Treponema pallidum is a spirochete--a simple type of bacteria possessing less than 1,000 genes. Spirochetes form characteristic helical coils that are tight in some species or loose in others. Treponema pallidum has medium-sized coils. It also possesses flagella, allowing it to move in a corkscrew manner. Treponema pallidum reproduces by asexual transverse fission, dividing across its width into two distinct organisms.
Pathogen
Treponema pallidum is the primary pathogen in the sexually transmitted disease, syphilis. There are three principle stages to the disease--primary, secondary and tertiary--that each possess their own distinct signs and symptoms.
Primary Stage
The primary stage of syphilis presents as a lesion known as a chancre, which is a clean, indurated ulcer on the skin or mucous membrane that contains a localized infection. The painless chancre forms at the site where the organism first enters the body. If multiple spirochetes enter at different locations, multiple chancres may occur. These lesions generally last up to five weeks and may resolve spontaneously even if left untreated.
Secondary Stage
Around six weeks after the initial appearance of the chancre, the infection becomes systemic, spreading throughout the body, and a second stage begins. Symptoms may include general malaise, fever, sore throat, anorexia, headaches and swollen glands, lasting anywhere from two to six weeks. The symptoms generally subside whether treated or not.
Tertiary Stage
The tertiary stage, also called late syphilis, results from infections lasting longer than four years. Tertiary stage syphilis can affect the skin, heart, skeletal system and central nervous system, causing permanent damage resulting in a variety of symptoms including heart failure and blindness.
Transmission
Transmission of treponema pallidum happens when the lesions of the skin or mucous membranes are exposed during sexual activity. Women with syphilis also may transmit the disease to their unborn child.
Treponema pallidum can remain infectious within the host for a period of up to two years after initial infection. However, if no active chancres exist on the host, the disease cannot be spread, despite the host continuing to be infected.
Treatment
All stages of infection with treponema pallidum are relatively easy to treat with proper medication. The drugs of choice for treating syphilis are antibiotics, which can include penicillin or tetracycline, delivered as intramuscular injection. Because treatment cannot resolve any permanent damage to the body caused by the disease, the earlier treatment is administered, the better.
Tags: after initial, permanent damage, skin mucous, stage syphilis, Treponema pallidum, Treponema pallidum
