Case Report: Symptoms and Prognosis of Trimeresurus gracilis Envenomation

Abstract

Trimeresurus gracilis is a pit viper inhabiting the high mountains of Taiwan. No specific antivenom against T. gracilis is available, and we did not find any prior published case reports on its clinical envenomation. We present two patients with T. gracilis envenomation who were both bitten on the index finger and were administered bivalent hemotoxic antivenom against Trimeresurus stejnegeri and Protobothrops mucrosquamatus. In case 1, the patient was administered seven vials of antivenom within 2 days of envenomation. She received surgical intervention on day 26 and recovered from the wound 3 months after envenomation, but her left index finger was slightly and irreversibly bent. In case 2, the patient was administered 12 vials of antivenom within 10 hours after envenomation, received surgical intervention on day 1, and underwent debridement and reconstruction surgery on day 7 after envenomation. The wounds healed 1.5 months after envenomation, and no deformity occurred. Laboratory data showed elevated D-dimer levels and prothrombin times. The cross-neutralizing ability of bivalent hemotoxic antivenom against T. stejnegeri and P. mucrosquamatus appeared insufficient to treat the local effects of T. gracilis envenomation. The deformity of the finger of the patient in case 1 might have been caused by the lower dose, later administration of antivenins, and a delay in the necessary surgery.

Comparisons of the Oral Microbiota from Seven Species of Wild Venomous Snakes in Taiwan Using the High-Throughput Amplicon Sequencing of the Full-Length 16S rRNA Gene

“…Compared to Ts, victims of Pm have a higher rate (37% vs. 6%) of local necrosis or cellulitis [ 89 ]. Victims of Ds, Da, and Tg are rare in Taiwan [ 90 , 91 ], and a Ds bite seems to have less complication of local tissue necrosis [ 91 , 92 ]. Tissue necrosis may be initiated by the action of snake toxins [ 93 , 94 ].…”

Oral Bacteria and Their Antibiotic Susceptibilities in Taiwanese Venomous Snakes

“…Among the less common venomous snakebites, wounds caused by D. acutus are more likely to become infected and require antibiotics or even surgery than wounds caused by D. siamensis [ 25 , 35 ]. There is not enough information to determine wound infection rates for other snakebites, which are less frequently reported in Taiwan, such as those caused by Trimeresurus gracilis and Ovophis makazayazaya [ 36 , 37 ]. The nature and susceptibilities of the oral bacterial flora of these two venomous pit vipers need to be determined in future studies.…”

In vitro immunoreactivity and in vivo neutralization of Trimeresurus gracilis venom with antivenoms targeting four pit viper species

“…mucrosquamatus envenomation, bullae or necrosis is present, but coagulopathy and thrombocytopenia are uncommon. Patients can be administered two to four vials of TsPmAV initially and the median total dose of the specific antivenom was 5.5 vials [ 5 – 9 ]. D .…”

“…acutus envenomation is usually associated with hemorrhagic bullae or necrosis, prolonged PT/activated partial thromboplastin time, thrombocytopenia, and patients can be administered two to four vials of the monovalent antivenom against D . acutus (DaAV) initially [ 5 , 6 , 8 , 10 , 11 ]. In O .…”

“…However, the case reports available to date indicate that patients bitten on the finger by this species, not only experience local swelling, bruising, hemorrhagic blisters, or tissue necrosis but also systemic symptoms such as coagulopathy [ 5 ]. Moreover, even after immediate administration of 6–12 vials of TsPmAV within 20 h post-bite, patients still require surgical debridement or skin grafting [ 5 ]. This casts doubt on the effectiveness of TsPmAV for cross-neutralization.…”