Management of poisonous snake bites in southern Taiwan

Snake bite envenomation is not uncommon in Taiwan. This study focuses on the pattern of poisonous snake bites and their management in southern Taiwan over a 5-year period. The case histories of 37 patients with poisonous snake bites admitted to the Kaohsiung Medical University Hospital between June 2001 and July 2005 were analyzed retrospectively. Three patients, bitten by unknown species of venomous snakes, were excluded from this study. The frequency of snakebites from each species of snake, the local and systemic manifestations of snake bite, treatment of complications and final outcomes were analyzed. Of the remaining 34 patients, 11 (32.4%) were bitten by bamboo vipers, 10 (29.4%) by Russell's pit vipers, 8 (23.5%) by Taiwan cobras and 5 (14.7%) by Taiwan Habu. The majority of snake bites (28) occurred between May and November. Those affected were mainly outdoor hikers (14) and workers (9). The antivenin requirements for treatment in the emergency room were in accordance with standard procedures. No mortality was noted among those envenomed by poisonous snakes. Although poisonous snake bite is not a common life-threatening emergency in the study area, we observed both an environmental risk and a seasonal incidence of snake bite. Keeping the varied clinical manifestations of snake bite in mind is important for effective management. Ready availability and appropriate use of antivenin, close monitoring of patients, institution of ventilatory support and early referral to a larger hospital when required, all help reduce mortality.     

Envenomation by Micrurus coral snakes in the Brazilian Amazon region: report of two cases

Two cases of proven coral snake bites were reported in Belém, Pará State, Brazil. The first case was a severe one caused by Micrurus surinamensis. The patient required mechanical ventilation due to acute respiratory failure. The second case showed just mild signs of envenomation caused by Micrurus filiformis. Both patients received specific Micrurus antivenom and were discharged without further complications. Coral snake bites are scarcely reported in the Amazon region and there is a broad spectrum of clinical manifestations, varying from extremely mild to those which may rapidly lead to death if the patient is not treated as soon as possible.     

Estimates of disease burden due to land-snake bite in Sri Lankan hospitals

Snake bite is a common cause of hospital admission in Sri Lanka. Despite this, there have been no countrywide studies or national estimates of disease burden due to snake bites in Sri Lankan hospitals. We assessed the disease burden due to snake bite in our hospitals and estimated the frequency of admissions due to bites by different snake species. Sri Lanka was divided into four zones based on climate and topography. Hospital morbidity and mortality data, which are available on an administrative district basis, were collated for the four zones. A survey of opinion among specialist physicians (the Delphi technique) was used to estimate the proportion of bites by different species, and requirements for anti-venom (AV) and intensive care facilities for management of snake bites in hospitals in each of the four zones. A study of hospital admissions due to snake bites in seven selected hospitals was also performed to validate the opinion survey. There was a clear difference in the incidence of hospital admissions due to snake bites in the different zones. Estimates of hospital admissions due to bites by different species also varied considerably between zones. These trends corresponded to estimates of requirements of AV and other supportive health care. Health care planning using data based on environmental information, rather than merely on political boundaries, could lead to targeted distribution of AV and intensive care requirements to manage snake bites.     

Use of enzyme immunoassays to compare the effect and assess the dosage regimens of three Brazilian Bothrops antivenoms. The Butantan Institute Antivenom Study Group (BIASG).

The effect of the three main Brazilian polyspecific antivenoms on venom clearance was assessed in 118 moderately envenomed victims of bites by Bothrops species (mainly B. jararaca) in Sao Paulo State, Brazil. Serum samples taken from patients at intervals during their stay in the hospital and at followup approximately four weeks later were tested by enzyme immunoassay for the presence of whole venom and therapeutic antivenom. Results indicated that in patients treated with the standard regimen of either four (40 ml) or eight (80 ml) ampules of each antivenom, venom was cleared from the circulation within four days of antivenom administration. However, high concentrations of antivenom persisted for approximately 10 days and remained detectable until 30-50 days after administration. This suggests that patients may be being treated with excessive amounts of antivenom in Brazil. This practice increases the national cost of antivenom therapy and may contribute to the high frequency of antivenom reactions. Clinically, there was no obvious difference in the efficacy between the three antivenoms.     

Envenomation by the neotropical colubrid Boiruna maculata (Boulenger, 1896): a case report

This is a case report of a Boiruna maculata snake bite in a child admitted to the Hospital Municipal de Pronto Socorro de Porto Alegre, Porto Alegre, RS, Brazil. The patient was bitten on the lower left limb, and exhibited pronounced local manifestations of envenomation. She was treated with Bothrops antivenom and was discharged from the hospital five days later with marked improvement of envenomation.     

Epidemiological aspects of snake bites on a Liberian rubber plantation

During a one-year period 95 patients with a history of snake bite were admitted to the hospital of a Liberian rubber plantation. The population at risk included the field workers (tappers and slashers) with an incidence of 4.2 symptomatic snake bites per thousand per year. The incidence of symptomatic bites was 1.7 per thousand in the group of non-field employees and 0.4 per thousand per year in the group of non-employees. The temporary disability was between 3 and 5 days, and the loss of workings days due to snake bites was one day per 10,000 working days on the plantation. Among the 95 patients 27 did not show any symptoms of envenoming except occasional fang marks. 64 patients developed cytotoxic symptoms alone. In this group, the night adder (Causus maculatus) was the main responsible snake. 4 patients showed signs of systemic envenoming. Two were haematological and two were neurological in nature and caused by Bitis species and Naja species, respectively. No fatalities were noted. A definite maximum of snake bites was observed during October and November which corresponds to the transition from rainy to dry season.     

Envenomation by neotropical opisthoglyphous colubrid Thamnodynastes cf. pallidus Linne, 1758 (Serpentes:Colubridae) in Venezuela

This is a case report of a "non-venomous" snake bite in a herpetologist observed at the Sciences Faculty of the Universidad de los Andes (Mérida, Venezuela). The patient was bitten on the middle finger of the left hand, and shows signs of pronounced local manifestations of envenomation such as bleeding from the tooth imprint, swelling and warmth. He was treated with local care, analgesics, and steroids. He was dismissed from the hospital and observed at home during five days with marked improvement of envenomation. The snake was brought to the medical consult and identified as a Thamnodynastes cf. pallidus specimen. This report represents the first T. pallidus accident described in a human.     

Crotalidae polyvalent immune Fab (ovine) antivenom is efficacious for envenomations by Southern Pacific rattlesnakes (Crotalus helleri)

STUDY OBJECTIVE: Southern Pacific rattlesnake (Crotalus helleri ) venom is not 1 of the 4 venoms used to produce Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV). There is currently no published clinical experience regarding the efficacy of this new antivenom for confirmed C helleri envenomation, and animal data suggest greatly diminished efficacy. We assessed the efficacy of FabAV for patients with confirmed C helleri envenomation. METHODS: We conducted a prospective observational study of 23 consecutive rattlesnake envenomations that were treated with FabAV at our center. Patients were excluded if the species of snake could not be confirmed, if FabAV antivenom was not given, or if Antivenin (Crotalidae) polyvalent (equine) was given. We collected serial physical examination and laboratory data over a 24-hour period to serially evaluate the severity score and performed follow-up to evaluate delayed reactions. RESULTS: There were 15 patients who received FabAV and had the species of rattlesnake confirmed (9 C helleri, 4 C scutulatus scutulatus, 1 C mitchellii pyrrhus, 1 C ruber ruber ). C helleri envenomations demonstrated similar improvement in serial snakebite severity scores to those of other species. Three patients treated with scheduled dosing had recurrence of progressive swelling (2 C helleri and 1 C mitchellii pyrrhus ) during the 24-hour study period. CONCLUSION: We observed similar improvement in FabAV-treated patients with C helleri envenomation compared with those of other species and conclude that this treatment in standard doses appears efficacious for bites by this species. Progressive swelling may recur despite scheduled dosing.     

Recurrent and persistent coagulopathy following pit viper envenomation

BACKGROUND: Coagulation abnormalities following crotaline (pit viper) snakebite have traditionally been considered short-lived, but laboratory studies have rarely been reported beyond the first few days of treatment for envenomation. During the course of an antivenom clinical trial, we observed coagulation defects as late as 2 weeks following envenomation. OBJECTIVES: To document and characterize the recurrence or persistence of coagulopathy among patients envenomed by pit vipers and treated with a Fab antivenom. METHODS: Patients with moderate pit viper envenomation were enrolled in a multicenter, prospective clinical trial. A Fab-based antivenom preparation, antivenom polyvalent crotalid (ovine) Fab, was administered in all cases. Platelet count, fibrinogen level, presence of fibrin split products, prothrombin time, and partial thromboplastin time were determined before treatment and at standard intervals during the following 2 weeks. RESULTS: Of 38 patients completing the study, 20 (53%) had recurrent, persistent, or late coagulopathy 2 to 14 days after envenomation. Thrombocytopenia occurred in patients with prior thrombocytopenia; hypofibrinogenemia occurred only in those with prior hypofibrinogenemia or positive fibrin split products. No patient experienced significant spontaneous bleeding. One patient with coagulopathy developed minor bleeding following minor surgery 12 days after envenomation. CONCLUSIONS: Prolonged or recurrent coagulopathy may occur after envenomation by North American pit vipers. Patients treated with Fab-based antivenom may benefit from periodic rather than single-bolus dosing. Patients with coagulopathy should undergo close monitoring during the first 2 weeks after snakebite.     

Cross neutralization of common Southeast Asian viperid venoms by a Thai polyvalent snake antivenom (Hemato Polyvalent Snake Antivenom)

Snake envenomation is a serious public health threat in many rural areas of Asia and Africa. Antivenom has hitherto been the definite treatment for snake envenomation. Owing to a lack of local production of specific antivenom, most countries in these regions fully depend on foreign supplies of antivenoms. Often, the effectiveness of the imported antivenoms against local medically important species has not been validated. This study aimed to assess cross-neutralizing capacity of a recently developed polyvalent antivenom, Hemato Polyvalent Snake Antivenom (HPAV), against venoms of a common viper and some pit vipers from Southeast Asia. Neutralisation assays showed that HPAV was able to effectively neutralize lethality of the common Southeast Asian viperid venoms examined (Calloselasma, Crytelytrops, Popeia, and Daboia sp.) except for Tropidolaemus wagleri venom. HPAV also effectively neutralized the procoagulant and hemorrhagic activities of all the venoms examined, corroboratively supporting the capability of HPAV in neutralizing viperid venoms which are principally hematoxic. The study also indicated that HPAV fully prevented the occurrence of hematuria and proteinuria in mice envenomed with Thai Daboia siamensis venom but was only partially effective against venoms of Myanmar D. siamensis. Thus, HPAV appears to be useful against its homologous venoms and venoms from Southeast Asian viperids including several medically important pit vipers belonging to the Trimeresurus complex. Nevertheless, the effectiveness of HPAV as a paraspecific antivenom for treatment of viperid envenomation in Southeast Asian region requires further assessment from future clinical trials     

Wound care of spider and snake envenomations

Venomous bites and stings are numerous but severe local tissue damage is uncommon. Venoms may be simple substances or complex mixtures of many poorly characterized components whose interactions are still not fully understood. The best studied example of a dermonecrotic venom is that produced by the brown recluse spider (Loxosceles reclusa). Rattlesnake envenomation also causes significant wound injuries. Many spider and snake envenomation management modalities are controversial and the evidence is mounting against the use of a number of these treatments.     

Effectiveness of Rapid Transport of Victims and Community Health Education on Snake Bite Fatalities in Rural Nepal

Snake bite is a major public problem in the rural tropics. In southern Nepal, most deaths caused by neurotoxic envenomation occur in the village or during transport to health centers. The effectiveness of victims'' transport by motorcycle volunteers to a specialized treatment center, combined with community health education, was assessed in a non-randomized, single-arm, before-after study conducted in four villages (population = 62,127). The case-fatality rate of snake bite decreased from 10.5% in the pre-intervention period to 0.5% during the intervention (relative risk reduction = 0.949, 95% confidence interval = 0.695–0.999). The snake bite incidence decreased from 502 bites/100,000 population to 315 bites/100,000 population in the four villages (relative risk reduction = 0.373, 95% confidence interval = 0.245–0.48), but it remained constant in other villages. Simple educational messages and promotion of immediate and rapid transport of victims to a treatment center decreased the mortality rate and incidence of snake bite in southeastern Nepal. The impact of similar interventions should be assessed elsewhere.     

Scorpion envenomation and serotherapy in Morocco

A clinical and biologic study was conducted in Morocco to assess the efficiency of antivenom therapy for treating victims of scorpion stings. Epidemiologic and clinical data were collected from 275 patients envenomed by Androctonus mauretanicus mauretanicus and Buthus occitanus scorpions. Patients received antivenom or other drugs. Blood samples were collected at the time of hospital admission and 1 hr and 3 hr after treatment. Serum venom levels were quantified by using an ELISA. An association was found between clinical signs of envenoming and the level of venom in serum. Patients classified as grade II (moderate envenoming) had higher serum levels of venom level than patients classified as grade I (mild envenoming). At admission to the hospital, the mean venom concentration was not significantly different between the group not treated with antivenom, the group who received 2-5 ml of antivenom, and the group who received 10 ml of antivenom. A significant decrease in serum venom levels and an improvement in the clinical conditions were observed in patients administered 10 ml of antivenom. The lower decrease in serum venom levels in patients who received 2-5 ml of antivenom was due to lower doses of antivenom. No difference in the venom concentration was observed in patients who were not treated with antivenom. The absence of administration of antivenom increased the risk of developing clinical signs at the end of the hospitalization period. However, this risk was much higher when more than 1 hr elapsed between the time of the scorpion sting and the time of hospital admission. The results demonstrate that antivenom is effective in decreasing circulating venom and morbidity. Serotherapy is more efficient when given as soon as possible after envenomation and with adequate quantities of antivenom.     

Clinical predictors of in-hospital mortality in patients with snake bite: a retrospective study from a rural hospital in central India

OBJECTIVE: To determine the association between selected admission risk factors and in-hospital mortality in patients admitted with venomous snake bite to a rural tertiary care hospital in central India. METHODS: Retrospective cohort study of patients aged 12 years or older admitted to a rural hospital in central India between January 2000 and December 2003 with venomous snake bites. The primary endpoint was in-hospital mortality. We used Cox proportional-hazards regression analysis to evaluate the association between risk factors (home-to-hospital distance, bite-to-hospital time, vomiting, neurotoxicity, urine albumin, serum creatinine concentration and whole-blood clotting time) and in-hospital mortality. RESULTS: Two hundred and seventy-seven patients [mean age 32 (SD 12) years; 188 men (68%)] were admitted with venomous snake bite, 29 patients (11%) died. The probability of survival at day 7 was 83%. Vomiting [hazard ratio 6.51 (95% CI 1.94-21.77), P < or = 0.002], neurotoxicity [hazard ratio 3.15 (95% CI 1.45-6.83), P = 0.004] and admission serum creatinine concentration [hazard ratio 1.35 (95% CI 1.17-1.56), P < or = 0.001] were associated with higher risk of death in the adjusted analysis. CONCLUSIONS: In our rural hospital setting, the overall mortality rate was 11 per 100 cases of snake bite. Vomiting, neurotoxicity and serum creatinine are significant predictors of mortality among inpatients with snake bite. These predictors can help clinicians assess prognosis of their patients more accurately and parsimoniously and also serve as useful signposts for clinical decision-making.     

毒蛇咬伤的心电图改变及其临床意义

目的探讨毒蛇咬伤患者的心电图改变及相关临床意义。方法对2008年4月～10月119例蛇咬伤入院治疗者的心电图进行分析。结果心电图异常者62例,阳性率52%。结论毒蛇咬伤可导致心律失常改变,其发生率与早期的伤口排毒、防扩散处理及解毒措施的实施相关。     

The legitimacy of rattlesnake bites in central Arizona

Previous authors have classified poisonous snake bites as being legitimate or illegitimate, depending on whether the victim was taking unnecessary risks with a snake before being bitten. We reviewed medical records of 86 consecutive rattlesnake bite victims cared for at a single medical center to determine legitimacy of snake bites. A bite was considered illegitimate if, before being bitten, the victim recognized an encounter with a snake but did not attempt to move away from the snake. A legitimate bite was said to have occurred if a person was bitten before an encounter with a snake was recognized or was bitten while attempting to move away from a snake. The study group was made up of 75 male (87.2%) and 11 female (12.8%) victims. Seventy-four percent were 18 to 50 years old, and 15% had been bitten previously. Only 43.4% of all bites were considered legitimate, and pet (captive) snakes accounted for almost one third of all illegitimate bites. The ingestion of alcoholic beverages was associated with 56.5% of illegitimate bites versus 16.7% of legitimate bites (P less than .001). While 74.4% of bites were to upper extremities, only 27% of upper extremity bites were legitimate. All bites to the lower extremity were legitimate (P less than .001). Of 14 individuals bitten by pet snakes, all were men and 64.3% were under the influence of alcohol at the time of the bite.(ABSTRACT TRUNCATED AT 250 WORDS)     

Impact of snake bites and determinants of fatal outcomes in southeastern Nepal

Current available data on snake bites in Nepal are based solely on hospital statistics. This community-based study aimed at evaluating the impact of snake bites and determining the risk factors associated with a fatal outcome in southeastern Nepal. A total of 1,817 households, selected by a random proportionate sampling method, were visited by trained field workers in five villages. Extensive data from snake bite victims during the 14 previous months were recorded and analyzed. One hundred forty-three snake bites including 75 bites with signs of envenoming were reported (annual incidence = 1,162/100,000 and 604/100,000, respectively), resulting in 20 deaths (annual mortality rate = 162/100,000). Characteristics of krait bites such as bites occurring inside the house, while resting, and between midnight and 6:00 am were all factors associated with an increased risk of death, as were an initial consultation with a traditional healer, a long delay before transport, and a lack of available transport. An initial transfer to a specialized treatment center and transport by motorcycle were strong protective factors. Among the 123 survivors, wounds required dressing and surgery in 30 (24%) and 10 (8%) victims, respectively, the mean working incapacity period was 15 days, and the mean out-of-pocket expense was 69 U.S. dollars. Snake bite is a major but neglected public health problem in southeastern Nepal. Public health interventions should focus on improving victims' rapid access to anti-snake venom serum by promoting immediate and fast transport to adequate treatment centers, particularly for bites occurring at night.     

Initial postmarketing experience with crotalidae polyvalent immune Fab for treatment of rattlesnake envenomation

STUDY OBJECTIVE: We describe our postmarketing experience with patients receiving Crotalidae polyvalent immune Fab (CroFab; FabAV) antivenom for treatment of rattlesnake envenomation. METHODS: The charts of 28 patients admitted between March 1 and September 9, 2001, with rattlesnake envenomation and treated with FabAV were reviewed for demographic information, time until antivenom treatment, laboratory findings, evidence of hypersensitivity reaction, length of hospital stay, and readmission to the hospital. RESULTS: All patients had swelling, 20 patients had elevated prothrombin times (>14 seconds), 12 patients had low fibrinogen levels (<170 mg/dL), and 6 patients had thrombocytopenia (platelet count <120,000/mm(3)) on presentation. The total dose of FabAV ranged from 10 to 47 vials per patient. Hypofibrinogenemia was resistant to FabAV in some patients. On follow-up, recurrence of coagulopathy was detected in 3 patients, and recurrence of thrombocytopenia was detected in 1 patient. Two patients demonstrated delayed-onset severe thrombocytopenia. Recurrence or delayed-onset toxicity might have been underestimated because of incomplete follow-up in some patients. No acute hypersensitivity reactions occurred. Two patients reported mild symptoms of possible serum sickness on follow-up. CONCLUSION: FabAV effectively controlled the effects of envenomation; however, initial control of coagulopathy was difficult to achieve in some cases, and recurrence or delayed-onset hematotoxicity was common. When initially managing hematotoxicity, a trend toward normalization of laboratory values might be a more reasonable end point for FabAV treatment than attainment of normal reference values in nonbleeding patients.     

The importance of bites by the saw-scaled or carpet viper (Echis carinatus): epidemiological studies in Nigeria and a review of the world literature.

The incidence of Echis carinatus (saw-scaled or carpet viper) bite and its mortality have been investigated in the Nigerian savanna region. A geographical area was defined in which the snake was particularly abundant and bites were frequent. Perennial and seasonal fluctuations in incidence and mortality, the circumstances in which bites occurred and the types of people bitten were studied at Bambur, Zaria, Kaltungo and Gombe hospitals. Peak incidence coincided with the increase in farming during the rains whereas percentage mortality seemed to be greatest during the cold dry season. The majority of the patients were young males bitten on the foot while walking or farming. A review of the world literature indicated that E. carinatus was the principal cause of snake bite morbidity wherever data were available throughout its wide geographical range. Official statistics have seriously underestimated this important rural health problem.     

The problem of intoxication in the population of the Republic of Guinea due to venomous snake bites

Intoxication of the population of Guinea due to venomous snake bites (100-150 intoxications per 100,000 with an 18% mortality rate) is a serious public health problem in the Republic of Guinea. Guinea's fauna of venomous snakes is diverse and numbers 20 species that are dangerous to human beings. The representatives of the family Elapidae (cobras and mambas) whose venom is highly toxic (LD50 5-12 mg) are responsible for the bulk (59.6%) of their bites. There has been recently an increase in the number of deaths from venomous snake bites, as high as 60% of the patients consulting a doctor being notified in one of the prefectures. At the same time the situation associated with the availability of antisnake serum is critical in the country due to its minute amount and to the inaccessibility of its high prices. By taking into account the great demand for the serum in Guinea, as everywhere over West Africa (thousands of doses every year), its manufacture may be profitable for potential investors and partners of the Pasteur Institute of Guinea.