Nonvenomous snakebites that mimic venomous snakes in Sri Lanka

Document Type : Case Series

Authors

1 Department of Pharmacology, Faculty of Medicine, Sabaragamuwa University of Sri Lanka, Hidellana, Ratnapura, Sri Lanka

2 Teaching Hospital, Ratnapura, Sri Lanka

Abstract
Introduction: Venomous snakes are of significant medical importance and are categorized into two groups: highly medically important snakes and lesser medically important snakes. In Sri Lanka, seven species of terrestrial snakes are classified as highly medically important. Accurate identification of these snakes can be challenging because several nonvenomous species closely resemble them in appearance. This case report describes two such snakebite incidents in Sri Lanka, highlighting the difficulties in snake identification and the potential clinical implications of misidentification.
Case Report: Two patients presented with nonvenomous snakebites. A 14-year-old schoolgirl was admitted to the Emergency Treatment Unit at Teaching Hospital Ratnapura, Sri Lanka in 2020 due to a python bite to her left 4th toe. A 44-year-old female was transferred from a local hospital for further management of a suspected krait bite, which was later identified as a common wolf snake. The patient was bitten on the left 3rd finger. Neither patient developed envenoming features and was discharged on day 2 of the snakebite.
Discussion: Even though nonvenomous snakebites do not cause envenoming effects, they are important. Juvenile pythons closely resemble adult Russell’s vipers, whereas wolf snakes mimic kraits. Antivenoms are indicated for bites by Russell’s vipers and kraits. Therefore, the correct identification of the snake is essential when managing these patients.
Conclusion: Some nonvenomous snakes mimic medically important snakes through morphological similarity, particularly in colour variation. Therefore, characteristic features should be used to identify these snakes.

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  1. Rathnayaka RMMKN. Medically important snakes in Sri Lanka. The SLMA Monthly. Official Newsletter of the Sri Lanka Medical Association. June 2025;18(7):8-9.
  2. Silva A, de Alwis T, Wijesekara S, Somaweera R. Minimising misidentification of common medically important snakes of Sri Lanka in the hospital setting. Anuradhapura Medical Journal. 2023;21;17(2).
  3. Somaweera R, Wijayasekara S, Bandara S. Serpents in Sri Lanka (Text in Sinhala). 2nd Edition -2023. P 26-27.
  4. Rathnayaka RMMKN, Ranathunga PEAN, Kularatne SAM. Pulmonary haemorrhage following Russell's viper (Daboia russelii) envenoming in Sri Lanka. Asia Pac J Med Toxicol. 2020;9(2):72-76.
  5. Rathnayaka RMMKN, Ranathunga PEAN, Kularatne SAM. Thrombotic microangiopathy, hemolytic uremic syndrome and thrombotic thrombocytopenic purpura: Rare manifestations of Russell's viper envenoming in Sri Lanka. Asia Pac J Med Toxicol. 2021;10(3):117-123.
  6. Rathnayaka RMMKN, Ranathunga PEAN, Kularatne SAM. Paediatric cases of Ceylon krait (Bungarus ceylonicus) bites and some similar-looking non-venomous snakebites in Sri Lanka: Misidentification and antivenom administration. Toxicon, 2021;198:143-150.
  7. Rathnayaka RMMKN, Anusha Nishanthi Ranathunga PE, De Silva MLI, Y.N.M.P. Abeyrathna YNMP, Kularatne SAM. Cat-eyed snake (Genus: Boiga) bites in Sri Lanka: First authentic case series. Toxicon,2023; 225(15),107052,ISSN 0041-0101.
  8. Silva A, Jayakody S, Ranasinghe N, Manawaduge A, Perera K. First authenticated case of a bite by rare and elusive blood-bellied coral snake (Calliophis haematoetron). Wilderness environ. Med, 2020;31(4):466-469.
  9. Maduwage K, Buddika H, Ranasinghe J, Wijesooriya K. Second case report of slender coral snake (Calliophis melanurus sinhaleyus) envenomation of Sri Lanka. Toxicon. 2021;15;189:7-9.
  10. Silva A, Weerawansa P, Pilapitiya S, Maduwage T, Siribaddana S. First authenticated case of Sri Lankan flying snake (Chrysopelea taprobanica) bite. Wilderness environ. Med, 2013;24(3):273-276.
  11. Waiddyanatha S, Silva A, Wedasingha S, Siribaddana S, Isbister GK. Incidence of serum sickness following Indian polyvalent antivenom therapy in a cohort of snake-envenomed patients in rural Sri Lanka. Clin. Toxicol, 2023;61(7),518-23.