Syphilis- Explained

Syphilis

Syphilis (also knows as lues or “bad blood”) is a chronic infectious disease caused by the spirochete Treponema pallidum.  Nearly all cases of syphilis are acquired by sexual contact with infectious lesions. Treponema pallidum enters the body through mucous membranes or breaks in the skin. Outside the human host, the organism is exquisitely fragile. The spirochete is destroyed within seconds by drying, heat, cold, soap and water, or disinfectants. The incubation period for syphilis is usually 3 weeks. However, symptoms can appear as early as 9 days or as long as 3 months after exposure, which is the case for rectal infections in homosexual men.

Venereal disease (VD), particularly syphilis and gonorrhea, is still widely prevalent despite the existence of curative antibiotic therapy. A patient with a newly diagnosed case of syphilis usually requires only outpatient services, while patients in the late stages of the disease may require hospitalization.

Untreated syphilis is characterized by four stages of disease: primary, secondary, latent, and late. Portals of entry include the external genitalia, cervix, mouth, perianal area, and anal canal. Although a single sore is most common, multiple chancres can occur. The pathologic process is basically the same in the various stages of syphilis. Treponema pallidum shows a penchant for involving the blood vessels. It invades the perivascular lymphatics causing endothelial swelling, obliterative endarteritis, and infiltration by lymphocytes and plasma cells. After this, fibroblastic proliferation occurs, leading to fibrosis and healing. Treponema pallidum is rarely demonstrated in gummatous lesions. Gummas are thought to be cellular hypersensitivity reactions to the treponemal infection, although this has not been proved.

Epidemiology

Reported cases of syphilis reached an all-time high during World War II, with 575, 593 cases being reported in 1943. Recently there has been a dramatic increase in number of cases of infectious syphilis (primary and secondary) reported to the Center of Disease Control (CDC). The current syphilis epidemic is occurring primarily among young heterosexual minority populations and is believed to be related to cocaine use and the exchange of sex for drugs. This same population is at risk for HIV infection, and treatment of syphilis is more problematic in the presence of HIV infection.

The incidence of syphilis went down among homosexual/ bisexual men, especially White males. This decrease in incidence is believed to result from safer sexual practices by this population because of education about how to prevent HIV infection. The cause of increase of syphilis is unknown but several possible reasons are being investigated.

The increases in infectious syphilis among females and heterosexuals are causing concern for three reasons:

1. An increase in syphilis in females will probably be followed by increased incidence and or deaths from congenital syphilis.

2. The marked increased in syphilis among inner-city, heterosexual minority, groups indicates that high-risk sexual activity is increasing despite the risk of HIV infection. This is especially distressing, because among these known group risks are already increased because of the high prevalence of intravenous drug abuse in their communities.

3. Studies conducted in Africa and in the United States suggest that genital ulcer diseases such as primary syphilis increase the risk of HIV transmission.

It is believed that the greatest percentage of cases of syphilis goes unreported, and thus the incidence is much greater than the figures clearly indicate.