A national survey examining recognition, demand for antivenom, and overall level of preparedness for redback spider bites in Japan

Rhabdophis tigrinus (Yamakagashi) Bites in Japan Over the Last 50 Years: A Retrospective Survey

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.

Clinical characteristics of jellyfish stings in Japan

Aim

Jellyfish known as “habu‐kurage” (Chironex yamaguchii) inhabit the waters surrounding Okinawa and Amami, Japan, and jellyfish stings are limited to areas outside the Japanese main island. However, the shifts promoted by global warming and increasingly intensive interactions with people have led to concerns regarding the possibility of increased jellyfish stings on the main island of Japan. Similar concerns are being raised all over the world. However, studies examining clinical characteristics of jellyfish stings have been limited to Australia, the USA, Europe, and South‐East Asia. Thus, this study aimed to examine for the first time the clinical characteristics of jellyfish stings in Japan.

Methods

We undertook retrospective questionnaire surveys from January 2013 to December 2017 to determine patient characteristics, treatment, and clinical outcomes. We compared patient characteristics between tourists and non‐tourists. The primary end‐point of the present study was to clarify the clinical characteristics of jellyfish stings.

Results

Over the 5‐year study period, 204 patients were identified from eight hospitals based on the basic questionnaire, and 35 patients with moderate‐to‐severe jellyfish stings were also identified. All patients recovered well, including five patients with severe jellyfish stings. Antivenom was not given. The time intervals from the occurrence of jellyfish stings to hospital arrival significantly differed between tourists and non‐tourists (P = 0.049), and all tourists visited the emergency department (P = 0.009).

Conclusions

Approximately 40 cases of jellyfish stings occurred annually in Japan between 2013 and 2017. Patients recovered well without the use of antivenom.