Tetanus (redirected from Tetnis)

Tetanus 

Definition

Tetanus is a rare but often fatal disease that affects the central nervous system by causing painful muscular contractions. It begins when tetanus bacteria enter the body, usually through a wound or cut exposed to contaminated soil. Tetanus is easily preventable through vaccination.

Description

Tetanus is rare in the United States, with nearly all cases occurring in adults who were not vaccinated as children. About 100 cases are reported each year; 63% of these occur in people over the age of 50. The number of tetanus cases in the United States has steadily decreased since the 1940s (500 to 600 cases per year); the number of reported cases has remained at approximately 50 to 100 cases per year since the mid-1970s. In 1999, however, the lowest number of annual cases to date was reported (33, or 0.02 per 100,000).

Tetanus causes convulsive muscle spasms and rigidity that can lead to respiratory paralysis and death. It is sometimes called "lockjaw" because one of the most common symptoms is a stiff jaw, unable to be opened. Sometimes, tetanus affects only the part of the body where the infection began, but in almost all of reported cases, it spreads to the entire body. The incubation period from the time of the injury until the first symptoms appear ranges from two to 50 days. Symptoms usually occur within five to 10 days. When symptoms occur early, the chance of death is increased. Tetanus is not contagious.

Causes and symptoms

Tetanus is caused by a bacteria called Clostridium tetani, whose spores (the dormant form) are found in soil, street dust, and animal (or even human) feces. Tetanus spores germinate in the body, producing a highly poisonous neurotoxin in the blood, spreading to the nervous system. The infection is usually transmitted through deep puncture wounds or cuts or scratches that are not cleaned well. Between 1997 and 1999, approximately 64% of tetanus cases in the United States were associated with such wounds as punctures, lacerations, or abrasions. Many people associate tetanus with rusty nails and other dirty objects, but any wound can be a source. Less common ways of getting tetanus are animal scratches and bites, surgical wounds, dental work, and therapeutic abortion. About 18% of cases reported between 1997 and 1999 were a result of intravenous drug use. Cases have also been reported in people with no known wound or medical condition.

The first symptom of tetanus is often a stiff or "locked" jaw that prevents the patient from opening his/her mouth or swallowing. This is also called trismus and results in a facial expression called a sardonic smile (or risus sardonicus). Stiffness of the neck and other muscles throughout the body and uncontrollable spasms often follow. Sometimes these convulsions are severe enough to cause broken bones. The bacterial toxin (tetanospasmin) affects the nerve endings, causing a continuous stimulation of muscles. Other symptoms include irritability, restlessness, loss of appetite, and drooling. People with tetanus that is localized experience pain and tingling only at the wound site and spasms in nearby muscles.

In the underdeveloped world, neonatal tetanus accounts for about one-half of tetanus deaths and is related to infection of the umbilical stump in a baby born of an unimmunized mother. The Centers for Disease Control and Prevention (CDC) estimate that over 270,000 deaths occur annually worldwide as a result of neonatal tetanus. In contrast, only two cases of neonatal tetanus in the United States were reported to the CDC between 1989 and 1999. Mothers who have been adequately immunized against tetanus protect their newborns by passing the antibody through the placenta.

Diagnosis

Tetanus is diagnosed by the clinical symptoms and a medical history that shows no tetanus immunization. Early diagnosis and treatment is crucial to recovery from tetanus.

Treatment

Tetanus is a life-threatening disease that requires immediate hospitalization, usually in an intensive care unit (ICU). Treatment can take several weeks and includes antibiotics to kill the bacteria and shots of antitoxin to neutralize the toxin. It also includes muscle-relaxing drugs to control muscle spasms or barbiturates for sedation. In severe cases, patients are placed on an artificial respirator. Recovery can take six weeks or more. After recovery, since the levels of circulating toxin are too low to stimulate natural antibody production, the patient must still be immunized against this disease to prevent reinfection.

Prognosis

Up to 30% of tetanus victims in the United States die. Early diagnosis and treatment improves the prognosis. Neonatal tetanus has a mortality rate of more than 90%.

Prevention

Pre-exposure vaccination

Tetanus is easily preventable through vaccination. All children should have a series of five doses of DTaP, a combined vaccine that offers protection against diphtheria, tetanus, and pertussis, before the age of seven, according to the Centers for Disease Control and Prevention's national immunization guidelines, the Advisory Committee on Immunization Practices, the Committee on Infectious Diseases of the American Academy of Pediatrics, and the American Academy of Family Physicians. Children will not be admitted to school without proof of this and other immunizations.

The DTaP (diptheria, tetanus, accellular pertussis) vaccine should be given at ages two months, four months, six months, 15 to 18 months, and four to six years. DTaP is the preferred vaccine for children up to the age of seven in the United States; it has fewer side effects than DTP and can be used to complete a vaccination schedule begun with DTP. DTaP was first approved by the Food and Drug Administration (FDA) in September 1996. In December 1996, it was approved for use in infants. Between the ages of 11 and 13, children should have a booster for diphtheria and tetanus, called Td.

Adults should have a Td booster every 10 years. Statistics from the Centers for Disease Control and Prevention (CDC) show that fewer than half of Americans 60 years of age and older have antibodies against tetanus. The CDC suggests adults may be revaccinated at mid-decade birthdays (for example, 45, 55). Adults who have never been vaccinated against tetanus should get a series of three injections of Td over six to 12 months and then follow the 10-year booster shot schedule.

Side effects of the tetanus vaccine are minor: soreness, redness, or swelling at the site of the injection that appear anytime from a few hours to two days after the vaccination and go away in a day or two. Rare but serious side effects that require immediate treatment by a doctor are serious allergic reactions or deep, aching pain and muscle wasting in the upper arms. These symptoms could start from two days to four weeks after the shot and could continue for months.

In early 2001, a shortage of the tetanus vaccine became evident after the pharmaceutical company Wyeth-Ayerst Laboratories decided to stop production of the tetanus vaccine, leaving Aventis-Pasteur as the sole manufacturer of the vaccine. As a result, hospitals were provided with only a minimal amount of the drug on a weekly basis—enough to vaccinate patients with potentially infected wounds and other priority cases. Despite stepped-up production efforts on the part of the manufacturer, however, a spokesperson for Aventis-Pasteur predicted that the shortage would last until the end of 2001, as the vaccine takes 11 months to produce.

Post-exposure care

Keeping wounds and scratches clean is important in preventing infection. Since this organism grows only in the absence of oxygen, wounds must be adequately cleaned of dead tissue and foreign substances. Run cool water over the wound and wash it with a mild soap. Dry it with a clean cloth or sterile gauze. To help prevent infection, apply an antibiotic cream or ointment and cover the wound with a bandage. The longer a wound takes to heal, the greater the chance of infection. If the wound doesn't heal, or, it is red, warm, drains, or swells, consult a doctor.

Following a wound, to produce rapid levels of circulating antibody, a doctor may administer a specific antitoxin (human tetanus immune globulin, TIG) if the individual does not have an adequate history of immunization. The antitoxin is given at the same sitting as a dose of vaccine but at separate sites. Some individuals will report a history of significant allergy to "tetanus shots." In most cases, this occurred in the remote past and was probably due to the previous use of antitoxin derived from horse serum.

Key terms

Clostridium — A genus of deadly bacteria that are responsible for tetanus and other serious diseases, including botulism and gangrene from war wounds. Clostridia thrives without oxygen.

DTaP — Diphtheria and tetanus toxoids and accellular pertussis combination vaccine.

DTP — Diphtheria, tetanus, and whole-cell pertussis vaccine.

Td — Tetanus and diphtheria vaccine.

Toxin — A poisonous substance that flows through the body.

Wound — Any injury that breaks the skin, including cuts, scratches, and puncture wounds.

Resources

Periodicals

Landers, Susan J. "Tetanus vaccine shortage leads to rationing." American Medical News. March 19, 2001. 〈http://www.ama-assn.org/sci-pubs/amnews/pick_01/hlsb0319.htm〉.

Other

"Tetanus." Centers for Disease Control and Prevention. http://www.cdc.gov/nip/publications/pink/tetanus.pdf.

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tetanus /tet·a·nus/ (tet´ah-nus)

1. an acute, often fatal, infectious disease caused by a neurotoxin (tetanospasmin) produced by Clostridium tetani, whose spores enter the body through wounds. There are two forms: generalized tetanus, marked by tetanic muscular contractions and hyperreflexia, resulting in trismus (lockjaw), glottal spasm, generalized muscle spasm, opisthotonos, respiratory spasm, seizures, and paralysis; and localized tetanus, marked by localized muscular twitching and spasm, which may progress to the generalized form.

2. a state of muscular contraction without periods of relaxation.

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neonatal tetanus , tetanus neonato´rum tetanus of very young infants, usually due to umbilical infection.

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tet·a·nus (ttn-s)

n.

1. An acute, often fatal disease that is characterized by spasmodic contraction of voluntary muscles, especially one occurring in the neck and jaw, and that is caused by the bacterium Clostridium tetani, which usually enters the body through an infected wound and produces a neurotoxin. Also called lockjaw.

2. A state of continuous muscular contraction, especially when induced artificially by rapidly repeated stimuli.

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tetanus,

n a spastic/paralytic condition of the central nervous system caused by an exotoxin known as tetanospasmin produced by
Clostridium tetani, an anaerobic bacillus that enters the body through an abrasion, puncture wound, burn, or laceration; characterized by headache, irritability, and painful muscle spasms that cause risus sardonicus, lockjaw, laryngeal spasm, and opisthotonos. Can be fatal.

Tetanus: characteristic muscle spasms.

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tetanus (tet´ns),

n an acute, potentially fatal infection of the central nervous system caused by tetanospasmin, which is an exotoxin, elaborated by an anaerobic bacillus,
C. tetani.

tetanus and diphtheria toxoids (Td),

n an active immunizing agent containing detoxified tetanus and diphtheria toxoids that slowly produce an antigenic response to the diseases. Typically administered as part of the immunization series of preschool children.

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tetanus

a highly fatal disease of all animal species caused by the neurotoxin of Clostridium tetani. The bacterial spores are deposited in tissue, usually by traumatic injury, retained placenta or endometrial injury and under anaerobic conditions vegetate. Clinical features of the disease are remarkably similar in all species but there are differences in susceptibility to the disease. The muscle spasms cause a stiff gait, rigid posture (sometimes called 'sawhorse stance'), extension or elevation of the tail, protrusion of the third eyelid and trismus (lockjaw). Horses show flaring of the nostrils. In dogs, spasms of facial muscles cause abnormally erect ears and retraction of the lips that resembles the 'risus sardonicus' seen in humans with tetanus. Stimulation precipitates generalized muscle contractions and tetanic spasms or convulsions. The disease can be prevented by immunization with tetanus toxoid or the use of antitoxin, but this is done routinely only in humans and horses.

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tetanus antitoxin

see tetanus antitoxin.

idiopathic tetanus

a loosely defined syndrome of outbreaks of tetanus in young cattle without a wound being found; current practice is to refer to such outbreaks as being caused by the ingestion of pre-formed tetanus toxin.

localized tetanus

tetany occurs predominantly in one limb, closest to the site of entry of the organism, but then usually spreads to the opposite limb and then the whole body. Seen in dogs and particularly cats.

tetanus toxin

see tetanus toxin.

tetanus toxoid

see toxoid.

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tetanus Lockjaw Infectious disease Acute infection by the anaerobic spore-forming bacillus Clostridium tetani, manifest by uncontrolled muscle spasms due to tetanospasmin; it is often fatal, especially at the extremes of age, and preventable by immunization Epidemiology C tetani is ubiquitous, and may infect virtually any open wound; no longer a major health problem in socioeconomically advanced countries or the US–incidence ± 0035/105, in developing nations, it is a 'top 10' killer, causing ±1 million deaths/yr Substrate Tetanus develops in a menagerie of mishaps from minor mayhem to sloppy abortions, ♀ circumcision, and so on, rolling rural romanticism into a reality sandwich Clinical ±2 wk incubation, followed by localized or generalized weakness, cramping, dysphagia, trismus–lockjaw, ↑ muscle rigidity–eg, risus sardonicus, opisthotonus, laryngospasm, and ± death Management Benzodiazepines–↓ anxiety, sedation, anticonvulsant, muscle relaxant facilitating GABA-inhibitory transmission in the brain stem and spinal cord, ventilatory support, tetanus immune globulin Vaccine The tetanus vaccine is 96% effective; in the US rates of immunity to tetanus ranges from 80% in white ♂ to < 20% in Mexican-American ♀; immunity is ↑ in those with a ↑ education and income See Clostridium tetani Cf Tetany Neurology Tonic muscle contraction, see there.