Long-term health manifestations of hump-nosed pit viper (Genus: Hypnale) bites

Abstract

Introduction

The hump-nosed pit viper (Genus: Hypnale) is a highly medically significant snake in Sri Lanka, responsible for the majority of venomous snakebites (22–77%). They are found throughout Sri Lanka and the Western Ghats region of India. The venom can lead to two types of effects: acute and long-term. Acutely, bites often result in local symptoms, with less common systemic effects such as acute kidney injury, venom-induced consumption coagulopathy, and thrombotic microangiopathy.

Methods

We conducted a prospective observational study at Teaching Hospital Ratnapura, Sri Lanka, spanning six years, starting in June 2015. Patients bitten by hump-nosed pit vipers were followed up for two years, with assessments every three months to identify long-term effects. Data was gathered through interviewer-administered questionnaires.

Results

Out of 728 patients bitten by hump-nosed pit vipers, 22 (3%) were lost to follow-up. Forty-four (6.2%) experienced long-term effects, including chronic kidney disease (24; 3.4%), chronic wounds (five; 0.7%), amputations (five; 0.7%), fasciotomy-related wounds (four; 0.6%), and psychological illnesses (four; 0.6%). There were nine (1.3%) deaths in this group. Among those with chronic effects, 27 (61%) were males, and 17 (39%) were females, with ages ranging from 29 to 82 years (mean 57.6 years). The time it took to diagnose acute kidney injury from the snakebite was 18 h (interquartile range: 15–23.5 h), while the time to diagnose chronic kidney disease was 69 days (interquartile range: 64–74.75 days). In these patients, the estimated glomerular filtration rate was 29.3 mL/min/1.73 m² (interquartile range: 14–50.75 mL/min/1.73 m²). Among the patients who did not develop long-term complications (662; 91%) 660 (90.7%) experienced local effects, and 82 (11.3%) developed systemic manifestations, including acute kidney injury in 60 (8%) and coagulopathy in 35 (5%).

Conclusion

Following hump-nosed pit viper bites, a subset of patients may experience long-term health complications, including chronic kidney disease, chronic ulcers, amputations, fasciotomy-related wounds, and psychological illnesses, with chronic kidney disease being the most frequently observed among these manifestations.

Keywords:

• Hump-nosed pit viper
• Hypnale spp.
• long-term effects
• chronic kidney disease
• snakebites

Acknowledgements

We are grateful to the staff of medical wards and the consultant physicians (Dr. N. Sritharan, Dr. A.G.H. Sugathapala, Dr. K.D.M. Kumarasinghe, Dr. K. Jeganadan, Dr. Lalith Abeywardhana, Dr. Bandusiri Rathnayaka and Dr. Sanath Jayasinghe) in Teaching Hospital, Ratnapura, Sri Lanka. Dr. Disala Welgama is acknowledged for her assistance in statistical analysis.

Disclosure statement

No conflict of interest was reported by the authors.

Additional information

Funding

The study was not funded by any agency.