Sexually Transmitted Infections

Sexually transmitted infections (STIs) are infections that are passed primarily from person to person during sexual activity. Many people delay seeking medical help for STIs because of embarrassment, but early diagnosis often prevents complications. Most STIs can be treated successfully with drugs.

The diseases covered in this section are grouped according to the type of organism that causes them. The first few articles discuss bacterial infections such as gonorrhoea. The protozoal infection trichomoniasis is then described, and the following articles deal with viral infections, such as genital warts. The final article looks at parasitic infestation with pubic lice.

Early treatment of STIs is essential because some, such as chlamydial infection, may cause infertility. Sexually active people who change their partners should have tests because some STIs may not cause symptoms, and many people are unaware that they have an STI. Syphilis, a progressive and once fatal disease, can now usually be fully cured if it is treated in its early stages. STIs such as genital herpes and genital warts can often recur. Some types of genital wart virus increase the risk of cancer of the cervix. Pregnant women with an STI must carefully follow their recommended treatment because STIs can pass to the baby during pregnancy or in the birth canal during childbirth.

HIV infection and AIDS and certain forms of hepatitis are viral infections that can also be transmitted by sexual contact.

The risk of contracting STIs can be reduced by using the safe sex practices, covered here and in detail elsewhere (see Sex and health).


Nongonococcal Urethritis

Chlamydial Pelvic Infection



Genital Herpes

Genital Warts

Pubic Lice

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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