Syphilis is a very commonly found sexually transmitted disease, caused by the bacterium Treponema pallidum.
Initial infection causes a sore or chancre at the place of infection, but this is easily missed, as it is not painful and disappears by itself.
There are four stages of the disease – the primary stage, the secondary stage, the latent stage and the tertiary stage.
It can take as long as thirty years or more for the infection to reach the tertiary stage.
Initial symptoms are negligible, but from the secondary stage onwards, symptoms are dramatic and can include, skin rashes, heart failure, insanity, blindness, paralysis and death.
Syphilis is treatable in any of the four stages by means of an antibiotic injection – usually penicillin, but the tissue damage someone may already have suffered by the tertiary stage is irreversible.
A simple blood test can determine whether someone has contracted syphilis or not.
Syphilis can largely be avoided by choosing sex partners carefully, or by sticking to a monogamous relationship with one partner.
Syphilis antibodies can be detected in the body for years after the infection has cleared up.
What is syphilis?
Besides Aids, syphilis is the next most serious sexually transmitted disease. If left untreated, it will be fatal. It is caused by a bacterium called Treponema pallidum. Today it can be successfully treated with antibiotics, mostly penicillin, but in the past devastating epidemics of syphilis caused the deaths of thousands of people, including King Henry VIII.
Syphilis, though most often spread through direct sexual contact, can also be transmitted by means of blood transfusions and mother-to-child transmission, or in rare cases by kissing, when the disease is in its secondary stage. Being bitten by an infected person can also lead to transmission of the disease.
The initial infection causes an ulcer, or chancre, at the site of infection. This is called the primary stage of the disease. It is followed by three more stages, called, the secondary, latent and tertiary stages.
The secondary stage is characterised by a skin rash and a variety of other signs. Mouth ulcers and genital sores are frequently found. This stage lasts approximately one year.
This is followed by a latent stage in which no symptoms appear. This stage can last for years or even decades. Many people die of other causes, before the tertiary stage of syphilis sets in.
The tertiary stage of syphilis causes symptoms that can range from mild to extremely serious. The three main symptoms are syphilitic lumps, which can leave scars, heart problems, which could lead to heart failure, and neurosyphilis, of which hallucinations and delusions of grandeur are the most noticeable symptoms.
But in certain cases, almost no organ of the body remains unaffected. In the past, many people also suffered destruction of the bones, which often led to a flattening of the nose and holes appearing in the palate.
Congenital syphilis, in which the infection is transferred from mother to unborn child, can be devastating in that it can lead to the death of the baby before or after birth. Babies can be born with a variety of problems in different parts of the body because of syphilis.
What are the causes?
The cause of syphilis is now known to be a bacterium called Treponema pallidum. This bacterium enters the body through mucous membranes, such as those found in the mouth, the vagina or the anus. It can also enter the body through other parts of the skin that may be broken.
It most often causes a small ulcer, or chancre, at the site of infection. This ulcer is often sufficiently insignificant that people do not seek treatment, thereby enabling the spread of this sexually transmitted disease, as people in the primary stage of syphilis are highly infectious.
It is most often spread through sexual contact with a person who has an active infection. It is passed on by means of vaginal, anal or oral sex. It can also be passed on to a foetus during pregnancy, which can result in serious mental and physical defects.
Within a few hours, the bacterium reaches nearby lymph nodes and then spreads throughout the body via the blood. Neither the chancre, nor the lymph nodes are painful. This process can take many decades, but if left untreated, syphilis is a devastating disease, which can cause heart abnormalities, mental disorders, facial disfiguration, blindness, neurological problems and ultimately can be fatal.
Course, signs and symptoms of syphilis
Medical experts describe the course of syphilis by dividing it into four different stages: Primary, secondary, latent and tertiary or late.
The primary stage
The first sign of this infection is a small painless sore at the site of the infection. This is called a chancre. The sore usually appears within ten days to three weeks of syphilitic exposure. It usually begins as a small raised area and turns into a small ulcer. It usually occurs on the genitals or mouth, but can sometimes be found on other parts of the skin. It is painless and does not bleed. The nearby lymph nodes are also enlarged, but painless.
If left untreated the chancre will disappear by itself within three to 12 weeks. Because the sore is relatively insignificant, many people ignore it or even remain unaware that they have been infected, especially if the site of infection is inside the vagina.
Primary chancre of syphilis on the hand
Source: CDC Public Health Image Library
Within six to 12 weeks after initial infection, a skin rash appears. This rash most often consists of brownish coloured sores more or less 2cm in diameter. The rash can appear while the initial chancre is still on the body. It typically affects any area of the body, but most often the palms of the hands and the soles of the feet. Active bacteria are present in these sores, and the infection can be passed on to others at this stage. This skin rash could last for months, or clear up by itself within days, even if left completely untreated.
There can also be characteristic sores in the mouth and genital area. These are very infectious. These sores have been described as “snail track ulcers”, since the ulcers have a similar appearance to the tracks left by snails – somewhat windy and irregular. People also sometimes develop large painless, grey plaque-like lesions (called condylomata lata) in warm, moist areas of the body (such as the perineal region). Many people will suffer a variety of symptoms affecting the whole body at this stage of the illness, e.g. fever, tiredness, loss of appetite, aching joints or enlargement of the lymph nodes all over the body.
Typical presentation of secondary syphilis rash on the palms of the hands and usually also seen on soles of feet.
Secondary syphilis in 52-year-old man with AIDS; the reddish papules and nodules—some pustular—extend over his face, chest, arms, and back
Intensely pruritic, papulonodular eruption of secondary syphilis in a 23-year-old man, extening over his arms and back
Source: CDC Public Health Image Library
The latent stage
If no treatment has been received, syphilis passes into a latent stage. During this stage there are no symptoms although people can sometimes have recurrent attacks of the symptoms of secondary syphilis. Not everyone will get these relapses. A person with latent syphilis is not usually infectious to others, especially if more than four years have passed since their initial infection. However, a pregnant mother with latent syphilis can infect her unborn baby. The latent stage can last for many years, or even decades, and many people die of other diseases before syphilis reaches its tertiary and most devastating phase.
The tertiary stage
This final stage of syphilis is usually only reached by approximately one third of those who had secondary syphilis. At this stage the disease is not contagious and some people experience only mild symptoms. But there are possibly devastating and fatal symptoms that can occur in this third and final stage of syphilis.
The three main types of symptoms are benign tertiary syphilis, cardiovascular syphilis and neurosyphilis. All symptoms are not present in all infected persons.
Benign tertiary syphilis. This condition is not seen frequently anymore since the development of antibiotics. Lumps, called gummas, develop anywhere in the body. The most common parts of the body involved are bones, skin and mucous membranes. Gummas heal slowly, but leave scars.
Cardiovascular syphilis. Up to 25 years after the initial infection, an aneurysm (weakening or ballooning out of the blood vessel), a leakage of the aorta or leaking of some of the heart valves can develop. Any of these conditions can cause heart failure and/or death.
Neurosyphilis. There are three types of neurosyphilis:
The first type is called tabetic neurosyphilis, in which part of the spinal cord is damaged leading to problems with sensation in the lower half of the body. Odd movement when walking, urinary incontinence and general tremors are common symptoms of this condition.
The second type is called paretic neurosyphilis, and the main symptom is a change in behaviour as dementia slowly sets in. Mood swings, lack of insight into reality and convulsions are typical of this condition.
The third type is called meningovascular neurosyphilis and is a chronic form of meningitis. Dizziness, disorientation and lack of muscle control and general wasting are typical symptoms of this type of neurosyphilis.
Model of the head of a patient with tertiary syphilis.
Effect of syphilis on the skull.
Source: Axel Boldt (original work)
Source: Project Gutenburg
This condition occurs when a child is infected while still in the uterus (the womb). The infection is passed on by an infected mother. The symptoms and signs of congenital syphilis will vary depending on when the foetus is infected. In severe cases, congenital syphilis may result in stillbirth or death soon after birth. Some children with congenital syphilis may have no symptoms, or they may have symptoms such as a rash, runny nose (sometimes bloody), inflammation of the bones and enlarged lymph nodes, liver and spleen. These symptoms are usually present very soon after birth. If the congenital syphilis is untreated, the child also enters a latent stage, with late complications including deafness, neurosyphilis, inflammation of the cornea, abnormal teeth and joint problems.
The best way to prevent congenital syphilis is to screen all pregnant women with one of the blood tests (see below). Treatment of an infected woman during pregnancy is very effective at preventing congenital syphilis.
How is syphilis diagnosed?
Initial diagnosis of syphilis is sometimes complicated by the fact that symptoms in the primary phase are easily missed. Symptoms in the later stages of syphilis are far more obvious and would not be overlooked by competent medical staff. Because the signs of syphilis are so varied, it is wise to test any patient with possible signs of syphilis for the disease, even though many will have other diseases identified later.
Syphilis is usually diagnosed by blood tests that test for antibodies to Treponema pallidum, the bacteria that causes syphilis. (This bacterium does not grow in artificial media in the laboratory – it has to be injected into animals to grow and therefore is seldom done.)
There are two types of blood tests for syphilis. The one type tests for specific antibodies to Treponema pallidum. The other type tests for antibodies to certain tissues in the body that are somehow produced after infection with Treponema pallidum. An example of the first kind of test, which is specific for syphilis, is the FTA test. Examples of the second type of test (which are also known as non-specific tests) include WR test, VDRL test and RPR test.
If the specific test is positive, it means a person has had syphilis at some stage in the past. Unfortunately, the test does not provide any information on when a person had syphilis, and whether the person was treated or not. The specific test becomes positive on infection and remains positive for life.
The advantage of the non-specific tests is that they can be used to monitor the effects of treatment, and can also give some information about the stage of syphilis. After treatment, the level of non-specific antibodies goes down, and the antibodies can even disappear after treatment. However, the disadvantage of the non-specific tests is that they occasionally give false positive results, i.e. the test is positive when the person doesn’t really have syphilis. This is more likely to occur in someone who suffers from an autoimmune disease like rheumatoid arthritis where the body tends to react against its own tissues. Therefore in some instances if a person has a positive non-specific test, it is necessary to confirm the result by doing a specific test as well, e.g. in someone who has no symptoms of syphilis.
As you can imagine, interpretation of syphilis tests can be complicated and should be done by qualified medical personnel who can take into account many other factors, e.g. the signs and symptoms of the person, any other medical problems they have, the likely time since infection started and the risk of acquiring syphilis in that particular community.
Sometimes it can be difficult to prove that a person has active infection, but it is usually better to treat anyway because of the serious potential consequences of untreated syphilis.
Diagnosis in children is also difficult, since the mother’s antibodies can also be found in the baby, so a positive test on the baby doesn’t necessarily mean the child has syphilis. There are some tests that can be done to diagnose syphilis in a baby, but they are not always readily available. However, if the mother has evidence of syphilis, and there is any suspicion of congenital syphilis, it is prudent to treat the child, since the treatment is very safe and effective. Some doctors would say that any child born to a mother who has a positive test for syphilis should be treated, if the mother wasn’t treated during pregnancy.
How is it treated?
Unlike in the past, when many people died of complications of third-stage syphilis, every stage of syphilis can now be treated with an antibiotic like penicillin. This is usually given by injection. Depending on the stage to which the syphilis has advanced, several injections may be necessary over a period of time.
While the prognosis is excellent for treatment of primary or secondary stage syphilis, tissue damage, as may already have occurred in the tertiary stage of syphilis, cannot be reversed.
It must be remembered that people in both the primary and secondary stages can pass on the infection to sex partners. It is therefore of the utmost importance that sex partners (of the preceding three months in the case of primary syphilis and in the case of secondary syphilis, the preceding year) must be informed of the diagnosis, so that they too can be tested.
Prevention of syphilis requires much the same vigilance as prevention of HIV. A monogamous relationship is the best possible protection, followed by a careful choice of sex partners. It is essential to notify previous sex partners, if you become aware of the fact that you have been infected with syphilis.
The wearing of condoms, unlike in the case of HIV, provides only partial protection as it only protects against infection in the genital area, and not against oral infection or infection on any other part of the body where there may be broken skin.
Generally, syphilis cannot be contracted in a casual manner through normal social contact.
Reviewed by Dr Andrew Whitelaw, MBBCh (Witwatersrand), MSc (UCT), FCPath (Micro) (SA), Clinical Microbiologist, Department of Microbiology, University of Cape Town and Groote Schuur Hospital.