Title: Study of neurotoxic manifestations of snake bite in a tertiary centre in North Kerala

Authors: Manu Mathews, Sudha Balakrishnan

 DOI: https://dx.doi.org/10.18535/jmscr/v7i10.13

Abstract

  

Background: Snake bite is an important cause of mortality and morbidity in India. This study was designed to determine the neurotoxic snakes, neurological manifestations, disease course, and outcome in neurotoxic envenomation in north Kerala. Hemotoxic snake bites with viper are common in this area. However neurotoxic snakebites with cobra and Krait, though comparatively rare, also produce significant morbidity, and studies of neurotoxic snake bites from this area are sparse.

Materials & Methods

Study Design: A retrospective descriptive study in Academy of Medical education, Pariyaram, Kannur district in North Kerala. The study centre is a tertiary hospital catering to patients from three districts in North Kerala - kannur, Kasargode and Wynad. Data were obtained fom medical record section of hospital. Clinical profile of patients including age, sex, residence ,site of  snake bite, neurological symptoms and signs, time taken for onset of symptoms, and time taken for recovery and outcome were recorded in pre designed proformas.

Study period was from January 2018 to September 2018.

Results: 90 cases of snake bite with envenomation came in the study period. A total of 12 cases of neurotoxic snake bites were included in the study. The species of snake bites with neurological manifestations were Krait in 6 patients, Cobra in 2 patients, Russells viper in 3 patients and species could not be identified in 1 patient. Ptosis was the commonest neurological manifestation seen in 10 patients, ophthalmoplegia in 4 patients, limb weakness 4 patients, respiratory failure 4 patients, palatal weakness 1 patient, neck muscle weakness 4 patients. Neurological symptoms were experienced usually within 6 hours after the bite. Following administration of antivenom, the signs of recovery became evident within a few hours to several days. The duration for complete recovery ranged from four hours to 1 week.

Conclusions: Complete recovery of neuromuscular weakness was observed in all patients Training of the peripheral doctors regarding early recognition of neurotoxic snakebite, species diagnosis as per the WHO syndromic approach, prompt institution of initial management and quick referral to a  higher centre with ventilator facility would  help in reducing the morbidity and mortality due to neurotoxic snake bites..

Keywords: North Kerala, Russell’s viper, common krait, neurotoxic.

References

  1. Warrell DA. Injuries, envenoming, poisoning, and allergic reactions caused by animals. In: Weatherall DJ, Ledingham JGG, Warrell DA, editors. Oxford Textbook of Medicine. 3rd ed. Oxford: Oxford University Press; 1996. pp 1124-51
  2. Warrell DA. Snake venoms in science and clinical medicine. 1.Russell’s viper: biology, venom, and treatment of bites. Trans R Soc Trop Med Hyg 1989;83:732-40.  
  3. Kalantri S, Singh A, Joshi R, et al. Clinical predictors of in-hospital mortality in patients with snakebite: a retrospective study from a rural hospital in central India. Trop Med Int Health. 2006; 11(1):22–30.
  4. Kasturiratne A, Wickremasinghe AR, de Silva N, and et al. estimating the global burden of snakebite: a literature analysis and modelling based on regional estimates of envenoming and deaths. PLoS Med. 2008;5:e218
  5. Mohapatra B, Warrell DA, Suraweera W, et al. Snakebite mortality in India: a nationally representative mortality survey. PLoS Negl Trop Dis. 2011;5(4):e1018.
  6. Singh G, Pannu HS, Chawla PS, Malhotra S. Neuromuscular transmission failure due to common krait (Bungarus caeruleus) envenomation. Muscle Nerve 1999; 22:1637-43.  
  7. Ariaratnam CA, Sjostrom L, Raziek Z, Kularatne SA, Arachchi RW, Sheriff MH, et al. An open, randomized comparative trial of two antivenoms for the treatment of envenoming by Sri Lankan Russel’s viper (Daboia russelii russelii). Trans R Soc Trop Med Hyg 2001;95:74-80.
  8. Kumar S, Usgaonkar RS. Myasthenia gravis like picture resulting from snake bite. J Indian Med Assoc 1968;50:428-9
  9. Dixon RW, Harris JB. Nerve terminal damage by beta-bungarotoxin: Its clinical significance. Am J Pathol 1999;154:447-55
  10. Silva A, Hodgson WC, Isbister GK. Antivenom for neuromuscular paralysis resulting from snake envenoming. Toxins (Basel) 2017;9:143.

Corresponding Author

Dr Manu Mathews

Associate Professor, Dept. of Medicine, Govt Medical College, Kannur, Kerala, India