Epidemiology and clinical effects of hump-nosed pit viper (Genus: Hypnale) envenoming in Sri Lanka

Abstract

Hump-nosed pit vipers of Genus Hypnale are the commonest cause of snake bite in Sri Lanka. Although there are many reports of local effects, coagulopathy and acute kidney injury, it remains unclear how frequent these clinical effects are and therefore the medical importance of this snake genus. The genus has been recently revised to include Hypnale hypnale from Sri Lanka and Western Ghats of Southern India, and the two endemic species to Sri Lanka, Hypnale zara and Hypnale nepa. This was a prospective hospital-based clinical study of definite Hypnale spp. bites from July 2008 to July 2010 in six Sri Lankan hospitals. There were 114 patients included and all snakes were correctly identified by hospital staff as Hypnale spp. Of these, 93 snakes were identified as H. hypnale by an expert, 16 as H. zara and five as H. nepa. Most bites occurred on the lower limbs in the daytime. There was no difference in the clinical effects between the three species. Pain and fang marks were present in all patients, 101 had local swelling and only 16 (14%) developed extensive local swelling that spread proximally and involved more than half of the bitten limb. Systemic symptoms occurred in 18 patients; four patients had an abnormal 20 min whole blood clotting test and one patient developed an acute kidney injury that required haemodialysis. All patients were discharged alive with a median length of stay of 2 days. This study confirms that hump-nosed viper bites cause only minor effects in most cases. Future studies need to undertake formal coagulation studies and identify important early indicators of renal impairment.

Proteomic investigation of Sri Lankan hump-nosed pit viper (Hypnale hypnale) venom

“…In view of the various financial and technical challenges faced confronting the production of good antivenom, the Global Snakebite Initiative (GSI) in collaboration with the International Society on Toxinology has proposed integrated strategies (Guti errez et al, , 2014Williams et al, 2011), one of which is the utilisation of venom proteomics as toxin profiling tool. The context is highly relevant for the envenomation problem caused by the endemic species Hypnale hypnale (hump-nosed pit viper) in Sri Lanka and Western Ghats of India (Joseph et al, 2007;Ariaratnam et al, 2008;Maduwage et al, 2013). In view of the lack of clinically indicated antivenom for H. hypnale envenomation, profiling of the venom composition hence becomes essential as the approach would contribute remarkably to the design, development and assessment of an effective antivenom.…”

A clinical profile of poisonous snake bite in children of North Kerala, India

“…Swelling of the affected limb was the most common presenting sign in our study and our findings were similar to the previous study done by Maduwage et al and others. 10 Among the fifty patients, 48% had vomiting and 32% of patients had abdominal pain as constitutional symptoms. In this study majority had hemotoxicity (94%) and neurotoxicity (6%) was comparatively less.…”

“…Data were analyzed using computer software, Statistical Package for Social Sciences (SPSS) version 10 …”

Hump-nosed Pit Viper Bite in Sri Lanka?Unravelling an Enigma

“…Overt bleeding manifestations like haematuria, hematemesis and bleeding per rectum are rare, and coagulopathy is often detected by the 20WBCT. The recent demonstration by Maduwage et al [17] of the low sensitivity of the 20WBCT in detecting coagulopathy after envenomation by D. russelli may compromise the utility of this bed side test [36]. The precise nature of the coagulopathy is poorly understood, and is most likely due to venom induced consumption coagulopathy.…”

“…Since the turn of the century, many have independently recognized the propensity of hump-nosed viper to give rise to coagulopathy and acute kidney injury (AKI) [9][10][11][12][13][14][15][16][17]. Several deaths due to systemic envenomation have also been reported [13,18].…”