Tetanus Causes

• Clostridium tetani is the type of bacteria responsible for the disease. The bacteria are found in two forms: as a spore (dormant) or as a vegetative cell (active) that can multiply.



• The spores are in soil, dust, and animal waste and can survive there for many years. These spores are resistant to extremes of temperature.



• Contamination of a wound with tetanus spores is rather common. Tetanus, however, can only occur when the spores germinate and become active bacterial cells.



• The active bacterial cells release two exotoxins, tetanolysin and tetanospasmin. The function of tetanolysin is unclear, but tetanospasmin is responsible for the disease.



• The disease typically follows an acute injury that results in a break in the skin. Most cases result from a puncture wound, laceration (cut), or an abrasion (scrape).



• Other tetanus-prone injuries include the following:



• frostbite,



• surgery,



• crush wound,



• abscesses,



• childbirth, and



• IV drug users (site of needle injection).



• Wounds with devitalized (dead) tissue (for example, burns or crush injuries) or foreign bodies (debris in them) are most at risk of developing tetanus.



• Tetanus may develop in people who are not immunized against it or in people who have failed to maintain adequate immunity with active booster doses of vaccine.