TETANOS

1. TETANOS

2. Tetanus is a disease of the nervous system characterized by persistent tonic spasm, with violent brief exacerbations. The onset is acute and the spasm almost always commences in the muscles of the neck and jaw, causing trismus, and involves the muscles of the trunk more than those of the limbs.

3. Microbiology and Pathophysiology • Clostridium tetani is an obligate anaerobic rod • Two exotoxins, tetanospasmin and tetanolysin, are released by some strains of the organism while it is actively dividing.

4. Pathophysiology • Tetanospasmin act at three levels: central motor control, autonomic function and neuromuscular junction. • The 150-kD peptide tetanospasmin inhibits release of inhibitory neurotransmitters g-aminobutyric acid (GABA) and glycine. The resulting imbalance in the central nervous system predisposes the patient to reflex spasms. • The process involves three steps: • binding to the presynaptic membrane, • translation of the toxin to the active site • induction of paralysis

5. Clinical manifestations • abortions, intramuscular injections, dental infections, penetrating eye injuries, and umbilical stump infections. • The incubation period range from 3 to 30 days (11 days). • The disease has four forms: • Generalized tetanus. • The most commonly presenting sign is trismus • risus • the typical generalized spasm • Other positions are orthotonus and pleurosthotonus • Generalized spasms can involve abdominal, diaphragmatic, and laryngeal muscles, • Autonomic dysfunction is the leading cause of death in tetanus patients.

6. Localized tetanus • Cephalic tetanus: • -Facial paresis is usually present • -Ophtalmoplegic tetanus when there is a paresis of the III rd, IV th and VI th cranial nerves. • Neonatal tetanus

7. Rating scales for tetanus severity • Veronesi scale • Incubation period<7 days • Period of onset*<48 hours • High-risk portal of entry (surgical, abortion,etc) • Generalized tetanus • Core temperature above 40 C • Tachycardia (heart rate >120 in adults, >150 in neonates) • Score one point for each: *period from the first symptom to the first reflex spasm.

8. Severity and prognosis

9. Modified Ablett scale of severity

10. Diagnosis • The average annual incidence of tetanus in the world is about 1 million cases. • Due to its rarity, the initial clinical symptoms may be missed and the diagnosis may not be made until a generalized tetanic spasm occurs. • Diagnosis is established in the presence of a portal of entry, trismus, tonic contraction, sudden spasms and a descending manner of contraction progression.

11. Differential diagnosis • Trismus in tetanus must be distinguished by: alveolar ridge abscess, temporomandibular joint arthritis, tonsillitis; • Spasms and rigidity must be distinguished by: generalized convulsive status epilepticus, strychnine intoxication, tetany precipitated by hypocalcemia, meningitis, encephalitis, brain hemorrhage; • Local tetanus-with transverse myelitis.

12. Complications • Respiratory dysfunction: • Cardiovascular complications: cardiomiopathy • Urinary tract infections and acute renal failure caused by rhabdomyolysis • Vertebral compression, fractures, hyperostoses • CNS and systemic consequences of hypoxia.

13. Management • Management of tetanus involves • Neutralizing wound and circulating toxin, • Eradicating the source of toxin • Standard supportive care • Treating related complications • Treatment of the portal of entry

14. Mortality • Even with today's advanced level of care, during 1995-1997 the case fatality ratio of tetanus was 11%.

15. LEPTOSPIROSIS • Leptospirosis is a zoonotic disease that affects human on all continents, in both urban and rural areas. Clinical presentation of this febrile illness may include in severe forms liver involvement, renal failure, meningitis, myocarditis, hemorrhagic pneumonitis, and hemodynamic collapse. • The first description of the leptospirosis was done in 1886 by Weil.