Abstract
Introduction: Rhabdophis snakes, which include 27 species, are rear-fanged venomous snakes that are widely distributed from India to East Asia and Russia. Severe envenomation by R. tigrinus (Yamakagashi snake) in Japan and R. subminiatus in Southeast Asia has been reported. The epidemiology of R. tigrinus bites, such as geographical features, the incidence, and changes in the number of bites over time have not been comprehensively examined. Hence, we intended to clarify the epidemiological features of R. tigrinus bites through a careful review of scientific data over the last 50 years in Japan.Methods: Patient records of R. tigrinus bites between 1971 and 2020 at the Japan Snake Institute were examined retrospectively. The following were ascertained: patient characteristics, clinical symptoms, laboratory data, treatment-related factors, and hospital mortality. These variables were compared in the antivenom and the without-antivenom groups.Results: Over the 50-year study period, 43 R. tigrinus bites, including five fatal cases, were encountered. Severe cases of R. tigrinus bites have been treated with antivenom since 1985; however, fatalities occurred in 2006 and 2020. R. tigrinus bite cases have been well-distributed in the western part of Japan since 2000. The mortality rate in the antivenom group was significantly lower in the patient group that was not administered the antivenom (0 vs. 23.8%, p = 0.048).Conclusion: This study clarified the epidemiology of R. tigrinus bites in Japan over a 50-year period. Almost all severe cases of R. tigrinus bites have been treated with the antivenom in the current situation, and fatalities occurred in cases not treated with the antivenom. It is important to diagnose R. tigrinus bites in the early phase of the clinical course. The antivenom, the definitive treatment for R. tigrinus bites, is an unapproved drug. Hence, approval needs to be obtained for the drug.
Highlights
Rhabdophis snakes, which include 27 species, are rear-fanged venomous snakes that are widely distributed from India to East Asia and Russia
R. tigrinus bite cases were found in almost all parts of Japan, except Hokkaido and Okinawa areas, and have been distributed in the western part of Japan since 2000
Patients with R. tigrinus bites have been treated with the antivenom since 1985, and fatalities occurred in 2006 and 2020 in patients who were not treated with the antivenom
Summary
Rhabdophis snakes, which include 27 species, are rear-fanged venomous snakes that are widely distributed from India to East Asia and Russia. Severe envenomation by R. tigrinus (Yamakagashi snake) in Japan and R. subminiatus in Southeast Asia have been reported [1,2,3,4,5]. Their bites lead to venom-induced consumption coagulopathy (VICC), resulting in hemorrhage [6, 7]. Our research group is currently working on the supply of antivenom as a serum therapy against R. tigrinus bites [9,10,11,12,13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
