Clostridium tetani is the bacterium that causes lockjaw, also known as tetanus, according to Healthline. This bacterium is present in dirt and animal droppings and may enter the bloodstream through a deep cut or a wound.
Spores of Clostridium tetani can be found anywhere in the environment, including in manure, soil and dust, reports the New York State Department of Health. These spores are usually resistant to high heat and other harsh environmental elements, according to Healthline.
Tetanus cannot be transmitted from one person to another and only spreads when an unvaccinated individual has a cut or a wound that becomes contaminated by the bacteria, states the New York State Department of Health. There are situations where tetanus infections have been associated with intravenous drug use, dental infections and insect bites.
When the bacterium spreads through the body, it produces tetanospasmin, which is a toxin that blocks nerve signals from the spinal cord to the muscles, explains Healthline. This is what leads to the severe muscle convulsions.
Individuals are at a high risk of contracting the lockjaw infection if they have severe infections and sores, burns, or wounds that have been contaminated by feces, saliva or dirt, states Healthline. Though lockjaw is a global disease, it is more common in areas that are densely populated and in hot and humid regions.