Profile of Syphilis By Karley Delahoussaye Etiologic Agent: Treponema pallidum₁ Transmission: People transmit syphilis to each other directly through contact with a sore. The sores are known as chancres and can appear on the vagina, anus, in the rectum, external genitals, lips or in the mouth. Transmission commonly takes place during vaginal, anal, or oral sex. Syphilis can also be transmitted from an infected pregnant woman to the child.₁ Reservoirs: Humans, thus far. 9 General Characteristics of Microorganism: Treponemes are spirochetes: helically coiled; corkscrew-shaped cells. They are typically 6 to 15 µm long and 0.1 to 0.2 µm wide.₂ They move by means of endoflagella where the flagellar filaments are contained between the cell wall peptidoglycan and an outer membrane. When the filaments rotate, they cause the cell to move.₃ Treponema pallidum are Gram negative obligate internal parasites. They attach to the host s mucosal epithelium during intercourse. T. pallidum are microaerophilic chemoheterotrophs.₈ Key Tests for Identification: The definitive method for diagnosing syphilis is visualizing the spirochete via dark-field microscopy. Because this is a difficult method, blood tests are the more common method. There are two types; nontreponemal and treponemal tests. Nontreponemal (e.g., VDRL and RPR) tests are inexpensive and simple, however they are nonspecific to syphilis. They can produce false-positive results and must therefore be confirmed using a treponemal test. Treponemal tests (e.g., FTA- ABS, TP-PA, various EIAs, chemiluminescence immunoassays, immunoblots, and rapid treponemal assays) detect the antibodies specific to syphilis. These results can be problematic as well because treponemal antibodies are detectable for life, even after
treatment. Both the nontreponemal followed by treponemal algorithm and the treponemal followed by the nontreponemal algorithm are employed and interpreted depending on the circumstances of the patient.₁ Signs and Symptoms: Syphilis follows a progression of stages of variable length; the primary stage, secondary stage, and late/latent stage. The primary stage is the appearance of the chancre; a firm, round, painless bump at the site where the syphilis entered the body. They can be hard to find if they manifest in the anus or vagina and will heal regardless of treatment. Without treatment, however, the infection will progress. The secondary stage usually starts with a rash somewhere on the body. It is characteristically a rough, non-itchy, red rash on the palms or bottoms of the feet. Some rashes are faint and are unnoticeable. Condyloma lata are large, raised, gray lesions that may appear on the mouth or groin area. Other symptoms of the secondary stage include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue. Again, these symptoms will appear to heal without treatment, but will continue to progress without intervention. The latent stage occurs when the previous symptoms have disappeared and the person is exhibiting no signs or symptoms, the hidden stage. Latent syphilis is classified when the infection is younger than 12 months; the late latent stage when the infection lasts longer than 12 months and can last for decades. In about 15% of people who were not treated, syphilis can advance to the late latent stage where damage to internal organs occurs, paralysis, numbness, gradual blindness, and dementia can also occur. When syphilis invades the nervous system, it is referred to as neurosyphilis. Neurosyphilis can occur at any stage of the infection and includes ocular syphilis which leads to visual deterioration and potentially permanent blindness.₁ Historical Information: The first written records of an outbreak of syphilis in Europe occurred in 1494 or 1495 in Naples, Italy, during a French invasion. In 1530, the pastoral name "syphilis" (the name of a character) was first used by the Italian physician and poet Girolamo Fracastoro as the title of his Latin poem describing the ravages of the disease in Italy. It was also known historically as the "Great Pox". The causative
organism, Treponema pallidum, was first identified by Fritz Schaudinn and Erich Hoffmann in 1905. The first effective treatment (Salvarsan) was developed in 1910 by Paul Ehrlich, which was followed by trials of penicillin and confirmation of its effectiveness in 1943. Virulence Factors: Syphilis has three related surface adhesions: P1, P2, and P3 are peptides on the outer membrane. They bind to the receptor s surface protein fibronectin although it is not yet clear whether this is totally for the attachment to the host or if the spirochete coats itself in the fibronectin to avoid the host s defenses.₆ Syphilis does not display more common virulence factors such as a capsule, M-proteins, fimbriae, antigenic variation or enzymes. They do have a unique physical feature in that they have much fewer membrane-spanning proteins than other typical Gram negative bacteria. These special membrane-spanning proteins are called TROMPs and represent the potential for surface-dependent virulence factors of the host s defenses.₇ Control/Treatment: Syphilis is easy to treat in the early stages with antibiotics. A single intramuscular injection of penicillin is effective in persons with primary, secondary and early latent syphilis. Three doses of long acting penicillin given at weekly intervals is recommended for people with late latent syphilis. These treatments will kill the bacteria responsible but it will not repair damage to tissues already done.₁ Syphilis can be controlled using behavioral approaches including sex education, and pre- and post- test counselling, interventions targeted at key populations such as sex workers or men who have sex with men. The promotion of barrier methods like male and female condoms are effective.₅ Prevention/Vaccine Information: There is no vaccine to protect against syphilis. Consistent and correct use of condoms can protect against contracting the disease, however areas outside the barrier of the condom can have sores that allow transmission. The only way to completely prevent risk of infection is to abstain from sex or be in a mutually monogamous relationship with a partner that has been tested and is
not infected. Partner-based interventions including partner notification can be effective in preventing the spread of syphilis. Local cases: Texas reported 1,475 cases of primary or secondary infection in 2013. In 2013, Travis county had a rate of greater than 2.2 cases of primary or secondary syphilis per 100,000 people. That same year, Texas reported 75 cases of congenital syphilis.₄ Global cases: According to the world health organization, there were a 12 million new cases of syphilis worldwide in 1999. There were 10.6 million new cases worldwide in 2008. 10 References: 1. Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, and Centers for Disease Control and Prevention. "Syphilis - CDC Fact Sheet (Detailed)." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 02 Nov. 2015. Web. 28 Apr. 2016. http://www.cdc.gov/std/syphilis/stdfact-syphilis-detailed.htm 2. Radolf, Justin D. "Treponema." Treponema. U.S. National Library of Medicine, n.d. Web. 28 Apr. 2016.http://www.ncbi.nlm.nih.gov/books/NBK7716/ 3. odar, Kenneth, Ph.D. "Mechanisms of Bacterial Pathogenicity." Mechanisms of Bacterial Pathogenicity. Online Textbook of Bacteriology, n.d. Web. 28 Apr. 2016. http://textbookofbacteriology.net/pathogenesis_3.html 4. Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, and Centers for Disease Control and Prevention. "Texas 2013." Centers for Disease Control and Prevention. N.p., 6 Feb. 2015. Web. 5 May 2016. http://www.cdc.gov/std/syphilis2013/tx13.pdf 5. "Sexually Transmitted Infections (STIs)." World Health Organization. N.p., Dec. 2015. Web. 05 May 2016. http://www.who.int/mediacentre/factsheets/fs110/en/ 6. Kenneth Todar, Ph. D. "Some Specific Bacterial Adhesins and Their Receptors." Todar's Online Textbook of Bacteriology. N.p., 2012. Web. 09 May 2016.http://textbookofbacteriology.net/pathogenesis_3.html
7. Lovett MA., Miller JN, and Blanco DR. "Surface Antigens of the Syphilis Spirochete and Their Potential as Virulence Determinants."Pubmed.gov. N.p., Jan. 1997. Web. 09 May 2016.http://www.ncbi.nlm.nih.gov/pubmed/9126440 8. Edited by Jasmin Eshragh, Student of Rachel Larsen at UCSD. "Treponema Pallidum." Microbewiki. Kenyon College, 22 Apr. 2011. Web. 9 May 2016.https://microbewiki.kenyon.edu/index.php/Treponema_pallidum 9. R. W. Peeling, and D. C. W. Mabey. "Disease Watch Focus: Syphilis." TDR For Research on Diseases of Poverty. World Health Organization, n.d. Web. 9 May 2016.http://www.who.int/tdr/publications/disease_watch/syphilis/en/ 10. "Global Incidence and Prevalence of Selected Curable and Preventable Sexually Transmitted Infections- 2008." (n.d.): n. pag. WHO.int. 2012. Web. 9 May 2016.http://apps.who.int/iris/bitstream/10665/75181/1/9789241503839_eng.pdf