After a person gets syphilis, the disease begins in the primary stage. A person gets syphilis by having sex with a person who has syphilis. Usually, the person who has syphilis has wounds on their genitals caused by syphilis. Touching these wounds during sex (including oral sex or anal sex) can give a person syphilis.
Later, a chancre (skin sore) usually appears at the place on the body that touched the infected wounds. The chancre can be painful. The most common type of chancre gets bigger and bigger until it becomes an ulcer.
Chancres can appear in places other than the genitals. In women, chancres most often appear on the cervix - the bottom of the uterus. Some people get no chancres at all. Many people who have secondary syphilis (40–85% of women and 20–65% of men) say they never had a chancre during the primary stage.
Around the place where syphilis entered the body, the lymph nodes usually get bigger about 7 to 10 days after the chancre forms. If the person does not get treatment, their wound(s) can last for three to six weeks.
If a person does not get treatment, syphilis will get worse. The secondary stage of syphilis will start about four to ten weeks after the person first got infected. Secondary syphilis can cause many different symptoms. However, the most common three symptoms are:
All of the sores that people get during this stage can spread syphilis. The bacteria lives inside the wounds.
The symptoms of secondary syphilis usually get better after three to six weeks. However, in about 25% of cases (1 out of every 4), these symptoms can return.
In the latent stage of syphilis, a person has no symptoms, but blood tests show that he has syphilis. Latent syphilis is described as either early or late.
If a person with syphilis does not get treatment, the disease can reach the worst stage - tertiary syphilis. Usually this happens about three to 15 years after the person first got infected. Without treatment, one-third of people with syphilis get tertiary disease. People with tertiary syphilis cannot infect other people with syphilis.
There are three different forms of tertiary syphilis.
Gummatous syphilis can happen anywhere from one to 46 years after the person first got syphilis. On average, it happens after 15 years. It causes soft, tumor-like balls of inflammation (swelling), of many different sizes. Usually they appear on the skin, bone, and liver, but they can happen anywhere.
About 15% of people who do not get treated for syphilis get gummatous syphilis.
In neurosyphilis, the syphilis infects the central nervous system (the brain and spinal cord). In some people, neurosyphilis happens soon after they get syphilis. (This is called "early neurosyphilis".) Some of these people have no symptoms of neurosyphilis. Others get syphilitic meningitis, a dangerous infection of the meninges (the protective layers which line the brain and spinal cord).
Neurosyphilis can also appear later, usually four to 25 years after a person first got syphilis. (This is called "late neurosyphilis".) Late neurosyphilis can cause many serious problems. For example:
About 6.5% of people who do not get treated for syphilis get late neurosyphilis.
This type of tertiary syphilis causes problems with the cardiovascular system (the heart and blood vessels). It usually happens 10 to 30 years after the person first got infected with syphilis.
The most common problem it causes is syphilitic aortitis, which affects the aorta. The aorta is the most important artery in the heart; it helps carry blood to the entire body. Syphilitic aortitis can make the aorta become too big. If the aorta is too big, it cannot work correctly.
About 10% of people who do not get treated for syphilis get cardiovascular syphilis.
Congenital syphilis is spread from a mother to her fetus during pregnancy or childbirth.
Two out of every three infants born with syphilis have no symptoms. In the other infants, symptoms can appear as the baby gets older. The most common symptoms are:
If babies with syphilis do not get treated, they can get "late congenital syphilis", which has much more serious symptoms. For example, the child can have seizures, and their body and brain may not grow normally.
Syphilis is caused by the "Treponema pallidum" bacterium. "Treponema pallidum" is a species of bacterium which is shaped like a spiral: a spirochaete. There are different types of "Treponema pallidum" bacteria, which are called subspecies.
Scientists think that "Treponema pallidum" can only live inside humans. The bacterium cannot survive outside a human for more than a few days.
Syphilis is spread mostly by sexual contact or during pregnancy from a mother to her fetus. Syphilis can pass through undamaged mucous membranes, or through damaged skin. Because of this, syphilis can be spread through oral sex, vaginal sex, and anal sex. It can also be spread by kissing, if the person with syphilis has a sore in their mouth.
Only a very small amount of the "Treponema pallidum" bacterium needs to get into a person's body to cause syphilis. However, not everybody who is exposed to primary or secondary syphilis will get the disease.
A person can get syphilis if they get a blood transfusion from someone with the disease. However, many countries test blood donations for syphilis. In countries that do not do this, getting syphilis from a blood transfusion is much more likely.
Scientists think syphilis is usually not spread by sharing needles (using the same needles to inject drugs).
A person cannot get syphilis from sitting on a toilet seat; using a hot tub or a swimming pool; sharing plates, cups, or utensils; sharing clothing; or doing other regular daily activities.
It is hard for doctors to diagnose syphilis just from the signs and symptoms that happen early on, because many diseases can cause skin sores and rashes. Instead, they can diagnose syphilis by doing a blood test, or by looking at the blood under a microscope. Blood tests are used more often, because they are easier to do. However, blood tests cannot tell which stage of syphilis a person has.
, there is no vaccine that prevents syphilis.
Not having sexual contact with a person who has syphilis is one of the best ways to prevent getting syphilis.
If a person does not know if their sexual partner has syphilis, having safer sex can help protect them. For example, using a latex condom the right way lowers the risk of getting a sexually transmitted disease like syphilis. However, even if a person uses a condom, it is still possible for him to get syphilis.
Because of this, the United States Centers for Disease Control and Prevention (CDC) says that the best ways to prevent syphilis are:
Congenital syphilis in newborn babies can be prevented by testing mothers for syphilis during early pregnancy and treating women who are infected. By following these steps, in 2015, Cuba became the first country in the world to eradicate the spread of syphilis from Cuban mothers to their babies.
The United States Preventive Services Task Force (USPSTF) and the World Health Organization say that all pregnant women should be tested for syphilis. If a woman tests positive, her sexual partners (the people she has had sex with) should also be treated.
In most developed countries, congenital syphilis is not common. It still happens once in a while, when women do not get any health care during pregnancy. However, congenital syphilis is much more common in developing countries. Many women in these countries do not get healthcare during pregnancy, and others get healthcare that does not include testing for syphilis. When there are programs that make syphilis testing easier to get, fewer babies get congenital syphilis in these countries.