Treponema pallidum infection
Syphilis is an infection caused by a bacteria called Treponema pallidum. Syphilis appears in three sequential stages, and is initially transmitted by sexual activity, via the placenta, or just by skin-on-skin contact with an infection lesion.
Antibiotics quickly cure Treponema pallidum infection, but still in 1999, 12 million people contracted the infection, with over 90 per cent of those in the developing world. Over 700,000 pregnancies per year are affected by syphilis, which can cause miscarriage, stillbirths, and congenital syphilis.
Up until the 1980s and 1990s, Treponema pallidum infections were on the decline due to widespread use of antibiotics. After 2000, however, syphilis infection rates have been increasing in the United States, United Kingdom, Australia and Europe, most often in men who have sex with men.
Untreated syphilis can cause death.
Symptoms of syphilis
Syphilis can appear, disappear, and reappear at one or many of the stages. Syphilis mimics many other diseases, so identifying the infection can be difficult. Symptoms can appear anywhere on the body, and differ depending on the stage.
Stage one – primary syphilis
Symptoms of the initial infection may not appear for three to four weeks after transmission. The incubation period of Treponema pallidum can be up to 13 weeks, with a red papule or lesion (called a chancre) appearing at the site of transmission.
The red papule turns into a painless ulcer with a firm base, and when you rub it, a clear fluid appears. This fluid is the contagious part. Lymph nodes near to the site of infection/lesion may be enlarged and firm, but not tender.
The most common places to find the lesions are on the genitals, anus and rectum in men, and on the vulva, cervix, rectum and perineum in women. Papules can be found on the lips or mouth of anyone. The syphilis lesions cause very few symptoms and no pain, so they can go unobserved in many people, particularly in the mouth or rectum. Lesions heal in 3-12 weeks, after which the person appears perfectly healthy.
Stage one symptoms of syphilis
- Painless genital ulcers
- Skin lesions anywhere on the body
- Lymphatic system symptoms
Stage two – secondary syphilis – weeks or months after initial infection
The spirochete (bacteria) spread into the bloodstream producing lesions throughout all mucosal tissue in the body, and causing the lymph nodes to swell. Symptoms in other organs may appear.
Secondary syphilis symptoms occur 6-12 weeks after the first lesions appeared, but about a quarter of people will still have a lesion from the first stage. Lesions can appear anywhere.
Without treatment, lesions can persist for days, weeks or months, and can return after healing. Usually secondary syphilis lesions will heal up without scarring. The eyes, bones, joints, meninges, kidneys, liver, or spleen can be affected.
Other signs of secondary syphilis include:
Symmetrical markings on the palms and soles of the feet may appear, known as syphilitic dermatitis. The lesions are round, scaly, and may join together to form larger lesions. Syphilitic dermatitis lesions do not tend to itch or hurt.
Once these markings have healed, the affected area may be lighter or darker than usual. With the scalp, alopecia areata often occurs.
Condyloma lata – warts
Condyloma lata are flat, dull pink or grey papules that appear in skin folds or joins (under breasts, perianal area). These papules are highly infectious, and can appear in the mouth, throat, larynx, penis, vulva, or rectum. The wart-like structures are circular, raised, and grey-white with a red border.
Symptoms of stage two of syphilis
- Headache (from meningitis)
- Hearing loss (from ear inflammation)
- Balance issues
- Neck stiffness
- Visual disturbances
- Bone pain
- Mucous membrane sores
- Hair loss
- Loss of appetite
- Many other varied symptoms
Periods of latency before stage three of syphilis
Usually no symptoms, but may get a resurgence of genital ulcers.
Stage three – late stage tertiary syphilis
Stage three is classified as benign tertiary syphilis, cardiovascular syphilis, or neurosyphilis. Stage three syphilis is also known as meningovascular or parenchymatous neurosyphilis, or tabes dorsalis.
Diagnosis of syphilis
Blood tests are conducted, with other tests as required. Antibodies to the bacteria or its proteins can be detected.
Treatment of syphilis
Penicillin is the drug of choice for syphilis. Sometimes another health condition treated with antibiotics (colds, flus) has resulted in the inadvertent treatment of unknown syphilis. Sexual partners must also be treated.
About T. pallidum
T. pallidum is called a spirochete, which means a flexible, spirally, twisted bacterium. This bacteria can’t survive for long outside the human body, however it enters via mucous membranes or the skin, heading directly for the lymph nodes. From there, it spreads throughout the body via the lymphatic system within hours.
How syphilis appears
The three stages of syphilis are classified as primary, secondary, and tertiary stages, with each stage including a long symptom-free period between. If you are infected with T. pallidum, you are contagious during the first two stages only.
Transmission of syphilis
Sexual transmission is the most common way to end up with syphilis. This can occur via the genitals, mouth, or anus, or just skin-to-skin contact, sexually related or not. T. pallidum can cross the placenta, so an infected pregnant woman can pass it on to her child.
A once-off sexual encounter with someone with primary syphilis results in transmission 30 per cent of the time. A mother has a 60-80 per cent chance of transmitting syphilis to her baby. Infection does not result in immunity.
Types/manifestations of syphilis
Late syphilis is untreated syphilis that appears years after the initial infection. This can be defined clinically as benign tertiary syphilis, cardiovascular syphilis, or neurosyphilis.
Benign tertiary gummatous syphilis
This type of syphilis develops within 3-10 years of infection, involving the skin, bones, and internal organs. Gummas are masses that develop causing inflammation and destruction on or through an organ or soft tissue. Gummas may grow and heal slowly, leaving scars.
Benign tertiary syphilis
This type of syphilis results in bone inflammation or destructive lesions that results in a deep, boring pain, usually worse at night.
This type of syphilis appears 10-25 years after initial infection and affects the aorta and possibly coronary arteries. Symptoms include a brassy cough, trouble breathing due to pressure on the trachea, hoarse voice, and erosion of the sternum, ribs, and spine, causing pain.
Neurosyphilis comes in several forms: asymptomatic neurosyphilis, meningovascular neurosyphilis, parenchymatous neurosyphilis, and tabes dorsalis.