The severity of acute kidney injury correlates with plasma venom levels in Bothrops atrox envenomings.

The Brazilian Amazon has high rates of snakebite envenomings (SBEs), with ∼90% caused by Bothrops atrox. Envenomings by this species can trigger local and systemic effects, such as acute kidney injury (AKI). Our aim was to identify predictors of AKI in Bothrops SBEs in patients from Manaus, Western Brazilian Amazon. A total of 127 patients were enrolled, with a predominance of men between 16 and 45 years old from rural areas. Of the 127 patients, 38.6% developed AKI, with 61.2% presenting stage I, 34.7% presenting stage II and 4.1% presenting stage III severity. The age groups 0-10 years and ≥60 years presented a significantly higher frequency of AKI compared to the 11-40 years group. Moderate/severe edema in the affeccted limb was significantly associated with lower risk of AKI [p = 0.01; OR = 0.11 (95%CI 0.02-0.53)]. Nausea [p = 0.01; OR = 54.44 (95%CI = 3.26-909.27)] and high blood urea levels [p = 0.01; OR = 5.38 (95%CI = 2.12-13.66)] were risk factors for AKI. There was a significant positive correlation between circulating venom levels and the highest creatinine serum values during the hospital stay (p = 0.03) and with the difference between the maximum creatinine levels and the creatinine levels on admission (p = 0.02). A positive correlation between serum venom concentrations and creatinine levels suggests a direct or indirect dose-dependent participation of the venom toxins in the pathogenesis of AKI.

Association of cfDNA levels and bothrops envenomation.

In the Amazon, around 90% of snakebites are caused by the Bothrops genus. Complications arising from Bothrops envenomations result from the inflammatory and coagulotoxic activities of the venom. The aim of this study was to investigate the potential of cell-free DNA (cfDNA) as a biomarker of severity in Bothrops snakebites. Patients were treated at the Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD), Manaus, in the Brazilian Amazon. cfDNA plasma levels were measured by amplifying the human telomerase reverse transcriptase (hTERT) sequence using quantitative RT-PCR. Median levels of cfDNA were compared between envenomed and healthy volunteers and among patients presenting different complications, such as renal failure, bleeding and infection. Of the 76 patients included, 82.9% were male, with a mean age of 32.8 years, and envenomations were mainly classified as severe (39.5%). ROC curve analysis showed a good accuracy of cfDNA levels (AUROC of 0.745) in envenomation diagnosis. A correlation analysis using laboratory variables showed positive correlation with lactate dehydrogenase (p = 0.033) and platelet count (p = 0.003). When cfDNA levels were compared with clinical complications, significant statistical differences were only found among individuals with mild and severe pain (p < 0.05). In summary, our results demonstrated that cfDNA levels are sufficiently accurate for discriminating between envenomed and non-envenomed patients, but are not able to distinguish different complications and the level of severity among envenomed patients. Thus, the role of cfDNA in the pathogenesis of the snakebite envenomations needs to be further investigated.

Perspectives and recommendations towards evidence-based health care for scorpion sting envenoming in the Brazilian Amazon: A comprehensive review.

Although underreported across the Amazon region, scorpion stings are very prevalent in some areas and can be potentially life-threatening, especially in children. The most vulnerable populations are those living in locations far from the capitals, hence having limited access to the health system where the appropriate structure for the treatment of severe cases is found. An abundant and diverse fauna of scorpions is found in the region, but few studies have been conducted to decipher the clinical characteristics and therapeutic response of the available antivenoms in envenomings caused by the various species. Antivenom underdosage as well as delayed medical assistance are common among indigenous populations, resulting in poor outcome rates. An in depth understanding of the epidemiological, clinical and therapeutic aspects of scorpion sting envenomings in the Amazon is necessary to improve the outcome of these cases.