Is severity of Daboia (Vipera) palaestinae snakebites influenced by season of exposure?

Abstract

IntroductionThe most common venomous snake in Israel, both in geographic spread and in number of snakebite incidents, is Daboia (Vipera) palaestinae. The clinical presentation of D. palaestinae envenomation varies and includes both local and systemic symptoms. Studies conducted on D. palaestinae revealed different amounts of venom in the snakes' glands in different seasons, however little is known regarding the potential impact of this finding on the clinical presentation after D. palaestinae bites during different seasons. ObjectiveTo evaluate whether there is a difference in the severity of the clinical presentation of D. palaetinae bites in different seasons. Material and methodsA retrospective chart review study including all patients diagnosed with D. palaestinae bites treated at Shamir Medical Center from 2006 through 2020. Patients were divided into two groups: early bite season – spring and early summer, and late bite season – late summer and autumn. Variables examined included demographic features, admission details and treatment administrated. ResultsOne hundred and seven D. palaestinae bite victims were included, forty-five were bitten during the early season and sixty-two during the late season. Four patients in the early season (8.9%) and one patient (1.6%) in the late season presented with decreased level of consciousness, and four patients, all from the early season group, required mechanical ventilation (p < 0.05) Vasopressors were used in six patients (13.3%) during the early season and two (3.2%) during the late season; (p = 0.06). There were no other differences between the groups, except for a lowest platelet count during hospitalization (mean 161.5 ± 51 K/μl during early season and 196.9 ± 77 K/μl during late season (p < 0.01). ConclusionsD. palaestinae bite victims more often present as critically ill patients during the spring and early summer compared to late summer and autumn. Hospitals should be prepared with appropriate staff training and medications for treating such patients, especially during the early season. However, in general, D. palaestinae bites are as dangerous during the late season as they are during the early season, and all snake bite victims should be treated with a high index of suspicion regardless of the season.