Syphilis is a bacterial infection primarily known as a sexually transmitted infection (STI). Questions often arise about its transmission through less direct means, such as kissing. Casual kissing is highly unlikely to transmit syphilis. Transmission typically involves direct contact with a syphilis sore, known as a chancre, which can appear on the lips or inside the mouth.
How Syphilis Spreads
Syphilis is caused by the bacterium Treponema pallidum. It primarily spreads through direct skin-to-skin or mucous membrane contact with an infectious syphilis sore during sexual activity. These sores, called chancres, are typically found on the genitals, anus, or rectum, but can also occur on the lips or within the mouth. Transmission happens when an uninfected person’s skin or mucous membranes come into contact with these open sores.
Transmission can also occur from a pregnant person to their baby during pregnancy or childbirth, leading to congenital syphilis. Syphilis is not transmitted through casual contact with objects like toilet seats, doorknobs, eating utensils, or by sharing food and drinks. The bacteria responsible for syphilis cannot survive for long outside the human body.
Recognizing Syphilis Symptoms
Syphilis progresses through distinct stages, each with characteristic symptoms.
The first stage, primary syphilis, typically presents with one or more small, firm, and usually painless sores called chancres. These chancres appear at the site where the bacteria entered the body, often on the genitals, anus, or mouth, about three weeks after exposure, though this can range from 10 to 90 days. The sore may go unnoticed due to its painless nature and can heal on its own within three to six weeks, even without treatment, but the infection remains in the body.
Without treatment, the infection advances to secondary syphilis, usually one to six months after the primary sore disappears. This stage is often marked by a non-itchy skin rash that can appear anywhere on the body, including the palms of the hands and soles of the feet. Other symptoms may include fever, fatigue, sore throat, swollen lymph nodes, muscle aches, headaches, and patchy hair loss. These symptoms may also resolve without treatment, but the infection is still present and can be highly contagious during this stage.
Following the secondary stage, syphilis enters a latent phase where there are no visible signs or symptoms, but the bacteria remain in the body. This latent stage can last for many years, even decades. If untreated, a portion of individuals may develop tertiary syphilis, the most severe stage, which can affect various organs including the brain, nerves, eyes, heart, and blood vessels, potentially leading to serious health problems.
Testing and Diagnosis
Diagnosing syphilis typically involves a blood test, which is the primary method for detecting the infection. These tests look for antibodies produced by the body in response to the Treponema pallidum bacteria. If a chancre or rash is present, a healthcare provider might also take a fluid sample directly from the sore to examine under a microscope. This microscopic examination can directly identify the bacteria.
It is advisable to get tested if there is any suspicion of exposure to syphilis or if symptoms appear, even if they are mild or resolve on their own. The time between infection and a detectable blood test result, known as the window period, can vary. Early diagnosis allows for prompt and effective treatment, preventing the progression of the disease to more severe stages.
Treatment and Prevention
Syphilis is curable with antibiotics, especially when treated in its early stages. The preferred medication is penicillin, administered as an injection. For early syphilis, a single dose of penicillin may be sufficient, while later stages or syphilis of unknown duration may require multiple weekly injections over several weeks. It is important to complete the full course of treatment, even if symptoms disappear, to ensure the infection is eradicated.
After treatment, healthcare providers usually recommend follow-up blood tests to confirm the infection has been successfully treated. Partner notification is also an important step; individuals diagnosed with syphilis should inform their recent sexual partners so they can also be tested and treated. This helps prevent further spread of the infection.
Prevention strategies focus on reducing exposure to the bacteria. Consistent and correct use of latex condoms during vaginal, anal, and oral sex can lower the risk of transmission. However, condoms only protect covered areas, so if a sore is in an uncovered area, transmission is still possible. Regular testing for syphilis and other STIs is recommended for sexually active individuals, particularly those with multiple partners or new partners. Avoiding sexual contact when sores or rashes are present is also a practical measure to prevent transmission.