Infection: Syphilis

Definition
Description
Demographics
Causes and Symptoms
Diagnosis
Treatment
Prognosis
Prevention
The Future
For more information

Definition

Syphilis is a sexually transmitted disease (STD) caused by a spiral-shaped bacterium, Treponema pallidum. It can be transmitted by an infected mother to her unborn child as well as by genital, oral, or anal sexual contact. Although the disease has been known for centuries, the organism that causes it was not identified until 1913. The discoverer was Hideyo Noguchi (1878–1928), a Japanese bacteriologist who was working at the Rockefeller Institute in New York as a research assistant.

Description

Syphilis was for many years one of the deadliest STDs, not only because there was no effective treatment for it before the twentieth century, but also because its symptoms are difficult to distinguish from those of other diseases. Syphilis was nicknamed the “Great Imitator” because it could be easily confused with leprosy, infectious mononucleosis, fungal infections of the skin, meningitis, genital herpes, lymphoma, and many other diseases.

To add to the diagnostic confusion, the symptoms of syphilis have changed somewhat since the first recorded European outbreak in 1494. French troops fighting in Italy were stricken with an STD that caused death within a few months. Medical historians think that this first epidemic, called the great pox to distinguish it from smallpox, was so severe because the disease was either new to Europe or that the spirochete that causes syphilis had mutated over the centuries. Some researchers hold that syphilis was brought to Europe by Columbus's sailors, while others maintain that skeletons from the Middle Ages found in both Italy and England show evidence of late-stage syphilis. In either case, syphilis as it is known in the twenty-first century is rarely fatal unless it is not treated.

Syphilis is a disease that attacks the body in stages:

• Primary syphilis: Acquired by direct sexual contact with an infected person, this stage usually appears after about ten days after the spirochete is transmitted, but can take several months to appear. Its major symptom is the chancre (pronounced SHANK-er), a painless skin ulcer that appears at the location of exposure to the bacterium, usually on the penis, anal area, or vagina. There may be one or several chancres. The patient may also develop swollen lymph nodes, but there are rarely any other symptoms in this stage. Chancres go away after about a week or two even if untreated, but the disease does not.
• Secondary syphilis: This stage develops about six to eight weeks after the primary infection. Its symptoms are the reason syphilis has been called the great pretender—they range from fever, loss of appetite, joint pains, and other flu-like symptoms to a reddish-pink skin rash, hair loss, headache, and swollen lymph nodes. The disease is most contagious in this stage.
• Latent syphilis: Also known as dormant syphilis, in this stage the patient may have no symptoms or occasional flare-ups of the symptoms of secondary syphilis. The patient is not usually infectious but will still test positive for the disease if given a blood test. A woman in this stage of syphilis can still transmit syphilis to her unborn child.
• Tertiary syphilis: Between a third and a half of patients with latent syphilis will progress to third-stage, or tertiary, syphilis. This stage can occur as early as one year after the initial infection or as late as fifty years afterward. It is marked by the development of gummas, large noncancerous tissue growths that may occur anywhere on the skin or inside the body, including the skeleton. Untreated tertiary syphilis, which is rarely seen in the 2000s, can lead to movement disorders, heart failure, dementia, and other disorders of the central nervous system. Patients with dementia caused by syphilis usually die within two to three years.

Demographics

Syphilis has been on the increase in the United States in recent years. The number of cases dropped after the introduction of penicillin as an effective treatment in the 1940s. In the 1980s, however, the number of cases began to rise again as a result of the growing use of crack cocaine and intravenous drugs, the exchange of sex for drugs, and the increase in the number of people with multiple sexual partners.

Dr. Hinton's Blood Test

The first modern treatment for syphilis, a drug containing a form of arsenic, was developed in Germany in 1908. Although not as effective as penicillin later proved to be, this useful drug prompted researchers to look for better ways to diagnose syphilis. In the early 1930s, a blood test more accurate than the previously accepted tests was developed by Walter Augustus Hinton (1883–1959), a graduate of Harvard Medical School and the first African American to become a full professor in any department at Harvard. Hinton, the son of two former slaves, acquired an international reputation as a public health expert in the prevention and treatment of syphilis.

Hinton's blood test was not only more accurate, but simpler and less expensive than former tests. It was officially endorsed as the diagnostic standard by the U.S. Public Health Service in 1934. In 1936 Hinton published the first medical school textbook written by an African American; it was on syphilis and its treatment. Hinton continued teaching at Harvard until 1950. After his retirement he worked as a staff physician at a hospital for crippled children in Canton, Massachusetts.

According to the Centers for Disease Control and Prevention (CDC), the number of reported cases of primary and secondary syphilis rose 12 percent between 2005 and 2006. In 2006, there were 36,000 cases of syphilis reported in the United States; most of these occurred in adults between the ages of twenty and thirty-nine. The rates for syphilis were highest in women twenty to twenty-four years of age and in men thirty-five to thirty-nine years of age. There were 349 cases of congenital syphilis reported in 2006. In the same year, 64 percent of the reported syphilis cases in males were among men who have sex with men (MSM).

The rates of syphilis vary in different parts of the United States. The CDC reports that half of all cases of syphilis in the country are found in twenty counties and two cities. Syphilis also disproportionately affects African Americans, who accounted for 41 percent of all cases of the disease in 2006.

Some people are at increased risk of becoming infected with syphilis:

• Men who have sex with men. The highest rates of syphilis in the United States as of 2008 were in this group.
• Those who are HIV-positive. About 50 percent of men diagnosed with syphilis since the early 2000s are also HIV-positive.
• People who drink heavily or use mood-altering drugs. These substances do not cause syphilis, but they do affect a person's ability to think clearly and practice safe sex.
• People who have many different sexual partners or have sex with strangers.

Causes and Symptoms

Syphilis is caused by Treponema pallidum, a bacterium that is usually transmitted by direct oral, anal, or vaginal contact with an infected person but can also be transmitted by an infected mother to her baby before birth. The bacteria can cross the mucous tissues lining the mouth and the genitals; they can also enter the body through a crack or break in the skin elsewhere on the body. In addition, the disease can be transmitted through transfusion with infected blood. Syphilis cannot be spread, however, through casual contact with toilet seats, doorknobs, swimming pools, hot tubs, bathtubs, shared clothing, drinking glasses, or food utensils.

As has been noted earlier, the symptoms of syphilis vary depending on the stage of the infection:

• Primary syphilis: one or more chancres, possibly swollen lymph nodes.
• Secondary syphilis: Skin rashes, flu-like symptoms, headache, loss of appetite, fever, fatigue.
• Latent (dormant) syphilis: Flare-ups of symptoms of secondary syphilis or no symptoms at all.
• Tertiary syphilis: Difficulty coordinating muscle movements, paralysis, numbness, gradual blindness, and dementia, possibly ending in death.

Diagnosis

Primary syphilis is diagnosed by taking a sample of chancre cells and sending it to a laboratory for examination under a microscope to look for Treponema pallidum. This test is also useful in distinguishing the spiro-chete that causes syphilis from those that cause Lyme disease or yaws, a tropical disease.

Blood tests are more effective in diagnosing secondary than primary syphilis. The two blood tests most commonly used as screeners are called the Venereal Disease Research laboratory Test (VDRL), and the rapid plasma reagin test (RPR). These tests work by showing the presence of antibodies stimulated by the bacteria in the patient's blood. Some other diseases, such as lupus, infectious mononucleosis, and rheumatoid arthritis can give a positive result on these tests, however. For this reason a patient who has a positive test result on either the VDRL or the RPR is usually given another test that is specific for T. pallidum.

Patients with tertiary syphilis have their cerebrospinal fluid checked periodically by a spinal tap in order to monitor the progress of treatment for the disease.

Treatment

Syphilis can be treated with a single injection of penicillin (or another antibiotic if the patient is allergic to penicillin) during its primary and secondary stages. Patients in the later part of the latency stage or those diagnosed with tertiary syphilis are given three injections of penicillin, each one week apart. Patients with tertiary syphilis that has affected the brain may require intravenous penicillin every four hours for ten to fourteen days.

Some patients, especially with secondary syphilis, have a brief reaction to treatment marked by fever, chills, and headache. This reaction is caused by the death of large numbers of spirochetes in a short period of time. It usually lasts only a day and can be treated at home with aspirin or acetaminophen.

Having syphilis does not make a person immune to it; it is possible to become reinfected with the disease after having been successfully treated for it.

People being treated for syphilis should not have sex with anyone until the doctor confirms that they are no longer infectious, which may take 2–3 months. The usual schedule for follow-up is blood tests at three, six, and twelve months after treatment to make sure that the spirochete has been

eliminated. Patients with tertiary syphilis should have repeat blood tests and tests of spinal fluid every six months for at least three years.

Prognosis

Antibiotic treatment for primary and secondary syphilis has a very high cure rate. As of 2008, there were no reports of penicillin-resistant strains of T. pallidum.

Untreated primary or secondary syphilis has a one in two or one in three chance of progressing to tertiary syphilis and possible death.

Prevention

Syphilis can be prevented by:

• Abstaining from sexual intercourse, or having sex with only one partner who is uninfected and faithful.
• Using latex condoms when having sex with someone whose health status is not known.
• Avoiding excessive drinking and drug use.

The Future

Researchers are looking into newer oral antibiotics as effective ways of treating syphilis, particularly in developing countries where injectable penicillin is difficult to obtain or to keep refrigerated. Other areas of research include the development of effective diagnostic tests based on urine or saliva samples rather than blood. Last, the sequencing of the genome (genetic code) of T. pallidum in 1998 has encouraged scientists to work on developing a vaccine against syphilis, although such a vaccine lies at least several years in the future.

WORDS TO KNOW

Chancre: A painless ulcer that forms on the skin during the early stage of syphilis.

Congenital: Present at birth.

Gumma: A soft noncancerous growth of tissue found in patients with tertiary syphilis.

Yaws: A spirochete-caused tropical infection of the skin, bones, and joints.

SEE ALSO AIDS; Chlamydia; Genital herpes; Gonorrhea

For more information

BOOKS

Sherman, Irwin W. Twelve Diseases That Changed Our World. Washington, DC: ASM Press, 2007. Syphilis is the subject of Chapter 6, “The Great Pox.”

Silverstein, Alvin, Virginia Silverstein, and Laura Silverstein Nunn. The STDs Update. Berkeley Heights, NJ: Enslow Elementary, 2006.

Winters, Adam. Syphilis. New York: Rosen Publishing Group, 2007.

WEB SITES

American Academy of Family Physicians (AAFP). Syphilis. Available online at http://familydoctor.org/online/famdocen/home/common/sexinfections/sti/380.html (updated April 2008; accessed September 2, 2008).

Centers for Disease Control and Prevention (CDC). Sexually Transmitted Diseases: Syphilis. Available online at http://www.cdc.gov/std/syphilis/default.htm (updated July 23, 2008; accessed September 2, 2008).

eMedicine Health. Syphilis. Available online at http://www.emedicinehealth.com/syphilis/article_em.htm (accessed September 2, 2008).

National Institute of Allergy and Infectious Diseases (NIAID). Syphilis. Available online at http://www3.niaid.nih.gov/topics/syphilis/default.htm (updated November 13, 2006; accessed September 2, 2008).

TeensHealth. Syphilis. Available online at http://kidshealth.org/teen/infections/stds/std_syphilis.html (updated March 2007; accessed September 2, 2008).