Effect of Agkistrodon halys antivenom in patients bit by green pit viper and the prognostic role of the disease - a retrospective cohort study

BACKGROUND AND AIMS

In Mainland China and Hong Kong, health authorities utilize Agkistrodon halys antivenom in the treatment of patients who sustained bites from green pit vipers. However, the treatment benefit of Agkistrodon halys antivenom among such patients is still controversial. The purpose of this study is to evaluate the coagulation parameters normalization time of Agkistrodon halys antivenom in patients who sustained green pit viper bites and explore independent risk factors of patient prognosis.

METHODS

Data were extracted from the Donghua Hospital Information System. Comparison of the two groups of patients - who used antivenom (GPUA) and who did not use antivenom (GPNUA) were performed using stratified analysis, univariate and multivariate ordered logistic regression models to evaluate the coagulation parameters normalization time. Univariate and multivariate ordered logistic regression models were used to explore independent risk factors of patient prognosis.

RESULTS

Between the GPUA and GPNUA groups, there is no significant difference in the coagulation parameters normalization time with the treatment of Agkistrodon halys antivenom. GPNUA consumed more cryoprecipitate and platelets and had a lower cost. The patient's severity of the bite, first coagulation profile, and dosages of fresh frozen plasma, platelet, and red cell suspension was found to be risk factors for the normalization time of coagulation parameters.

CONCLUSIONS

The therapeutic effect of Agkistrodon halys antivenom in green pit vipers bite patients is not quite satisfying. In addition, more attention should be paid to the first coagulation profile, blood clotting factors indices, platelet count (PLT), and hemoglobin when treating such patients.

Sri Lankan green pit viper (Trimeresurus trigonocephalus) bites in Deniyaya: A clinico-epidemiological study

Green pit viper (Trimeresurus trigonocephalus) is endemic to Sri Lanka and bites are reported from tropical rain forest and plantation areas. As scant data exists on clinico-epidemiological features of Sri Lankan green pit viper bite, objective of this study was to address this knowledge gap. A prospective observational study was conducted in Base Hospital Deniyaya from October 2013 to September 2015. Green pit viper as the offending snake was identified when the victims brought live or dead specimens. When the specimen was not available, green pit viper was identified by the victim pointing to preserved specimens and photographs of green pit viper and different similar appearing snakes. Clinical details were recorded during the hospital stay. Twenty four green pit viper bite patients (17-68 years) were studied. All cases were daytime bites despite green pit viper being a nocturnally active snake. Sixteen patients (67%) were bitten while they were working in tea plantation. Hands (42%), feet, (33%), forearms (8%), legs (8%), thighs (4%) and shoulders (4%) were the sites of bites. Thirteen (54%) had extensive limb swelling. Nine (38%) had local swelling and two had no swelling. Three (12.5%) developed haemorrhagic blisters. Four (17%) had regional lymphadenopathy. Two (8%) developed non clotting blood by the TWBCT. Green pit viper bites caused substantial morbidity. Risk factors included day time outdoor activities in bordering villages of tropical rain forests and occupation. Pain, extensive limb swelling and bite site swelling were prominent clinical features. However haemorrhagic blisters, regional lymphadenopathy and coagulopathy were reported. Nephrotoxicity and neurotoxicity were notably absent.

Incidence of snakebites in 3 different geographic regions in Thua Thien Hue province, central Vietnam: Green pit vipers and cobras cause the majority of bites

BACKGROUND

The annual incidence of snakebites in Vietnam is not known and only few publications about snakebite envenoming and medically relevant snakes can be found in English language literature. The present community-based surveys provide data on incidence of snakebites in three different geographic regions of Thua Thien Hue (TT Hue) province, central Vietnam and snake species responsible for bites in this region.

METHODOLOGY/RESULTS

The cross-sectional community based surveys were conducted from March to July 2017. Multistage cluster sampling was applied and snakebite incidence was calculated at 58 snakebites per 100,000 person-years for the entire province, and 172, 69 and 10 snakebites per 100,000 person-years in the mountainous, coastal and urban region of TT Hue province, respectively. Thirty-one snakebite victims interviewed during the surveys reported 18 (58%) green pit viper bites (Trimeresurus species), 5 (16%) cobra bites (Naja kaouthia, Naja siamensis), 2 (7%) krait bites (Bungarus candidus, Bungarus fasciatus), 2 (7%) red-necked keelback bites (Rhabdophis subminiatus) and 4 bites from unidentified snakes (13%). The outcome was favourable for 28 snakebite victims (90%), two (6%) had minor sequelae and one (3%) victim died after a Malayan krait bite. Two hundred and twenty-one snakebite patients were treated in 9 district hospitals and one central hospital in TT Hue between 2014 and 2016. Eighty green pit vipers (84%), 12 cobras (13%) and 3 kraits (3%) were responsible for bites in 95 patients where snake identification was documented.

CONCLUSIONS

Incidence of snakebites is surprisingly low in TT Hue province in central Vietnam in comparison to other regions in Asia, particularly to neighbouring Lao PDR. However, snakebites are still a significant health problem in the mountainous region and green pit vipers and cobras cause the vast majority of bites.

Epidemiology and clinical features of Green pit viper (Trimeresurus trigonocephalus) envenoming in Sri Lanka

Green pit viper is a venomous endemic snake in Sri Lanka. But little is known regarding its envenoming in the country. This study was carried out in order to find out epidemiology and clinical profile of its bites. A series of 17 patients with Sri Lankan Green pit viper (Trimeresurus trigonocephalus) bites was prospectively studied over 4 years. The mean age was 36 ½ years (range 12-61 years) and comprised 14 (82%) males. Except one case, all bites occurred during day time (0600 h-1800 h) due to inadvertent provocation. In 13 cases (76%) bite took place in estates (tea or cinnamon) and 8 patients (47%) were estate workers. The bitten sites were upper limbs in 11 cases (65%) and lower limbs in 6 cases (35%). Ten patients (59%) brought the offending snake to the hospital and one patient was asymptomatic. Sixteen (94%) developed local envenoming features- 16 (94%) local pain and swelling, 6 (35%) local bleeding and lymphadenopathy and blistering in 4 (24%) patients. Systemic envenoming developed in 4 (24%) patients including 3 (18%) with coagulopathy that was treated with fresh frozen plasma. One (6%) patient developed bradycardia. Sri Lankan Green pit viper bites commonly occurs in estates and causes local envenoming frequently and coagulopathy occasionally.

Coagulopathy and extensive local swelling following Green pit viper (Trimeresurus trigonocephalus) envenoming in Sri Lanka

Trimeresurus trigonocephalus (Sri Lankan Green pit viper) is a moderately venomous arboreal snake endemic to Sri Lanka. Even though, its bites are not uncommon, published reports of such cases are limited to three in literature. We report three cases of coagulopathy following Green pit viper bites and treatment with fresh frozen plasma.