Screening Women for Rectal Chlamydia and Gonorrhea: More Questions than Answers?

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Screening Women for Rectal Chlamydia and
Gonorrhea More Questions than Answers?

• Susan S. Philip MD, MPH
• Medical Director, San Francisco City Clinic
• San Francisco Department of Public Health
• Assistant Clinical Professor of Medicine
• University of California, San Francisco

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What are the Questions?

• How prevalent are rectal chlamydia (CT) and
  gonorrhea (GC) infections in women?
• Can we predict which women are likely to be
  infected?
• What are the sequelae of rectal infections in
  women who do not report anal sex?

• What should be our recommendations for screening?

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What do we Know from Men?
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Prevalence of chlamydial and gonococcal
infections among MSM, - San Francisco, 2003
Urethral Infections
n5305 n783
n5283 n783
Rectal Infections
n3300 n492
n3300 n525
Pharyngeal Infections
n3300 n492
n3300 n525
Chlamydia
Gonorrhea
Kent, CK et al, Clin Infect Dis July 2005
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Proportion of asymptomatic rectal and urethral
chlamydial and gonococcal infection among MSM
San Francisco, 2003
Rectal Infections
Gonorrhea
Chlamydia
n316
n264
Asymptomatic
Urethral Infections
Symptomatic
Gonorrhea
Chlamydia
n315
n364
Kent, CK et al, Clin Infect Dis July 2005
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Proportion of chlamydial and gonococcal
infections missed if only urine/urethral
screening performed among MSM San Francisco,
2003
Gonorrhea
Chlamydia
n574
n574
Identified
Not Identified
Kent, CK et al, Clin Infect Dis July 2005
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Chlamydia and Gonorrhea are associated with
increased HIV infection rates
Odds ratio for HIV infection (compared to no STD)
Women 2-6
MSM 3-5
Fleming and Wasserheit STI 1999
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Risk of recent HIV acquisition among MSM with
rectal infections San Francisco STD Clinic
2001 to 2004

• Incident HIV measured by STARHS
• RR rectal CT or GC 3.7 (2.2 6.4)
• RR rectal CT and GC 9.5 (4.4 20.6)
• Similar estimates if look at only asymptomatic
  rectal infections

Kent et al. 1st Intnatl Wkshp HIV Transmission
2006
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What is in the Literature?
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How common are rectal infections in Women?

• Primarily older studies with limitations
• STD clinic populations
• Selective testing (lapses, contacts, those
  reporting anal sex)
• Used older diagnostic tests (culture, IF), not
  nucleic acid amplification tests (NAATs)
• Gonorrhea 40-63 of women with GC had rectal
  infection in a 1977 review of 23 papers1
• Chlamydia Cervical prevalence 13, rectal 5 in
  101 consecutive new patients at a GUM clinic in
  Edinburgh2. Rectal prevalence 10 in another
  study from Liverpool3

1Klein 1977 2Thompson 1989 3Pratt 1989
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Other Aspects of Rectal Infections

• 3-7 had rectal infection without cervical
  infection1,2,4,5
• If infected with GC at both sites concordance
  between cervical and vaginal isolates 40-906,7
  (by antibiotic susceptibility testing, gel
  electrophoresis patterns, serologic typing)
• Reported anal sex varied from as low as 0 to as
  much as 40-50 in different studies1-3.

1Klein 1977 2Thompson 1989 3Pratt 1989
4Stansfield 1979 5Asbel Abstract 113 CDC STD
Prevention Conference 2006 6Coghill 1989 7Noble
1980
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Possible Explanations?

• Incomplete or inaccurate behavior reports
• Penile-anal contact other than anal sex
• Auto-inoculation via infected vaginal secretions

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City Clinic Study Methods

• Evaluation period March 2007-February 2008
• Convenience sample of 60 of female clinic
  patients (n3300) were asked about sex practices
  in the prior 3 months
• Chlamydia and Gonorrhea NAATs using vaginal swabs
  (Aptima Combo2, GenProbe Inc., San Diego CA) were
  offered to
• Any women lt30 years
• Contact to GC or CT (any age)
• Vaginal symptoms (any age)
• Clinician-collected rectal CT and GC NAATs were
  obtained from those women undergoing pelvic exam

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City Clinic Study Results

• Receptive anal sex in the prior 3 months reported
  by 14 of women (465/3300)
• Median age 26, 60 were nonwhite
• Women were positive for rectal GC at 1.8
  (15/801) of visits. The correlation with vaginal
  results was strong (r0.93, plt0.0001)
• Rectal CT was positive at 5.1 (42/818) of visits
  and had less correlation with vaginal results
  (r0.68, plt0.0001)

Pearson correlation coefficient
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Prevalence of Rectal GC by reported behavior
n756 visits
p0.007
Chi-square test
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Prevalence of Rectal CT by reported behavior
n762 visits
p0.14
Chi-square test
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Proportion of additional gonorrhea and
chlamydiacases identified by rectal testing
7
21
93
79
Gonorrhea n15
Chlamydia n42
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City Clinic Study Conclusions

• Rectal GC and CT were present in women who did
  not report anal sex
• Reported risk behaviors may not be helpful in
  guiding rectal testing in women, in contrast to
  men
• There was less correlation with vaginal NAAT
  results for rectal CT than GC
• The addition of rectal testing increased case
  finding for both GC and CT

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City Clinic Study Conclusions, continued

• The clinical implications of asymptomatic rectal
  CT and GC infections in women require further
  study
• We also do not yet know whether infection at
  multiple anogenital anatomic sites in women is
  associated with increased risk of subsequent
  reinfection, PID or other sequelae

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Next steps?

• Routine rectal testing in asymptomatic women has
  been discontinued at City Clinic due to uncertain
  clinical benefit and budget constraints
• We aim to review San Francisco morbidity data in
  our database to compare recurrent CT or GC
  outcomes in women who are infected at both sites,
  compared to those with cervico-vaginal infection
  only.

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Back to the Questions

• How prevalent are rectal gonorrhea (GC) and
  chlamydia (CT) infections in women?
• Depends on testing method
• Multiple studies with gt5 prevalence of either
  infection in female STD clinic attendees
• May be the only site of infection
• Can we predict which women are likely to be
  infected?
• Reported anal sex not accurate
• What are the sequelae of rectal infections in
  women who do not report anal sex?
• ???
• What should be our recommendations for screening?
• ????????

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Acknowledgements

• Jeff Klausner MD, MPH
• Kyle Bernstein PhD
• Robert Kohn MPH
• SF City Clinic Clinicians and staff
• City Clinic patients