Tetanus is an infection caused by a bacterium called *Clostridium tetani*, which is commonly found in soil, dust, and animal feces. The bacterium itself does not invade the body like many other germs; instead, it produces a powerful toxin called tetanospasmin once it enters the body. This toxin affects the nervous system, causing severe muscle stiffness and painful spasms.
You get tetanus when *Clostridium tetani* spores enter your body through a break in the skin. This can happen through various types of wounds, especially those that are deep or puncture-like, because these wounds create an environment with low oxygen where the bacteria can grow. Common ways the spores enter include:
– Puncture wounds from nails, splinters, or needles
– Deep cuts or lacerations
– Burns
– Animal bites or scratches
– Minor wounds that are untreated or not properly cleaned
– Contaminated tattoo or piercing instruments
The spores are extremely hardy and can survive for a long time in harsh conditions like dry soil or dust. When they get into a wound, they can germinate and produce the toxin if the wound environment is suitable, particularly if it is deep and lacks oxygen.
Tetanus is not contagious, meaning it cannot spread from person to person. Instead, the infection is acquired only when the spores enter the body through a wound contaminated with dirt, soil, or feces containing the spores.
Once inside, the bacteria produce tetanospasmin, which travels through the bloodstream and nervous system to the central nervous system. This toxin blocks the normal signals between nerves and muscles by interfering with neurotransmitters that usually calm nerve activity. Without this calming effect, muscles contract uncontrollably, leading to the characteristic stiffness and spasms of tetanus. The jaw muscles are often affected first, causing difficulty opening the mouth, which is why tetanus is sometimes called “lockjaw.”
Because the spores thrive in low-oxygen environments, wounds like punctures, deep cuts, or crush injuries are particularly risky. Even small wounds can be dangerous if contaminated and not cleaned properly. In places where people walk barefoot or have frequent contact with soil and animal waste, the risk of tetanus infection is higher.
The symptoms of tetanus usually appear within about two weeks after the spores enter the body, but this can vary. Early signs include muscle stiffness near the wound, difficulty swallowing, and muscle spasms that can spread throughout the body. Without treatment, these symptoms worsen rapidly and can lead to severe complications, including difficulty breathing due to chest muscle spasms.
Prevention is mainly through vaccination and proper wound care. If someone gets a wound that might be contaminated, cleaning it thoroughly and seeking medical care is important. Doctors may give tetanus immune globulin to neutralize the toxin and a tetanus vaccine booster if needed.
In summary, you get tetanus when *Clostridium tetani* spores enter a wound contaminated with soil or animal waste, especially if the wound is deep and not properly cleaned. The bacteria produce a toxin that causes severe muscle spasms and stiffness, making tetanus a serious medical emergency if untreated.
