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The clinical manifestations of tetanus are caused when tetanus toxin blocks inhibitory nerve impulses, by interfering with the release of [[neurotransmitter]]s. This leads to unopposed muscle contraction and spasm. [[Seizures]] may occur, and the [[autonomic nervous system]] may also be affected. The term [[tetany]] refers to sustained muscle contraction that is not caused by tetanus. | The clinical manifestations of tetanus are caused when tetanus toxin blocks inhibitory nerve impulses, by interfering with the release of [[neurotransmitter]]s. This leads to unopposed muscle contraction and spasm. [[Seizures]] may occur, and the [[autonomic nervous system]] may also be affected. The term [[tetany]] refers to sustained muscle contraction that is not caused by tetanus. | ||
==Historical Perspective== | |||
Tetanus was first produced by Carle and Rattone in 1884 in animals by injecting them with [[pus]] from a fatal human tetanus case.Tetanus [[toxoid]] was developed by Descombey in 1924 and It was widely used during World War II. | |||
==Pathophysiology== | |||
Clostridium tetani enters the body through a [[wound]]. Toxins are produced and disseminated via [[blood]] and [[lymphatics]]. [[Toxins]] act at several sites within the [[central nervous system]], including [[peripheral]] motor end plates, [[spinal cord]], and [[brain]], and in the [[sympathetic nervous system]]. | |||
==Causes== | |||
''Clostridium tetani'' is a rod-shaped, anaerobic [[bacterium]] of the genus ''[[Clostridium]]''. Like other ''Clostridium'' species, it is [[Gram-positive]], and its appearance on a [[gram stain]] resembles tennis rackets or drumsticks.<ref name=Sherris>{{cite book | author = Ryan KJ; Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | publisher = McGraw Hill | year = 2004 | id = ISBN 0838585299 }}</ref> ''C. tetani'' is found as [[endospore|spores]] in soil or as [[parasite]]s in the [[gastrointestinal tract]] of animals. ''C. tetani'' produces a potent biological toxin, [[tetanospasmin]], and is the causative agent of [[tetanus]]. | |||
==Differentiating Tetanus from other Diseases== | |||
Tetanus must be differentiated from *[[Strychnine poisoning]]s differential diagnosis== | |||
==Epidemiology and Demographics== | |||
Tetanus is the only vaccine-preventable disease that is [[infectious disease|infectious]] but is not contagious. In the US, there are fewer than 100 cases and approximately five deaths each year. There are about one million cases of tetanus reported worldwide, causing an estimated 300,000 to 500,000 deaths each year. | |||
==Risk Factors== | ==Risk Factors== | ||
People in developing countries are more at risk because of lack of vaccination. | People in developing countries are more at risk because of lack of vaccination. | ||
==Natural History, Complications and Prognosis== | |||
The fatality rate of Tetanus is approximately 11% of reported cases. It may be associated with prolonged [[contractions]] and [[convulsions]] | |||
==Diagnosis== | ==Diagnosis== | ||
===History and Symptoms=== | |||
Tetanus incubation period ranges from 3 to 21 days. Tetanus may present with either Local Tetanus, Cephalic Tetanus or Generalized Tetanus. Neonatal Tetanus occurs through infection of the unhealed umbilical stump, particularly when the stump is cut with a non-sterile instrument. | |||
===Physical Examination=== | ===Physical Examination=== | ||
The diagnosis of tetanus is completed through a physical examination. Tetanus infection produces some very clear symptoms that will be used for a clinical diagnosis. | The diagnosis of tetanus is completed through a physical examination. Tetanus infection produces some very clear symptoms that will be used for a clinical diagnosis. | ||
===Laboratory Findings=== | ===Laboratory Findings=== | ||
There are no laboratory findings characteristic of tetanus. The [[diagnosis]] is entirely clinical and does not depend upon [[bacteriologic]] confirmation. C. tetani is recovered from the [[wound]] in only 30% of cases and can be isolated from patients who do not have tetanus. Laboratory identification of the [[organism]] depends most importantly on the demonstration of [[toxin]] production in mice. | There are no laboratory findings characteristic of tetanus. The [[diagnosis]] is entirely clinical and does not depend upon [[bacteriologic]] confirmation. C. tetani is recovered from the [[wound]] in only 30% of cases and can be isolated from patients who do not have tetanus. Laboratory identification of the [[organism]] depends most importantly on the demonstration of [[toxin]] production in mice. | ||
==Treatment== | ==Treatment== | ||
===Medical Therapy=== | |||
Dead and infected tissue should be removed by surgical [[debridement]]. [[Metronidazole]] treatment decreases the number of [[bacteria]] but has no effect on the bacterial toxin. [[Passive immunization]] with human anti-[[tetanospasmin]] [[immunoglobulin]] or tetanus immune globulin is crucial. Drugs such as [[chlorpromazine]] or [[diazepam]], or other muscle relaxants can be given to control the muscle spasms | |||
===Primary Prevention=== | ===Primary Prevention=== | ||
A very common primary prevention method for tetanus is vaccinating against the [[bacteria]] which causes tetanus, clostridium tetani. | A very common primary prevention method for tetanus is vaccinating against the [[bacteria]] which causes tetanus, clostridium tetani. | ||
===Secondary Prevention=== | |||
Tetanus vaccine can prevent Tetanus for approximately 10 years. Post-exposure care is indicated in people who do not know exactly when their last Tetanus booster was and who did not complete their primary prevention set of vaccinations. These patients will typically receive [[passive immunity]] with tetanus immune globulin (TIG). | |||
===Cost-Effectiveness of Therapy=== | ===Cost-Effectiveness of Therapy=== | ||
Revision as of 14:52, 6 August 2015
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Tetanus overview On the Web |
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American Roentgen Ray Society Images of Tetanus overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Tetanus is a medical condition that is characterized by a prolonged contraction of skeletal muscle fibers. The primary symptoms are caused by tetanospasmin, a neurotoxin produced by the Gram-positive, obligate anaerobic bacterium Clostridium tetani. Infection generally occurs through wound contamination, and often involves a cut or deep puncture wound. As the infection progresses, muscle spasms in the jaw develop hence the common name, lockjaw. This is followed by difficulty swallowing and general muscle stiffness and spasms in other parts of the body.[1] Infection can be prevented by proper immunization and by post-exposure prophylaxis.[2]
Tetanus affects skeletal muscle, a type of striated muscle. The other type of striated muscle, cardiac or heart muscle cannot be tetanized because of their intrinsic electrical properties. In recent years, approximately 11% of reported tetanus cases have been fatal. The highest mortality rates are in unvaccinated persons and persons over 60 years of age. C. tetani, the bacteria that causes tetanus, is recovered from the initial wound in only about 30% of cases, and can be found in patients who do not have tetanus.
The clinical manifestations of tetanus are caused when tetanus toxin blocks inhibitory nerve impulses, by interfering with the release of neurotransmitters. This leads to unopposed muscle contraction and spasm. Seizures may occur, and the autonomic nervous system may also be affected. The term tetany refers to sustained muscle contraction that is not caused by tetanus.
Historical Perspective
Tetanus was first produced by Carle and Rattone in 1884 in animals by injecting them with pus from a fatal human tetanus case.Tetanus toxoid was developed by Descombey in 1924 and It was widely used during World War II.
Pathophysiology
Clostridium tetani enters the body through a wound. Toxins are produced and disseminated via blood and lymphatics. Toxins act at several sites within the central nervous system, including peripheral motor end plates, spinal cord, and brain, and in the sympathetic nervous system.
Causes
Clostridium tetani is a rod-shaped, anaerobic bacterium of the genus Clostridium. Like other Clostridium species, it is Gram-positive, and its appearance on a gram stain resembles tennis rackets or drumsticks.[3] C. tetani is found as spores in soil or as parasites in the gastrointestinal tract of animals. C. tetani produces a potent biological toxin, tetanospasmin, and is the causative agent of tetanus.
Differentiating Tetanus from other Diseases
Tetanus must be differentiated from *Strychnine poisonings differential diagnosis==
Epidemiology and Demographics
Tetanus is the only vaccine-preventable disease that is infectious but is not contagious. In the US, there are fewer than 100 cases and approximately five deaths each year. There are about one million cases of tetanus reported worldwide, causing an estimated 300,000 to 500,000 deaths each year.
Risk Factors
People in developing countries are more at risk because of lack of vaccination.
Natural History, Complications and Prognosis
The fatality rate of Tetanus is approximately 11% of reported cases. It may be associated with prolonged contractions and convulsions
Diagnosis
History and Symptoms
Tetanus incubation period ranges from 3 to 21 days. Tetanus may present with either Local Tetanus, Cephalic Tetanus or Generalized Tetanus. Neonatal Tetanus occurs through infection of the unhealed umbilical stump, particularly when the stump is cut with a non-sterile instrument.
Physical Examination
The diagnosis of tetanus is completed through a physical examination. Tetanus infection produces some very clear symptoms that will be used for a clinical diagnosis.
Laboratory Findings
There are no laboratory findings characteristic of tetanus. The diagnosis is entirely clinical and does not depend upon bacteriologic confirmation. C. tetani is recovered from the wound in only 30% of cases and can be isolated from patients who do not have tetanus. Laboratory identification of the organism depends most importantly on the demonstration of toxin production in mice.
Treatment
Medical Therapy
Dead and infected tissue should be removed by surgical debridement. Metronidazole treatment decreases the number of bacteria but has no effect on the bacterial toxin. Passive immunization with human anti-tetanospasmin immunoglobulin or tetanus immune globulin is crucial. Drugs such as chlorpromazine or diazepam, or other muscle relaxants can be given to control the muscle spasms
Primary Prevention
A very common primary prevention method for tetanus is vaccinating against the bacteria which causes tetanus, clostridium tetani.
Secondary Prevention
Tetanus vaccine can prevent Tetanus for approximately 10 years. Post-exposure care is indicated in people who do not know exactly when their last Tetanus booster was and who did not complete their primary prevention set of vaccinations. These patients will typically receive passive immunity with tetanus immune globulin (TIG).
Cost-Effectiveness of Therapy
The major cost encountered with tetanus is in the form of the vaccine. There are many different trade names associated with the tetanus vaccine that come with slightly different costs. The prices of the vaccines are all listed in the following tables. The tables are separated based upon pediatric doses versus adult doses. The DTaP vaccine that is mentioned in the passage stands for Diptheria, Tetanus, and Pertussis.
References
- ↑ Wells CL, Wilkins TD (1996). Clostridia: Sporeforming Anaerobic Bacilli. In: Baron's Medical Microbiology (Baron S et al, eds.) (4th ed. ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
- ↑ "Tetanus" (PDF). CDC Pink Book. Retrieved 2007-01-26.
- ↑ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed. ed.). McGraw Hill. ISBN 0838585299.