Tetanus is infection of the nervous system with the potentially deadly bacteria Clostridium tetani (C. tetani).
Causes, incidence, and risk factors:
Spores of the bacteria C. tetani live in the soil and are found around the world. In the spore form, C. tetani may remain inactive in the soil, but it can remain infectious for more than 40 years.
Infection begins when the spores enter the body through an injury or wound . The spores release bacteria that spread and make a poison called tetanospasmin. This poison blocks nerve signals from the spinal cord to the muscles, causing severe muscle spasms. The spasms can be so powerful that they tear the muscles or cause fractures of the spine.
The time between infection and the first sign of symptoms is typically 7 to 21 days. Most cases of tetanus in the United States occur in those who have not been properly vaccinated against the disease.
Tetanus often begins with mild spasms in the jaw muscles (lockjaw). The spasms can also affect the chest, neck, back, and abdominal muscles . Back muscle spasms often cause arching, called opisthotonos .
Sometimes the spasms affect muscles that help with breathing, which can lead to breathing problems.
Prolonged muscular action causes sudden, powerful, and painful contractions of muscle groups. This is called tetany. These episodes can cause fractures and muscle tears.
Other symptoms include:
Signs and tests:
Your doctor will perform a physical exam and ask questions about your medical history. No specific lab test is available to determine the diagnosis of tetanus.
Other tests may be used to rule out meningitis , rabies , strychnine poisoning, and other diseases with similar symptoms.
Treatment may include:
- Antibiotics, including penicillin, clindamycin, erythromycin, or metronidazole (metronidazole has been most successful)
- Bedrest with a nonstimulating environment (dim light, reduced noise, and stable temperature)
- Medicine to reverse the poison (tetanus immune globulin)
- Muscle relaxers such as diazepam
- Surgery to clean the wound and remove the source of the poison (debridement)
Breathing support with oxygen, a breathing tube, and a breathing machine may be necessary.
Without treatment, one out of four infected people die. The death rate for newborns with untreated tetanus is even higher. With proper treatment, less than 10% of infected patients die.
Wounds on the head or face seem to be more dangerous than those on other parts of the body. If the person survives the acute illness, recovery is generally complete. Uncorrected episodes of hypoxia (lack of oxygen) caused by muscle spasms in the throat may lead to irreversible brain damage.
Calling your health care provider:
Call your health care provider if you have an open wound , particularly if:
- You are injured outdoors.
- The wound has been in contact with soil.
- You have not received a tetanus booster (vaccine) within 5 years or you are not sure of your vaccination status.
Call for an appointment with your health care provider if you have never been immunized against tetanus as an adult or child, if your children have not been immunized, or if you are unsure of your tetanus immunization (vaccine) status.
Tetanus is completely preventable by active tetanus immunization. Immunization is thought to provide protection for 10 years. Studies of soldiers suggest that good protection persists up to 12 years after the last immunization.
In the United States, immunizations begin in infancy with the DTaP series of shots. The DTaP vaccine is a "3-in-1" vaccine that protects against diphtheria , pertussis , and tetanus. It is a safer version of an older vaccine known as DTP, which is no longer used in the U.S.
Td vaccine or Tdap vaccine is used to maintain immunity in those age 11 and older. Tdap vaccine should be given once, prior to age 65, as a substitute for Td for those who have not had Tdap. Td boosters are recommended every 10 years starting at age 19.
Older teenagers and adults who have sustained injuries, especially puncture-type wounds, should receive booster immunization for tetanus if more than 10 years have passed since the last booster.
Thorough cleaning of all injuries and wounds and the removal of dead or severely injured tissue (debridement), when appropriate, may reduce the risk of developing tetanus. If you have been injured outside or in any way that makes contact with soil likely, contact your health care provider regarding the possible risk for tetanus.
Many people believe injuries caused by rusty nails are the most dangerous. This is true only if the nail is dirty as well as rusty, as is usually the case. It is the dirt on the nail, not the rust, that carries the risk for tetanus.
Barlett JG. Clostridial infections. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 319.
Recommended Adult Immunization Schedule -- United States 2009. MMWR Morb Mortal Wkly Rep. 09 Jan 2009;57(53);Q-1-Q-4.
Recommended Immunization Schedules for Persons Aged 0 Through 18 Years -- United States 2009. MMWR Morb Mortal Wkly Rep. 02 Jan 2009;57(51&52);Q-1-Q-4.