Tetanus

Tetanus is an infection caused by bacteria called Clostridium tetani. When the bacteria invade the body, they produce a poison (toxin) that causes painful muscle contractions. Another name for tetanus is “lockjaw”. It often causes a person’s neck and jaw muscles to lock, making it hard to open the mouth or swallow. Tetanus is different from other vaccine-preventable diseases because it does not spread from person to person.

Cause

Tetanus is an infection caused by a bacterium called Clostridium tetani. Spores of tetanus bacteria are everywhere in the environment, including soil, dust, and manure. The spores develop into bacteria when they enter the body.

Transmission

The spores can get into the body through broken skin, usually through injuries from contaminated objects. Tetanus bacteria are more likely to infect certain breaks in the skin. These include:

• Wounds contaminated with dirt, poop (feces), or spit (saliva)
• Wounds caused by an object puncturing the skin (puncture wounds), like a nail or needle
• Burns
• Crush injuries
• Injuries with dead tissue
• Clean superficial wounds (when only the topmost layer of skin is scraped off)
• Surgical procedures
• Insect bites
• Dental infections
• Compound fractures (a break in the bone where it is exposed)
• Chronic sores and infections
• Intravenous (IV) drug use
• Intramuscular injections (shots given in a muscle)

Opisthotonus in a patient suffering from tetanus

Pathogenesis

Clostridium tetani (C. tetani) spores usually enter the body through a wound or breach in the skin. Neonatal tetanus usually occurs because of umbilical stump infections. In the presence of anaerobic conditions, the spores germinate. The bacteria produce very potent toxins, most of which the blood stream and lymphatic system disseminate through the body. Toxins act at several sites within the central nervous system, including peripheral motor end plates, spinal cord, and brain, as well as in the sympathetic nervous system. Tetanus toxin causes the typical clinical manifestations of tetanus by interfering with the release of neurotransmitters and blocking inhibitor impulses. This leads to unopposed muscle contraction and spasm. Seizures may occur, and the autonomic nervous system may also be affected.

Types

There are three clinical forms of tetanus:

1. Generalized
2. Localized
3. Cephalic

Generalized Tetanus Generalized tetanus is the most common form, accounting for more than 80% of cases. The most common initial sign is spasm of the muscles of the jaw or “lockjaw”. Other signs may follow “lockjaw.” These can include painful spasms in other muscle groups in the neck, trunk, and extremities and generalized, seizure-like activity or convulsions in severe cases. Nervous system abnormalities, as well as a variety of complications related to severe spasm and prolonged hospitalization, can accompany generalized tetanus. The clinical course of generalized tetanus is variable and depends on the

• Degree of prior immunity
• Amount of toxin present
• Age and general health of the patient
• Even with modern intensive care, generalized tetanus is associated with death rates of 10% to 20%.

Localized Tetanus Localized tetanus is an unusual form of the disease consisting of muscle spasms in a confined area close to the site of the injury. Although localized tetanus often occurs in people with partial immunity and is usually mild, progression to generalized tetanus can occur.

Cephalic Tetanus The rarest form, cephalic tetanus, is associated with lesions of the head or face and may also be associated with otitis media. The incubation period is short, usually 1 to 2 days. Unlike generalized and localized tetanus, cephalic tetanus results in flaccid cranial nerve palsies rather than spasm. Spasm of the jaw muscles may also be present. Like localized tetanus, cephalic tetanus can progress to the generalized form.

Symptoms

People often call tetanus “lockjaw” because one of the most common signs of this infection is tightening of the jaw muscles. Tetanus infection can lead to serious health problems, including being unable to open the mouth and having trouble swallowing and breathing. Symptoms of tetanus include:

• The first sign is most commonly spasms of the muscles of the jaw, or “lockjaw.”
• Jaw cramping
• Sudden, involuntary muscle tightening (muscle spasms) — often in the stomach
• Painful muscle stiffness all over the body
• Trouble swallowing
• Jerking or staring (seizures)
• Headache
• Fever and sweating
• Changes in blood pressure and heart rate.

Complications

• Serious health problems that can happen because of tetanus include:
• Uncontrolled/involuntary tightening of the vocal cords (laryngospasm)
• Broken bones (fractures)
• Infections gotten by a patient during a hospital visit (hospital-acquired infections)
• Blockage of the main artery of the lung or one of its branches by a blood clot that has travelled from elsewhere in the body through the bloodstream (pulmonary embolism)
• Pneumonia, a lung infection, that develops by breathing in foreign materials (aspiration pneumonia)
• Breathing difficulty, possibly leading to death (1 to 2 in 10 cases are fatal)

Diagnosis

Doctors can diagnose tetanus by examining the patient and looking for certain signs and symptoms. There are no hospital lab tests that can confirm tetanus.

Treatment

Tetanus is a medical emergency requiring:

• Care in the hospital
• Immediate treatment with medicine called human tetanus immune globulin (TIG)
• Aggressive wound care
• Drugs to control muscle spasms
• Antibiotics
• Tetanus vaccination
• Depending on how serious the infection is, a machine to help you breathe may be required.

Treatment of tetanus cases with TIG

• Medical experts recommend a single dose of human TIG for treatment of persons with tetanus. Researchers have not established the optimal therapeutic dose. However, experts recommend 500 international units (IU), which appears to be as effective as higher doses ranging from 3,000 to 6,000 IU and causes less discomfort.

• If TIG is not available, clinicians can use IGIV at a dose of 200 to 400 milligrams per kilogram (mg/kg). However, the Food and Drug Administration has not approved IGIV for this use. In addition, anti-tetanus antibody content varies from lot to lot.

Vaccination during Recovery Tetanus disease does not result in tetanus immunity. Clinicians should begin or continue active immunization with a tetanus toxoid-containing vaccine as soon as the person’s condition has stabilized.

Prevention

Vaccination and good wound care are important to help prevent tetanus infection.

Vaccination Being up to date with your tetanus vaccine is the best tool to prevent tetanus.Protection from vaccines, as well as a prior infection, do not last a lifetime. This means that if you had tetanus or got the vaccine before, you still need to get the vaccine regularly to keep a high level of protection against this serious disease.

Several vaccines protect against tetanus, all of which also protect against other diseases:

• DTaP protects against diphtheria, tetanus, and pertussis (whooping cough)
• DT protects against diphtheria and tetanus
• Tdap protects against tetanus, diphtheria, and pertussis
• Td protects against tetanus and diphtheria

Good Wound Care Immediate and good wound care can also help prevent infection.

• Don’t delay first aid of even minor, non-infected wounds like blisters, scrapes, or any break in the skin.
• Wash hands often with soap and water or use an alcohol-based hand rub if washing is not possible.

External links

• CDC tetanus page
• Mayo Clinic

Tetanus Resources
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NIH genetic and rare disease info

• NIH info on Tetanus

Tetanus is a rare disease.