A Clinico-Epidemiological Profile of Neuroparalytic Snake Bite, Using Low Dose ASV in a Tertiary Care Centre from Western Maharashtra

According to the World Health Organization, snakebites cause more death and disability and are more notorious than some tropical diseases. Snakebite is a leading medical emergency in Asia/Pacific. It is one of the major causes of mortality in India. The objective of this study was to determine the clinico-epidemiological profile of a neuroparalytic snake bite at the Department of Medicine, Krishna Institute of Medical Sciences, Karad, one of the tertiary care centers of Western Maharashtra, in India.METHODSA descriptive study of 80 patients was carried out at the Department of Medicine, KIMS, Karad, a tertiary care center of Western Maharashtra, India. Present study showed outcome, delay in arrival, and epidemiology of patients with low dose of ASV in neuroparalytic snakebites and ventilator support. Descriptive statistics were shown by using MS Excel and SPSS Version 25.RESULTSOut of 80 cases 56.2% were males and 43.8% were females with a mean age of 28.16 years. 63.7% of the snakebite victims were bitten outside and 85% of the snakebites occurred on the lower extremity. On an average, 15.24 vials of ASV were administered. 80% patient were in Intensive Care and they were on ventilator support and 91% patients recovered from these snake bites. 51.25% of the patients reached the hospital within the interval of 3-7 hours.CONCLUSIONSStudy signifies the importance of snakebite threat to the community. Delay in reaching a hospital in time where snakebite patients can be treated, was the most important cause of death. Public health programs should be strengthened. Administration of Low dose ASV and ventilator support can provide sufficient cure if patients reach on time. Lack of awareness, delay in reaching the hospital, and treatment by non-medical persons are important factors that should to be addressed.

Proteomics and antivenom immunoprofiling of Russell's viper (Daboia siamensis) venoms from Thailand and Indonesia

The Eastern Russell's viper, Daboia siamensis, is a WHO Category 1 medically important venomous snake. It has a wide but disjunct distribution in Southeast Asia. The specific antivenom, D. siamensis Monovalent Antivenom (DsMAV-Thailand) is produced in Thailand but not available in Indonesia, where a heterologous trivalent antivenom, Serum Anti Bisa Ular (SABU), is used instead. This study aimed to investigate the geographical venom variation of D. siamensis from Thailand (Ds-Thailand) and Indonesia (Ds-Indonesia), and the immunorecognition of the venom proteins by antivenoms. Methods: The venom proteins were decomplexed with reverse-phase high-performance liquid chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by in-solution tryptic digestion, nano-liquid chromatography-tandem mass spectrometry and protein identification. The efficacies of DsMAV-Thailand and SABU in binding the various venom fractions were assessed using an enzyme-linked immunosorbent assay optimized for immunorecognition profiling. Results: The two most abundant protein families in Ds-Thailand venom are phospholipase A2 (PLA2) and Kunitz-type serine protease inhibitor (KSPI). Those abundant in Ds-Indonesia venom are PLA2 and serine protease. KSPI and vascular endothelial growth factor were detected in Ds-Thailand venom, whereas L-amino acid oxidase and disintegrin were present in Ds-Indonesia venom. Common proteins shared between the two included snaclecs, serine proteases, metalloproteinases, phosphodiesterases, 5'nucleotidases and nerve growth factors at varying abundances. DsMAV-Thailand exhibited strong immunorecognition of the major protein fractions in both venoms, but low immunoreactivity toward the low molecular weight proteins e.g. KSPI and disintegrins. On the other hand, SABU was virtually ineffective in binding all fractionated venom proteins. Conclusion: D. siamensis venoms from Thailand and Indonesia varied geographically in the protein subtypes and abundances. The venoms, nevertheless, shared conserved antigenicity that allowed effective immunorecognition by DsMAV-Thailand but not by SABU, consistent with the neutralization efficacy of the antivenoms. A specific, appropriate antivenom is needed in Indonesia to treat Russell's viper envenomation.(AU)

Study of clinical and epidemiological profile of poisonous snake bite in a tertiary centre in North Kerala

Background: Snakebites are well-known medical emergencies in many parts of the world, especially in rural areas.The incidence of snakebite mortality is particularly high in South-East Asia. Rational use of snake anti-venom can substantially reduce mortality and morbidity due to snakebites. Snake bite is an important health problem in India also especially in North Kerala which has an agricultural background. There is a lack of study regarding this topic in this area. North Kerala differs from other areas in the country as hump nosed pit viper bites are more common here due to its proximity to western Ghats where it .Anti snake venom is ineffective to bites by hump nosed pit viper. Authors objectives  was to assess the clinical and epidemiological profile and outcome of poisonous snake bites.Methods: Retrospective observational study done among patients with snake bite with envenomation admitted in Academy of Medical education, Pariyaram, Kannur, Kerala from January 2018 to September 2018.Results: There were 90 cases of venomous snake bite during the study period. Of these males were predominant (70%). Majority were in the age group between 20 and 40. Majority of bites occurred in the months of June and July. Bite in the extremities were more common. Nine patients were brought 1 day after the bite. Snake identified most common was Russell’s viper followed by pit viper. Majority of the systemic envenomation was hemotoxic 80 patients (85%).Conclusions: The study stress the fact that snake bite is an important problem in North Kerala. The study also shows that delay in treatment is a major risk factor for morbidity. Hump nosed pit viper bites are more common in this area.

Laboratory measurement of bleeding risk for patients receiving Dabigatran / 临床检验杂志

Objective To observe the correlation between conventional coagulation tests and Dabigatran concentration in order to find proper test method to predict the bleeding risk of patients receiving Dabigatran.Methods The clinical data of forty-nine non-valvular atrial fibrillation (NVAF) patients who took Dabigatran in Peking University Third Hospital from 2015 to 2017 were analyzed and the bleeding rates were calculated.The plasma samples from twenty healthy volunteers were collected and mixed up into normal pooled plasma (NPP).Different doses of active Dabigatran were mixed with NPP,making Dabigatran concentrations from 0 to 1 000 ng/mL.Prothrombin time (PT),activated partial thromboplastin time (APTT),thrombin time (TT),fibrinogen (Fib) and diluted Russell viper venom time (dRVVT) were determined.Fresh whole blood samples from three normal volunteers were collected and mixed with Dabigatran in the same way to perform thromboelastogram (TEG).Results The total bleeding rate of NVAF patients receiving Dabigatran was 28.6％,among which gastrointestinal bleeding accounts for the most.APTT,dRVVT,R time (R) and clot index (CI) showed a good linear correlation with Dabigatran concentration.The sensitivity of dRVVT was the best,followed by APTT.R and CI showed low sensitivity compared with APTT and dRVVT.Conclusion APTT and dRVVT should be good parameters for monitoring the bleeding risk of Dabigatran and helpful for physicians to choose proper point-in-time for withdrawal of Dabigatran and reduce bleeding events.

Dabigatran en plasma: tiempos de trombina diluido, Ecarin y veneno de víbora de Russell diluido / Plasma dabigatran: diluted thrombin time, Ecarin and diluted Russell Viper Venom Time / Dabigatrana em plasma: tempos de trombina diluído, Ecarin e veneno de víbora de Russell diluído

Los objetivos del trabajo fueron verificar la calidad analítica del ensayo tiempo de trombina diluido (DTI) para medición de la concentración plasmática (cc) de dabigatran comparando dos coagulómetros de detección foto-óptica, comparar los resultados con el tiempo de Ecarin (ECT) y correlacionar las cc con las pruebas básicas de coagulación Tiempo de protrombina (TP), APTT y Tiempo de trombina (TT), y tiempo de veneno de víbora de Russell con fosfolípidos concentrados (DRVVTC). Se tomaron 43 muestras de plasma en el valle (10-14 h de la última toma) de 40 pacientes que recibían dabigatran. DTI y ECT presentaron (%) repetitividad <5,4% y <7,5%, CV interensayo <6% y <9%, respectivamente, en el protocolo EP15A2, aceptables para un Error Total permitido (TEa) <15%. Las cc medidas en pacientes fueron: mediana 83 (4-945) ng/mL. La comparación de equipos ACL TOP 300 y 500 dio resultados equivalentes por procedimiento alternativo de comparación de métodos. La comparación ECT vs. DTI fue satisfactoria por regresión de Deming (pendiente 1,143, ordenada al origen -19,33). Las correlaciones de cc vs. APTT, TP y DRVVTC fueron moderadas y no lineales tendiendo a plateau a cc>350 ng/mL, r2 0,59, 0,66 y 0,59, respectivamente. El TT fue extremadamente sensible: >120 s a cc 50 ng/mL. DTI presentó un buen desempeño analítico y permitió cuantificar dabigatran plasmático a cc bajas y altas en ambos equipos utilizados. ECT presentó resultados comparables a DTI. Se verifica una correlación moderada entre cc de dabigatran y las pruebas clásicas y DRVVTC, pudiendo ser estimadores de cc a partir de los 50 ng/mL.

The aims of the study were to verify the analytical performance of Dilute Thrombin Time (DTI) test to measure plasma dabigatran concentration (cc) in two photo-optical coagulometers, compare Ecarin clotting Time (ECT) and DTI results, and correlate cc with classical coagulation tests: prothrombin time (PT), APTT, thrombin time (TT) and diluted Russell Viper Venom Time tests with high phospholipid concentration (DRVVTC). Forty three plasma samples from 40 patients taking dabigatran were drown at through (10-14 hs.since last dose). DTI and ECT showed repetitivity (%) <5.4% and <7.5%, interassay CV <6% and <9%, respectively, following EP15A2 protocol, acceptable considering a Allowed Total Error (TEa)<15%. Patients` cc: median 83 (4-945) ng/mL. The comparison between ACL TOP 300 and 500 coagulometers showed equivalent results by using the alternative method comparison test. ECT vs. DTI: acceptable by Deming`s regression (slope 1.143, Y insert -19.33). cc vs. APTT, TP and DRVVTC: nonlinear and moderate correlations with plateau reached at cc >350 ng/mL, r2 0.59, 0.66 y 0.59, respectively. TT is extremely prolonged at cc >50 ng/mL. In conclusion: DTI showed a good analytical performance in both coagulometers. ECT showed comparable results to DTI. We verified that dabigatran cc presented moderate correlations with PT, APTT and DRVVTC, and that these tests could only qualitative estimate cc >50 ng/mL.

Os objetivos do trabalho foram verificar a qualidade analítica do ensaio tempo de trombina diluído (DTI) para medição da concentração plasmática (cc) de dabigatrana, comparando dois coagulômetros de detecção foto-óptica, comparar os resultados com o tempo de Ecarina (ECT) e correlacionar as cc com os testes básicos de coagulação Tempo de protrombina (TP), APTT e Tempo de trombina (TT), e tempo de veneno de víbora de Russell com fosfolipídios concentrados (DRVVTC). Foram tomadas 43 amostras de plasma no vale (10-14 h. da última toma) de 40 pacientes que recebiam dabigatrana. DTI e ECT apresentaram (%) repetitividade <5,4% e <7,5%, CV interensaio <6% e <9%, respectivamente, no protocolo EP15A2, aceitáveis para um Erro Total permitido (TEa) <15%. Cc medidas em pacientes: mediana 83 (4-945) ng/mL. Comparação de equipamentos ACL TOP 300 e 500: resultados equivalentes por procedimento alternativo de comparação de métodos. Comparação ECT vs. DTI: satisfatória por regressão de Deming (pendente 1,143, ordenada à origem -19,33). Correlações cc vs. APTT, TP e DRVVTC: moderadas e não lineares tendendo a plateau a cc>350 ng/mL, r2 0,59; 0,66 e 0,59, respectivamente. O TT é extremamente sensível: >120 s a cc 50 ng/mL. DTI apresentou um bom desempenho analítico e permitiu quantificar dabigatrana plasmática a cc baixas e altas em ambos os equipamentos utilizados. ECT apresentou resultados comparáveis com DTI. Verifica-se uma correlação moderada entre cc de dabigatrana e os testes clássicos e DRVVTC, podendo ser estimadores de cc a partir dos 50 ng/mL.

Challenges in diagnosis and management of snake bites in resource poor settings: A case report of suspected Russell’s viper envenomation.

Snake bite is a common and neglected problem resulting in a large global mortality and morbidity per year. In India alone, an estimated 45,900 deaths occur per annum. The outlined case of suspected Russell’s Viper (Daboia russelii) envenomation occurred in rural West Bengal. The case was misdiagnosed on two occasions resulting in a substantial delay in antivenom therapy. The resultant delay contributed to a significant morbidity and prolonged hospital admission. The case report illustrates some practical difficulties faced by clinicians pertaining to diagnosis, complications and resource limitations. These areas are discussed with a view to improving awareness and management. Simple practical tools are included to assist a clinician faced with snake bites in South Asia.

New approaches & technologies of venomics to meet the challenge of human envenoming by snakebites in India.

The direct estimate of 46,000 snakebite deaths in India in 2005 (1 for every 2 HIV/AIDS deaths), based on verbal autopsies, renders unrealistic the total of only 47,000 snakebite deaths in the whole world in 2010, obtained indirectly as part of the “Global Burden of Disease 2010” study. Persistent underestimation of its true morbidity and mortality has made snakebite the most neglected of all the WHO’s “neglected tropical diseases”, downgrading its public health importance. Strategies to address this neglect should include the improvement of antivenom, the only specific antidote to envenoming. To accommodate increased understanding of geographical intraspecific variation in venom composition and the range of snake species that are medically important in India, the design of antivenoms (choice of venom sources and species coverage) should be reconsidered. Methods of preclinical and clinical testing should be improved. The relatively new science of venomics involves techniques and strategies for assessing the toxin composition of snake venoms directly through proteomics-centred approaches or indirectly via high-throughput venom gland transcriptomics and bioinformatic analysis. Antivenomics is translational venomics: a proteomics-based protocol to quantify the extent of cross-reactivity of antivenoms against homologous and heterologous venoms. These approaches could revolutionize the preclinical assessment of antivenom efficacy, leading to a new generation of antivenoms that are clinically more effective.

Risk Factors Associated with Bites due to Two Viperid Snakes: A Case Control Study.

Aims: This study was to assess victim’s environmental and behavioural risk factors that promote bites from two viperid snakes. Study Design: A case control study. Place and Duration of Study: Medical wards, General Hospital, Kurunegala, Sri Lanka, between June to December 2010. Methodology: Cases were recruited prospectively from consecutive admissions to the General Hospital, Kurunegala, Sri Lanka with proven viperid bites. Age and gender matched control group was selected from relatives and neighbourhood of the cases in a ratio of 1 case: 2 controls. Results: There were 56 cases and 112 controls with mean age 44 years and 45 years respectively. Of the 13 risk factors assessed, 7 risk factors showed a significant association with viperid bites. Those were (1) being in an ill lit place (OR, 95% CI= 6.6 (3.25-13.4), (2) being in outdoor places (OR, 95% CI= 148.8 (43.7-506), (3) working in a field (OR, 95% CI= 175 (31.4 – 976), (4) occupation as a field worker (OR, 95% CI= 5.3 (2.3-12 ), (5) low level of financial status (OR, 95% CI=9.9(2.75- 35.5), (6) lack of attached toilet (OR, 95% CI= 7.38 (2.15- 25.3), (7) presence of small rodents in the compounds (OR, 95% CI= 11 (4.88-24.9). Conclusion: Identifying easily remediable risk factors would help in preventing viperid snake bites.

Recombinant Russell’s viper venom-factor X activator (RVV-X)-specific antibody: neutralization and crossreactivity with Cryptelytrops albolabris and Calloselasma rhodostoma venoms.

Background: Russell’s viper venom-factor X activator (RVV-X) is a major procoagulant in Russell’s viper venom, and is composed of a heavy chain (RVV-XH) and two light chains (RVV-XL). It directly activates factor X in the final common coagulation pathway, which leads to rapid formation of blood clots. Objective: Produce rabbit anti-recombinant protein antibodies and identify their cross-reactivity with two viperine snake venoms. Methods: cDNA clones encoding RVV-XH and one of the light chains (RVV-XL; LC1) were recombinantly expressed in E. coli BL21 and used as antigens for rabbit immunization. The cross-reactivity of these anti-recombinant protein antibodies with two viperine snake venoms was determined using Western blot analysis. Results: rRVV-XH was more immunogenic than rRVV-XL. Rabbit anti-rRVV-XH and rRVV-XL IgG antibodies bind specifically to RVV-X, but they do not neutralize purified RVV-X. In addition, rabbit anti-rRVV-XH IgG antibody also bind to an 18-kDa protein in C. rhodostoma venom, and many proteins in C. albolabris venom. Rabbit antirRVV- XL IgG antibody recognized protein bands of crude venoms of C. rhodostoma and C. albolabris at about 25-kDa and 23-kDa, respectively. Conclusion: Rabbit anti-rRVV-XH and rRVV-XL IgG antibodies cross-reacted with molecules in other viperine venoms, which could have molecules with similar antigenic determinants. These antibodies could be useful to purify snake venom molecules by affinity chromatography as the first step in purification of factor X activator and other cross reacting molecules.

Posterior fossa infarct following Viper bite: a paradox

Cerebral infarction after a viper bite is relatively uncommon. A combination of factors has been implicated in the pathophysiology of infarct following snakebite. In this case report, the clinical outcome after a posterior circulation infarct and various possibilities that could lead to such a catastrophic event are discussed. The present study stresses the need to keep hydration, blood pressure and central venous pressure optimal in all snakebite patients. Cerebral infarction should be considered a differential diagnosis, in any patient with neurological deterioration following snakebite. Prognosis of such patients with posterior circulation stroke remains poor and decompressive craniectomy has not been found to be helpful.(AU)

Usefulness of Silica Clotting Time for Detection of Lupus Anticoagulants / 대한진단검사의학회지

BACKGROUND: The presence of lupus anticoagulants (LA) is a strong risk factor for thrombosis in antiphospholipid syndrome. We investigated the usefulness of addition of silica clotting time (SCT) to the pre-existing dilute Russell's viper venom test (dRVVT) for detection of LA. Also, we analyzed differences in the thrombotic features and the characteristics of antiphospholipid antibodies between dRVVT and SCT. METHODS: A total of 167 patients positive for LA or anti-cardiolipin (anti-CL) antibody and 76 healthy controls were enrolled. The dRVVT and SCT were used for detection of LA. Anti-CL, anti-beta2-glycoprotein I (anti-beta2 GPI) and anti-prothrombin (anti-PT) antibodies were measured using commercial ELISA kits. RESULTS: In detection of thrombosis, the sensitivity of the combined test of SCT and dRVVT was 56.4%, which was higher than that of dRVVT alone (46.2%) or SCT alone (23.1%). The specificity of the combined test (80.9%) was comparable to that of dRVVT (81.9%). Also, odds ratio for predicting thrombosis was higher in the combined test than in dRVVT or SCT alone. When normalized LA ratio of the two tests was compared, the group of patients with higher ratio of SCT showed significantly higher prevalence of recurrent abortion and higher positivity of IgG types of anti-CL, anti-beta2 GPI and anti-PT than the group with higher ratio of dRVVT. CONCLUSIONS: Addition of SCT to dRVVT can improve the detection sensitivity of thrombosis in LA test. And the high normalized LA ratio of SCT may be a useful parameter for detection of recurrent abortion.

Novel role of antiplatelet agents (aspirin plus clopidogrel) in an incoagulable blood of a victim of russell's viper snakebite

Snake antivenom is a specific antidote to the venom action, neutralizing the circulating venom. However, it fails to neutralize the venom fixed to target organs such as platelets, renal tubules, etc. Russell's viper venom initiates rapid coagulation in a victim by activating blood platelets, factors V, X, and anticoagulant cofactors. Activation of thrombin, resulting in formation of micro-thrombi, fibrinolysis, and a vicious cascade, sets in. Inhibition of activated platelets by aspirin (cyclooxygenase inhibitor) and clopidogrel (ADP receptor inhibitor) helps to break this vicious circle induced by Russell's venom and may initiate the natural physiological clotting mechanism. They can be utilized as an adjuvant treatment.(AU)