Tetanus

1. Tetanus By: Omar Ramirez

2. What is Tetanus? • Tetanus is an illness characterized by an acute onset of hypertonia, painful muscular contractions (usually of the muscles of the jaw and neck), and generalized muscle spasms without other apparent medical causes. • Despite widespread immunization of infants and children in the United States since the 1940s, tetanus still occurs in the United States.

3. Statistics • Tetanus has declined significantly since the mid-1940’s due to increased use of Tetanus immunizations. • Overall, mortality is approximately 45%. The mortality rate in the United States is 6% for those who previously had received 1-2 doses of tetanus toxoid and 15% for unvaccinated individuals. • Mortality rate is highest for those older than 60 years. • In the United States, African Americans from the rural south have a greater risk of tetanus than individuals of other races.

4. Statistics (cont.) • Men are better protected from Tetanus because of the higher vaccinations received during military service or other professional activities. • Incidence of tetanus increases with advancing age. 54% of the patients with tetanus in the United States are older than 59 years old.

5. How it forms… • The nonencapsulated spore-forming bacterium Clostridium tetani causes Tetanus. • Spores that gain entry can survive for months to years. Under anaerobic conditions, these spores geminate and produce tetanospasmin. Tetanospasmin that is released by the maturing bacilli is distributed via the lymphatic and vascular circulations to the end plates of all nerves. Tetanospasmin then enters the nervous system peripherally at the myoneural junction and is transported centripetally into neurons of the central nervous system (CNS).

6. How it forms… (cont.) • These neurons become unable of neurotransmitter release. The neurons, which release gamma-aminobutyric acid (GABA) and glycine, the major inhibitory neurotransmitters, are sensitive to tetanospasmin, leading to failure of inhibition of motor reflex responses to sensory stimulation. This results in generalized contractions of the agonist and antagonist musculature characteristic of a tetanic spasm. The shortest peripheral nerves are the first to deliver the toxin to the CNS, which leads to the early symptoms of facial distortion and back and neck stiffness.

7. Causes • In 77% of patients with tetanus in the United States, tetanus occurred after an acute injury, including puncture wounds (49%), lacerations (22%), abrasions (12%), and animal bites (2.6%). • Stepping on a nail accounted for 39% of the puncture wounds. • Tetanus can occur in burn victims, patients receiving intramuscular injections, and with frostbite, dental infections (such as periodontal abscesses), penetrating eye injuries, and umbilical stump infections. • Tetanus has been reported after tooth extractions, root canal therapy, and intraoral soft tissue trauma.

8. Causes (cont.) Neonatal tetanus is caused by: • Unvaccinated mothers, home delivery, and unhygienic cutting of the umbilical cord. • History of neonatal tetanus in a previous child is a risk factor for subsequent neonatal tetanus.

9. The Spatula Test • This simple test involves touching the oropharynx with a spatula or tongue blade. • Usually, this test causes a gag reflex with the patient, and the patient tries to expel the spatula. (This means they have tested negative.) • In tetanus, patients develop a reflex spasm of the masseters and bite the spatula (a positive test).

10. Medications Used for Treatment • Diazepam (Valium) -- Most commonly used drug for treatment of tetanic spasms and tetanic seizures. Depresses all levels of CNS, including limbic and reticular formation, possibly by increasing activity of GABA, a major inhibitory neurotransmitter. • Tetanus immune globulins (Hyper-Tet) -- Used to induce active immunity against tetanus in selected patients.

11. Medications (cont.) • Metronidazole (Flagyl) -- Active against various anaerobic bacteria and protozoa. Appears to be absorbed into cells, and intermediate-metabolized compounds that are formed bind DNA and inhibit protein synthesis, causing cell death. • Penicillin G (Pfizerpen) -- Interferes with synthesis of cell wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms.

12. Complications • Long bone fractures • Glenohumeral and temporomandibular joint dislocations • Adverse effects of autonomic instability, such as cardiac dysrhythmias and hypertension • Malnutrition • Coma, neuropathies, and psychological aftereffects

13. Prognosis • Prognosis is dependent on incubation period, time from spore inoculation to first symptom, and time from first symptom to first tetanic spasm. • In general, shorter intervals indicate more severe tetanus and a poorer prognosis. • Patients usually survive tetanus and return to their predisease state of health. • Recovery is slow and usually occurs over 2-4 months. • Clinical tetanus does not produce a state of immunity; therefore, patients who survive the disease require active immunization with tetanus toxoid to prevent a recurrence.

14. Works Cited • www.emedicine.com – Tetanus article by Daniel J. Dire, MD, FACEP, FAAEM • www.emedicinehealth.com – Tetanus article by Robert N Bilkovski, MD