【文章內(nèi)容簡介】 inject drugs also constitute a highrisk group. Symptom : ? Symptoms usually begin 8 days after the infection, but onset may range from 3 days to 3 weeks. ? Patients may report a sore throat with dysphagia (early sign). ? Localized tetanus causes muscle rigidity at the site of spore inoculation. ? The initial manifestation may be local tetanus, in which the rigidity affects only 1 limb or area of the body where the clostridiumcontaining wound is located. Physical examination : ? Common first signs of tetanus are headache and muscular stiffness in the jaw ( ie, lockjaw), followed by neck stiffness, difficulty swallowing, rigidity of abdominal muscles, spasms, and sweating. . ? Patients often are afebrile. . ? Severe tetanus results in opisthotonos, flexion of the arms, extension of the legs, periods of apnea resulting from spasm of the intercostal muscles and diaphragm, and rigidity of the abdominal wall. . ? Late in the disease, autonomic dysfunction develops, with hypertension and tachycardia alternating with hypotension and bradycardia. . Opisthotonos Diagnosis : Depend on clinical findings, Laboratory findings are not diagnostically valuable. Differentiation : ? Tardive Dystonia ? Strychnine poisoning ? Dental infections ? Local infections ? Hysteria ? Neoplasms ? Encephalitis Complications ? Spasm of the vocal cords and/or spasms of the respiratory muscles that cause interference with breathing . ? Fractures of the spine or long bones ? Hypertension ? Abnormal heartbeats ? Coma ? Generalized infection ? Pneumonia ? Death Treatment Passive immunization with human tetanus immune globulin (TAT) shortens the course of tetanus and may lessen its severity. A dose of 1500 U appears as effective as larger doses. . The goals of pharmacotherapy are to prevent plications and to reduce morbidity. . Gas gangrene Conception : A clostridial infection typically involves underlying muscle, is also termed clostridial myonecrosis . . An anaerobic, grampositive, sporeforming bacillus of the genus Clostridium causes gas gangrene. The most mon anisms are C. perfringens, C. novyi, and C. septicum . . Etiology and pathophysiology These anisms are in soil, dust, and isolated from the GI tract and the female genital tract. Clostridia are obligate anaerobes, but some species are relatively aerotolerant. Other bacteria capable of producing gas, and nonclostridial anisms have been isolated in 6085% cases of gas gangrene. . C perfringens produces at least 20 exotoxins. The important exotoxins and their biologic effects are as follows: ? Alpha toxin Lethal,* lecithinase, necrotizing, hemolytic, cardiotoxic ? Beta toxin Lethal,* necrotizing ? Epsilon toxin Lethal,* permease ? Iota toxin Lethal,* necrotizing ? Delta toxin Lethal,* hemolysin ? Phi toxin Hemolysin, cytolysin ? Kappa toxin Lethal,* collagenase, gelatinase, necrotizing ? Lambda toxin Protease ? Mu toxin Hyaluronidase ? Nu toxin Lethal,* deoxyribonuclease, hemolytic, necrotizing ? *Lethal as tested by injection in mice Anatomically, these infections are marked by a layer of necrotic tissue, which is not walled off by a surrounding inflammatory reaction and thus does not present a clear boundary. . Symptom : ? Sudden onset of pain is usually the first symptom. The pain gradually increases in severity but spreads only as the underlying infection spreads. ? Patients sometimes report a feeling of heaviness in the affected extremity. ? A lowgrade fever and apathetic mental status may develop. These infections are marked by the absence of clear local boundaries or palpable limits. This