SEVERE COAGULOPATHY AFTER A BITE OF A GREEN BUSH VIPER (ATHERIS SQUAMIGER) - CASE-REPORT AND BIOCHEMICAL-ANALYSIS OF THE VENOM

A 34 year old male bitten by an adult Atheris squamiger snake develope d symptoms of nausea, vomiting, diarrhea which were followed by drowsi ness and impaired breathing. Local hemorrhage, edema and pain at the b ite-site occurred, but no systemic bleeding or hemorrhagic diathesis d eveloped. All clinical and laboratory parameters were in the normal ra nge except for afibrinogenemia, thrombocytopenia and slight proteinuri a. Replacement therapy (fibrinogren and platelet concentrates) and tre atment of shock stabilized the patient within 2 d and coagulation retu rned to normal. Atheris squamiger venom was subjected to biochemical a nd biological analysis. The LD50 Of the venom was 5 mg/kg (mice, s.c.) . It produced local hemorrhage corresponding to about 25% of the activ ity of puff adder venom (Bitis arietans). In vitro the venom had a fib rinogen-converting activity, it did not activate purified prothrombin but very likely contained a. F V and Ca2+-dependent prothrombin activa tor. The venom exhibited strong platelet-aggregating activity, which w as not inhibited by protease inhibitors and by EDTA or EGTA. The venom also aggregated acetylsalicylic acid treated platelets indicating, th at the arachidonic acid pathway was not essential for activation. Rat serum rapidly inhibited the platelet-aggregating activity of the venom ; human serum, however, had only a partial inhibitory effect. Prelimin ary experiments showed that platelet-aggregating activity may be separ ated from fibrinogen-converting activity by anion-exchange chromatogra phy. (C) 1998 Elsevier Science Ltd. All rights reserved.