Abstract
Diagnosis of Snake Envenomation Using a Simple Phospholipase A2 Assay
Snake envenomations are a major public health concern worldwide, with an estimated 1 to 2 million cases reported annually and as many as 100,000 deaths per year. The accurate diagnosis of a snake envenomation requires the combination of patient history, clinical features, and laboratory testing. Unfortunately, resource-poor areas may lack trained medical personnel and the appropriate tests to accurately diagnose snake envenomation. The goal of this investigation was to evaluate a simple bedside test for a common component of snake venom and its ability to accurately predict envenomation.
Phospholipase A2 (PLA2) is a common toxin in snake venoms in nearly all elapid and viperid snakes. The authors recognize that although PLA2 may not represent clinically important venom toxicity, it can be used to identify systemic envenomation. This prospective study included patients from 2 hospitals in Sri Lanka presenting with envenomation from a Russell’s viper, hump-nosed pit viper, cobra, and krait snakes from 2007 to 2011. The PLA2 activity and its correlation to a venom-specific assay was tested before and after antivenom administration and was compared to PLA2 activity in nonenvenomated patients. The researchers found that PLA2 activity directly correlated with free venom concentrations, and its activity decreased correspondingly with antivenom administration.
The authors propose that a bedside PLA2 assay would be beneficial in areas with limited access to medical care. This assay could help to quickly identify patients with systemic envenomation requiring antivenom administration. Limitations of the study include the small number of patients evaluated and envenomation of only 3 snake species tested with the assay. Additionally, the authors recognize the need to develop a PLA2 assay that is less expensive and allows for individual patient testing.
(Sci Rep. 2014;4:4827). K Maduwage, MA O’Leary, G Isbister.