Local Envenoming Research Articles

Envenomation by the Hump-Nosed Viper (Hypnale hypnale)

We carried out a prospective clinical study from June to December 1993 at the Base Hospital in Avissawella, Sri Lanka to determine the clinical features of envenomation by the hump-nosed viper (Hypnale hypnale). Sixty-two consecutive adult patients (63% males and 37% females, with a median age of 30 years [age range 13-68 years]) admitted to the medical unit following hump-nosed viper bites were surveyed. Most (85.48%) of the patients were bitten on the feet, while 14.52% of the patients were bitten either on the hands or forearms. Most (61.29%) of the patients were bitten during the evening hours (6:00-10:00 PM). The mean time for admission to the hospital following the bite was 1.5 hr (range 0.25-13 hr). All patients had signs of local envenomation manifested by pain, swelling, and induration at the site of the bite, which was occasionally associated with local hemorrhagic blister formation (11.29%) and regional lymphadenopathy (24.19%). None of the patients had signs of systemic envenomation.

Seastroke: a new entity?

Three previously healthy young male patients had brain stem infarction (stroke) after swimming or wading in shallow water along the southeastern North Carolina coastline. Each patient remembered an unusual encounter with something in the water. None sustained any obvious local envenomation. Although these cases may be a highly unusual coincidence, I believe they represent a previously unidentified entity--"seastroke." I speculate that the injuries could be caused by contact with a toxic marine animal.

Randomized comparative trial of three antivenoms in the treatment of envenoming by lance-headed vipers (<italic>Bothrops jararaca</italic>) in São Paulo, Brazil

In São Paulo City, Brazil, 121 patients with moderately severe envenoming by Bothrops snakes (principally B. jararaca) were randomized for treatment with Brazilian polyspecific Bothrops antivenoms: Instituto Butantan (39 patients), Instituto Vital Brazil (41), Fundação Ezequiel Dias (FUNED) (41). The initial dose was four ampoules (40 ml) in 89 patients with less severe envenoming and eight ampoules (80 ml) in 32 patients with more severe envenoming. A second dose of four ampoules was required in 20 patients. Patients receiving the three antivenoms were comparable in all respects before treatment. There were no deaths. The majority showed rapid clinical improvement, resolution of local envenoming, cessation of bleeding and restoration of blood coagulability. No differences in the efficacy of the three antivenoms were revealed by clinical or laboratory observations, including measures of haematological, haemostatic and biochemical abnormalities. Twelve patients developed abscesses (Butantan 1, Vital Brazil 6, FUNED 5) and seven developed local necrosis (3,1,3). Of 88 patients followed up 20-30 days after the bite 33 (37.5%) still had symptoms or signs of local envenoming, especially swelling. Early (anaphylactic) reactions were unexpectedly frequent after all three antivenoms but were significantly more frequent with Butantan (87%) than with Vital Brazil (37%) or FUNED (56%) antivenoms (p < 0.001). A possible explanation was the higher total protein content and percentage immunoglobulin of Butantan antivenom. The doses of antivenom recommended in Brazil and used in this study may be unnecessarily high, resulting in an unacceptably high incidence of reactions. Results of the study should prompt a critical re-evaluation of antivenom production techniques and dosage recommendations in Brazil.

Antisnakevenom: an over-used medication.

Fifty-five cases of snakebite were retrospectively analysed for the indications for the use of anti-snakevenom (ASV). Sixty-seven per cent of patients received treatment with ASV. Of these, 47% had features of systemic envenoming, 30% had features of local envenoming and 22% had no features of envenoming, either systemic or local. When WHO guidelines were strictly applied, it was found that in 44% of cases, ASV was used without adequate indication.

Bites by the King Cobra (&lt;italic&gt;Ophiophagus hannah&lt;/italic&gt;) in Myanmar: Successful Treatment of Severe Neurotoxic Envenoming

Three patients bitten by the world's largest species of venomous snake, the king cobra (Ophiophagus hannah), were observed in Myanmar (Burma). All three were involved in the famous snake dance in Yangon (Rangoon) Zoological Gardens. One patient showed no signs of envenoming despite a sustained bite, another developed only signs of local envenoming, but in a third there was severe neurotoxic envenoming requiring mechanical ventilation for 64 1/2 hours, episodes of hypotension and massive swelling of the bitten limb. This patient showed some signs of recovery before delayed treatment with specific antivenom. It is possible that all three patients had some immunity to king cobra venom resulting from traditional 'immunization' achieved by scratching venom into the skin. The literature on king cobra bites is reviewed and recommendations given for antivenom and ancillary treatments.

ELISA confirmation of acute and past envenoming by the monocellate Thai cobra (Naja kaouthia).

The monocellate Thai cobra (Naja kaouthia) is a major cause of snake bite mortality and morbidity throughout Thailand, but neither the local nor the systemic effects of its venom are diagnostic. Species diagnosis is important because only monospecific antivenoms are available for treatment in Thailand. We tested the ability of the ELISA technique to detect venom antigen in the sera of 58 acute snake bite cases including 4 fatalities, and venom antibody in 51 patients bitten between 1 month and 19 years previously. N. kaouthia venom antigen was found in 8 of 33 patients with only local envenoming and in 14 of 20 with local plus systemic (neurotoxic) envenoming, but the mean venom concentration was 33 times greater in the latter group. The serum of 1 fatal case contained banded krait (Bungarus fasciatus) but no cobra venom antigen. N. kaouthia venom antibody was present in sera of patients bitten between 1 month and 7 years previously. Antibody was found in 6 of 8 patients who had had local envenoming alone but in only 19 of 41 who had had systemic envenoming treated by antivenom. The titer of antibody declined with an approximate half time of 2-3 years. One patient had a significant titer of B. fasciatus venom antibody. This study confirms the value of ELISA-immunodiagnosis and the predominance of N. kaouthia as a cause of neurotoxic envenoming in the Bang Phli area. However, the attribution of 1 fatal case to B. fasciatus bite suggests that patients with neurotoxic signs should be given B. fasciatus antivenom if they fail to respond to cobra antivenom.

Local tissue destruction and Australian elapid envenomation

Local tissue destruction and Australian elapid envenomation