There is an alarming increase in the rate of syphilis cases being reported in some areas according to the Centers for Disease Control and Prevention. The rate of syphilis infection has increased 84.3% in Norfolk, Virginia, 45% in Detroit, and 25% in Newark in the past year.

Co-infection of syphilis and HIV disease can be a vexing clinical issue. First, people who are immune-compromised may not produce the antibodies to the disease and may therefore have a false-negative syphilis test. Second, if a person is positive for syphilis then they are two to five times at risk to become infected with HIV. Persons with syphilis increase their risk of acquiring HIV infection due to the break in the integrity of the skin.1

Generally the incubation period for syphilis infection is 90 days with the development of a chancre on the genital area. A chancre typically develops as a painless papule that evolves into a necrotic ulcer that has serous drainage. It can self-resolve within two to six weeks and frequently goes unnoticed by patients. Syphilis that is not diagnosed or treated can lead to life-threatening cardiovascular and neurological diseases that can occur one to two decades or more after initial infection.

Syphilis is caused by the Treponema pallidum organism and its course is divided into three distinct stages: primary syphilis, secondary syphilis, and tertiary (or latent) syphilis.

Primary syphilis occurs with the development of a chancre at the site of infection approximately 3 weeks after coming into contact with the organism.

Secondary syphilis occurs about 2 months after infection; the patient may develop viral-like symptoms along with a generalized maculopapular skin rash. If these patients are left untreated, tertiary syphilis may result.

Tertiary syphilis occurs many years after initial untreated primary syphilis. Gummas, or internal tissue granulation, form and result in severe damage to the bone, liver, and the skin. Cardiovascular complications may include destruction of cardiac valves and the development of aneurysms. Neurologically, sensory-motor deficits may be present with loss of vision, paresis, and degeneration of brain tissue. Theses symptoms define neurosyphilis.

Syphilis can be diagnosed by clinical examination if a chancre is present or by the typical skin rash. Serological testing should also be done and should include the Venereal Disease Research Laboratory (VDRL) and the rapid plasma reagin (RPR) tests. Confirmatory tests include the Fluorescent treponemal antibody (FTA-ABS) and the microhemagglutination-Treponema pallidum (MHA-TP) assay.2 All persons with HIV disease should be tested annually for any indication of syphilis.

Eradication of syphilis is possible with adequate drug therapy. Primary or early syphilis can be treated with 2.4 million units of Benzathine penicillin IM in one dose or doxycycline 100 mg bid for 14 days. Syphilis that is latent or of unknown duration is treated with 2.4 million units of Benzathine penicillin IM weekly for three weeks. Neurosyphilis requires aqueous crystalline penicillin G 3-4 million units IV Q4h for 2 weeks. Any suspicion of neurosyphilis should also result in a comprehensive neurological exam and lumbar puncture.3

Syphilis is on the rise in certain communities. Co-infection with HIV disease is of great concern. Clinicians need to be vigilant in clinical examinations and in annual tracking of any possible infection.

New STD management guidelines are constantly evolving. The latest updates and information can always be obtained at: <http://www.cdc.gov/std/>.

See Dr. Ferri's bio on page 85.

References

     1.   Centers for Disease Control and Prevention. Primary and secondary syphilis among HIV-infected patients. MMWR. 1993;42:RR-14, 27-44.

     2.   Johnson PDR, Graves SR, Stewart L, et al. Specific syphilis serological tests may become negative in HIV infection. AIDS. 1991;5:.

     3.   Dowell ME, Ross PG, Musher DM, et al. Response of latent syphilis or neurosyphilis to ceftriaxone therapy in persons infected with human immunodeficiency virus. Am J Med. 1992;93:.