Syphilis is transmitted by bacteria during sexual intercourse. For a long time numbers of new infections in the Western industrial countries were on the decline. However, the infection rate has recently begun to rise again.

Sex tourism and neglect of the rules of safer sex have contributed significantly to this increase.

Congenital syphilis can also occur if a mother infects the child via the placenta before birth. The infection can also be passed on to the child by direct contact during birth.

Symptoms and signs

Syphilis has a number of different stages.

About three weeks after infection a painless, hard ulcer (hard chancre), which often goes unnoticed, develops at the site of entry of the pathogen. This stage is known as primary syphilis. The ulcer usually develops on the genitals, e.g. on the labia, in the vagina or on the penis. After oral sex the ulcer can also develop in the mouth or the throat, after anal sex in the rectum.

The local lymph nodes become enlarged within about a week. The ulcer heals after 2 to 6 weeks even without treatment. Because it causes no pain, an ulcer on an inaccessible part of the body is easily overlooked. Therefore syphilis frequently goes untreated at this early stage.

The next stage is secondary syphilis. The bacteria can spread to the entire body via the lymphatic channels and blood vessels producing a wide range of symptoms. Typical features are generalized lymph node enlargement and local or generalized rash on the skin and mucous membranes (crops of pale to brown-red spots). Frequent general symptoms are fever, loss of appetite and headaches.

Primary and secondary syphilis heal even without treatment.

After an interval of several years with no symptoms (latent syphilis) tertiary syphilis develops with severe neurological symptoms (damage to the nerves and the central nervous system), heart and bone changes and involvement of the internal organs.

Neonates with congenital syphilis are underweight and have an enlarged spleen and liver. The symptoms of congenital syphilis are the same as those of secondary syphilis in adults. Characteristic features are syphilitic rhinitis (snuffles) and a saddle-shaped nose. Symptoms of tertiary syphilis can occur as early as age three. These include tooth defects and deafness. Manifest tertiary syphilis develops from age 10 onwards.

Diagnosis

The course of the disease and the symptoms allow the doctor to determine which stage of syphilis is present.

In the primary stage the bacteria can be detected in a smear taken from the ulcer. Detection of antibodies in the blood can also contribute to diagnosis of syphilis. In advanced illness it may be necessary to obtain a sample of spinal fluid to determine whether the infection has already spread to the central nervous system.

Prevention and treatment

The best protection against syphilis is safer sex.

The disease is usually treated with penicillin or alternative antibiotics. It can be cured if treatment is started early enough.

Sexual partners should always be treated as well in order to prevent late complications and spread of the infection.