelvic pain
• Up until recently required urethral/endocervical
  swabs
• New methods require less invasive sampling
  (NAATs)
• Allows screening in asymptomatic people
• Opportunistic screening now rolled out across the
  UK 16-24yrs when seeking healthcare advice
• Urine samples and vulvovaginal swabs
• Contact tracing
• Opportunistic vs population based screening

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The CLaSS project

• 186 page document
• Based in Birmingham and Bristol
• Performed to address gaps in evidence regarding
  opportunistic screening
• 6 components
• Establishing prevalence in men and women in the
  general population
• Social research emotional and psychological
  effects of screening and partner notification
• Find the best screening test
• Partner notification best methods
• Case-control study cost-effectiveness
• Economic evaluation

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Details of the study

• Multicentre multidisciplinary series of studies
• Screening tests sent to eligible men and women
  via post
• Positive tests required a 2nd test and a 3rd 6
  weeks after Rx
• Questionnaires regarding anxiety, depression,
  self-esteem were sent to random subjects
• Comparisons of diagnostic tests in the lab with
  pooling of samples
• ve tests placed in RCT for partner notification
• Systematic review of economic evaluations
• Computerised models of spread of Chlamydia

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Results
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Results
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Results

• Chlamydia prevalence not significantly related to
  any demographic factors except number of new
  partners in the last 12 months
• 68.8 of 16-24 yr olds attended their general
  practice during the screening study
• Postal screening well accepted by the public
• Only mild anxiety whilst waiting for results in a
  few cases
• Poorer uptake rate when sample included
  vulvovaginal swab
• Cost per major outcome averted in screening
  annually for 8 years 27000. ? only 29000

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Results

• Contact tracing
• RCT comparing GUM based tracing with practice
  nurse
• Practice nurse method more accepted and 12.4-22
  more partners traced
• Best test
• Urine swab
• NAATs - gt90 sensitive for swabs and urine
• Pooling reduced number of tests by 50 but missed
  5-8 of positive specimens

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Conclusions

• Proactive screening is justified and accepted but
  poor uptake rates
• Opportunistic screening requires higher uptake
  rates
• Could use practice registers and central
  screening offices to maximise uptake
• Males should be more intensively targeted for
  screening
• Screening could increase health inequalities

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Conclusions

• Practice based contact tracing could be
  introduced
• Further research
• More research required into methods of detection
• RCT required into whether screening will
  significantly reduce adverse events
• More research and investment in health education
  and encouraging young males to participate

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References

• Low N, McCarthy A, Macleod J, Salisbury C,
  Campbell R, Roberts TE, et al. Epidemiological,
  social, diagnostic and economical evaluation of
  population screening for genital chlamydial
  infection. Health Technol Assess 200711(8)
• All new episodes seen at GUM clinics 1997-2006
  Health Protection Agency, July 2007
• MacLeod J et al. Coverage and uptake of
  systematic postal screening for genital Chlamydia
  trachomatis and prevalence of infection in the UK
  general population cross sectional study. BMJ
  2005330940-

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Questions??