Syphilis is a bacterial infection that can be cured by antibiotics, usually peni- cillin, but that can cause serious problems if left untreated. The disease is much less common today than before the development of penicillin, and safer sex prac- tices to curb HIV transmission also helped reduce the incidence of syphilis. Congenital (from birth) syphilis, which occurs in babies born to mothers with syphilis, is very rare today.
The spiral-shaped bacterium Treponema pallidum, which causes syphilis, enters the body through broken skin or through mucous membranes in the geni- tals, rectum, or mouth during sex. One intimate contact with someone who is infected—even if it’s only kissing—can increase your chances of becoming infected by as much as 30 percent.
Left untreated, syphilis usually passes through four stages:
Primary stage. The ﬁrst sign of the disease—a small, smooth, painless sore called a chancre—usually appears within 3 to 4 weeks of contact with an infected person. The sore grows on the penis but also may appear on the anus,
rectum, mouth, or ﬁngers. The sore does not bleed, but it may leak a clear ﬂuid that is highly infectious. The surrounding lymph nodes may become enlarged and rubbery but are not tender. Since no pain is involved, about one third of infected men are not aware of the sore, which usually heals in 4 to 8 weeks.
Secondary stage. A skin rash usually introduces the secondary stage of syphilis, which begins 6 to 12 weeks after infection and may last up to a year. The rash may be short-lived, last for months, or disappear and then recur. Usu- ally the lymph nodes are greatly enlarged at the same time, and the infected per- son may have one or more of the following symptoms:
• bone aches
• loss of appetite
• inﬂammation of the eyes, which can cause blurred vision
• inﬂammation of the kidneys, which can cause protein to leak into the urine
• inﬂammation of the liver, which may cause jaundice (a yellowing of the skin and the whites of the eyes)
• meningitis, which can cause headaches, neck stiffness, and sometimes deaf- ness
• hair loss
• thick gray or pink patches on the skin (condylomata latum), which are highly infectious
Latent stage. During this stage, there are no symptoms, even though the infec- tion is present. In some people, syphilis remains latent for the rest of their lives. But about one third of people who are untreated will enter the last (tertiary) stage.
Tertiary stage. There is no predicting when the tertiary stage will begin. It can be as early as 3 years into the infection or as long as 25 years later. Similarly, the effects are varied, from mild to severe. A process called gumma formation destroys tissues and organs—bones, brain, heart, blood vessels, liver, or skin. One consequence, called cardiovascular syphilis, affects the aorta and can lead to the formation of aneurysms (ballooning of an artery caused by blood pressing against a weakened area) and damage to the heart valve.
The active bacteria in the ﬂuid from a chancre make primary syphilis easy to detect under a microscope. Blood tests can conﬁrm the diagnosis at any stage.
Caught early, syphilis can be cured with a single high-dose injection (called a depot injection) of penicillin; later, a longer course of treatment is needed. How- ever, more than half of those treated have an adverse reaction to the antibiotic within hours. In response to the sudden, massive death of bacteria, the body may
produce a fever, headache, sweating, shaking, chills, or temporary worsening of the sores.
While organ damage caused by syphilis cannot be reversed, the prognoses for primary-, secondary-, and latent-stage syphilis are good. It is important to note, however, that infection does not confer immunity; once cured, you can become infected again.
Syphilis is infectious only during the primary and secondary stages, during which even practicing safer sex cannot provide complete protection. For this rea- son, abstinence is the best course early in the disease.
Neurosyphilis, syphilis of the nervous system, can occur during the tertiary stage of the disease but is rare in developed countries. Diagnosis may require testing a sample of cerebrospinal ﬂuid. The outlook for recovery is poor. There are three major types of neurosyphilis:
• Meningovascular neurosyphilis is a chronic form of meningitis in which the linings of the brain and the spinal cord are inﬂamed.
• Paretic neurosyphilis causes behavioral changes and, ultimately, dementia.
• Tabetic neurosyphilis (tabes dorsalis) is a progressive disease of the spinal cord that begins with intense, stabbing pains in the legs and eventually affects walking and bladder control, among other symptoms. The person may develop tremors and spasms of pain in various organs.