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.     

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.     

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 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)     

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.     

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.     

Parallels between Russell's viper (Daboia russelii) and hump-nosed viper (Hypnale species) bites in the central hills of Sri Lanka amidst the heavy burden of unidentified snake bites

ObjectiveTo describe the epidemiology of snake bite in the region and attempt to compare proven Russell's viper with hump-nosed viper bites.MethodsAll snake bite admissions to the Toxicology Unit of Teaching Hospital Peradeniya over three year from 2006 were included.ResultsOf the 776 snakebites, 665(86%) were unidentified and non-envenomed. Hump-nosed viper and Russell's viper accounted for 55(7%) and 40(5%) bites respectively, of them, incriminated snakes were found in 36(65%) and 19(48%) cases. The cobra bites-5, krait bites-0. The median ages: Russell's viper bites-41(range 16-66), hump-nosed viper bites-42(range 15-75). The gender incidence, time of bite (>58% daytime) were similar. In hump-nosed viper bite; upper limb involved in 13(36%), happened at home garden in 22(61%), none in paddy fields. In Russell's viper bite; 6(33%) occurred in paddy fields. Dry bites were similar at 5%. In hump-nosed viper bite: local effects 94%, coagulopathy 3%, acute renal failure 3% and one patient died. In Russell's viper bite; local effects 84%, coagulopathy 53%, neurotoxicity 21%. Abdominal pain occurred only in Russell's viper bites 10(53%).ConclusionsOverwhelming numbers of unidentified, non-envenomed snakebites are common in the central hills. Some distinctive differences were observed between Russell's viper and hump-nosed viper bites.     

Snake bites in Moyen Chari district, Chad: a five-year experience

Snake bites are of major public health importance in Africa as a cause of morbidity and mortality. Echis ocellatus is responsible for the majority of envenomation cases in West Africa. Antivenom immunotherapy is the only specific treatment available for envenomed patients. From January 1997 to December 2001, 325 patients suffering from snake bites were enrolled in a survey undertaken at Goundi Hospital, Chad. We analysed the percentage of envenomed patients, sex distribution, distribution along the year, lethality, hospital stay and recovery clotting time. Two hundred and ninety-eight patients showed signs of envenomation and were treated with antivenom immunotherapy with three different sera in consecutive periods. Young males were more frequently involved. The overall lethality was 8%. Lethality and hospital stay were significantly different in the differently treated patients. Most of the data in our series were similar to those from other sub-Saharan countries but, overall, the percentage of snake bite victims who were admitted to hospital was higher.     

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.     

Distinctive epidemiologic and clinical features of common krait (Bungarus caeruleus) bites in Sri Lanka

A prospective study was designed to define epidemiologic and clinical features of krait bites to improve diagnosis, management, and prevention. Among 762 cases of venomous snake bites admitted to 10 Sri Lankan hospitals in which the snake responsible was brought and identified, 88 (11.5%) were caused by common kraits (Bungarus caeruleus). Bites were: most frequent in September through November. Distinctive features of B. caeruleus bites (compared with bites by other species in parentheses) were bitten while sleeping on the ground, 100% (1%); indoors, 100% (49%); between 2300 and 0500 hours, 100% (3%). Only 13% of krait victims were bitten on their lower limbs (82%), only 9% had local swelling (in all cases mild) at the site of the bite (93%), 64% developed respiratory paralysis (2%), and 91% experienced (often severe) abdominal pain (10%). Case fatality was 6% (3%). This distinctive pattern of epidemiology and symptoms will aid clinical recognition (syndromic diagnosis) and prevention of krait bite envenoming.     

Prevalence of snake bites in Kangar District Hospital, Perlis, west Malaysia: a retrospective study (January 1999-December 2000)

The records of 284 snake bite cases presenting to the Kangar District Hospital, Perlis, west Malaysia, from January 1999 till December 2000 were carefully reviewed. Data on prevalence and types of snake bites, were recorded. The majority of the cases were among Malays (60.2%), followed by Chinese (16.9%), Indians (13%), and others which include Thai nationals, army personnel from Sabah and Sarawak, and foreign tourists (9.8%). A higher incidence was found in males (60.2%) and most cases were seen in the age group of 10-19 years (33%). Snake bites were more common between 2 PM and 9 PM (47.6%) and from 7 AM to 2 PM (33.4%). The snakes were positively identified in 68 cases, of which 50 were common cobras (Naja naja) (73%), 16 were Malayan pit vipers (Agkistrodon rhodostoma) (24%) and two were sea-snakes (3%).     

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.     

Case Report: Saw-Scaled Viper Bites in Sri Lanka: Is It a Different Subspecies? Clinical Evidence from an Authenticated Case Series

The saw-scaled viper (SSV) (Echis carinatus) is considered to be a highly venomous snake in Sri Lanka despite any published clinical justification. Being a rarity, the clinical profile of SSV bites is not well established in Sri Lanka. We report a series of 48 (n-48) SSV bites from the Northern Province of Sri Lanka. The majority (65%) of victims had evidence of local envenoming at the site of the bite; however, 29% showed spontaneous bleeding and 71% had coagulopathy. There were no deaths in the series. The envenoming was mild in contrast to the mortality and significant morbidity associated with SSV bites in West Africa and some parts of India. These observations need to be further explored with laboratory studies to identify the venom components, study of morphological characteristics, and genetic profiling of the Sri Lankan SSV to see if it is different from the subspecies found elsewhere.     

Acute Renal Failure Following the Saharan Horned Viper (Cerastes cerastes) Bite

Introduction: The Saharan horned viper (Cerastes cerastes) is a common snake in the sandy and rocky regions in the south of Morocco. Although nearly all snakes with medical relevance can induce acute renal failure (ARF), it's unusual except with bites by some viper species. ARF has very rarely been reported following Cerastes cerastes bite. Case Report: A 55-year-old Moroccan man was bitten on his right hand by a Saharan horned viper, Cerastes cerastes. He presented 24 hours later in a state of confusion, agitation and hypotension with marked swelling of his right hand. Investigations revealed evidence of disseminated intravascular coagulation (DIC) and rhabdomyolysis. The appropriate antivenom was not available. Despite adequate hydration, he developed acute renal failure necessitating prolonged hemodialysis. He subsequently improved and was discharged from the hospital after four weeks with normal renal function. Conclusion: Although uncommon, the bite of Cerastes cerastes can result in ARF due to DIC and rhabdomyolysis. The appropriate antivenom should be made available in areas where this snake is prevalent. Keywords: Acute Renal Failure; Antivenom; DIC; Cerastes Cerastes; Rhabdomyolysis; Snake Bite.     

Thrombotic microangiopathy from Australian brown snake (Pseudonaja) envenoming

Background: Australian brown snake (genus Pseudonaja) envenoming causes a venom‐induced consumptive coagulopathy (VICC). A proportion of cases go on to develop thrombotic microangiopathy characterized by thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and acute renal failure (ARF). Aim: The aim of the study was to define better the natural history and empirical treatments for thrombotic microangiopathy in brown snake envenoming. Methods: A review of brown snake bites recruited to the Australian Snakebite Project (ASP), a national multicentre study of snake envenoming was undertaken. Serial data are recorded on clinical effects and laboratory results, including measurement of venom concentrations. We describe cases of thrombotic microangiopathy and compare these to cases without thrombotic microangiopathy. Results: From 32 cases of brown snake envenoming with severe VICC, four (13%) developed thrombotic microangiopathy, we also included two cases of thrombotic microangiopathy from prior to ASP. All six developed severe thrombocytopenia (<20 × 10⁻⁹/L), worst 3 days after the bite and resolving over a week, MAHA with fragmented red blood cells on the blood film and five developed anuric ARF requiring dialysis and lasting 2–8 weeks. All six received antivenom, which was delayed compared with other brown snake‐envenoming cases. Four were treated with plasmapheresis. The severity and recovery of the thrombocytopenia, anaemia and renal function were similar with and without plasmapheresis. The median length of stay for MAHA cases was 14 days (interquartile range (IQR) 12–14) compared to 1.8 days (IQR 1.3–2) for all other cases. Conclusion: Thrombotic microangiopathy resulting from brown snake bite appears to have a good prognosis and management should focus on early antivenom therapy and supportive care including dialysis. The role of plasmapheresis is yet to be defined.     

Epidemiology of dog bites: a community-based study in India

Rabies is a deadly disease with no cure which is mainly caused by dog bites. Data on dog bites and knowledge, attitude and practices (KAP) related to dog bites are not generally available to rural communities. We made a cross-sectional study of a rural community of ten villages served by a primary health centre selected by random sampling. Ten per cent of households selected by systematic random sampling were interviewed for KAP regarding dog bites. The dog bite rate was 25.7/1000 population per year. The rate for males was higher than for females; half of the bites were in summer; 40% did not go for any prophylaxis; half of the victims treated their wounds with chilli powder. Eighty per cent of the bites were class II or III and leg bites were most common. The majority of the community knew dog bites can cause death but they did not know the correct incubation period. Most knew that injections were available to prevent rabies. Only half said they would visit a hospital for treatment. Around 50% received tetanus toxoid.     

Epidemiological studies of snake bite in French Guiana

The incidence of snake bite and the presence of venom antibody in previous snake bite victims was investigated in French Guiana. The incidence proved to be highest (600/100,000) in inhabitants of bush regions and lowest (45/100,000) in urban areas. Of 43 sera tested for specific venom antibody 22 (51%) were positive, and most of these individuals suffered severe or moderate poisoning. The main species involved, as assessed by detection of venom antibody by ELISA, were Lachesis muta, Bothrops brazili, B. bilineatus and B. atrox. The significance of these findings is discussed.     

Protection against snake bites by sleeping under a bed net in southeastern Nepal

Snake bites in persons while they are asleep indoors are associated with a high risk of fatal outcome in southeastern Nepal. The preventive impact of sleeping under a bed net was assessed in four villages in a case-control study. A case was defined as a person with a history of snake bite that occurred indoors while asleep. Cases were matched with controls by village, type of household, sex, and age category. Of the 11,176 households visited, 56 cases, including 13 (23%) with a fatal outcome and 56 controls were included in the analysis. Sleeping under a bed net was a strong protective factor (odds ratio = 0.02, 95% confidence interval = 0.007-0.07, P < 0.0001), whereas the place of sleeping in the household and the use of a cot were not associated with the risk of snake bite. These findings provide further support for use of bed nets in this region.     

Venomous bites, stings, and poisoning

This article discusses the epidemiology, prevention, clinical features, first aid and medical treatment of venomous bites by snakes, lizards, and spiders; stings by fish, jellyfish, echinoderms, and insects; and poisoning by fish and molluscs, in all parts of the world. Of these envenoming and poisonings, snake bite causes the greatest burden of human suffering, killing 46,000 people each year in India alone and more than 100,000 worldwide and resulting in physical handicap in many survivors. Specific antidotes (antivenoms/antivenins) are available to treat envenoming by many of these taxa but supply and distribution is inadequate in many tropical developing countries.