Sexually Transmitted Diseases (STDs) of the anus are caused by a wide range of microorganisms. The possibility of STI (Sexually Transmitted Infection) should be seriously taken into consideration both in men having sex with men (MSM) and in those who have anal sex. STDs are common in HIV-positive men because the immunosuppression caused by HIV-infection facilitates the development sexual related pathogens. Infections without any symptoms are common after the anal intercourse. An asymptomatic infection by HPV is common in MSM and its incidence reaches up to 90% in HIV-positive men.
The most common manifestation of a STD is the anal and perianal inflammation (proctitis). The proctitis is manifested with:
- pain in the anus
- constipation and a feeling of an incomplete defecation
- liquid discharge (purulent or bloody)
- tenesmus (continuous tendency to defecate).
The most frequent causes of a proctitis in MSM are gonococcus (30%), chlamydia (19%), herpes (16%) and syphilis (2%). In a significant percentage, the infectious agent is not always found. If proctocolitis appears (when the infection spreads to the intestine), then the symptoms are:
- bloody stool
- pain in the low abdomen
- Sense of incomplete evacuation.
Most frequent infective agents related to proctocolitis are Shigella, Campylobacter, Salmonella, CMV and amoeba.
HPV (one of the most important infections), molluscum contagiosum, and Haemophilus ducreyii are also included in STDs. Moreover, HIV infection and Hepatitis (A and B) are also frequent among the people who practise anal sex.
Prevention of infections
Men and women with anal penetration need yearly tests for HIV, hepatitis B, syphilis, chlamydia, and gonococcus.
In addition, in people who practise sex with multiple partners or when at the same time there is also use of illicit substances or drugs, STD diagnostic tests should be repeated with greater frequency. Furthermore, the patient has to be checked regularly with anal cytology or even better with high resolution anoscopy for possible anal dysplasia and warts, caused by HPV (usually every three years or every year if an HIV infection co-exists). Of course, necessary precautions during the anal intercourse should always be taken.
The 9-valent vaccine for HPV virus is considered to be essential for both men and women.