Anorectal symptoms and anorectal STIs are prevalent among men who have sex with men, female sex workers, transgender people and heterosexual women who engage in anal sexual intercourse.
11.1. Anatomical sites of infection
Infections of the anorectal region can be divided into the following anatomical sites:
anal infections: infections of the anus and perianal area involving the stratified squamous epithelium – a common site for pathogens such as HPV, HSV and syphilis;
proctitis: infections from the dentate line to the rectosigmoid junction – a common site for gonococcal and chlamydial infections and HSV (the dentate line is the line between the simple columnar epithelium of the rectum and the stratified epithelium of the anal canal, usually defined as being at the level of the anal valves; and
proctocolitis: infections of the rectum and colon – a common site for infections with Shigella, Campylobacter, Salmonella and cytomegalovirus and amoebiasis.
For syndromic diagnosis and management, these infections have been grouped under anorectal infections. Anorectal infections may be associated with anorectal pain, itching, discharge, bleeding, sensation of rectal fullness, tenesmus, constipation and mucus streaking of stools.
Asymptomatic anorectal infections are not uncommon, although precise data are scarce. The people at highest risk of asymptomatic anorectal infections are men who have sex with men, male and female sex workers, transgender people and women who have had receptive anal intercourse with men with STIs.
11.2. Sexual practices that may be associated with anorectal infections
Specific high-risk sexual behaviour associated with anorectal infections include receptive anal sex, oro-anal contact (anilingus or rimming), fisting (inserting a hand into the rectum or vagina), fingering (touching another’s genitals or anus using fingers or digital-vaginal penetration), nudging (unprotected penile-anal external contact without penetration), dipping (partly inserting or briefly inserting the penis into the anus without a condom, followed by immediate withdrawal) and sharing sex toys.
11.3. Examination
An examination for anal infections includes an external examination of the anus and, where available, an anoscopy. In asymptomatic infections, anoscopy can be performed, possibly with Gram-stained smear and a count of the number of polymorphonucleated leukocytes to screen for STIs. However, an anoscope is not available in most primary point-of-care settings, and an external examination may be the only practical procedure to observe a discharge, ulcers or external warts.
Although an anoscopic examination can be used to take samples for Gram-stained smear for N. gonorrhoeae and for leukocytes, as well as for culture of N. gonorrhoeae, samples for nucleic acid amplification tests for Chlamydia and dark-field microscopy for T. pallidum, the performance of such tests on rectal specimens is not well established. However, some test kits have been licensed for use on rectal specimens. Little or no data exist to validate using microscopy in diagnosing anorectal infections.
In many low- and middle-income countries, male and females sex workers have similar rates of anorectal infection (70–72). A more practical approach in such a situation might be periodic presumptive treatment for high-risk men or presumptive treatment at the first visit, but there is limited experience with the outcomes of such an approach in anorectal infections for both men and women.
Given the limited data and information on both symptomatic and asymptomatic anorectal infections, the providing care for people with STIs associated with anorectal infections requires close supervision and research, especially in populations at high risk of infection. Research is also needed to validate laboratory tests on rectal specimens and to validate the treatment choices for anorectal infections.
Knowledge of the prevalence of asymptomatic, seroreactive syphilis infection among men who have sex with men can be helpful in adapting the flow chart to include syphilis treatment for those at high risk of infection and for those with ulcerative disease.
11.4. Recommendations for the management of anorectal discharge
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For people with symptom of anorectal discharge and report receptive anal sex, WHO recommends management based on the results of quality-assured molecular assays. However, in settings with limited or no molecular tests or laboratory capacity, WHO recommends syndromic treatment to ensure treatment on the same day of the visit. |
(Strong recommendation; moderate-certainty evidence)
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Good practice includes:
taking a medical and sexual history and assessing the risk of STIs; performing a physical examination of the genital and perianal areas and a digital rectal examination, if acceptable (and anoscopy, if available and acceptable); offering HIV and syphilis testing and other preventive services as recommended in other guidelines; and referring for other investigations when anorectal discharge is unrelated to a sexually transmitted infection, such as other gastrointestinal conditions.
| Good practice statement |
Settings with quality-assured molecular testing in a laboratory with a fully operational quality management system and results available on the same day of the visit WHO recommends the following.
Perform molecular assays (NAAT) using a self-collected or clinician-collected anorectal swab to confirm or exclude infection with N. gonorrhoeae and/or C. trachomatis and treat the individual infections detected. Treat, additionally, for herpes simplex virus if there is anorectal pain. Follow the genital ulcer guidelines if ulceration is present.
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(Strong recommendation; moderate-certainty evidence)
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Settings in which same-day treatment is not feasible with molecular testing or with limited or no molecular testing WHO suggests the following.
Treat for N. gonorrhoeae and C. trachomatis if discharge is present. Treat, additionally, for herpes simplex virus if there is anorectal pain.
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(Conditional recommendation; moderate-certainty evidence)
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Good practice includes:
following the genital ulcer guidelines if ulceration is present; and referring people with persistent anorectal discharge to a centre with laboratory capacity to diagnose N. gonorrhoeae, C. trachomatis (including lymphogranuloma venereum serovars) and M. genitalium and determine antimicrobial resistance for N. gonorrhoeae and M. genitalium.
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Good practice statement
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Flow chart for the management of anorectal discharge. NG, N.gonorrhoeae; CT, C. trachomatis; MG, M. genitalium.
11.4.1. Evidence summary (Annex 7)
These recommendations were informed by evidence that was of moderate certainty from a systematic review of the sensitivity and specificity of using syndromic management based on anorectal discharge to diagnose N. gonorrhoeae and/or C. trachomatis (supplementary materials – systematic review anorectal discharge). When available, performing molecular assay tests for N. gonorrhoeae and C. trachomatis as well as C. trachomatis (serovars L1, L2 and L3) causing lymphogranuloma venereum and M. genitalium and basing treatment on these results leads to the most people treated correctly. If the previously recommended syndromic management algorithm was used for 100 people with anorectal discharge in which 20–50% would typically have N. gonorrhoeae or C. trachomatis (with 32% sensitivity and 82% specificity), then 9–15 would be falsely identified with N. gonorrhoeae or C. trachomatis and unnecessarily treated and 14–34 would be missed. The previously recommended algorithm is based on assessment of risk, anorectal pain and discharge. The Guideline Development Group agreed that the numbers of cases missed using syndromic management means many people would continue to harbour the infections, which would increase the risk of transmission to others and the risk of acquiring and transmitting HIV. Instead, when molecular assay tests are not available, although the number of people treated unnecessarily would be high, if everyone with anorectal discharge were treated for N. gonorrhoeae or C. trachomatis, no cases would be missed.
Managing people presenting with anorectal discharge based on a syndromic approach results in minor benefits and moderate harm compared with molecular testing or treating everyone. Molecular testing may not be feasible in all settings and, alternatively, treating everyone would be feasible and the costs would be negligible.
11.5. Treatment recommendations for anorectal infections
In implementing a flow chart for managing people with anorectal infections, the following should be considered:
establishing that the person engages in anal sex;
differentiating between anorectal infection and other disease; and
thresholds for adding treatment for HSV, lymphogranuloma venereum or syphilis.
The choice of medicines, dosage and duration of treatment do not generally differ from those for infections at other anatomical sites. summarizes treatment options for anorectal infections.
Generally, the following syndromic treatment of symptomatic people is recommended: for chlamydia, doxycycline 100 mg twice daily for seven days (extended to 21 days to cover lymphogranuloma venereum if NAAT is positive for C. trachomatis) or azithromycin 1 g at once (25) plus ceftriaxone 250 mg intramuscularly or cefixime 400 mg orally as single doses for gonorrhoea, and with acyclovir, valaciclovir or famciclovir for HSV infection (27), if indicated.
If ulcerations are seen, treatment should follow the flow chart for genital ulcers as well and consider managing the person for syphilis and/or lymphogranuloma venereum.
Treatment options for people with anorectal discharge.