The bacterium Treponema pallidum pallidum is a spirochetal bacterium that is the cause of syphilis. T. pallidum pallidum is a spirochete it can range from 6 to 20 um in length and 18 to 20 um in diameter it requires low amounts of oxygen which it is able to draw from the atmosphere around it. Spirochetes are usually Gram negative but T. pallidum pallidum will not show up on a gram stain because the organism is too thin. It can however be detected using special stains such as the Dieterle stain.

Spirochetal bacterium have long helical shaped cells the reason for the helical shape if because of the different arrangement of the axial filaments which is known as endocellular flagella the filaments run the length of the cell causing the spiral shape, these flagella are used to move the spirochete. Spirochetes are usually found in liquid environments such as blood, lymph or water. (Encyclopedia Britannica 2010.)

The disease that is caused by T. pallidum pallidum is Syphilis; syphilis is usually a sexually transmitted disease though it can be passed in several other ways such as from mother to child.

Syphilis can present in four different forms, Primary, Secondary, Latent and Tertiary. These forms of syphilis all present with different symptoms and they all progress from each other.

Primary syphilis is the first stage of the infection this is where a sore or Chancre (possibly more than one) appears at the site of the infection, it is small and white and usually painless this usually heals in 2 to three weeks.
(18/11/2010, http://www.nlm.nih.gov/medlineplus/ency/article/000861.html, Website)

The symptoms of the secondary stage of syphilis are a skin rash and mucus lesions, the rash usually appears first in one or more places on the body usually the palms of the hands and the soles of the feet. The rash can appear as the chancre is healing or two to six weeks after. The rash appears as rough red or reddish brown spots that do not itch but in some cases a different rash can occur on different parts of the body. There can be more severe symptoms of secondary syphilis such as lymph gland swelling, patchy hair loss, weight loss and fatigue but these are rarer. The symptoms of secondary syphilis also disappear without treatment but once again the infection will not heal without treatment.
(18/11/2010, http://www.nlm.nih.gov/medlineplus/ency/article/000854.htm, website)

After the second stage the infection will enter the latent phase in which there are no symptoms this stage can last anywhere from 1 year to 50 years without progression or recovery. If a person is infected with latent stage syphilis then there is only around a fifty percent chance that it will progress into tertiary syphilis the remaining fifty percent will either stay in the latent stage or the body will fight off the infection.

Tertiary syphilis is identified by the formation of gummas or granulomas these can appear anywhere on the body, these granulomas are chronic and can cause a chronic inflammatory response which can severely alter the physical appearance of the person.

In other cases the tertiary syphilis can infect the heart and become cardiovascular syphilis or it can infect the brain and become neurosyphilis.
Cardiovascular syphilis causes complications such as, syphilitic aortitis, aortic aneurysm, aneurysm of sinus of valsalva and aortic regurgitation. After years of infection and after one of these conditions become apparent heart failure may be a possibility. If the infection presents in the coronary arteries it causes narrowing of the blood vessels which in turn leads to de Musset’s sign which is bobbing of the head mirroring the heartbeat
(Sapira, 1981)

Neurosyphilis is where the infection involves the central nervous system, this can occur at any stage of the infection. Nearly 40 percent of people with secondary stage syphilis present wth some central nervous symptoms.
There are four types of neurosyphilis, asymptomatic neurosyphilis, meningovascular syphilis, general peresis and tabes dorsalis. The last two are very rarely seen since most cases of syphilis are diagnosed and treated before the condition reaces that satge.
Meningovascular syphilis can occur anywhere from 4 moths to ten years after infection and symptoms range from headaches and insomnia to personality changes.
(Jamess, 2002)

Syphilis is a sexually transmitted disease. Syphilis is spread when contact is made with syphilis sore or chancre, these are usually near the genitals, anus or lips though in rare cases they can be elsewhere. As the syphilis bacteria is fragile it is not passed through unbroken skin but as the skin is thinner around the genitals and lips it is easier to become infected in those areas, contact with broken skin will also cause infection.
(20/11/2010, http://www.dhpe.org/infect/syphilis.html, website)

Syphilis can be detected in numerous ways these include, Dark-field microscopy, Nontreponemal tests and Treponemal-specific tests
Dark-field microscopy is the test used when there are obvious symptoms of syphilis such as a chancre. The test involves the chancre being cleaned and then abraded so there is some fluid forming on it, this fluid is the put on a slide and examined under a microscope with a dark-field condenser fitted, the helical spirochetes should be visible.
(Larson, Steiner and Rudolph, 1995)

There are several Nontreponemal tests (called so because there is no use of the bacterium itself) such as the VDRL test and the Rapid Plasma Reagin test these are both flocculation type tests that use the antigen-antibody interactions to form complexes which the flocculate together to form a suspension which is then visible. These tests however can be unreliable during early primary syphilis and late tertiary syphilis.
(Luger, 1988) (Cummings et al, 1996)

Treponemal-specific tests use antibodies and antigens specific to T. pallidum pallidum, these tests are usually used when the Nontreponemal tests are inconclusive Treponemal-specific tests include the EIA for anti-treponemal IgG, the T. pallidum pallidum hemagglutination (TPHA) test, the microhemagglutination test with T. pallidum pallidum antigen, the fluorescent treponemal antibody-absorption test (FTA-abs), and the enzyme-linked immunosorbent assay. Treponemal-specific tests are not as specific as to the point of testing; they usually work regardless of stage, however they are expensive so are usually a last resort.
(Larson, Steiner and Rudolph, 1995)

Methods to control syphilis depend on the stage of the infection and the location of any sores. With primary syphilis depending on the location of the chancre use of condoms could prevent transmission but it is not guaranteed as if any contact is made transmission could occur, the easiest way to avoid transmission with primary syphilis is to avoid any possible contact completely.
Transmission can occur at any stage of syphilis transmission is most likely during the primary and secondary stages due to the external clinical symptoms but transmission can occur in the early latent phase and can but is less likely to occur in the late latent phase. Transmission in the latent phase is due to the presence of the bacterium in the bodily fluids that are passed during unprotected sex of any nature.

Transmission can occur between a mother and an unborn child if the mother is infected or becomes infected while pregnant, infection is usually fatal to infants.
(20/11/2010, http://syphilis.emedtv.com/syphilis/syphilis-transmission.html, website)

Syphilis is a well documented disease that has been known for centuries, it has gained a high profile due to several high profile historical figures either having syphilis or having died from it. The symptoms of syphilis can be easily mistaken for many other diseases and infections such as Flu or the common cold which has led to syphilis being dubbed ‘the great imitator’ late stage syphilis is more recognizable due to disfiguration caused in certain sufferers.
Syphilis was documented in 1494 during the siege of Naples by the French due to Spanish mercenaries that had carried it over from the new world where modern scientists believe it to have originated in a non venereal form. Once reaching Europe where the population had no immunity the disease ran rampant becoming one of the main causes of death in renascence Europe. In modern times the advent of superior diagnostic methods and the use of antibiotics has dramatically reduced the lethality and abundance of syphilis in the modern world.

References:

Cummings MC, Lukehart SA, Marra C, Smith BL, Shaffer J, Demeo LR, et al. Comparison of methods for the detection of Treponema pallidum in lesions of early syphilis. Sex Transm Dis. 1996;23:366–9.

Larsen SA, Steiner BM, Rudolph AH. Laboratory diagnosis and interpretation of tests for syphilis. Clin Microbiol Rev. 1995;8:1–21.

Linda Vorvick, MD, Seattle Site Coordinator, Maternal & Child Health Lecturer 8/1/2008, Primary syphilis http://www.nlm.nih.gov/medlineplus/ency/article/000861.htm Linda Vorvick, MD, Seattle Site Coordinator, Maternal & Child Health Lecturer 8/1/2008, Secondary syphilis http://www.nlm.nih.gov/medlineplus/ency/article/000854.htm secondary syphilis

Luger AF. Serological diagnosis of syphilis: current methods. In: Young H, McMillan A, eds. Immunological diagnosis of sexually transmitted diseases. New York: Dekker, 1988:250–9.

Richard B. Jamess, MD, PhD (2002). "Syphilis- Sexually Transmitted Infections, 2006.". Sexually transmitted diseases treatment guidelines.

Sapira JD (April 1981). "Quincke, de Musset, Duroziez, and Hill: some aortic regurgitations". South. Med. J. 74 (4): 459–67. PMID 7013091.

spirochete." Encyclopædia Britannica. 2010. Encyclopædia Britannica Online. 25 Nov. 2010

syphilis http://www.dhpe.org/infect/syphilis.html

syphilis transmission , http://syphilis.emedtv.com/syphilis/syphilis-transmission.html