What is syphilis?
Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum.
What are the symptoms of syphilis?
Primary Stage: The stage between infection with T. pallidum and the start of the first symptom can range from 10 to 90 days (average 21 days). The primary stage of syphilis is usually marked by the appearance of a single sore (called a chancre), but there may be multiple sores. The chancre is usually firm, round, small and painless. It appears at the spot where syphilis entered the body. The chancre lasts 3 to 6 weeks and it will heal on its own. If adequate treatment is not administered, the infection progresses to the secondary stage. 

Secondary Stage: The second stage starts when one or more areas of the skin break into a rash that usually does not itch. Rashes appear as the chancre is fading or can be delayed for weeks. The rash often appears as rough, red or reddish brown spots both on the palms of the hands and on the soles of the feet. The rash may also appear on other parts of the body with different characteristics, so faint that they are not noticed. Even without treatment, the rash can clear up on its own. In addition to rashes, second stage symptoms can include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches and tiredness.
Latency and tertiary syphilis: The latent (hidden) stage of syphilis begins when the secondary symptoms disappear. Latent syphilis is divided into early and late latency. Early latency refers to relapses that occur within one year of the onset of latency. After one year without the reoccurrence of disease and before the onset of tertiary syphilis, untreated persons are said to have entered the late latent period. Without treatment, the infected person still has syphilis even though there are no signs or symptoms. Syphilis remains in the body, and it may begin to damage the internal organs, including the brain, nerves, eyes, heart, blood vessels, liver, lungs, bones and joints. This internal damage may show up many years later in the tertiary stage of syphilis. Late stage signs and symptoms include loss of muscle coordination, paralysis, numbness, gradual blindness and dementia. This damage may be serious enough to cause death. 

How is syphilis spread?
Syphilis is spread from person to person through direct contact with a syphilis sore. Sores occur mainly on the external genitals, vagina and anus or in the rectum. Sores can also occur on the lips and in the mouth. Transmission of the bacterium occurs during vaginal, anal or oral sex. Untreated syphilis can also result in the transmission of T. palladium from a pregnant woman to her foetus.

A person can easily transmit the disease to sex partners when primary, secondary, or early latent stage signs or symptoms are present. Up to 50% of people infected with syphilis show no symptoms, but can still pass it on to others during sex.
Can a newborn get syphilis?
Infection during pregnancy may lead to stillbirth, neonatal death and congenital defects. If not treated immediately, an infected baby may be born without symptoms but could develop them within a few weeks. These signs and symptoms can be very serious. Untreated babies may become developmentally delayed, have seizures, or die. It is recommended that all pregnant women should have a blood test for syphilis. Once detected, maternal infection can be treated to prevent transmission of the infection to the baby. 
How is syphilis diagnosed?
Syphilis can be diagnosed by examining material from infectious sores by dark field microscopy. If syphilis bacteria are present in the sore, they will show up with a characteristic appearance. 

A blood test is another way to determine whether someone has syphilis. Shortly after infection occurs, the body produces syphilis antibodies that can be detected by an accurate, safe and inexpensive blood test. A low level of antibodies will stay in the blood for months or years after the disease has been successfully treated. It is recommended that all pregnant women should have a blood test for syphilis. The goal of antenatal syphilis screening is to diagnose and treat infections before transmission to the baby occurs.

How common is syphilis?
Since January 2000 there has been a dramatic increase in syphilis amongst men who have sex with men (MSM) in Dublin. This was against a low incidence of syphilis throughout the 1990s, which in 1999 reached its lowest level in 10 years. Rising trends in the incidence of syphilis have also been reported across the rest of the country and among heterosexuals. Interventions to control the outbreak were targeted primarily at MSM in Dublin. These interventions may have had an impact as the outbreak amongst MSM in Dublin peaked in 2002 and syphilis notifications decreased by 22.4% in 2003 and by a further 38.7% in 2004. However, notifications have not returned to their previous levels of the 1990s and syphilis remains endemic in Ireland. In 2004 there were 144 notifications reported (3.7 per 100,000).

Recently concern has been raised over a resurgence of risky sexual behaviours and infections. The rising incidence of gonorrhoea and syphilis reported since 1995 across Europe are consistent with an increase in unsafe sex, perhaps reflecting an increase in risk behaviour associated with the availability of highly active antiretroviral therapy for HIV infection and a loss of impact of the HIV prevention campaigns of the 1980s and early 1990s.
What is the link between syphilis and HIV?
Syphilis, like other genital ulcer diseases increases the risk of transmitting and acquiring HIV. Concurrent HIV infection may also increase the risk of neurosyphilis. There is a 2 to 5 fold increased risk of acquiring HIV infection when syphilis is present.

Can syphilis be treated?
Syphilis, once a cause of devastating epidemics, can be effectively diagnosed and treated with antibiotic therapy. A single dose of penicillin, an antibiotic, will cure a person who has had syphilis for less than a year. Larger doses are needed to cure someone who has been infected for longer than a year. For those allergic to penicillin, other antibiotics are available to treat syphilis. Penicillin treatment will kill the syphilis bacterium and prevent further damage, but it will not repair any damage already done. Those on antibiotic therapy for syphilis must abstain from sexual contact with new partners until the syphilis sores are completely healed. Persons with syphilis must notify their sex partners so that they also can be tested and if necessary, receive treatment.

The cornerstone of congenital syphilis elimination is early detection of syphilis and treatment with penicillin, which is effective and safe for mother and foetus.

Will syphilis recur?
Being infected with syphilis does not protect a person from being re-infected. Antibodies are produced as a person reacts to the disease, and after the treatment, these antibodies may offer partial protection from getting infected again, if exposed right away. Even though there may be a short period of partial protection, the antibody levels naturally decrease in the blood, and people become susceptible to syphilis infection again. 

How can people protect themselves against infection?
Two people who know that they are not infected and who have sex only with each other cannot contract syphilis. When someone's syphilis status is unknown, a good defense against becoming infected during sex is to use a latex condom before beginning sex and to keep it on until the penis is withdrawn. However, condoms do not provide complete protection because syphilis sores can sometimes be on areas not covered by a condom. This is equally important for other STIs, including HIV. Only laboratory tests can confirm whether someone has syphilis. Syphilis sores can be hidden in the vagina, rectum, or mouth; it therefore may not be obvious that a sex partner has syphilis.

Last updated: 26 February 2009