An Overview of Tetanus

Causes, Treatment, and Prevention of Lockjaw

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Tetanus is a serious but preventable bacterial infection that affects the nerves. Commonly referred to as lockjaw, the disease is spread by contact with an object or surface that has been contaminated with Clostridium tetani. Transmission is most often the result of a puncture wound that provides the bacterium easy access into the body.

Tetanus can be prevented with a simple vaccine. However, if you have not been vaccinated and are infected, the disease can cause muscle spasms ranging from mild to life-threatening. There are currently no blood tests available to diagnose tetanus. As such, treatment would begin upon the appearance of symptoms and may include a tetanus antitoxin, intravenous antibiotics, antispasmodic drugs, and mechanical ventilation.

If left untreated, a tetanus infection can progress from mild spasms to powerful whole-body contractions, suffocation, and heart attack.

There is no cure for tetanus.

Types

In addition to generalized tetanus, there are other, less common forms of the disease:

  • Local tetanus only affects the muscles around the immediate area of infection. The spasms tend to be mild and last for only a few weeks, although they can sometimes precede generalized tetanus.
  • Cephalic tetanus is limited only the muscles of the head. It usually occurs after an injury to the head such as a skull fracture, laceration, or even a tooth extraction. Paralysis of the facial nerve is the most common symptom, resulting in lockjaw, Bell’s palsy, or the drooping of the upper eyelid (ptosis). Cephalic tetanus will almost always progress to generalized tetanus but tends to be far more serious, with a 15 to 30 percent risk of death.
  • Neonatal tetanus involves newborns of mothers who have not been vaccinated for tetanus. Because the baby has no inborn immunity to C. tetani, it is vulnerable to infection, most often as a result of an infected umbilical stump. Symptoms usually appear within a week, translating to a greater than 70 risk of death. While rare in the developed world, neonatal tetanus is the second leading cause of vaccine-preventable diseases among children worldwide.

    Symptoms

    Tetanus typically begins with mild spasms of the jaw muscles, referred to as trismus or lockjaw. The facial muscles may also be affected, causing a spontaneous grimace or grinning expression, referred to as risus sardonicus.

    In cases of generalized tetanus, the involuntary contractions will descend from the head and eventually affect the entire body. This is the typical pattern in around 80 percent of cases. From the jaw and face, the spasms will move downward to cause neck stiffness, difficulty swallowing, and rigidity of the chest and calf muscles.

    As the spasms worsen, they can lead to painful contractions, known as opisthotonos, in which the entire body will literally arch with spasms from the head right down through the neck, back, buttocks, and legs. The contractions can last for minutes at a time and become so violent that they tear muscles and break bones. Other common symptoms include sweating, episodic high blood pressure, and the episodic loss of bowel and bladder control.

    The spasms can also close off breathing passages, resulting in the shortness of breath, choking, and periods when there is no breathing at all. The episodes are often triggered by minor stimuli, such as a sudden draft, loud noise, bright light, or even a light touch.

    In severe cases, sympathetic overactivity (SOA) will occur in which sympathetic nerves, which govern involuntary body responses, are hyperstimulated, triggering the spasmodic constriction of blood vessels. Symptoms of SOA include:

    • Episodic and volatile high blood pressure (paroxysmal hypertension)
    • Rapid heart rate (tachycardia)
    • Irregular heart rate (arrhythmia)
    • Profuse sweating
    • High fever (over 100.4 F)

    In combination with tetanus-induced spasms, SOA can trigger life-threatening complications including pulmonary embolism (blood clot in the lungs) and heart attack. Respiratory failure is the most common cause of death.

    Even with comprehensive treatment, 10 percent of tetanus infections will result in death.

    Causes

    Clostridium tetani is an anaerobic bacterium, meaning that it cannot live or grow where oxygen is present. When exposed to air, the bacterium will form a protective spore which allows it to remain in a dormant state, largely impervious to heat, dryness, ultraviolet radiation, or household disinfectants.

    The spores can remain viable for years in soil and be reactivated when it is returned to a favorable moist environment. One such environment is a deep puncture wound in which the reactivated bacteria is able to establish an infection.

    Once in the body, tetanus will release toxins—known as tetanospasmin toxins—that bind to nerve cells. The toxins will then spread through peripheral nerves until they finally reach the central nervous system (the brain and spinal cord). As the bacteria multiply and amplify this effect, the tetanospasmin toxins will begin to block the production of certain chemical messengers, known as neurotransmitters, that control voluntary muscle movement.

    In terms of toxicity, tetanospasmin toxin is the second deadliest bacterial neurotoxin next to the botulinum toxin found in Botox.

    Routes of Transmission

    Tetanus occurs almost exclusively in people who have not been vaccinated against C. tetani. It is seen more commonly in warm, moist climates and in areas where there is a lot of manure in the soil.

    The disease has long been associated with puncture wounds caused by rusty nails. While the rust itself plays no role in the transmission of the disease—a common misconception—it readily harbors C. tetani spores. Stepping on a nail simply delivers the spores deeper into the body, whether it is rusty or not.

    Tetanus is also associated with injecting heroin use, usually as the result of spores found in contaminated heroin rather than on the needle itself. Animal bites can also transmit the bacterium, as can compound bone fractures, burns, and body piercings or tattoos performed with unsterile equipment.

    While dental procedures have also been implicated, they most commonly occur in developing countries where standard surgical hygiene practices are not in place. Medical procedures, such as surgery or injections, are unlikely routes of transmission.

    Today, with routine vaccination of children and adults, only around 30 cases of tetanus occur in the U.S. each year. Worldwide, tetanus causes around 60,000 deaths annually.

    Diagnosis

    There are no blood tests able to diagnose tetanus. While a bacterial culture may provide evidence of an infection (by extracting a fluid sample from an open wound), it has a true positive rate of only around 30 percent.  Because of this, tetanus will be treated presumptively based on the appearance of symptoms and your vaccination history.

    One in-office procedure that may support a diagnosis is the spatula test. This involves the insertion of a tongue depressor in the back of your throat. If you have been infected, you would react abnormally and reflexively bite down on the depression. If you have not been infected, the natural gag reflex would compel you to push the depressor out of your mouth.

    In cases where the symptoms are either inconsistent or non-specific, your doctor may order tests to check for other possible causes. The differential diagnoses may include:

    • Diphtheria
    • Generalized seizures
    • Hypercalcemia (excess calcium in the blood)
    • Intracranial hemorrhage (a brain bleed)
    • Meningitis (inflammation of the membrane surrounding the spinal cord)
    • Meningoencephalitis (inflammation of the membrane around both the spinal cord and brain)
    • Neuroleptic malignant syndrome (an uncommon, life-threatening reaction to an antipsychotic drug)
    • Stiff person syndrome (a rare autoimmune disorder)
    • Strychnine poisoning

    Treatment

    The treatment of tetanus will vary based on your vaccination status.

    If you have a deep wound but have been previously vaccinated against tetanus, you may be given a drug called tetanus immunoglobin (TIG). Also known as tetanus antitoxin, TIG is a medication made up of immune proteins, known as antibodies, that are able to neutralize the tetanospasmin toxin. TIG is delivered by an injection into the muscle of either the upper arm or thigh. Localized pain and swelling are the most common side effects.

    However, if you have not been vaccinated or did not complete your vaccine series, TIG may be given alongside the appropriate round of vaccinations (see below). This would need to be started as soon as possible after the injury, ideally no less than 48 hours.

    If you have symptoms of tetanus, you would need to be hospitalized and undergo a more aggressive course of treatment. The course of treatment would vary based on the severity of your symptoms.

    Mild tetanus would typically involve the involve treatments:

    • TIG, given intramuscularly or intravenously
    • Flagyl (metronidazole), a broad-spectrum antibiotic, given intravenously for 10 days
    • Valium (diazepam), a psychoactive drug used to reduce seizures, delivered either orally or intravenously

    Severe tetanus may involve multiple medications and mechanical interventions to prevent some of the more severe manifestations of the disease. Options may include:

    • TIG, delivered intrathecally (into the spinal cord)
    • Tracheotomy (an incision in the windpipe) and the insertion of an endotracheal tube to aid in mechanical respiration
    • Magnesium sulfate, also known as Epsom salt, delivered intravenously to control spasms
    • Valium (diazepam), given as a continuous intravenous infusion to relax muscles
    • Adalat (nifedipine) or labetalol, delivered intravenously to reduce blood pressure
    • Morphine to alleviate pain and induce sedation

    To maintain nutrition, a high-calorie diet may be delivered in liquid form through either a drip in the arm (parenteral nutrition) or through a tube inserted into the stomach (percutaneous gastrostomy).

    Severe cases may require four to six weeks of hospitalization before you are stable enough to be released, although it can take months to recover from some of the damage done to the central nervous symptom. While most adults can achieve recovery, tetanus seizures can cause permanent brain damage in infants due to the restriction of oxygen.

    Vaccination

    Since the introduction of the tetanus vaccine in the 1940s, the rate of tetanus infections worldwide has decreased by over 95 percent. Today, the tetanus vaccine is combined with other vaccines able to prevent common childhood diseases.

    They include:

    Primary Vaccination Series

    The DTaP vaccine provides protection against three diseases: diphtheria (a bacterial respiratory infection, pertussis (also known as whooping cough), and tetanus. The DTaP vaccine is given in a series of three shots in the upper arm or thigh at the following intervals:

    • Two months
    • Four months
    • Six months
    • 15 to 18 months
    • Four to six years

    Booster Vaccination

    It is also recommended that adolescents get a dose of the Tdap vaccine between the ages of 11 and 12. Thereafter, a Td booster shot should be given every 10 years.

    A similar protocol would be applied to adults who have either not been vaccinated or never completed the vaccine series. In such case, the Tdap or Td vaccine can be delivered as a single injection, followed by Td booster shots every 10 years.

    Post-Exposure Prevention

    In the event of a suspected exposure to tetanus without symptoms, the Tdap vaccine may be given as a means to avert infection. Known as post-exposure prophylaxis (PEP), it is indicated for people who have not been previously vaccinated for tetanus, did not complete the vaccine series, or are unsure of their status. It should be given within 48 hours of the injury, either with or without TIG.

    You may or may not be given the PEP vaccine under the following conditions

    • If you have had less than three previous vaccine doses but a booster shot less than five years ago, no vaccination is needed.
    • If you have had less than three previous vaccine doses and a booster shot between five and 10 years ago, you would be given Tdap (preferred) or Td.
    • If you have had less than three previous vaccine doses and a booster shot more than 10 years ago, you would be given Tdap (preferred) or Td.
    • If you have had less than three previous vaccine doses with no booster shot, you would be given Tdap along with TIG.
    • If you have never been vaccinated or are of unknown status, both Tdap and TIG would be given.

    A Word From Verywell

    Even though tetanus is rare in the United States, you would still need to take the appropriate precautions if you experience any significant break in the skin to prevent C. tetani or any other potentially serious infection.

    If you get a cut or puncture wound, is important to clean it immediately with hot water and soap. Take extra care to remove any dirt, foreign object, or dead tissue that may be embedded in the wound. If you cannot clean the wound on your own, see your doctor or visit the nearest urgent care clinic.

    After cleaning the wound, apply an antibiotic cream or ointment, such as Neosporin or Bacitracin, and cover the wound with a sterile bandage or gauze. Change the dressing once a day or as needed, and avoid getting the wound wet.

    If you develop any worrying symptoms, do not hesitate to call your doctor or seek treatment as soon as possible. Bring your immunization records if you can to ensure you are given the appropriate treatment.

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