Envenomations by coral snakes in an Amazonian metropolis: Ecological, epidemiological and clinical aspects

Does Covid-19 influence the dynamics of envenomation by animals in a country strongly affected by both conditions? Epidemiological data from Brazil

The impact of Covid-19 on envenomations by venomous animals in countries heavily affected by both conditions has not been quantified yet. Brazil shows high incidence of envenomations by scorpions, spiders and snakes and was heavily affected by waves of Covid-19. To determine how the pandemic impacted the epidemiology of envenomations by those three groups of venomous animals, we used online databases from two surveillance sources on number of cases and mortality. During the years before and during the pandemic, scorpion stings typically occurred in adults of both sexes in urban zones in the Southeast and Northeast regions. Spider bites occurred mainly in the South region, in adults of both sexes in urban zone. Snakebites affected mainly rural adult men in the Amazon. Between 2007 and 2021, overall incidence of cases by scorpions, spiders and snakes decreased after the beginning of the pandemic, snakebites did not show changes after the pandemic started in Brazil, but cases by scorpions and spiders decreased. No changes in the incidence of deaths were observed. On national level, Covid-19 affected some demographic, clinical and epidemiological aspects in cases by scorpions, spiders and snakes.

Neurological and neuro-ophthalmological manifestations of snake bite: a systematic review

Objective

Snakebites, a major health concern in developing countries, affect rural farming communities. Venom, primarily neurotoxin, injected during a snake bite disrupts the nervous system, causing symptoms like muscle weakness, paralysis, altered sensation, and coordination issues. This review focuses on evaluating neurological and neuro-ophthalmological manifestations associated with snakebites.

Methods

A database search was conducted in EMBASE and PubMed for studies published from 2000 to 2023. The investigation centered on examining neurological and neuro-ophthalmological symptoms and signs, treatment approaches, treatment outcomes, and long-term complications of snake bites.

Results

Neurological and neuro-ophthalmological symptoms were common in both neurotoxic and hemotoxic snake bites, especially in neurotoxic cases. Ptosis was a prevalent manifestation across various snake bites, along with respiratory paralysis, limb weakness, dysphasia, and visual disturbances in some instances. However, most patients improved without residual neurological symptoms after treatment.

Conclusions

Understanding patterns of neurological manifestations contributes valuable insights for the comprehensive management of snakebite.

The challenge in detecting risk areas of snakebite when case rates are low: the case of Amazonian coral snakes

Identifying risk areas for envenomation by animals is relevant for public health, such as strategic distribution of antivenoms. Coral snakes are highly diverse in the Amazon, inhabit natural and human-modified environments, and the outcome of the cases tends to be serious and potentially lethal due to their neurotoxic venom. By integrating species' geographical records and environmental variables, we used species distribution modeling to predict the distribution of coral snake species in the Brazilian Amazonia. We analyzed the relationship between the predicted distribution of coral snake species, along with envenomation data in the region, to propose actions to reduce the number of cases and to provide tools for a better policy of public health. We conclude that the entire Amazon shows high environmental suitability for coral snakes, and such suitability explains little about the incidence of cases. This is probably due to the low human density in the Amazon and to coral snake traits such as secretive habits and non-agressive behavior. Differently from other venomous snakes, the scenario regarding coral snakebites precludes the detection of prominent geographical areas of concern and demands a broad and equitable availability of health centers throughout Amazonia and along other areas of occurrence of the genus Micrurus.

Snakebites in Northeastern Brazil: accessing clinical-epidemiological profile as a strategy to deal with Neglected Tropical Diseases

BACKGROUND

Brazil ranks first in the number of snakebites in South America. A detailed analysis of these cases is required to improve the public health planning. In this study, we retrospectively examined the clinical and epidemiological profiles of snakebites in Maranhão between January 2009 and December 2019.

METHODS

Data were obtained from the compulsory notification forms provided by the Health Department of Maranhão.

RESULTS

A total of 17,658 cases were recorded during the study period. Most of the bites were from snakes belonging to the genus Bothrops. Medical care was mostly within three hours after the bite. Most cases were classified as mild and most victims recovered; however, 139 deaths were recorded. Most bites occurred among people aged 20-39 years, mainly among rural workers. The most frequent local clinical manifestations were pain, edema, and ecchymosis. The most common systemic clinical manifestations include neuroparalysis, vagal syndrome, and myolysis. Most snakebites occurred between January and March. The municipalities with the highest number of notifications were Buriticupu (936 cases), Arame (705 cases), and Grajaú (627 cases).

CONCLUSIONS

The clinical profile of snakebites in Maranhão is similar to that observed in other states of Northeast Brazil. However, we found that some systemic manifestations are not compatible with the etiology of snakebites, which leads us to believe that the problem could be the lack of knowledge of the health professionals at the site of envenomation, who may not be ready for attendance, and an important lack of health centers with snake antivenom to treat snakebites.

Envenomation by Micrurus hemprichii in Brazilian Amazonia: A report of three cases

Herein, we report three new separate cases of human envenomations by Micrurus hemprichii for the Amazon, which is a biome where envenomations by Micrurus are seldom reported. Two women were bitten after stepping on the snakes and one man was bitten while handling the animal. All cases occurred in the peridomicile, in rural areas. The first case evolved mainly to local symptoms, but the patient was discharged before the identification of the snake and had to be called back for observation before being eventually discharged. In the second case, the patient presented transitory dyspnea and she was discharged after four days in hospital. In the third case, the patient showed only local symptoms, but he was about to receive unnecessary antivenom against coral snakes. Cases like these show the importance of educational problems regarding local venomous snakes in order to avoid bites and to provide the correct hospital treatment. For this, trained professionals in cases involving venomous animals are needed.

Primer registro de accidentes ofídicos por mordedura de Micrurus ortoni y Micrurus hemprichii (Serpentes: Elapidae) en Colombia y Perú

Se reportan dos casos de mordedura por serpientes de la especie Micrurus ortoni en Colombia y uno por M. hemprichii en Perú. En dos de los casos se observó afección neurológica motora leve a moderada y, en todos, se presentó un acentuado trastorno sensitivo con hiperestesia e hiperalgesia irradiada desde el sitio de la mordedura hacia todo el hemicuerpo comprometido. El único paciente que recibió antiveneno, el cual no era específico para el tipo de envenenamiento, desarrolló una reacción al suero equino a los ocho días de su aplicación.

Se presentan y discuten los resultados de las pruebas de laboratorio, incluido el estudio electromiográfico, así como el registro fotográfico de las manifestaciones clínicas y de los agentes causales.