Pinta disease is caused by infection with a specific type of bacterium called *Treponema carateum*, which belongs to the same family of bacteria that cause other related diseases like yaws and syphilis. Unlike syphilis, which is primarily transmitted through sexual contact, pinta is transmitted through direct skin-to-skin contact, especially when there is broken or damaged skin involved. This means that the bacteria enter the body through small cuts, abrasions, or fissures on the skin.
The bacterium *Treponema carateum* is a spirochete, which means it has a distinctive spiral or corkscrew shape. This shape helps it move through tissues and invade the skin. Once the bacteria penetrate the skin, they multiply locally and cause characteristic skin lesions. These lesions typically start as small, red or blue spots that gradually enlarge and change color over time, often becoming scaly or thickened. The infection mainly affects the skin and does not usually involve internal organs.
Pinta is considered a chronic infectious disease, meaning it can persist for a long time if untreated. It is most common in tropical regions, especially in rural areas where people live in close contact and hygiene conditions may facilitate transmission. The disease spreads primarily among children and young adults who have frequent skin contact with infected individuals or contaminated objects.
The exact process of how *Treponema carateum* causes the skin changes involves the bacterium evading the immune system initially, allowing it to multiply and spread in the skin. The immune system eventually responds by producing antibodies and activating immune cells that cause inflammation and tissue changes, which are visible as the skin lesions of pinta.
In summary, pinta disease is caused by the bacterium *Treponema carateum*, transmitted through direct skin contact, especially when the skin is broken. The bacteria invade and multiply in the skin, leading to chronic skin lesions that change color and texture over time. This disease is distinct from sexually transmitted treponemal infections and is primarily found in tropical, rural communities where close skin contact is common.
