A sexually transmitted disease is one that is passed from one sexual partner to another. It is most commonly associated with penetrative intercourse but may be passed through oral sex as well. Transmission can be divided into groups.

Viral infections

Acquired immuno-deficiency syndrome (AIDS) is transmitted by passing the human immunodeficiency virus (HIV). Herpes around the genitals is caused by herpes simplex type 2, and the human papillomavirus (HPV) causes warts. These are all discussed in their own sections.

Bacterial infections

The better-known bacterial infections are syphilis and gonorrhoea. These are stored in some part of the urogenital system and transmitted through associated fluid. Bacterial infections from other parts of the body, such as the bowel, may also be transmitted by the act of intercourse. Vaginal, uterine and bladder infections are commonly caused by a bacterium known as Escherichia coli, which thrives in the bowel and is part of the normal bowel flora. If this bacterium finds its way into another organ, it can be quite devastating and produces very unpleasant symptoms.

Other infections

Some organisms behave more like parasites, existing within cells in the same manner as viruses but also behaving like bacteria in their metabolism. Chlamydia and Trichomonas are commonly found in association with non-specific urethritis (NSU) and typically spread by sexual intercourse.

Pubic lice, or crabs as they are colloquially known, are generally spread through sexual intercourse.

Candidal infection, most commonly known as thrush, is typically spread through sexual intercourse.

Safe sex

Safe sex is a phrase that has been coined since the rise of HIV/AIDS. It is an extremely accurate definition and it is becoming more relevant as Western societies become less critical of sexual promiscuity. This attitude is pervading the so-called Third World countries where unprotected sex is more common than not because of the lack of availability of condoms. Add to this an apparent increase in homosexual activity and the use of anal intercourse in poorer nations as a form of contraception and you have several reasons why the importance of practising safe sex is increasing. There is some controversy as to whether oral sex is safe sex. Vigorous oral activity that produces small cuts or lesions will allow the transmission of infective agents. Bacterial infections such as gonorrhoea and syphilis are known to transfer from male ejaculate causing throat and tonsillar problems, as does Candida (thrush). It is unlikely that HIV will transfer in this way but the possibility cannot be excluded. The herpes simplex type 2 virus (genital herpes) prefers to live in tissue other than that found around the oral cavity. However, in rare instances transmission can occur and it is best to avoid unprotected oral sex if a herpetic lesion is visible.

All of the above conditions are discussed in their relevant sections.

All sexually transmitted disorders are best treated by avoidance. Sexual promiscuity should be reduced and safe sex practised.

Maintaining hygiene and a personal high level of immune system activity will decrease the risk of transmission and encourage any infection to be destroyed effectively.

The use of drugs and alcohol reduces the immune system response and, in conjunction with sexual promiscuity, will increase the risk of an infection taking hold. Keep ‘abuse’ to a minimum.

The use of a condom is effective against diseases which are vaginally transferred or carried in the semen.

Anal intercourse and vigorous vaginal or oral sex will predispose to small (or large) lesions into which infected agents may travel directly into the bloodstream. Avoid these techniques or be gentle and use adequate amounts of lubrication.

Wash the genitals before and after intercourse where possible.

Urinate after intercourse when possible.