A sexually transmitted or CONGENITAL disease (the latter variety is now rare). Because in most cases the disease is acquired as a result of sexual intercourse with an infected individual, syphilis is classed as one of the SEXUALLY TRANSMITTED DISEASES (STDS). It normally affects only human beings.
Today, around 40 million new cases are noti?ed annually in the world, and this is probably an underestimate. In the UK the annual incidence of new cases of syphilis diagnosed in NHS genito-urinary medicine clinics has risen from 8.8 to 9.7 per million of male population between 1991 and 1999; among women the ?gures were 4.0 to 4.5 per million. The infection is most common in homosexual men (see HOMOSEXUALITY).
Causes The causative organism is the Treponema pallidum, a long, thread-like wavy organism with pointed tapering ends. It is found in large numbers in the sores in the primary stage of the disease and in the skin lesions in the secondary stage.
Syphilis may be acquired from people already suffering from the disease, or it may be congenital. The acquired form is usually got by sexual intercourse, kissing or other intimate bodily contact. The epithelium covering the general surface of the skin seems to be an e?cient protection, but the infective material penetrates mucous membranes. The acquired form of the disease is infectious from contact with sores, both in its primary and secondary stages; infants suffering from the congenital form are also highly infectious. Accordingly, anyone frequently handling such an infant is at risk of infection, although the mother may handle the baby with impunity.
Symptoms The acquired form of the disease is commonly divided into three stages – primary, secondary, and tertiary (although the latter is much less common than it was 50 years ago). The clinical manifestations are varied and are sometimes confused with those of other diseases. There are several laboratory tests for con?rming the diagnosis.
The incubation period ranges from ten to 90 days, although most frequently it is around four weeks. Then, a small persistent ULCER appears at the site of infection, which is accompanied by a typical cartilaginous hardness of the tissues immediately around and beneath it. This, which is known as the primary sore (or chancre), may be very much in?amed, or it may be so small as to pass almost or quite unnoticed. A few days later, the lymphatic glands in its neighbourhood, and then those all over the body, become swollen and hard. This condition lasts for several weeks before the sore slowly heals and the glands subside. After a variable period – usually about two months from the date of infection – the secondary symptoms appear and resemble the symptoms of an ordinary FEVER, with pyrexia, loss of appetite, vague pains through the body, and a faint red rash seen best upon the front of the chest. People with syphilis are infectious in the primary and secondary stages but not in the latent or tertiary stages.
In untreated or inadequately treated cases, manifestations of the tertiary stage develop after the lapse of some months or even years: this is known as the latent period. These consist in the growth, at various sites throughout the body, of masses of granulation tissue known as gummas. These gummas may appear as hard nodules in the skin, or form tumour-like masses in the muscles, or produce thickening of bones. They may develop in the brain and spinal cord, where their presence causes very serious symptoms. Gummas yield readily, as a rule, to appropriate treatment, and generally disappear speedily.
Still later, effects are apt to follow, such as disease of the arteries, leading to ANEURYSM (see also ARTERIES, DISEASES OF), to STROKE, and to mental deterioration (see MENTAL ILLNESS); also certain nervous diseases, of which tabes dorsalis and general paralysis are the chief.
The congenital form of syphilis, now rare, may affect the child before birth, leading then as a rule to miscarriage or to a stillbirth if born at full time. Alternatively he (or she) may show the ?rst symptoms a few weeks after birth, the appearances then corresponding to the secondary manifestations of the acquired form.
Laboratory con?rmation of a clinical diagnosis is done by identifying active spirochaetes (see SPIROCHAETE) in a smear taken at the site of the initial chancre, and by blood tests such as the treponomal antibody absorption tests. These tests are strongly positive at the secondary stage, and in patients with neurosyphilis the tests may have to be done on CEREBROSPINAL FLUID.
Treatment Any person with syphilis is a source of infection, and should take precautions not to spread it. PENICILLIN is the drug of choice in the disease in all its stages, but resistant strains of the Treponema pallidum have emerged and are causing problems, especially in developing countries. Treatment must be instituted as soon as possible after infection is acquired: (1) a full course of treatment is essential in every case, no matter how mild the disease may appear to be; (2) periodic blood examinations must be carried out on every patient for at least two years after he or she has been apparently cured.
Prevention is important and promiscuous hetero- or homosexual intercourse involves a risk of infection. Condoms provide some, but not complete protection. Infection can be avoided by maintaining a monogamous relationship.... syphilis
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