Effect of antivenom therapy of Rhabdophis tigrinus (Yamakagashi snake) bites

The current status of neglected tropical diseases in Japan: A scoping review

Little attention has been paid to neglected tropical diseases (NTDs) in high-income countries and no literature provides an overview of NTDs in Japan. This scoping review aims to synthesize the latest evidence and information to understand epidemiology of and public health response to NTDs in Japan. Using three academic databases, we retrieved articles that mentioned NTDs in Japan, written in English or Japanese, and published between 2010 and 2020. Websites of key public health institutions and medical societies were also explored. From these sources of information, we extracted data that were relevant to answering our research questions. Our findings revealed the transmission of alveolar echinococcosis, Buruli ulcer, Chagas disease, dengue, foodborne trematodiases, mycetoma, scabies, and soil-transmitted helminthiasis as well as occurrence of snakebites within Japan. Other NTDs, such as chikungunya, cystic echinococcosis, cysticercosis, leishmaniasis, leprosy, lymphatic filariasis, rabies, and schistosomiasis, have been imported into the country. Government agencies tend to organize surveillance and control programs only for the NTDs targeted by the Infectious Disease Control Law, namely, echinococcosis, rabies, dengue, and chikungunya. At least one laboratory offers diagnostic testing for each NTD except for dracunculiasis, human African trypanosomiasis, onchocerciasis, and yaws. No medicine is approved for treatment of Chagas disease and fascioliasis and only off-label use drugs are available for cysticercosis, opisthorchiasis, human African trypanosomiasis, onchocerciasis, schistosomiasis, and yaws. Based on these findings, we developed disease-specific recommendations. In addition, three policy issues are discussed, such as lack of legal frameworks to organize responses to some NTDs, overreliance on researchers to procure some NTD products, and unaffordability of unapproved NTD medicines. Japan should recognize the presence of NTDs within the country and need to address them as a national effort. The implications of our findings extend beyond Japan, emphasizing the need to study, recognize, and address NTDs even in high-income countries.

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.

A fatal case of traumatic brain injury with severe coagulopathy due to Rhabdophis tigrinus (yamakagashi) bites: a case report

Background

Yamakagashi venom is a prothrombin activator, leading to disseminated intravascular coagulation. We report a fatal case of severe coagulopathy from head trauma assumed to be caused by a yamakagashi bite.

Case presentation

An 80-year-old man fell and developed systemic tonic–clonic convulsions. Head computed tomography revealed brain contusion and acute subdural hematoma. Physical examination revealed two bite marks with persistent bleeding on the right lower leg. The patient stated that he had been bitten by some creature 3 days prior, but the bite was left untreated. Laboratory tests showed fibrinogen levels below the detection limit. Although eighteen units of fresh frozen plasma were administered for coagulopathy, fibrinogen levels did not improve. He died about 18 h after a head injury.

Conclusion

In this case of a yamakagashi bite with active bleeding due to trauma, early administration of yamakagashi antivenom should be considered to control coagulopathy.

Snakebite envenomings in the Republic of Korea from the 1970s to the 2020s: A review

Snakebite envenomings remain a neglected disease across the globe causing severe injuries and death. An understanding of regional snakebite patterns is a necessary prerequisite for public health programs aimed at reducing snakebite risks. However, such regional knowledge is poorly documented or lacking in many countries where the risk of snakebite envenomings receive little medical attention, and the Republic of Korea is one of these countries. Here, we reviewed the literature on snakebites published between 1970 and 2020 as well as public healthcare data recorded between 2010 and 2019 to determine the patterns of snakebite envenomings in the Republic of Korea. Our results, based on literature data, show Gangwon province as a hotspot of snakebite occurrences and identify middle-aged males living in rural areas as the demographic group at highest risk of venomous snakebites. We also highlight major limitations for further understanding snakebite patterns in the country, most notably the lack of proper species identification for snakes and conflicting patterns of envenomings revealed by different sources of data. Our study provides baseline information on venomous snakebites occurring in the Republic of Korea, thereby filling a gap in the knowledge of snakebite trends in the country.

Severe hypofibrinogenemia in patients bitten by Gloydius tsushimaensis in Tsushima Island, Nagasaki, Japan, and treatment strategy

Gloydius tsushimaensis is an endemic species inhabiting only Tsushima, a remote Japanese island, and is a distinct species from Gloydius blomhoffii widely distributed throughout mainland Japan and Gloydius brevicaudus and Gloydius ussuriensis which are geographically distributed in South Korea. This is the first multicenter retrospective study of G. tsushimaensis bites in Japan. A study of seventy-two patients who visited the former Izuhara Hospital, the former Naka Tsushima Hospital, Tsushima Hospital, and Kamitsushima Hospital during the fourteen years from January 1, 2005, to December 31, 2018, revealed the typical clinical characteristics of G. tsushimaensis bites. Five out of seventy-two cases (6.9%) showed severe hypofibrinogenemia, in which fibrinogen levels were below 100 mg/dl, which is an unreported clinical finding for G. blomhoffii bites. Generally, when fibrinogen levels are lower than 100 mg/dl, the bleeding risk increases, and it is perilous. Severe hypofibrinogenemia cases did not improve after G. blomhoffii antivenom administration. Additionally, all five cases had disseminated intravascular coagulation, and there were two cases of acute kidney injury and one death. five cases had a median maximum creatine kinase level of 5171 IU/l (Interquartile range: 4992-41,310). Although the mechanism is not precise, coagulation tests showed that the G. tsushimaensis venom contains a thrombin-like enzyme. Based on this research, we created an algorithm for the treatment of G. tsushimaensis bites and unified the treatment methods used on the island.

Effectiveness of repeated antivenom therapy for snakebite-related systemic complications

Objective

This study aimed to determine the effect of repeated antivenom therapy compared with that of single antivenom therapy for treating snakebite-related systemic complications.

Methods

A retrospective medical record review from January 2008 to September 2016 was performed. Patients with snakebite injury who visited the Emergency Department in one tertiary center of Korea were included. The primary outcome was the survival rate. The secondary outcome was the effect of repeated antivenom therapy for treating snakebite-related systemic complications compared with that of single antivenom therapy on hospital length of stay.

Results

A total of 110 patients with snakebites were included. All patients survived to discharge. Twenty-nine (26.4%) patients had snakebite-related systemic complications. Of these, nine patients received repeated antivenom therapy and 20 patients received single antivenom therapy. The length of stay was significantly longer in those who received repeated antivenom therapy compared with those who received single antivenom therapy (10.0 [4.0–11.0] vs. 3.5 [0–7.0] days).

Conclusion

We were unable to demonstrate any superiority of repeated versus single antivenom therapy. However, repeated antivenom therapy is associated with a longer hospital stay. The reason for this finding is unknown.

Early pathology in venom-induced consumption coagulopathy by Rhabdophis tigrinus (Yamakagashi snake) envenomation

Objective: Rhabdophis tigrinus (Yamakagashi in Japanese) is a venomous non-front-fanged colubroid snake capable of inflicting envenoming with life-threatening defibrinating coagulopathy. However, because of the uncommon incidence of bites and tendency for late development of symptoms/signs, the early effects of the venom on the coagulation system are poorly known. Case report: We describe a boy bitten by a wild R. tigrinus and report his clinical course starting at 30 min after the bite. Results: At 30 min after envenomation, only the thrombin-antithrombin complex (TAT) level was elevated. At 90 min after envenomation, laboratory data revealed a prolonged activated partial thromboplastin time (APTT) and increased prothrombin time international normalized ratio (PT-INR) with elevated fibrinogen degeneration product (FDP). At 5.5 h after envenomation, APTT and PT-INR increased beyond a measurable range, and fibrinogen levels dropped below the detection limit. We administered recombinant human soluble thrombomodulin and antivenom prepared against R. tigrinus antivenom. Venom-induced consumption coagulopathy (VICC), which is sometimes reported as disseminated intravascular coagulation (DIC), subsequently improved rapidly. Discussion: We found that TAT is the earliest marker to detect R. tigrinus envenomation and subsequent VICC occurrence. Although rTM was effective in this case, further studies are necessary to prove its safety and efficacy.

Generation of H7N9-specific human polyclonal antibodies from a transchromosomic goat (caprine) system

To address the unmet needs for human polyclonal antibodies both as therapeutics and diagnostic reagents, building upon our previously established transchromosomic (Tc) cattle platform, we report herein the development of a Tc goat system expressing human polyclonal antibodies in their sera. In the Tc goat system, a human artificial chromosome (HAC) comprising the entire human immunoglobulin (Ig) gene repertoire in the germline configuration was introduced into the genetic makeup of the domestic goat. We achieved this by transferring the HAC into goat fetal fibroblast cells followed by somatic cell nuclear transfer for Tc goat production. Gene and protein expression analyses in the peripheral blood mononuclear cells (PBMC) and the sera, respectively, of Tc caprine demonstrated the successful expression of human Ig genes and antibodies. Furthermore, immunization of Tc caprine with inactivated influenza A (H7N9) viruses followed by H7N9 Hemagglutinin 1 (HA1) boosting elicited human antibodies with high neutralizing activities against H7N9 viruses in vitro. As a small ungulate, Tc caprine offers the advantages of low cost and quick establishment of herds, therefore complementing the Tc cattle platform in responses to a range of medical needs and diagnostic applications where small volumes of human antibody products are needed.

Clinical Condition and Management of 114 Mamushi (Gloydius blomhoffii) Bites in a General Hospital in Japan

Objective Mamushi (Gloydius blomhoffii) snakebite is the most common type of snake injury in Japan and is also seen in China and Korea. Although the components of Mamushi venom have been investigated, epidemiological and clinical descriptions still remain limited in the English literature. The aim of this study was to review the clinical features and management of patients with injuries related to Mamushi snakebites. Methods We conducted a retrospective examination of 114 Mamushi snakebite cases encountered at a general hospital in Japan from January 2004 to November 2016. Data were collected from the medical records. Results We found that Mamushi snakebites commonly occurred during summer and the daytime, with elderly men typically being affected. The symptom grade at initial consultation was significantly worse in the walk-in group than in the ambulance admission group, probably due to treatment delay. The number of fangs that pierced the skin was not related to the severity of the symptoms. The group treated with a tourniquet more frequently exhibited exacerbation of symptoms than those that received other treatments (p<0.001). Conclusion The delay between patients being bitten and arriving at hospital as well as the number of fangs that pierced the skin did not affect the duration of hospitalization; however, proximal tourniquation should be avoided in such cases, as significant exacerbation of local symptoms was observed when this procedure was applied.

Clinical Serum Therapy: Benefits, Cautions, and Potential Applications

Blood serum from immunized humans or animals (e.g., horses) contains relevant antibodies and has been used as serum therapy to treat many diseases or envenomation events. The effectiveness of blood serum was initially discovered in 1890 when Kitasato and von Behring observed the effectiveness of this type of therapy against diphtheria and tetanus. Serum therapies played an important role in the advancement of modern medicine prior to the development of penicillin and steroids. At present, several types of serum therapy remain in clinical use. However, some physicians have a limited understanding of the nature and the benefits of serum therapy and the factors that require particular attention. In this review, we set out to clarify the benefits, cautions, and potential applications of serum therapy in the context of conditions such as gas gangrene, diphtheria, botulism, and tetanus and bites from three snake species (mamushi, habu, and yamakagashi) and the redback spider. It is hoped that this review will help clinicians to learn about clinical serum therapies and become familiar with their applications.

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

Aim

Redback spiders are rapidly becoming a nationwide problem in Japan. The domestic production of antivenom for redback spider bites has been started because of extremely low supply. The purpose of this study was to investigate the ability of emergency physicians to recognize redback spider bites and to examine the demand for antivenom and identify the ideal choice for storage.

Methods

Questionnaires examining the ability to recognize redback spider bites, the demand for antivenom, and overall level of preparedness were sent to 271 emergency medical service centers in Japan in March 2015.

Results

Completed questionnaires were returned by 156 medical institutions (58%). Only 25% of the institutes correctly answered regarding the recognition of redback spider bites. A demand for the new, domestically produced antivenom was reported by 55% of the institutes. Antivenom demand was high and increased with the ability to recognize redback spider bites (0 correct answers, n = 24 [42.9%]; 1-2 answers, n = 32 [55.2%]; three answers, n = 28 [71.8%]; P = 0.02). The storage of antivenom within their prefectures or regions was the best option for initial supply planning. Approximately 90% of the emergency centers showed an ability to use the antivenom safely.

Conclusion

The recognition of redback spider bites was low; however, the demand for antivenom was high. The storage of antivenom within their own prefectures or regions was considered to be the best option for initial supply planning. Emergency medical service centers are also good candidates for storage and safe use of antivenom.

Venomous snake bites: clinical diagnosis and treatment

Snake bites are life-threatening injuries that can require intensive care. The diagnosis and treatment of venomous snake bites is sometimes difficult for clinicians because sufficient information has not been provided in clinical practice. Here we review the literature to present the proper management of bites by mamushi, habu, and yamakagashi snakes, which widely inhabit Japan and other Asian countries. No definite diagnostic markers or kits are available for clinical practice; therefore, definitive diagnosis of snake-venom poisoning requires positive identification of the snake and observation of the clinical manifestations of envenomation. Mamushi (Gloydius blomhoffii) bites cause swelling and pain that spreads gradually from the bite site. The platelet count gradually decreases due to the platelet aggregation activity of the venom and can decrease to <100,000/mm(3). If the venom gets directly injected into the blood vessel, the platelet count rapidly decreases to <10,000/mm(3) within 1 h after the bite. Habu (Protobothrops flavoviridis) bites result in swelling within 30 min. Severe cases manifest not only local signs but also general symptoms such as vomiting, cyanosis, loss of consciousness, and hypotension. Yamakagashi (Rhabdophis tigrinus) bites induce life-threatening hemorrhagic symptoms and severe disseminated intravascular coagulation with a fibrinolytic phenotype, resulting in hypofibrinogenemia and increased levels of fibrinogen degradation products. Previously recommended first-aid measures such as tourniquets, incision, and suction are strongly discouraged. Once airway, breathing, and circulation have been established, a rapid, detailed history should be obtained. If a snake bite is suspected, hospital admission should be considered for further follow-up. All venomous snake bites can be effectively treated with antivenom. Side effects of antivenom should be prevented by sufficient preparation. Approved antivenoms for mamushi and habu are available. Yamakagashi antivenom is used as an off-label drug in Japan, requiring clinicians to join a clinical research group for its use in clinical practice.