|Year : 2014 | Volume
| Issue : 2 | Page : 76-80
A retrospective review of snake bite victims admitted in a tertiary level teaching institute
M Rajesh Kumar1, M Veeraprasad2, P Ramesh Babu1, S Satish Kumar3, BV Subrahmanyam4, P Rammohan5, M Srinivas3, Amit Agrawal6
1 Department of Medicine, Narayana Medical College Hospital, Chinthareddy Palem, Nellore, Andhra Pradesh, India
2 Department of Hospital Administration, Narayana Medical College Hospital, Chinthareddy Palem, Nellore, Andhra Pradesh, India
3 Department of Emergency Medicine, Narayana Medical College Hospital, Chinthareddy Palem, Nellore, Andhra Pradesh, India
4 Department of Forensic Medicine, Narayana Medical College Hospital, Chinthareddy Palem, Nellore, Andhra Pradesh, India
5 Department of Pharmacology, Narayana Medical College Hospital, Chinthareddy Palem, Nellore, Andhra Pradesh, India
6 Department of Neurosurgery, Narayana Medical College Hospital, Chinthareddy Palem, Nellore, Andhra Pradesh, India
|Date of Web Publication||2-Apr-2014|
M Rajesh Kumar
Department of Medicine, Narayna Medical College Hospital, Chinthareddypalem, Nellore, Andhra Pradesh
| Abstract|| |
Objective: Snake bite remains major public health problem worldwide. We present our experience with cases of snake bites managed in our tertiary care teaching center of South India.
Materials and Methods: The details of all patients with snake bite admitted to a tertiary teaching care hospital from 2010 to 2012 were retrospectively retrieved and reviewed. The details regarding age, gender, first aid received or not, time elapsed between the bite, emergency care management and ASV (Anti Snake Venom) administration, site of snake bite, clinical features at the time of presentation, local examination findings at the site of bite, duration of hospital stay, need for elective ventilation, details of investigations and outcome were reviewed. The data were analyzed in PSPP software (Free Software Foundation, Inc.) for window for statistical analysis, while standard deviation (SD) was applied for the continuous variables, and proportions were applied for the categorical variables.
Results: Mean age was 38.4 ± 14.8 years (range 4-70 years). Majority [72 (82.8%)] were farmers. In 86.2% patients, the site of bite was in lower limbs. Snake could be identified in only 20 cases [Cobra-12 (60%), Krait-2 (10%), and Viper-6 (30%)]. Mean time to reach to hospital was 12.1 ± 21.4 hours (range 1-120 hours). Mean anti-venom therapy duration was 3.2 ± 2.0 days (range 1-14 days). Mean hospital stay was 4.7 ± 3.1 days (range 1-15 days). Majority (72.4%) made good recovery; mortality was in 4.6% cases, and 20 (23%) patients left against medical advice.
Conclusions: This study identified major epidemiological and management variables related to snake bite. There is a need for a well-planned data collection and information dissemination system to avoid this potentially preventable disease.
| Abstract in Spanish|| |
Objectif : Morsure de serpent de reste le problème majeur de santé publique dans le monde entier. Nous présentons notre expérience avec des cas de morsures de serpent gérés dans nos soins tertiaires enseignement Centre du sud de l'Inde.
Matériel et méthodes :Les détails de tous les patients avec une morsure de serpent admis à l'hôpital de soins de 2010 à 2012 ont été rétrospectivement récupérée et examiné l'enseignement tertiaire. Les détails concernant l'âge, de sexe, de premiers soins reçus ou non, de temps s'est écoulé entre la morsure et l'administration de soins d'urgence administration ASV (Anti venin de serpent), site de morsure de serpent, des signes cliniques lors de la présentation, les résultats de l'examen local à l'emplacement de morsure, durée du séjour hospitalier, nécessité de ventilation élective, détails des enquêtes et des résultats ont été examinés. A analysé les données dans le logiciel PSPP (Free Software Foundation, Inc.) pour la fenêtre d'analyse statistique, tandis que l'écart-type (SD) a été appliquée pour les variables continues, et les proportions ont été appliquées pour les variables catégorielles.
Résultats :Moyenne d'âge était de 38,4±14,8 ans (fourchette de 4 à 70 ans). Majorité [72 (82,8 %)] étaient des fermiers. Dans 86,2 % des patients, le site de la morsure était dans les membres inférieurs. Serpent puisse être identifiés dans seulement 20 cas [Cobra-12 (60 %), Krait-2 (10 %) et Viper-6 (30 %)]. Délai moyen de parvenir à l'hôpital était 12.1 ± 21,4 heures (allant de 1 à 120 heures). Moyenne était de durée de traitement anti-venin 3.2 ± 2,0 jours (entre 1 et 14 jours). Moyenne d'hospitalisation était de 4,7 ± 3,1 jours (entre 1 à 15 jours). Majorité (72,4 %) fait un bon rétablissement, la mortalité était de 4,6 % des cas et 20 (23 %) patients contre avis médical.
Conclusions :Cette étude trouvée principales variables épidémiologiques et de gestion associés à morsure de serpent. On a besoin d'un système de diffusion collection et informations données bien planifié éviter cette maladie potentiellement évitable.
Mots clés: Morsure de serpent, envenomination, anti-venins, venin de anti-serpent
Keywords: Anti-snake venom, anti-venoms, envenomination, snake-bite
|How to cite this article:|
Kumar M R, M V, Babu P R, Kumar S S, Subrahmanyam B V, Rammohan P, Srinivas M, Agrawal A. A retrospective review of snake bite victims admitted in a tertiary level teaching institute. Ann Afr Med 2014;13:76-80
|How to cite this URL:|
Kumar M R, M V, Babu P R, Kumar S S, Subrahmanyam B V, Rammohan P, Srinivas M, Agrawal A. A retrospective review of snake bite victims admitted in a tertiary level teaching institute. Ann Afr Med [serial online] 2014 [cited 2014 Nov 23];13:76-80. Available from: http://www.annalsafrmed.org/text.asp?2014/13/2/76/129879
| Introduction|| |
Snake bite remains major public health problems worldwide, , and it has been estimated that in Asia alone, there are approximately four million cases per year of snake bites, of which approximately venomous snake bites account for approximately 50% of the cases with about 100,000 annual deaths. ,, Snake bite remains an underestimated cause of accidental death in India, , and it has been estimated that 200,000 persons fall prey to snake-bite annually, with an estimated fatality rate of
35,000-50,000 per year. , Snake bite is primarily a problem of the poorer rural populations involving mainly farmers,  and snake bites are not systematically reported, only very few countries possess a reliable epidemiological data on snake bites.  Most of the available data are based on hospital statistics, which constitute a very small percentage of cases of snake bite. , In this study, we present our experience with cases of snake bites managed in our tertiary care teaching center of South India.
| Materials and Methods|| |
The details of all patients with snake bite admitted to a tertiary teaching care hospital between 2010 and 2012 were retrospectively retrieved and reviewed. Ethical clearance was obtained from the Institutional Ethical Committee. The data were collected in a pre-designed proforma from the admission register and case records. The details regarding age, gender, first aid received or not, time elapsed between the bite, emergency care management and ASV administration, site of snake bite, clinical features at the time of presentation, local examination findings at the site of bite, duration of hospital stay, need of elective ventilation, details of investigations and outcome were collected. Laboratory investigations such as renal function tests, electrolytes, urine for hematuria, chest radiograph, bleeding and clotting time, arterial blood gas (ABG), and ECG were requested for and repeated when required. All patients received tetanus toxoid at the time of presentation to emergency room. All complicated snake bites were treated with polyvalent ASV. The anti-snake venom (ASV) was administered by the intravenous route after written and informed consent. Skin test was done before starting ASV (1 ml of 1:100 diluted) was given subcutaneously.
The data were analyzed in PSPP software (Free Software Foundation, Inc.) for window for statistical analysis, while standard deviation (SPSS) was applied for the continuous variables, and proportions were applied for the categorical variables.
| Results|| |
A total number of 87 patients with snake bites were reviewed [Table 1], [Figure 1].
|Table 1: Summary of the demographic details, clinical features of snake bite patients|
Click here to view
The mean age was 38.4 ± 14.8 years (range 4-70 years). There were 72 (82.8%) farmers, while 15 (17.2%) were non-farmers. In 75 (86.2%) of the patients, the site of bite was in the lower limbs, 10.3% in upper limbs and in 3.4% cases, it was in the head and neck region. Two patients had seizures. Snake could be identified in only 20 cases [Cobra- 12 (60%), Krait-2 (10%), and Viper-6 (30%)]. Majority of the patients were conscious (73.6%) at the time of presentation to emergency room, and 26.4% had altered sensorium. Fourteen (16.1%) patients had tachycardia at the time of presentation (Pulse rate > 100/minute) and in majority (83.9%), it was within normal range (60-100/minute). Twenty-four patients had ptosis (27.5%), 28 (32.2%) patients had hemorrhagic manifestations at the time of presentation, 10 patients had vomiting, 7 patients had blurring of vision, 4 patients each had abdominal pain and diplopia. At the time of presentation, 56.3% had cellulitis. Three patients were febrile at the time of admission. All three had leukocytosis, and two had evidence of cellulitis. Pupils were normal in size and reaction to light in all the patients, except three who had dilated and non-reacting pupils. Out of these, two improved and one was discharged against medical advice. There was leukocytosis in 47 cases (54%) at the time of admission. Serumurea was raised in 23% and was normal in 77% of cases. Serum sodium was normal at the time of admission in majority (90.8%), 4 patients each had hypernatremia (4.6%) and hyponatremia (4.6%). Serum potassium was normal in all the cases. Platelets were within normal range in majority (82.8%); however, 15 cases (17.2%) had thrombocytopenia. Prothrombin time was normal in 60 (69%) and was increased in 27 cases (31%). INR was increased in 10 cases (11.5%) and was normal in 77 cases (88.5%). Except in one case, bleeding time was normal in majority (98.9%). Clotting time was abnormal in 4 cases (4.6%). Urine myoglobin was present in 34.5% of patients. Two patients had oxygen saturation less than 90% at the time of admission. Arterial blood gas analysis showed acidosis in 5 cases (5.7%), alkalosis in 2 cases (2.3%), and it was normal in 80 cases (92%). Six patients had evidence of acute kidney injury at the time of discharge, and all received dialysis. CT scan brain showed infarction and hemorrhage in two cases each. Sixteen patients (18.4%) needed elective ventilation. Mean time to reach to hospital was 12.1 ± 21.4 hours (range 1-120 hours). Mean anti-venom therapy duration was 3.15 ± 2.0 days (range 1-14 days). Mean hospital stay was 4.7 ± 3.1 days (range 1-15 days). Majority (72.4%) made good recovery; mortality was in 4.6% of cases, and 20 (23%) patients were discharged against medical advice.
| Discussion|| |
It has been recognized time and again in most of the studies that majority of the snake bite victims were young adult males in second to fourth decades of life. ,,,,,,,,,,,,,,,,,,,, In this study, the predominance of male gender and farmers put them at increased risk because of their involvement in outdoor activities. ,,,,,,,,,,,,,,,,,,,, Although the identification of snake species is crucial for optimal clinical management,  unfortunately, in many cases, it may not be possible or the identification and or description can be misleading. ,,,,, We also noticed that lack of information was due to the fact that the patients were anxious and frightened, thus clouding their ability to identify the species,  ignorance, or poor visibility in darkness making the identification difficult and inability to spot the snake due to tall grass and crops.  Majority of the patients could reach the hospital and got primary treatment within 12 hours of snake bite incidence. In the scientific literature, the mean time taken by the patients to receive hospital care ranged from 0.5 to 10 h. ,,,,,,, Early reporting to the hospital may reflect the proximity of health care facilities and better connectivity by roads in our area. Delayed arrival to the hospital could be one of the major causes of increase mortality. Factors that could delay seeking health care include lack of transport facilities and inability to afford transportation,  trying traditional and folk medicine first rather than coming to the health care facilities. , The mortality rate form snake bite is low,  and if the victim is treated without losing too much time, this mortality is potentially preventable. ,, In a study from Malaysia, it was recognized that the majority of the snake bite cases were due to non-venomous snakes, but the venomous bites were the cause of significant morbidity and mortality.  Cobra bites can result in severe envenomation with local gangrene and significantly less chances of complete recovery than those with non-cobra bites.  But, a positive point here is that, even bites of venomous snakes are often not life-threatening for humans unless a sufficient amount of venom is injected at the time of the bite. Most of the bites could be dry bites, because they were defensive, resulting in insufficient amount of venom injection.  Intravenous snake anti-venom is the most effective treatment for envenoming by snakes.  Administration of snake anti-venom either monovalent or polyvalent ,,,,,,,,, and accessibility to hospital care within hours of the snake bite is the major factor for good outcome. ,,, The majority of the rural people do not seek medical attention contributing to increased morbidity and mortality from snake bites, , and this may be because of lack of awareness, lack of availability of snake anti-venins, lack of transport facilities, and inability to afford transportation. ,, To overcome this, it has been suggested that snake anti-venin should be made available free of cost, particularly in the remote rural areas.  Also, at the community level, inappropriate first-aid measures such as incision, suction, and herbal treatment should be discouraged, as these not only result in mismanagement but also result in loss of vital time in seeking medical attention. ,
Increase in snake bite cases is mainly seen during the monsoon season when there is rainfall and increase in harvesting activities. ,,,,,,,,,,,,,,, As in this study, majority of the snake bites involved the lower extremities, and it can be explained by the fact that most of the time, the snakes are trodden upon by the victims. ,,,,,,,,,, Also, many other outfield activities including fishing, plantation, wood collection, or tending crops or gardens where fairly a large number of people walk bare-footed, particularly in rural areas, there is increased risk of snake bite. , These facts emphasize that not only there should be focus on strengthening surveillance to allow a more accurate perception of the magnitude of the problem and aggressive management of snake bite victims, ,,, but also there is a need to develop preventive strategies.  Awareness and knowledge regarding prevention, particularly among farmers and field workers, should be disseminated, , and they should be advised not to disturb snakes, not to walk bare footed, and use protective boots, ,,, to use a torch while walking on footpaths at night,  sleeping on a cot (rather than on the floor) and under bed nets. ,
| Conclusions|| |
It has been recognized that hospital statistics on snake bites can underestimate the true burden.  In agreement with the literature, the findings of the present analysis emphasize the importance of early report to the hospital and aggressive management of snake bite victims to avoid morbidity and mortality.  We also recommend that there is a need for a well-planned data collection and information dissemination system to avoid this avoidable and preventable disease. Although the present study is able to identify major epidemiological and management variables related to snake bite, the major limitation of the present study is that this is a retrospective chart review and some of the important data may be incomplete or insufficient, thus may not reflect the exact statistics.
| References|| |
|1.||Chippaux JP. Snake-bites: Appraisal of the global situation. Bull World Health Organ 1998;76:515-24. |
|2.||Organization WH. Zoonotic disease control: Baseline epidemiological study on snake-bite treatment and management. Wkly Epidemiol Rec 1987;42:31920. |
|3.||Patil VC, Patil HV, Patil A, Agrawal V. Clinical Profile and outcome of envenomous snake-bite at tertiary care centre in western Maharashtra. International Journal of Medicine and Public Health 2011;1:28. |
|4.||Sharma SK, Chappuis F, Jha N, Bovier PA, Loutan L, Koirala S. Impact of snake bites and determinants of fatal outcomes in southeastern Nepal. Am J Trop Med Hyg 2004;71:234-8. |
|5.||Alirol E, Sharma SK, Bawaskar HS, Kuch U, Chappuis F. Snake bite in South Asia: A review. PLoS Negl Trop Dis 2010;4:e603. |
|6.||Mohapatra B, Warrell DA, Suraweera W, Bhatia P, Dhingra N, Jotkar RM, et al. Snakebite mortality in India: A nationally representative mortality survey. PLoS Negl Trop Dis 2011;5:e1018. |
|7.||Meenatchisundaram S, Michael A. Snake bite and therapeutic measures: Indian scenario. Indian Journal of Science and Technology 2009;2:69-73. |
|8.||Brunda G, Sashidhar R. Epidemiological profile of snake-bite cases from Andhra Pradesh using immunoanalytical approach. Indian J Med Res 2007;125:661-8. |
|9.||Chew KS, Khor HW, Ahmad R, Rahman NH. A five-year retrospective review of snakebite patients admitted to a tertiary university hospital in Malaysia. Int J Emerg Med 2011;4:1-6. |
|10.||Narvencar K. Correlation between timing of ASV administration and complications in snake bites. J Assoc Physicians India 2006;54:717-9. |
|11.||Mahmood K, Naqvi I, Talib A, Salkeen S, Abbasi B, Akhter T, et al. Clinical course and outcome of snake envenomation at a hospital in Karachi. Singapore Med J 2010;51:300-5. |
|12.||Sarker S, Sarker N, Patwary S. Epidemiological survey of snakebite incidences in Bangladesh. Dhaka University J Biol Sci 1999;8:53-68. |
|13.||Huq F, Islam M, Sarker M, Chowdhury B, Ali M, Kabir M. Epidemiology of snake bite in Bangladesh. Bangladesh Journal of Zoology 1995;23:61-4. |
|14.||Sharma SK, Khanal B, Pokhrel P, Khan A, Koirala S. Snakebite-reappraisal of the situation in Eastern Nepal. Toxicon 2003;41:285-9. |
|15.||Mulay D, Kulkarni V, Kulkarni S, Kulkarni N, Jaju R. Clinical profile of snakebites at SRTR Medical College Hospital, Ambajogai (Maharashtra). Ind Medl Gaz 1986;131:363-6. |
|16.||Buranasin P. Snakebites at Maharat Nakhon Ratchasima Regional Hospital. Southeast Asian J Trop Med Public Health 1993;24:186-92. |
|17.||Heap B, Cowan G. The epidemiology of snake bite presenting to British Military Hospital Dharan during 1989. J R Army Med Corps 1991;137:123-5. |
|18.||Rahman R, Faiz MA, Selim S, Rahman B, Basher A, Jones A, et al. Annual incidence of snake bite in rural Bangladesh. PLoS Negl Trop Dis 2010;4:e860. |
|19.||Sawai Y, Honma M. Snake bites in India. Animal, Plant and Microbial Toxins 1976;1:451-60. |
|20.||Banerjee S. Agricultural child labor in West Bengal. Indian Pediatr 1993;30:1425-9. |
|21.||Mukerji A, Mehta S. Female participation in agricultural labour in India patterns and associations. Tijdschr Econ Soc Geogr 1975;66:103-7. |
|22.||Nhachi CF, Kasilo OM. Snake poisoning in rural Zimbabwe-A prospective study. J Appl Toxicol 1994;14:191-3. |
|23.||Monteiro F, Kanchan T, Bhagavath P, Kumar G, Menezes R, Yoganarasimha K. Clinico-epidemiological features of viper bite envenomation: A study from Manipal, South India. Singapore Med J 2012;53:203-7. |
|24.||Agrawal P, Aggarwal A, Gupta D, Behera D, Prabhakar S, Jindal S. Management of respiratory failure in severe neuroparalytic snake envenomation. Neurol India 2001;49:25-8. |
|25.||Anil A, Singh S, Bhalla A, Sharma N, Agarwal R, Simpson ID. Role of neostigmine and polyvalent antivenom in Indian common krait (Bungarus caeruleus) bite. J Infect Public Health 2010;3:83-7. |
|26.||Whitehall J, Yarlini M, Arunthathy M, Varan, Kaanthan, Isaivanan, et al. Snake bites in north east Sri Lanka. Rural Remote Health 2007;7:751. |
|27.||Harris JB, Faiz MA, Rahman MR, Jalil MM, Ahsan MF, Theakston RD, et al. Snake bite in Chittagong Division, Bangladesh: A study of bitten patients who developed no signs of systemic envenoming. Trans R Soc Trop Med Hyg 2010;104:320-7. |
|28.||Joseph J, Simpson I, Menon NC, Jose MP, Kulkarni KJ, Raghavendra GB, et al. First authenticated cases of life-threatening envenoming by the hump-nosed pit viper (Hypnale hypnale) in India. Trans R Soc Trop Med Hyg 2007;101:85-90. |
|29.||Gold BS, Barish RA, Dart RC. North American snake envenomation: Diagnosis, treatment, and management. Emerg Med Clin North Am 2004;22:423-44. |
|30.||Jamaiah I, Rohela M, Roshalina R, Undan R. Prevalence of snake bites in Kangar District Hospital, Perlis, west Malaysia: A retrospective study (January 1999-December 2000). Southeast Asian J Trop Med Public Health 2004;35:962-5. |
|31.||Reid HA, Thean P, Martin W. Epidemiology of snake bite in north Malaya. Br Med J 1963;1:992-7. |
|32.||Ahmed SM, Nadeem A, Islam MS, Agarwal S, Singh L. Retrospective analysis of snake victims in Northern India admitted in a tertiary level institute. J Anaesthesiol Clin Pharmacol 2012;28:45-50. |
|33.||Kularatne S. Common krait (Bungarus caeruleus) bite in Anuradhapura, Sri Lanka: A prospective clinical study, 1996-98. Postgrad Med J 2002;78:276-80. |
|34.||Looareesuwan S, Viravan C, Warrell DA. Factors contributing to fatal snake bite in the rural tropics: Analysis of 46 cases in Thailand. Trans R Soc Trop Med Hyg 1988;82:930-4. |
|35.||Faiz M, Rahman M, Hussain A, Yunus E, Das J. A hospital based study of snake bite in Chittagong Medical College. J Bangladesh Coll Phys Surg 1995;13:3-8. |
|36.||Bawaskar H. Snake venoms and antivenoms: Critical supply issues. J Assoc Physicians India 2004;52:11-3. |
|37.||Bhetwal B, O′Shea M, Warrell D. Snakes and snake bite in Nepal. Trop Doct 1998;28:193-5. |
|38.||Searo W. Guidelines on management of snake-bites. New Delhi: WHO Regional Office for South-East Asia; 2010. |
|39.||Theakston R, Phillips R, Warrell D, Galagedera Y, Abeysekera DT, Dissanayaka P, et al. Envenoming by the common krait (Bungarus caeruleus) and Sri Lankan cobra (Naja naja naja): Efficacy and complications of therapy with Haffkine antivenom. Trans R Soc Trop Med Hyg 1990;84:301-8. |
|40.||Warrell DA. The clinical management of snake bites in the South East Asian region. Southeast Asian J Trop Med Public Health 1999;30:1-67. |
|41.||Warrell DA. Snake bite. Lancet 2010;375:77-88. |
|42.||Warrell DA. Snake bite: A neglected problem in twenty-first century India. Natl Med J India 2011;24:321-4. |
|43.||Lal P, Dutta S, Rotti S, Danabalan M, Kumar A. Epidemiological profile of snakebite cases admitted in JIPMER Hospital. Indian J Community Med 2001;26:36. |
|44.||Kasturiratne A, Wickremasinghe AR, De Silva N, Gunawardena NK, Pathmeswaran A, Premaratna R, et al. The global burden of snakebite: A literature analysis and modelling based on regional estimates of envenoming and deaths. PLoS Med 2008;5:e218. |
|45.||Ariaratnam CA, Sheriff MH, Theakston RD, Warrell DA. Distinctive epidemiologic and clinical features of common krait (Bungarus caeruleus) bites in Sri Lanka. Am J Trop Med Hyg 2008;79:458-62. |
|46.||Ahuja M, Singh G. Snake bite in India. Indian J Med Res 1954;42:661-86. |
|47.||Slowinski J. The diet of kraits (Elapidae: Bungarus). Herpetol Rev 1994;25:51-2. |
|48.||Kulkarni M, Anees S. Snake venom poisoning: Experience with 633 cases. Indian Pediatr 1994;31:1239-43. |
|49.||Sharma N, Chauhan S, Faruqi S, Bhat P, Varma S. Snake envenomation in a north Indian hospital. Emerg Med J 2005;22:118-20. |
|50.||Jamaiah I, Rohela M, Ng T, Ch′ng KB, Teh YS, Nurulhuda AL, et al. Retrospective prevalence of snakebites from Hospital Kuala Lumpur (HKL)(1999-2003). Southeast Asian J Trop Med Public Health 2006;37:200-5. |
|51.||Zulkifli A, Hashim M, Kharal Anuar A. Snake bites in kelantan, Peninsular Malaysia. Trop Biomed 1995;12:1-4. |
|52.||Gutiérrez JM, Williams D, Fan HW, Warrell DA. Snakebite envenoming from a global perspective: Towards an integrated approach. Toxicon 2010;56:122335. |
|53.||Pe T, Myint AA, Kyu KA, Toe MM. Acceptability study of protective boots among farmers of Taungdwingyi township. Myanmar Health Sciences Research Journal 1998; 10(2): 57-60. |
|54.||Bawaskar H, Bawaskar P. Profile of snakebite envenoming in western Maharashtra, India. Trans R Soc Trop Med Hyg 2002;96:79-84. |
|55.||Chappuis F, Sharma SK, Jha N, Loutan L, Bovier PA. Protection against snake bites by sleeping under a bed net in southeastern Nepal. Am J Trop Med Hyg 2007;77:197-9. |