References:
- Global Infectious Diseases and Epidemiology Online Network: Infectious Diseases of the Philippines, 2013 eBook Edition, ISBN 978-1-61755-582-4, by Stephen Berger. Accessed here.
| Agent | BACTERIUM. Clostridium tetani An anaerobic gram-positive bacillus |
| Reservoir | Animal feces Soil |
| Vector | None |
| Vehicle | Injury |
| Incubation Period | 6 to 8 days (As early or late as 1 to 90 days) |
| Diagnostic Tests | Isolation of C. tetani from wound is rarely helpful Serology (specimen taken before administration of antitoxin) |
| Typical Adult Therapy | Human antitoxin (see Vaccine module). Metronidazole (2 g daily) or Penicillin G (24 million u daily) or Doxycycline (200 mg daily). Diazepam (30 to 240 mg daily). Tracheostomy, hyperalimentation |
| Typical Pediatric Therapy | Human antitoxin (see Vaccine module). Metronidazole (30 mg/kg daily); or Penicillin G (300,000 units/kilo daily). Diazepam. Tracheostomy, hyperalimentation |
| Vaccines | DT DTaP DTP Td Tetanus immune globulin Tetanus |
| Clinical Hints | Trismus, facial spasm, opisthotonus, tachycardia and recurrent tonic spasms of skeletal muscle; sensorium is clear; disease may persist for 4 to 6 weeks; case fatality rate = 10% to 40%. |
| Synonyms | Lockjaw, Starrkrampf, Stelkramp, Tetano, Tetanos |
Tetanus may present in any of four clinical forms: generalized, localized, cephalic, and neonatal.
- In general, shorter incubation periods are associated with a worse prognosis.
- Certain portals of entry (compound fractures) and underlying conditions (heroin addiction) are also associated with poorer prognoses.
- A series of 11 cases of tetanus related to tungiasis (25% of all tetanus cases) was reported by a single hospital in Brazzaville over an 11-month period (1989 publication).
- An outbreak of 12 cases of tetanus in Argentina was reported among elderly women treated with sheep cell therapy (1996).
- In one case, tetanus was associated with chronic otitis media.
- Tetanus has been reported in a child who bit her own tongue during a convulsion and following a snake bite (2007 publication)
- An attack of tetanus does not result in immunity. Therefore, recurrent tetanus is possible, unless the patient is given a series of toxoid following recovery.
Generalized Tetanus
Generalized tetanus, the most common form, begins with trismus (“lockjaw”) and risus sardonicus (increased tone in the orbicularis oris).
- Abdominal wall rigidity may be present.
- The generalized spasm consists of opisthotonic posturing with flexion of the arms and extension of the legs.
- The patient does not lose consciousness, and experiences severe pain during these spasms.
- Spasms often are triggered by sensory stimuli.
- Respiration may be compromised by upper airway obstruction, or by participation of the diaphragm in the general muscular contraction.
- Autonomic dysfunction, usually occurring after several days of symptoms, is currently the leading cause of death in tetanus.
- Complications of tetanus include rhabdomyolysis and renal failure
- The illness can progress for two weeks, while the severity of illness may be decreased by partial immunity.
- Recovery takes an additional month, but is complete unless complications supervene.
- Lower motor neuron dysfunction may appear after the spasms remit, and persist for several additional weeks.
- A case of Clostridium tetani bacteremia has been reported.
- Case-fatality rates of 10% to 50% are reported, but may be as high as 70% in Africa.
- The differential diagnosis of tetanus includes strychnine poisoning and neuromyotonia (Isaac’s syndrome).
Localized Tetanus
Localized tetanus presents as rigidity of the muscles associated with the site of inoculation.
- Initial symptomatology may be limited to back pain.
- The illness may be mild and persistent, and tends to resolve spontaneously.
- Weakness and diminished muscle tone are often present in the most involved muscle.
- Localized tetanus is often a prodrome of generalized tetanus.
Cephalic Tetanus
Cephalic tetanus is a form of localized disease affecting the cranial nerve musculature. Facial nerve weakness, is often apparent, and extraocular muscle involvement is occasionally noted.
Neonatal Tetanus
Neonatal tetanus follows infection of the umbilical stump, most commonly as a result of a failure of aseptic technique following delivery of non-immune mothers.
- The condition usually manifests with generalized weakness and failure to nurse; followed by rigidity and spasms.
- The mortality rate exceeds 90%, and psychomotor retardation is common among survivors.
- Poor prognostic factors include age younger than 10 days, symptoms present for fewer than 5 days before presentation to hospital, fever, and the presence of risus sardonicus or fever.
- Apnea is the leading cause of death in the first week of disease, and sepsis in the second week.
- Bacterial infection of the umbilical stump leads to sepsis in almost half of babies with neonatal tetanus.
WHO Case Definition for Surveillance: Neonatal Tetanus
- Suspected case: Any neonatal death between 3-28 days of age in which the cause of death is unknown; or any neonate reported as having suffered from neonatal tetanus between 3-28 days of age and not investigated.
- Confirmed case: Any neonate with a normal ability to suck and cry during the first two days of life, and who between 3 and 28 days of age cannot suck normally, and becomes stiff or has convulsions (i.e. jerking of the muscles) or both.
- Hospital-reported cases of neonatal tetanus are considered confirmed.
- The diagnosis is purely clinical and does not depend upon laboratory or bacteriological confirmation.