Tetanus is a bacterial infection that is caused by Clostridium tetani bacteria. It can have serious and fatal outcomes, due to its effect on the nervous system and characteristic tightening of muscles in the body as a result.
There is a vaccination available that can protect individuals from the causative bacteria and prevent the infection from initially taking hold.
3D illustration of Clostridium bacteria. Image Credit: Kateryna Kon / Shutterstock.com
Causative bacteria
Tetanus is caused by Clostridium tetani, anaerobic bacteria that thrive in the absence of oxygen. They produce spores that can survive for many years in the surrounding environment. In this form, they are inactive but are able to remain infectious for more than 40 years.
The spores are most commonly present in soil and dirt, but can also be found in dust and mammalian animal droppings in the surrounding environment. If the spores of the causative bacteria enter the bloodstream of a mammal, they can become active and begin to infect the individual with the bacteria.
Initial infection
An individual can become infected with tetanus when the Clostridium tetani bacteria enter the bloodstream through broken skin. This can occur via:
- A cut or deep wound
- A dental infection
- A puncture wound from a piercing or tattoo
- Crash injuries
- Dead tissue injuries
- Injected drug use
- Animal bites
Occasionally, there is a case of tetanus that is linked to childbirth. The mother tends to develop an infection in the uterus, which can also affect the baby at the beginning of the umbilical cord.
Essentially, any individual who is cut with an object that is dirty, or comes into contact with dirt following a cut, is at risk of Clostridium tetani entering the wound and bloodstream.
Among developed nations, the majority of tetanus cases occur in elderly people after a surgical procedure and in users of injected drugs that reuse syringes without adequate hygiene practices.
Rarely, cases of tetanus have also been reported from other injuries, such as superficial wounds, insect bites, compound fractures and chronic sores.
Ideal conditions to thrive
As Clostridium tetani are anaerobic bacteria that thrive without oxygen, the infection becomes much more dangerous when the wound tissue they inhabit does not have a strong supply of oxygen. Therefore, ideal wound sites for the proliferation of tetanus includes deep puncture wounds, burns, surgical wounds and needle punctures.
With the growth and multiplication of bacteria, a toxin begins to be produced that can wreak havoc on the nervous system. It is worth noting that it is the toxin, not the causative bacteria, that leads to the effects and symptoms of tetanus. This toxin binds to nerve endings, disrupting their normal function to relax the muscles and resulting in the contraction of these muscles. The characteristic signs of tetanus of rigid muscles, particularly in the jaw, and subsequent spasms may become evident.
Clostridium tetani and Tetanus
Myth: rust
Many people associate rust with causing tetanus, particularly rusty nails. However, rust does not play any role in causing tetanus but this link has been made due to the fact that most rusty objects are left outdoors, where the Clostridium tetani bacteria can be found.
Therefore, the rusty surface is an ideal habitat for the bacteria and may be responsible for causing the infection, although it is the bacteria and not the rust that led to the infection.
References
Further Reading
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