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tetanus

Etiology: 1) most cases follow acute injury a) puncture wound b) laceration c) abrasion 2) complications of chronic conditions a) skin ulcers b) abscesses c) gangrene 3) other conditions a) burns b) frost bite c) middle ear infection d) surgery e) abortion f) childbirth g) drug abuse 'skin popping' 4) predisposing conditions - diabetes mellitus - injection drug use [5] Epidemiology: 1) occurs largely in inadequately immunized individuals 2) most common in warm climates & during summer months 3) occurs more commonly in males 4) in countries without immunization program, tetanus occurs largely in infants & young children 5) in USA, 60 cases of tetanus reported to CDC 1991-94; 37 cases in 2001 [3]; 21 cases in California 2008-2014 [5] Pathology: 1) contamination of wounds with spores of C. tetani is probably common 2) germination & toxin production takes place in wound with low redox potential 3) C tetani does not evoke inflammation 4) tetanus toxin released by autolysis of vegetative organisms binds to peripheral motor neuron terminals, is internalized, retrogradely transported to nerve cell bodies in spinal cord & brain stem, then migrates across synapse to presynaptic terminals of inhibitory neurons 5) tetanus toxin inhibits release of glycine & GABA from inhibitory neurons thus increasing the resting firing rate of alpha motor neurons 6) loss of inhibition may also affect preganglionic sympathetic neurons in the lateral gray matter of the spinal cord, resulting in increased adrenergic tone 7) tetanus toxin may also inhibit neurotransmitter release at neuromuscular junction 8) recovery requires sprouting of new nerve terminals 9) in localized disease, only the nerves supplying the affected muscle are involved 10) in generalized disease, the toxin enters the lymphatics & blood stream & is spread to distant nerve terminals 11) tetanus toxin does not cross the blood brain barrier Clinical manifestations: 1) onset 3-14 days after injury (median 7 days) 2) increased tone in masseter muscle (trismus, lockjaw) 3) dysphagia 5) neck, shoulder, & back pain 6) rigid abdomen 7) stiff proximal muscles 8) hands & feet relatively spared 9) sustained contraction of the face 10) sustained contraction of the back muscles (opisthotonos) 11) painful generalized muscle contractions 12) respiratory failure a) laryngospasm b) apnea 13) fever 14) autonomic dysfunction a) hypertension b) tachycardia c) cardiac arrhythmias d) hyperpyrexia e) diaphoresis f) peripheral vasoconstriction Laboratory: 1) wound cultures a) Clostridium tetani may be isolated from wounds of patients without tetanus b) Clostridium tetani may not be recovered from wounds of patients with tetanus 2) leukocytosis 3) cerebrospinal fluid is normal 4) see ARUP consult [4] Special laboratory: - electromyogram Differential diagnosis: 1) alveolar abscess (trismus) 2) strychnine poisoning 3) dystonic drug reactions a) phenothiazines b) metoclopramide 4) hypercalcemic tetany 5) meningitis 6) encephalitis 7) rabies 8) intra-abdominal disorder (rigid abdomen) Complications: 1) pneumonia 2) muscle rupture 3) rhabdomyolysis 4) thrombophlebitis 5) pulmonary embolus 6) decubitus ulcer 7) case fatality: 5 of 21 patients in Calfornia 2008-2014 [5] Management: 1) general measures - quiet room in intensive care unit (ICU) - cardiopulmonary monitoring - wound exploration, cleaning, debriding 2) prophylaxis a) tetanus toxoid (dT) if patient is > 6 years of age - immunization status unknown - human tetanus immune globulin (TIG) 250 units IM - < 3 immunizations with tetanus toxoid - no tetanus immunization in last 10 years - contaminated wound & no tetanus immunization in last 5 year b) a single dose of TdaP should be given to adults age >= 10 years to replace the next diphtheria-tetanus toxoid dT booster [5] c) TdaP is acceptable alternative to dT 3) antibiotics - penicillin G 10-12 million units QD for 10 days - clindamycin or erythromycin if allergic to penicillin 4) control of muscle spasms a) benzodiazepines (1st line) - diazepam - lorazepam b) barbiturates (2nd line) c) chlorpromazine (2nd line) d) propofol (Diprivan) e) dantrolene f) baclofen 5) airway protection a) intubation b) tracheostomy 6) autonomic dysfunction a) optimal therapy not defined b) suggested agents - labetalol (has been associated with sudden death) - esmolol (may be associated with unopposed alpha activity) - clonidine - morphine - magnesium sulfate Notes: - immunization status of 21 cases in California 2008-2014 from recall [5] - no other documentation of immunization status found

Related

Clostridium tetani diphtheria toxoid/tetanus toxoid (dT, Td) tetanus immune globulin (HyperTet, TIG, tetanus antitoxin) tetanus toxin (TeTx); tetanospasmin tetanus toxoid tetany

General

bacterial infection

References

  1. Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 633-34
  2. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 901-904
  3. Journal Watch 24(12):99, 2004 Kruszon-Moran DM, McQuillan GM, Chu SY. Tetanus and diphtheria immunity among females in the United States: are recommendations being followed? Am J Obstet Gynecol. 2004 Apr;190(4):1070-6. PMID: 15118644
  4. ARUP Consult: Clostridium tetani - Tetanus deprecated reference
  5. Yen C, Murray E, Zipprich J et al Missed Opportunities for Tetanus Postexposure Prophylaxis - California, January 2008-March 2014 MMWR Weekly. March 13, 2015 / 64(09);243-246 http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6409a2.htm
  6. Rhinesmith E, Fu L. Tetanus Disease, Treatment, Management. Pediatr Rev. 2018 Aug;39(8):430-432. PMID: 30068747