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Tetanus

(Lockjaw)

Tetanus is acute poisoning from a neurotoxin produced by Clostridium tetani. Symptoms are intermittent tonic spasms of voluntary muscles. Spasm of the masseters accounts for the name lockjaw. Diagnosis is clinical. Treatment is with human tetanus immune globulin and intensive support.

Tetanus bacilli form durable spores that occur in soil and animal feces and remain viable for years.

Worldwide, tetanus is estimated to cause over 200,000 deaths annually, mostly in neonates and young children, but the disease is so rarely reported that all figures are only rough estimates. In the US, 264 cases of tetanus and 19 deaths were reported from 2009 to 2017. Age distribution for cases was 23% in people ≥ 65 years, 64% in people aged 20 to 64 years, and 13% in people < 20 years, including 3 cases of tetanus neonatorum; all tetanus-related deaths occurred in people > 55 years

Disease incidence is directly related to the immunization level in a population, attesting to the effectiveness of preventive efforts. In the US, immunity levels tend to be lower in older age groups.

Patients with burns, surgical wounds, or a history of injection drug abuse are especially prone to developing tetanus. However, tetanus may follow trivial or even inapparent wounds. Infection may also develop postpartum in the uterus (maternal tetanus) and in a neonate's umbilicus (tetanus neonatorum) as a result of unsanitary delivery and umbilical cord care practices. Diabetes and a history of immunosuppression may be risk factors for tetanus. read more...

Pathophysiology of Tetanus

C. tetani spores usually enter through contaminated wounds. Manifestations of tetanus are caused by an exotoxin (tetanospasmin) produced when bacteria lyse. The toxin enters peripheral nerve endings, binds there irreversibly, then travels retrograde along the axons and synapses, and ultimately enters the central nervous system (CNS). As a result, release of inhibitory transmitters from nerve terminals is blocked, thereby causing unopposed muscle stimulation by acetylcholine and generalized tonic spasticity, usually with superimposed intermittent tonic seizures. Disinhibition of autonomic neurons and loss of control of adrenal catecholamine release cause autonomic instability and a hypersympathetic state. Once bound, the toxin cannot be neutralized.

Most often, tetanus is generalized, affecting skeletal muscles throughout the body. However, tetanus is sometimes localized to muscles near an entry wound.

Pearls & Pitfalls

Tetanus toxin binds irreversibly to nerve terminals, and once bound, it cannot be neutralized.

Symptoms and Signs of Tetanus

The incubation period ranges from 2 to 50 days (average, 5 to 10 days). Symptoms of tetanus include

• Jaw stiffness (most frequent)

• Difficulty swallowing

• Restlessness

• Irritability

• Stiff neck, arms, or legs

• Arching of the back (opisthotonos)

• Headache

• Sore throat

• Tonic spasmsLater, patients have difficulty opening their jaw (trismus).

Spasms

Facial muscle spasm produces a characteristic expression with a fixed smile and elevated eyebrows (risus sardonicus). Rigidity or spasm of abdominal, neck, and back muscles and sometimes opisthotonos (generalized rigidity of the body with arching of the back and neck) may occur. Sphincter spasm causes urinary retention or constipation. Dysphagia may interfere with nutrition.

Characteristic painful, generalized tonic spasms with profuse sweating are precipitated by minor disturbances such as a draft, noise, or movement. Mental status is usually clear, but coma may follow repeated spasms. During generalized spasms, patients are unable to speak or cry out because of chest wall rigidity or glottal spasm. Rarely, fractures result from sustained spasms.

Spasms also interfere with respiration, causing cyanosis or fatal asphyxia.

Autonomic instability

Temperature is only moderately elevated unless a complicating infection, such as pneumonia, is present. Respiratory and pulse rates are increased. Reflexes are often exaggerated. Protracted tetanus may manifest as a very labile and overactive sympathetic nervous system, including periods of hypertension, tachycardia, and myocardial irritability.

Causes of death

Respiratory failure is the most common cause of death. Laryngeal spasm and rigidity and spasms of the abdominal wall, diaphragm, and chest wall muscles cause asphyxiation. Hypoxemia can also induce cardiac arrest, and pharyngeal spasm leads to aspiration of oral secretions with subsequent pneumonia, contributing to a hypoxemic death. Pulmonary embolism is also possible. However, the immediate cause of death may not be apparent.

Localized tetanus

In localized tetanus, there is spasticity of muscles near the entry wound but no trismus; spasticity may persist for weeks.

Cephalic tetanus is a form of localized tetanus that affects the cranial nerves. It is more common among children; in them, it may occur with chronic otitis media or may follow a head wound. Incidence is highest in Africa and India. All cranial nerves can be involved, especially the 7th. Cephalic tetanus may become generalized.

Tetanus neonatorum

Tetanus in neonates is usually generalized and frequently fatal. It often begins in an inadequately cleansed umbilical stump in children born of inadequately immunized mothers. Onset during the first 2 weeks of life is characterized by rigidity, spasms, and poor feeding. Bilateral deafness may occur in surviving children.

Neonatal Tetanus
 

 

Neonatal tetanus most commonly affects infants born to nonimmune mothers. Exotoxin produced by Clostridium tetani gains entry to the circulation when the infant's umbilical cord is cut or the umbilical stump is cleaned in a nonsterile fashion. Generalized rigidity and spasm affect the child in the first 2 weeks of life and may be fatal.

Diagnosis of Tetanus

• Clinical evaluation

Tetanus should be considered when patients have sudden, unexplained muscle stiffness or spasms, particularly if they have a history of a recent wound or risk factors for tetanus.

Tetanus can be confused with meningoencephalitis of bacterial or viral origin, but the following combination suggests tetanus:

• An intact sensorium
• Normal cerebrospinal fluid
• Muscle spasms

Trismus must be distinguished from peritonsillar or retropharyngeal abscess or another local cause. Phenothiazines can induce tetanus-like rigidity (eg, dystonic reaction, neuroleptic malignant syndrome).

C. tetani can sometimes be cultured from the wound, but culture is not sensitive; only 30% of patients with tetanus have positive cultures. Also, false-positive cultures can occur in patients without tetanus.

Prognosis for Tetanus

Tetanus has a mortality rate of

• Worldwide: 50%
• In untreated adults: 15 to 60%
• In neonates, even if treated: 80 to 90%

Mortality is highest at the extremes of age and in drug abusers.

The prognosis is poorer if the incubation period is short and symptoms progress rapidly or if treatment is delayed. The course tends to be milder when there is no demonstrable focus of infection.

With use of modern supportive care, most patients recover.

Treatment of Tetanus

• Supportive care, particularly respiratory support

• Wound debridement

• Tetanus antitoxin

• Benzodiazepines for muscle spasms

• Metronidazole or penicillin

• Sometimes drugs for autonomic dysfunctionTreatment of tetanus requires maintaining adequate ventilation. Additional interventions include early and adequate use of human tetanus immune globulin (TIG) to neutralize nonfixed toxin; prevention of further toxin production; sedation; control of muscle spasm, hypertonicity, fluid balance, and intercurrent infection; and continuous nursing care. IV immune globulin (IVIG), which contains tetanus antitoxin, may be used if TIG is not available.

General principles

The patient should be kept in a quiet room. Several principles should guide all therapeutic interventions:

• Prevent further toxin release by debriding the wound and giving an antibiotic
• Neutralize unbound toxin outside the CNS with human tetanus immune globulin
• Immunize using tetanus toxoid, taking care to inject it into a different body site than the antitoxin
• Minimize the effect of toxin already in the CNS

Wound care

Because dirt and dead tissue promote C. tetani growth, prompt, thorough debridement, especially of deep puncture wounds, is essential. Antibiotics are not substitutes for adequate debridement and immunization but typically are given.

Antitoxin and toxoid

The benefit of human-derived antitoxin depends on how much tetanospasmin is already bound to the synaptic membranes—only free toxin is neutralized. For adults, human TIG 3000 to 6000 units IM is given once; this large volume may be split and given at separate sites around the wound. Dose can range from 500 to 6000 units, depending on wound severity, but some authorities feel that 500 units are adequate.

Supportive care

In moderate or severe cases, patients should be intubated. Mechanical ventilation is essential when neuromuscular blockade is required to control muscle spasms that impair respirations.

IV hyperalimentation avoids the hazard of aspiration secondary to gastric tube feeding. Because constipation is usual, stools should be kept soft. A rectal tube may control distention. Bladder catheterization is required if urinary retention occurs.

Chest physiotherapy, frequent turning, and forced coughing are essential to prevent pneumonia. Analgesia with opioids is often needed.

Prevention of Tetanus

A primary series of tetanus vaccinations followed by regular boosters is required. Children < 7 years require 5 primary vaccinations, and unimmunized patients > 7 years require 3. The vaccine may be tetanus toxoid alone (TT), but toxoid is typically combined with diphtheria and/or pertussis. Children's vaccines have higher doses of the diphtheria and pertussis components (DTaP, DT) than adults' vaccines (Tdap, Td).

Children are given DTaP at ages 2 months, 4 months, 6 months, 15 to 18 months, and 4 to 6 years; they should get a Tdap booster at age 11 to 12 years, and Td every 10 years thereafter

Unimmunized adults are given Tdap initially, then Td 4 weeks and 6 to 12 months later, and Td every 10 years thereafter. Adults who have not had a vaccine that contains pertussis should be given a single dose of Tdap instead of one of the Td boosters. Adults ≥ 65 who anticipate close contact with an infant < 12 months and who have not previously received Tdap should be given a single dose of Tdap.

Pregnant women should be given Tdap during each pregnancy, preferably at 27 to 36 weeks gestation, regardless of when they were last vaccinated; the fetus can develop passive immunity from vaccines given at this time.

For routine diphtheria, tetanus, and pertussis immunization and booster recommendations, see Diphtheria-Tetanus-Pertussis Vaccine and Tetanus-Diphtheria Vaccine.

After injury, tetanus vaccination is given depending on wound type and vaccination history; tetanus immune globulin may also be indicated (see table Tetanus Prophylaxis in Routine Wound Management). Patients not previously vaccinated are given a 2nd and 3rd dose of toxoid at monthly intervals.

Because tetanus infection does not confer immunity, patients who have recovered from clinical tetanus should be vaccinated unless they have completed a full primary series.

Tetanus Prophylaxis in Routine Wound Management

History of Adsorbed Tetanus Toxoid	Clean, Minor Wounds		All Other Wounds*
	Td†	TIG‡	Td†	TIG‡
Unknown or < 3 doses	Yes	No	Yes	Yes
≥ 3 doses	Yes if > 10 years since last dose	No	Yes if > 5 years since last dose	No
* Such as (but not limited to) wounds contaminated with dirt, feces, soil, or saliva; puncture wounds; crush injuries; avulsions; and wounds resulting from missiles, burns, or frostbite.
† For patients ≥ 10 years who have not previously received a dose of Tdap, a single dose of Tdap should be given instead of one Td booster. Children < 7 years should be given DTaP or, if pertussis vaccine is contraindicated, DT. Children aged 7–9 years should be given Td.
‡ TIG 250–500 units IM. People with HIV infection or severe immunodeficiency who have contaminated wounds (including minor wounds) should also receive TIG, regardless of their history of tetanus immunizations.
DT = diphtheria and tetanus toxoids (for children); DTaP = diphtheria and tetanus toxoids, acellular pertussis (for children); Td = tetanus and diphtheria toxoids adsorbed (for adults); Tdap = tetanus and diphtheria toxoids, acellular pertussis (for adults); TIG = tetanus immune globulin (human).

Key Points

• Tetanus is caused by a toxin produced by Clostridium tetani in contaminated wounds.
• Tetanus toxin blocks release of inhibitory neurotransmitters, causing generalized muscle stiffness with intermittent spasms; seizures and autonomic instability may occur.
• Mortality is 15 to 60% in untreated adults and 80 to 90% in neonates even if treated.
• Prevent further toxin release by debriding the wound and giving an antibiotic (eg, penicillin, doxycycline), and neutralize unbound toxin with human tetanus immune globulin.
• Give IV benzodiazepines for muscle spasm, and use neuromuscular blockade and mechanical ventilation as needed for respiratory insufficiency due to muscle spasm.
• Prevent tetanus by following routine immunization recommendations.

 

1. CORONA VIRUS
2. MONKEY POX
3. VAGINAL DRYNESS
4. FIBROID
5. INFERTILITY
6. OVULATION CYCLE
7. OVARIAN CANCER
8. VAGINAL BACTERIA
9. MALE INFERTILITY
10. BEST DAYS OF CONCIEVING
11. MUCUS AFTER OVULATION
12. FOODS FOR ERECTILE FUNCTIONS
13. PREGNANCY ANEMIA
14. DO AND DONT DURING PREGNANCY
15. ERECTILE DYSFUNCTION
16. U.T.I IN PREGNANCY
17. STROKE RISK
18. EAT THIS NOT THAT
19. HOOKWORMS INFECTION
20. OMEGA 3 BENEFITS
21. FASTING
22. WEIGHT LOSS TIPS
23. vitiligo
24. ABORTION
25. DENGUE VIRUS
26. EBORA VIRUS
27. FEVER
28. URINARY TRACT INFECTION
29. HOSPITAL INFECTIONS
30. WEST NILE VIRUS
31. YELLOW FEVER
32. EYE DISEASE
33. ZIKA VIRUS
34. STRESS
35. IRON DEFFICIENCE
36. INSOMNIA (SLEEPING PROBLEMS)
37. HEART PROBLEMS
38. COMPONENTS OF BLOOD
39. BLOOD DISORDER
40. LABORATORY TEST OF BLOOD DISORDER
41. BONE MARROW EXAMINATION
42. BLOOD ANEMIA
43. ANIMAL BITES
44. EYE BURN
45. CHOCKING
46. HEAT STROKE
47. SMOKE EFFECTS
48. SNAKE BITE
49. MALARIA VACCINE
50. BEST WAY TO SLEEP A CHILD
51. CHILD FEVER REDUCING
52. ELEPHANTIASIS
53. WOMEN BEARDS
54. DATES
55. PAPAYA FRUITS