A bacterial infection initially affecting the genitals that, left untreated, can damage other parts of the body years later

  • Can affect sexually active people of any age
  • Unprotected sex with multiple partners is a risk factor
  • Gender and genetics are not significant factors

Syphilis is caused by the bacterium Treponema pallidum. This organism enters the body through the mucous membranes of the genital area or the skin. Left untreated, the disease may be fatal.

Syphilis was once a widespread disease throughout the world but became less common with the introduction of penicillin in the 1940s. Today, it rarely reaches its most advanced stage. A rise in incidence in homosexual men in the 1960s and 1970s was reversed by safe sex practices to combat HIV in the 1980s. The incidence fell very low, but has since risen again, from about 140 new cases in 1995 to about 2,500 new cases in 2008.

A pregnant woman with syphilis can pass the disease to the fetus, causing it to develop congenital syphilis (see Congenital infections). However, screening during pregnancy has now made congenital syphilis very rare.

What are the symptoms?

The symptoms of syphilis develop in three stages. The primary and secondary stages are infectious for up to 2 years. The tertiary stage is not infectious.

Primary stage

Within 1–12 weeks of infection, the following may develop:

  • Hard, painless, and highly infectious sore known as a chancre. The chancre usually appears on the penis or vulva but may occur in the mouth or rectum as a result of oral or anal sex.

  • Painless enlargement of the lymph nodes in the groin or neck.

The chancre may go unnoticed and disappears after 1–6 weeks.

Secondary stage

About 6–24 weeks after the appearance of the chancre, the following symptoms may develop:

  • Nonitchy, infectious rash over the whole body, including the palms of the hands and soles of the feet.

  • Thickened, grey or pink, moist, wartlike patches in the skin folds of the genitals and anus.

  • In rare cases, patchy hair loss.

  • Fever and tiredness.

  • Headaches and muscle pain.

After about 4–12 weeks, these symptoms disappear, and the disease then enters a symptomless stage of indefinite length.

Tertiary stage

Some people remain without further symptoms for the rest of their lives. However, if treatment is not given, tertiary syphilis may develop 10–20 years after the initial infection. The symptoms vary and may include changes in personality; mental illness; meningitis; tabes dorsalis (destruction of the spinal cord), which causes weakness and difficulty in walking; and aortic aneurysm.

What might be done?

If you think you or your partner has syphilis go to a clinic specializing in STIs or consult your doctor. In the primary stage, you may have a swab of the chancre taken for microscopic examination. Diagnosis of both primary and secondary syphilis may be confirmed by a blood test. At the same time you will probably be tested for other STIs. If tertiary syphilis is suspected, a lumbar puncture may be carried out to look for antibodies to the bacterium in the cerebrospinal fluid.

Syphilis is treated with injections of antibiotics. In the primary or secondary stages, treatment usually results in complete recovery. Damage due to tertiary syphilis may be permanent.

Can it be prevented?

The risk of contracting syphilis is reduced by taking safe sex measures (see Preventing STIs). If you have the disease, or your partner has it, avoid sexual contact until you have both finished your treatment and your doctor confirms that you are free of infection.

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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