Clinical problems in the management of Australian snakebite

629 WAyr, G. (Department of Tropical Medicine, NAMRU-2, Manila, The Philippines. APO San Francisco 96528) Snakebite in the Philippines. Little has been published on snakebite in the Philippines. From 1983 until the present, attempts have been made to gather information on the medically important snakes of the Philippines and the clinical picture produced by their bite. Information was obtained from various sources. Manila's San l_azaro Hospital is the local referral center for snakebite. Hospital statistics over the past 6 years were reviewed and charts of recently hospitalised snakebite patients retrieved. When possible, sera was taken from these patients and assayed for snake venom antibody using an ELISA method. Chart review and venom antibody assay were also performed at 2 other hospitals on Luzon. Newly admitted patients were carefully examined. If signs of envenoming were present, ELISA detection of venom antigen was tried. In addition, seasnake bite victims were interviewed retrospectively at a small fishing village on the shore of Teal Lake, a large freshwater lake south of Manila. Sera from these patients was also taken for venom antibody detection. All cases of landsnake bite where definite envenoming occurred and where the identity of the biting snake was certain were caused either by Naja noja phUippinensis (Philippine cobra) or by Trimeresurus sp. (green pit-viper). Cardiotoxicity was a prominent feature of cobra envenoming. Although N.n. philippinensis is a 'spitting' cobra, no cases of snake venom opthahnla were seen. Since 1978, of about 450 snakebite victims admitted to San Lazaro Hospital, 11 patients died. In all fatal cases that could be investigated, N.n. philippinensis was the snake implicated. At least 8 bites with envenoming by H. cyanocinctus occurred in the fishing village StUdied over the past several years. This village has a population of about 3500, with less than 200 fishermen - - the population at risk. Three of the bites were during the past year. Almost all bites seemed to result in envenoming. One fatal case occurred. Although Ophiophagus hannah (king cobra) and coral snakes of the genera Calliophis and Matlcora are found in the Philippines, they do not seem to be of medical importance. To our knowledge, this is the first report of seasnake envenoming in a freshwater lake. Studies in other villages around the lake, as well as in Philippine coastal areas, are needed to determine whether seasnake bite is a significant problem among Filipino fishermen. Such studies are currently being carried out. WHrr~, J. (Poisons Centre, Adelaide Children's Hospital, North Adelaide, S. A. 5006, Australia) Clinical problems in the management of Australian snakebite. AUSTRALIA'Sdangerous snakes are all elapids, usually with small fangs, whose venoms are amongst the most toxic snake venoms known. Envenomation in man causes major systemic rather than local problems, but in many cases bites do not result in significant envenomation. The constellation of systemic problems vary from case to case and snake to snake, but may include paralysis, C.N.S. disturbances (including fitting), severe derrangement of coagulation function, haemolysis, myolysis, renal failure and other metabolic derrangements. Analysis of severe cases of envenomation presenting to our unit indicates that extent and progress of paralysis, level of conciousness and extent of coagulopathy are the most useful factors in determining extent of envenomation and response to treatment. All major primary problems of envenomation appear to be rectified by antivenom preferably monovalent. Use of an enzyme linked imrnunosorbent assay is proving useful in confirming the species of xnAke involved and allowing use of monovalent rather than polyvalent antivenom. However, distinct envenomatlon prof'des are now emerging for major types of Australian snakes which may also allow use of monovalent antivenom in the absence of venom identification assays. Nevertheless, unusual or atypical cases occur and these will be discussed. YANO. C. C. (Institute of Molecular Biology, National Tsing Hna University, Hsinchu, Talwan 300, Republic of China) lmmunochemical studies on cobrotoxin. COBROTOXIN, a neurotoxic protein, was isolated in the crystalline state from the venom of the Taiwan cobra (Noja naja atra) and was proved to be the toxic protein in cobra venom. Antisera have been prepared by injecting increasing doses of cobrotoxin with Freund's adjuvant into rabbits. One hundred per cent preeipitable antibody (At)) was isolated immunospeclfically by gel filtration on Sephadex G - 100 after the A g - Ab complex had been dissociated with 0.53 M formic acid-0.15 M NaCI, pH 2.05. The molecular weight of the soluble complex formed from its papaln fragments and cobrotoxin provides evidence that cobrotoxin has three Ab combining sites per molecule. When Ab preparations were applied to a cobrotoxin-Sepharose column, more than twice the amount of Ab determined by preeipitin reaction was always recovered from antisera and IgG. This indicates that rabbits hyperlmmunized with cobrotoxin produce non-precipitating (58%) as well as precipitating (42%) Ab. Non-precipitating Ab can recognize only two Ag determinants out of the three while the precipitating Ab bind with the three. The neutralizing capacity of the precipitating and non-precipitatin~ Ab increased 18-fold and 23-fold, respectively, over that of the antlsera. Recently, a stable hybridoma cell line producing monoclonal Ab to cobrotoxin was produced through fusion of NS-I cells with BALB/c mouse spleen cells hyperimmunized with cobrotoxin. The hybrid cells were cloned and the Ab was produced in large amounts, both by cell culture and by inducing Ab in ascites to BALB/c mice. The monoclonnl Ab purified by aff'mity chromatography was identified to be IgG2, and proved to combine with two molecules of cobrotoxin.