An Atypical Clinical Manifestation of a Hump-Nosed Pit Viper Envenomation

Hump-Nosed Pit Viper Envenomation in Western Coastal India: A Case Series

The hump-nosed pit viper (HNPV) has historically been considered less medically significant, causing local envenomation, renal injury, and coagulopathy; however, now, it is known to cause life-threatening complications. We describe the clinical presentation, treatment, and complications of 3 confirmed HNPV bites from the state of Karnataka (southwest coastal India). Patient 1, an 88-y-old woman, reported with the live specimen and developed venom-induced consumption coagulopathy (VICC) and thrombotic microangiopathy leading to acute kidney injury requiring blood product transfusions and dialysis. Patient 2, a 60-y-old woman, reported 3 d after envenomation followed by treatment at another hospital where 30 vials of polyvalent anti-snake venom (ASV) were given. She developed VICC and acute kidney injury requiring dialysis. On Day 9 of treatment, she developed a pontine hemorrhage. She died after a transfer to another treatment center closer to her residence. Patient 3, a 25-y-old man, was brought to our emergency department 6 h after being envenomed. He received topical ayurvedic treatment before arrival. He was unconscious and found to have severe VICC with a massive middle cerebral artery infarct. All 3 patients received Indian polyvalent ASV, which does not cover HNPV envenomation, clearly demonstrating the absence of paraspecificity and neutralization in a clinical setting. To our knowledge, Hypnale hypnale envenomation has not previously been reported from Karnataka state. The diagnosis of HNPV envenomation in a country without snake venom detection kits, under-reporting despite serious complications, financial burdens on rural populations afflicted, and poor outcomes due to the lack of a specific antivenom are discussed.

Documentation of a proven Mountain Pitviper (Ovophis monticola) envenomation in Kathmandu, Nepal, with its distribution ranges: implications for prevention and control of pitviper bites in Asia

We document inadequately diagnosed coagulopathy (potential to be life threatening) due to Ovophis monticola bite. Although its bites are common in the hills of Nepal, associated envenomations have not been documented elaborately. Herein, we present the clinical and treatment details of a proven O. monticola bite and areas where it may pose the risk of envenomations (suggesting huge populations in Asia to be vulnerable to its bites). Its envenomation was managed symptomatically with several non-evidence-based interventions. Since no specific pitviper antivenom is available in Nepal yet, managing coagulopathy associated to O. monticola envenomation is still challenging. This case emphasizes the need of developing the standard protocol for the diagnosis and management of pitviper bites and study of effectiveness of the available pitviper antivenoms until specific pitviper antivenom is available. Further, the demonstrated distribution localities of this species may have implications for snakebite prevention and designing and distribution of the effective antivenoms.

Snakebite associated thrombotic microangiopathy: a systematic review of clinical features, outcomes, and evidence for interventions including plasmapheresis

Snakebite is a neglected tropical disease with significant morbidity and mortality. Thrombotic microangiopathy (TMA) is an important but poorly understood complication of snakebite associated with acute kidney injury (AKI). Numerous treatments have been attempted based on limited evidence. We conducted a systematic review of TMA following snakebite using a pre-determined case definition of blood film red cell schistocytes or histologically diagnosed TMA. The search strategy included major electronic databases and grey literature. We present a descriptive synthesis for the outcomes of AKI, dialysis free survival (DFS), other end-organ damage, overall survival, and interventions with antivenom and therapeutic plasmapheresis (TPE). This study was prospectively registered with PROSPERO (CRD42019121436). Seventy-two studies reporting 351 cases were included, predominantly small observational studies. Heterogeneity for study selection, design, reporting and outcomes were observed. The commonest envenoming species were hump-nosed vipers (Hypnale spp.), Russell's viper (Daboia russelii) and Australian brown snakes (Pseudechis spp.). The prevalence of TMA was at least 5.4% in proven and probable Hypnale bites, and 10-15% of Australian elapid envenomings, AKI occurred in 94% (293/312) of TMA cases, excluding case reports. The majority of cases with AKI required dialysis. Included prospective and retrospective cohort studies reporting interventions and renal outcomes showed no evidence for benefit from antivenom or TPE with respect to DFS in dialysis dependant AKI. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) assessment for quality of accumulated evidence for interventions was low. The major complication of TMA following snakebite is AKI. AKI improves in most cases. We found no evidence to support benefit from antivenom in snakebite associated TMA, but antivenom remains the standard of care for snake envenoming. There was no evidence for benefit of TPE in snakebite associated TMA, so TPE cannot be recommended. The quality of accumulated evidence was low, highlighting a need for high quality larger studies.