What is syphilis?

Syphilis is a bacterial, highly contagious sexually transmitted disease (STD). It must be treated completely or the complications can affect your heart, the brain, and other organs in the body.

You can even miss the first appearing symptom of syphilis, which is a painless sore — typically on the genitals, rectum, or mouth. This ulcer heals on its own and the syphilis bacteria can remain dormant in the body for decades before becoming active again.

However, though dormant, the syphilis bacteria continue to grow and multiply inside your body. In other words, you may get this disease and not know it.

Early syphilis can be cured with antibiotics, the preferred choice being a single injection of penicillin. Untreated, it can severely affect your heart, brain, and other organs, and can even be fatal.

Causes and risk factors

Syphilis is caused by a spiral-shaped spirochete bacterium called Treponema pallidum. You can get it when you expose yourself to the following risk factors.

  • Unprotected sex
  • Multiple partners
  • Homosexual sex
  • Pre-existing HIV infection
  • Alcohol consumption can make you reckless and make you go in for sex without protection

You may not always get syphilis if you have sex with an infected partner. The risk of getting infected from one unprotected sexual encounter with an infected partner differs slightly in men and women.

  • In men, the risk is of getting infected from one unprotected sexual encounter with an infected partner 20%
  • In women, it is 30%

How does syphilis spread?

  • Syphilis is transmitted from one person to another through contact during a sexual act. This sexual act can be vaginal, oral, or anal intercourse. During the sexual act, the infecting bacteria pass from the infected partner to the healthy individual through the mucous membrane, which lines the penis, vagina, anus, and oral cavity.
  • Sharing sex toys with an infected person can also get you infected.
  • A syphilitic ulcer in the mouth can transmit the infection through kissing the other partner.
  • Syphilis can also be transmitted from an infected mother to her fetus. Infection contracted by the newborn in this fashion is called congenital syphilis.
  • You can also acquire it by receiving blood, which belongs to an infected person. But this mode of transmission is rare nowadays because blood meant for donation is thoroughly screened for STD infections. Secondly, the spirochete bacteria cannot survive for more than 48 hours in modern blood-storing methods used by blood banks.
  • Rarely, syphilis can be transmitted through cuts in the skin (for example, cuts on the fingers) when the cut part comes in contact with an open syphilitic sore.
  • It can also be spread by using shared needles that have been previously used by an infected person and contains his/her blood.

What is the incubation period of syphilis?

After getting infected due to unprotected sexual intercourse with an infected partner, the first sign of syphilis does not appear immediately. The first symptom, which is the appearance of a chancre appears 21 days after the initial infection. However, the incubation period can range from 10 to 90 days also. This can vary in some cases and this incubation period can extend even up to three months.

A person is not infective during the incubation period and cannot pass on the infection to others during this period before the appearance of the primary sore.

If left untreated, syphilis bacteria, spirochete Treponema pallidum, continue to grow and multiply in the body causing progressive harm. The infected person continues to experience varying symptoms and signs depending on the progress of the bacterial activity in the body.

This syphilitic bacterial activity is divided into four stages through which the untreated infection progresses in the body. Each stage of syphilis exhibits its own symptoms, signs, and timeline in men and women with variations.

Syphilis has often been referred to as “The Great Pretender” because its symptoms often resemble those caused by other diseases. The severity of this infection has decreased since the 19th and 20th centuries due to two factors;

  1. Availability of effective treatment with antibiotics
  2. Decreased virulence of the spirochete (syphilis bacteria)

Stagewise symptoms and timeline

Syphilis develops in four stages (primary, secondary, latent, and tertiary). Each stage has different symptoms and a varying timeline.

Primary syphilis symptoms and timeline

This is the first stage of syphilis and corresponds to the initial infection. Colloquially, it is called primary syphilis. The early symptom of this stage is represented by the appearance of a chancre (sore) at the point of contact of the healthy person with the infected partner during unprotective sexual intercourse.

This chancre can, therefore, appear on the

  • Glans penis in men,
  • Vulva, vagina and cervix in women,
  • Anus and rectum in men and women due to anal sex,
  • And, in the oral cavity due to oral sex.

This sore or chancre is firm, painless, non-itchy, and oozes fluid. It contains millions of spirochetes and is very contagious. It is usually single but can be multiple especially when HIV infection co-exists.

The neighboring draining lymph nodes get enlarged. These are the inguinal lymph nodes when the chancre appears on the penis or on the vulva/vagina.

Timeline: This primary chancre of syphilis lasts for about three to six weeks and disappears leaving no signs even when no treatment is taken.

Secondary syphilis symptoms and timeline

The secondary stage begins about six weeks to six months after the person got initially infected. This stage can appear early and overlap with the first stage’s late part when the primary chancre is healing.

During this stage, the spirochete bacteria have entered the bloodstream and spread throughout the body. About one-third of the untreated primary cases progress to the secondary stage.

This secondary stage of syphilis is the most contagious and the blood of the patient during this stage has a very high count of its bacteria.

The symptoms of secondary syphilis are typically represented by the appearance of a rash over the entire body. The rash is more prominent over the palms of the hands and soles of the feet. The rash is reddish pink, rough, and does not itch. At times, it is so faint that it can go unnoticed.

Condylomata latum, which are wart-like structures on the genitals may occur caused by the syphilis bacteria. These are highly contagious.

Other secondary symptoms include fever, enlarged lymph glands, sore throat, hair loss, headache, loss of weight, muscle pain, and weakness. These symptoms and skin rash usually last for three to six weeks.

In some individuals, these symptoms may go and recur during the second phase itself. Like the primary stage, the second-stage symptoms too resolve without treatment.

40–85% of women and 20–65% of men do not report an appearance of the first stage chancre (sore or ulcer) when questioned during this stage. It is not that it did not appear. It is just that it was missed for the simple reason that the sore is painless and cannot be seen when it occurs in hidden places such as the vagina or the anal canal.

Timeline: This stage lasts for about one to three months. Without treatment, one-third of the cases progress to the tertiary stage.

Symptoms of the latent stage of syphilis

This stage is also called the hidden stage of syphilis. As the name implies, the infection lies dormant and no symptoms are seen during this stage though the spirochetes are very much present in the blood.

In other words, though there is serological proof that syphilis is present, there are no symptoms. Serological proof means that the bacteria are seen in blood when blood tests for syphilis are done.

This latent stage is again subdivided into

  • The early latent stage is the first year of latent syphilis. This stage is infectious.
  • The late latent stage is the time after the first year of this stage. This late stage of latent syphilis is not as infectious as the first latent stage.

This latent stage can be short and can last for a year or it can be long and can last anywhere between five years to twenty-five years.

In some cases, this stage can last for life without progressing to the tertiary stage. Syphilis in this stage can only be diagnosed by blood tests as no signs or symptoms appear during this stage.

Tertiary stage symptoms, signs, and timeline

This is the last stage and is referred to as tertiary syphilis. Not all infected persons go into this last stage, but those who do face serious complications.

Major organs of the body get involved and damaged and symptoms of tertiary syphilis present accordingly. The tertiary stage can set in 10 to 15 years after the initial infection. This stage is not infectious. Only about 30% of patients without treatment progress into this stage. Damage caused by tertiary syphilis to the organs is irreversible.

This stage can be divided into three types according to the involvement.

  • Gummatous syphilis or late benign syphilis occurs 10 to 45 years after the initial infection, the average being 15 years. It is characterized by gummas, which are soft nonmalignant inflammatory growths that can occur anywhere in the body but are seen more commonly in the liver, bone, and skin. They disappear after treatment with antibiotics.
  • Neurosyphilis syphilis is an infection, which has invaded the central nervous system. Deafness and visual problems can occur due to neurological involvement. Neurological syphilis  can present as
      • Syphilitic meningitis
      • Meningovascular meningitis, which leads to cerebral atrophy
      • General paresis, which causes impairment of judgment, loss of memory and concentration, and dementia.
      • Tabes dorsalis also called syphilitic myelopathy is a slow degeneration of the dorsal columns of the spinal cord. Besides other symptoms, there is loss of coordination, burning sensation, and a typical tabetic gait.
  • Cardiovascular syphilis occurs 10 to 30 years after the initial infection. Aortitis is the most common complication, which results in an aortic aneurysm. Heart valves can also get damaged.

Taking complete treatment or better still preventing syphilis has never been so important.