Cerebrovascular Accidents Related to Snakebites in the Amazon-Two Case Reports.

The objective of this case series was to describe 2 patients presenting with subarachnoid hemorrhage with hydrocephalus and hemoventricle after a snakebite caused by presumed Bothrops ssp. Both cases occurred in the municipality of Guajará (Amazonas state), Western Brazilian Amazon. Both cases featured delay in administration of serum therapy, which may have contributed to the emergence of complications such as stroke. Patient 1 was admitted to hospital 16 h after the snakebite occurred. Before receiving antivenom, testing showed the patient as having unclottable blood. She developed hemorrhagic stroke (a subarachnoid hemorrhage with hydrocephalus and hemoventricle). On the seventh day, she was discharged from hospital. Patient 2 arrived at the hospital 3 d after the snakebite occurred and presented with unclottable blood. He had a stroke (right frontoparietal hemorrhage, intraparenchymal hemorrhage already open to the ventricle) and died on the eighth day after the snakebite. Delay in seeking health care after snake envenomation can result in worse outcome.

Mapping the Silent Threat: A Comprehensive Analysis of Chagas Disease Occurrence in Riverside Communities in the Western Amazon.

Chagas disease (CD) is a typical tropical illness caused by Trypanosoma cruzi. The objective of this study was to assess the prevalence of Chagas disease in communities in two states of the Brazilian Amazon. Data collection occurred in July in the Alto Juruá region of Acre and in December in the communities of Humaitá, Amazonas, in 2019. A total of 477 participants were included in the study. In the communities of Alto Juruá, triatomine collections and analyses of T. cruzi infection were also carried out. All confirmed cases were found in the state of Acre, resulting in a total prevalence of 1.67. Of these eight cases, seven underwent ECG, all of which were concluded as normal by the physician team's cardiologists. Seventeen triatomine bugs, all belonging to the Rhodnius genus, were captured. The natural infection rate by T. cruzi was 25% in the Nova Cintra community and 66.67% in the Boca do Moa community (Alto Juruá). This research found that more than 1% of the studied population exhibited positive serological results for Chagas disease in the riverine communities during the study period, representing a small portion of cases among those who have not yet been diagnosed.

Morbidity survey of the history of snakebites in different communities in the alto Juruá, western Brazilian Amazon.

The Alto Juruá region has a rich diversity of venomous snakes, and snakebites represent an important cause of morbidity. The present study was carried out in five communities in the Alto Juruá region, and aimed to evaluate the history of snakebites in terms of which snakes were involved and what was the victims' conduct in relation to first aid and prevention. Between 2017 and 2019, semi-structured interviews were applied to 260 residents, 56 (21.53%) of whom had a history of snakebites. The profile of the victims is 73.2% male, a resident of rural areas who develops activities mainly in agriculture and extractivism and who has a low level of education. Just over half of the snakebites occurred during the rainy season (52.8%) and the majority during the day (77%). Bothrops bites were the most frequently reported (90.3%) and B. atrox was the most mentioned snake (jararaca and surucucu) for being responsible for snakebites (80.8%). Approximately 87.5% of the bites occurred to the lower limbs, and 48.2% of the victims were barefoot at the time of the bite. Inadequate first-aid procedures were reported, such as using tourniquets and consuming the drink known as "Específico Pessoa", not drinking water, and treatment with traditional therapy (phytotherapics, zootherapeutics and faith healers), as well as not seeking hospital care. Thus, the need to facilitate access to hospital units in these communities and health education (prevention and first aid) are essential in order to minimize this situation.

Parasitism by Amblyomma rotundatum on Teiidae lizards in the eastern part of the state of Acre, Brazil.

The aim of the present study was to report on the occurrence of parasitism by Amblyomma rotundatum ticks on two species of Teiidae lizards and test the presence of rickettsiae in the collected ticks, in the western Brazilian Amazon region. Ticks were collected in July 2019, from a fragment of terra firme forest in the municipality of Senador Guiomard, Acre, Brazil. Two lizards that were infested by immature stages of ticks were caught using mist net and Tomahawk traps. Ectoparasites were collected manually, and the lizard specimens were identified and released at the same location where they had been caught. Three nymphs and 49 larvae were collected from Ameiva ameiva, while 25 nymphs and nine larvae were collected from Tupinambis cuzcoensis, which are both in the family Teiidae. The ticks were identified morphologically as belonging to the genus Amblyomma. Nymphs were identified at species level through molecular analysis, resulting in the tick species Amblyomma rotundatum. This is the first record of parasitism by the tick A. rotundatum on T. cuzcoensis lizard, and the first report of an association between A. rotundatum and the lizard species A. ameiva and T. cuzcoensis in Acre, in the western part of the Amazon region.

Occurrence of triatomines in public spaces: An atypical case in the Southwestern Brazilian Amazon.

BACKGROUND: Triatomines infest atypical public spaces in the Western Amazon. METHODS: Frequent visitors to these spaces captured the insects in the state of Acre, Brazil (Rio Branco and Cruzeiro do Sul). RESULTS: Six insects were found in a penitentiary, a church, a school, a university, a hospital, and a health center. Five of the insects were adults (three positive for Trypanosoma cruzi) and one was a nymph. CONCLUSIONS: This is the first report of triatomine occurrence in schools or churches. These data are important for implementing surveillance strategies and alerting individuals about possible changes in Chagas disease transmission dynamics.

When to think about a Lachesis muta envenomation in the Western Brazilian Amazon: Lessons from a case report.

In the Brazilian Amazon, envenomations by lancehead pit vipers prevail across the region, while bushmaster (Lachesis muta) envenomations are rarely confirmed. Here, we described a moderate snakebite, diagnosed as a lancehead pit viper envenomation upon admission and treated with four vials of Bothrops antivenom. Blood remained unclottable for 4 days of hospitalization. On day 4, after admission, the patient presented pictures of the perpetrating snake to the hospital staff, which was identified as a Lachesis muta specimen. After administering 10 vials of Lachesis antivenom, blood became clottable 12 hours after treatment. The patient was discharged without complaints.

Temporal trend and epidemiological profile of accidents involving venomous animals in Brazil, 2007-2019. / Tendência temporal e perfil epidemiológico dos acidentes por animais peçonhentos no Brasil, 2007-2019.

OBJECTIVE: to analyze the temporal trend of accidents involving venomous animals in Brazil from 2007 to 2019. METHODS: this was a cross-sectional study carried out with data from the Notifiable Health Conditions Information System (SINAN). Prais-Winsten linear regression was used for the temporal analysis. We calculated incidence rates according to sex and age group, relative risk and case fatality ratio. RESULTS: during the study period there were 2,102,657 cases of accidents involving venomous animals. With the exception of snakebite, the remaining accidents showed a rising temporal trend in most regions of the country. Scorpion stings, snake bites and spider bites were responsible for 86% of accidents, mainly affecting male people of working age. Accidents involving snakes (0.4%) and bees (0.3%) had the highest case fatality ratios. Children were the main victims of accidents involving bees, caterpillars and "others". CONCLUSION: accidents involving venomous animals showed a rising temporal trend for most conditions, as well as different epidemiological profiles.

Efficacy of the 20-minute whole blood clotting test (WBCT20) in the diagnosis of coagulation alteration related to snakebites in a Western Brazilian Amazon hospital.

INTRODUCTION: The efficacy of 20-minute whole blood clotting (WBCT20) and the Lee-White clotting time (LWCT) tests in diagnosing coagulation alterations from snakebites were compared. Methods: We evaluated 89 snakebite cases treated at the Hospital Regional do Juruá em Cruzeiro do Sul, Acre, Brazil. Results: WBCT20 results were normal in 33.7% and unclottable in 66.3% of cases, while LWCT results were normal in 23.6% and altered (prolonged or unclottable) in 76.4% of cases, with no significant differences. Conclusions: The WBCT20 is important for rapidly diagnosing coagulation alterations from snakebites. Furthermore, it is efficient, inexpensive, and can be deployed in isolated hospitals.

Crotalus Durissus Ruruima: Current Knowledge on Natural History, Medical Importance, and Clinical Toxinology.

Crotalus durissus ruruima is a rattlesnake subspecies mainly found in Roraima, the northernmost state of Brazil. Envenomings caused by this subspecies lead to severe clinical manifestations (e.g. respiratory muscle paralysis, rhabdomyolysis, and acute renal failure) that can lead to the victim's death. In this review, we comprehensively describe C. d. ruruima biology and the challenges this subspecies poses for human health, including morphology, distribution, epidemiology, venom cocktail, clinical envenoming, and the current and future specific treatment of envenomings by this snake. Moreover, this review presents maps of the distribution of the snake subspecies and evidence that this species is responsible for some of the most severe envenomings in the country and causes the highest lethality rates. Finally, we also discuss the efficacy of the Brazilian horse-derived antivenoms to treat C. d. ruruima envenomings in Roraima state.

Snakebites in "Invisible Populations": A cross-sectional survey in riverine populations in the remote western Brazilian Amazon.

In the Brazilian Amazon, long distances, low healthcare coverage, common use of ineffective or deleterious self-care practices, and resistance to seeking medical assistance have an impact on access to antivenom treatment. This study aimed to estimate snakebite underreporting, and analyze barriers that prevent victims from obtaining healthcare in communities located in 15 municipalities on the banks of the Solimões, Juruá and Purus Rivers, in the remote Western Brazilian Amazon. Information on the participants' demographics, previous snakebites, access to healthcare, time taken to reach medical assistance, use of self-care practices, and the reason for not accessing healthcare were collected through semi-structured interviews. In the case of deaths, information was collected by interviewing parents, relatives or acquaintances. A total of 172 participants who reported having suffered snakebites during their lifetime were interviewed. A total of 73 different treatment procedures was reported by 65.1% of the participants. Participants living in different river basins share few self-care procedures that use traditional medicine, and 91 (52.9%) participants reported that they had access to healthcare. Living in communities along the Juruá River [OR = 12.6 (95% CI = 3.2-49.7; p<0.001)] and the use of traditional medicine [OR = 11.6 (95% CI = 3.4-39.8; p<0.001)] were variables that were independently associated to the lack of access to healthcare. The main reasons for not accessing healthcare were the pprioritization of traditional treatments (70.4%), and the failure to recognize the situation as being potentially severe (50.6%). Four deaths from complications arising from the snakebite were reported, and three of these were from communities on the banks of the Juruá River. Only one of these received medical assistance. We found an unexpectedly high underreporting of snakebite cases and associated deaths. Snakebite victims utilized three main different healing systems: 1) self-care using miscellaneous techniques; 2) official medical healthcare generally combined with traditional practices; and 3) self-care using traditional practices combined with Western medicines. To mitigate snakebite burden in the Brazilian Amazon, an innovative intervention that would optimize timely delivery of care, including antivenom distribution among existing community healthcare centers, is needed.

Bothrops bilineatus: An Arboreal Pitviper in the Amazon and Atlantic Forest.

The two-striped forest-pitviper (Bothrops bilineatus) is an arboreal snake that is currently represented by two subspecies (B. b. bilineatus and B. b. smaragdinus) that comprise a species complex, and its distribution is in the Amazon and the Atlantic Forest. The rarity of encounters with this snake is reflected in the low occurrence of cases of snakebites throughout its geographic distribution and the resulting low number of published clinical reports. However, in some areas, B. bilineatus proves to be more frequent and causes envenomations in a greater proportion. Herein, we review the main aspects of the species complex B. bilineatus, including its biology, ecology, taxonomy, morphology, genetic and molecular studies, geographic distribution, conservation status, venom, pathophysiology and clinical aspects, and epidemiology. In addition, the different antivenoms available for the treatment of envenomations caused by B. bilineatus are presented along with suggestions for future studies that are needed for a better understanding of the snakebites caused by this snake.

Coral snake bites in Brazilian Amazonia: Perpetrating species, epidemiology and clinical aspects.

Coral snakes constitute a relatively diverse and little known group of venomous snakes. So far, data for this kind of snakebite in the Amazon region are based only on case reports. This study takes advantage of novel data from the Brazilian Health Ministry database from 2010 to 2015 and presents a review of the cases reported in the literature regarding the Amazonian biome both from Brazil and nearby countries. Thirty-four cases reported in the database were used in the study, representing 0.05% of the snakebites in Brazilian Amazonia for that period. The incidence rate was 0.123 cases/100,000 inhabitants/year. The most affected group is that of working age men, suggesting occupational risk. Most of bites were on lower limbs. Pain, edema and paresthesia were the most common symptoms. Systemic symptoms not usually associated with coral snakes envenomings, such as coagulopathy and thrombocytopenia, have been reported in Amazonia. Five patients received less antivenom than indicated by the Health Ministry. Based on these results, we recommend the execution of educational programs to avoid such accidents and to teach both the general public and health professionals the correct treatment for the bites. We also suggest that the covering of Intensive Care Units in the region needs to be improved to avoid deaths.

Snakebites in Rio Branco and surrounding region, Acre, Western Brazilian Amazon.

INTRODUCTION: Snakebites are considered a neglected tropical disease in many countries in Latin America, including Brazil. As few studies have assessed snakebites in the Amazon region and especially in the state of Acre, epidemiological studies are of great importance. The present study aimed to describe the epidemiological characteristics of snakebites in the Rio Branco region, observing their characteristics in rural and urban areas and their correlation with rainfall and river outflow. METHODS: This retrospective, descriptive study analyzed epidemiological information obtained from snakebite notifications registered on the Information System for Notifiable Diseases that occurred from March, 2018 to February, 2019. The cases of snakebite were correlated with rainfall and flow. RESULTS: A total of 165 cases of snakebite were registered in the period. Most cases were caused by Bothrops and affected mainly individuals of the male sex who were between 21 and 30 years old. Most of the snakebites occurred in Rio Branco (71.52%; 29 cases per 100,000 inhabitants). Of these, 60.2% occurred in the urban area and 39.8% in the rural area and the majority occurred during the rainy season. CONCLUSIONS: Although studies have shown that a majority of cases occur in rural areas, in this study, urbanization of snakebites was observed. The Bothrops genus was responsible for the highest number of snakebites and, during the rainy season, bites occurred more frequently. Educational prevention campaigns, population advice, and first aid in case of snakebites for the population are thus suggested.

Relationship between snake size and clinical, epidemiological and laboratory aspects of Bothrops atrox snakebites in the Western Brazilian Amazon.

In the Brazilian Amazon, snakebites are a significant problem, especially for populations in rural areas, particularly in forests, where victims are a considerable distance from hospital care. Several factors are associated with the severity of the accident, such as the size and age of the snake. This study aims to compare the clinical, epidemiological and laboratory aspects of envenomation to the size of Bothrops atrox snakes. Clinical, epidemiological and laboratory variables were collected from patients bitten by B. atrox and who were admitted to a hospital in the city of Cruzeiro do Sul (western Brazilian Amazon). When the two punctures of the teeth were present in the bite sign, the distance between these was measured. When taken to the hospital, the snake was measured; otherwise, its size was estimated via interviews with patients. In 92 cases, the size of the snake was estimated, and most of these were caused by small snakes. Bites of small snakes occur mainly on the feet, while larger specimens reach the legs or higher regions. Small snakes were associated primarily with mild and moderate snakebites, with more presence of hemorrhagic manifestations, while larger snakes were responsible for severe cases and characterized by local effects (necrosis, edema, flictena, compartment syndrome, and infection) and patients were treated with a higher amount of antivenom and for a longer period of hospitalization. The distance of the punctures was related to the size of the snake and the severity of the local envenomation. The observation of the distance between puncture marks when present, which is correlated with the length of the specimen, as well as the estimation of the snake size by the patient, may provide more support for the health professional on the prognosis of envenomation. The use of boots in activities in rural areas and forests could contribute to a lower rate of cases of snakebites, and health education on preventive measures and first aid for populations is fundamental.

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

Envenomation by coral snakes represents a little known burden in Brazilian Amazonia. So far, details on clinical and epidemiological aspects remain obscure in the region. We gathered data from medical charts and from the scientific collection of snakes from Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, finding 26 cases of envenomation by five species of Micrurus in Manaus region, between 1987 and 2018. They represent 0.7% of the snakebites treated in the hospital since the records began, in 1979. Micrurus lemniscatus was responsible for most of the bites (10), followed by M. hemprichii (five), M. spixii (three), M. surinamensis (three) and M. averyi (one). There was no difference between the sexes of the snakes that caused bites. Patients were mostly males, and most of the cases were reported in urban areas. Bites predominated in dry season, and there was a clear geographical segregation among species. We describe seven cases of envenomation, three mild and four severe, all of which evolved to cure. Paresthesia (six), pain (five) and edema (four) were the most common local symptoms. Systemic features such as dyspnea/shallow breath (four), palpebral ptosis (four), blurred vision (three), dysarthria (three) and difficulty to walk (three) were also detected. Two patients bitten by Micrurus sp. and M. hemprichii, showed slight increased serum levels of creatine kinase (reference level <190 U/L), 1184 U/L and 1229 U/L, respectively, indicative of mild systemic myotoxicity. This is the first report of myotoxic manifestation in the envenomation by M. hemprichii. No patient developed respiratory failure, though one bitten by an adult M. spixii required intubation and mechanical ventilation due to decreased level of consciousness during evolution, probably related to induced sedation caused by concurrent alcohol intoxication. All patients were treated with Brazilian Micrurus antivenom (soro antielapídico, median = 10 vials). Six patients were pretreated intravenously with H1 and H2 antagonists and steroids, with two patients developing early adverse reactions. The median length of hospital stay was four days. Envenomations by coral snakes in Manaus region are clinically severe, but rare and sparsely distributed over time, making the detection of epidemiological and clinical patterns a challenge for public health.

Trypanosoma cruzi vectors in a periurban area of the Western Brazilian Amazon.

The etiological agent of American trypanosomiasis is the protozoan Trypanosoma cruzi , typically transmitted by triatomines. The aim of this study was to investigate the triatomine fauna and trypanosomiasis infections in Acre State , Western Brazilian Amazon. Insect collection was performed by dissecting palm trees and installing traps. We found that T. cruzi infection rate was 24.5% and Rhodnius pictipes (57.1%) was the most abundant triatomine species. Health education as well as epidemiological and entomological surveillance are necessary to diagnose and prevent new cases of Chagas disease in the region.

Triatominae (Hemiptera, Reduviidae) in homes: Report of their occurrence in the municipality of Cruzeiro do Sul, Acre, South Western Amazon.

INTRODUCTION: Triatomines are hematophagous insects that are important to public health since they are the vectors of American Trypanosomiasis. The objective of this study was to describe the occurrence of triatomines in homes in Cruzeiro do Sul, Acre, Brazil. METHODS: The specimens were collected by an active search inside homes and also by a passive search by the residents. RESULTS: A total of 55 triatomines were captured comprising of 5 species each of the genera Rhodnius, Eratyrus, and Panstrongylus. No colonies were detected, ruling out the possibility of domiciliation. CONCLUSIONS: Information on regional epidemiological dynamics contributes to the prevention and control of disease.

Venomous snakes and people in a floodplain forest in the Western Brazilian Amazon: Potential risks for snakebites.

People who live in rural or forested areas are more likely to be affected by snakebites, due to their presence in the natural habitat of snakes and due to activities such as extractivism and agriculture. To conduct an ethnobiological study regarding the knowledge related to venomous snakes, snakebites and the attitudes of people who frequent areas of floodplain forests in the Alto Juruá (Brazilian Amazon), and correlate this information with data on snakebites in the region and the ecology of the ophiofauna, 100 residents, who are actively involved in extractivism, fishing, or hunting in the forests of the region were interviewed. Boards with photographs of venomous snakes from the region were used to ask questions about their experiences. The sampling of snakes was carried on trails in a forest used by residents of the region in their extractivism activities. Four venomous species (Bothrops atrox, B. bilineatus smaragdinus, Micrurus lemniscatus and M. surinamensis) were recorded. Among the interviewees, 31% claimed that they had already suffered at least one snakebite. The B. atrox snake is the species that the inhabitants encounter most and the one that is most associated with snakebites. Bothrops b. smaragdinus was the most common snake found during the search. Regarding accident prevention, 60% of them reported wearing boots when walking in the forest. In relation to practices adopted after a bite, the majority stated that they would seek medical attention; however, many reported using first aid measures that would not be medically effective for the victim's recovery. Despite B. b. smaragdinus being the most common snake found by researchers, it is responsible for very few snakebites. This is probably due to its arboreal habits, since it is found at a higher than average height (6.3 m) which is much higher than the height of a human being. The surveyed population demonstrated knowledge of the main preventive measures against snakebites, although some inadequate and/or ineffective first aid measures are still adopted.

Bothrops atrox, the most important snake involved in human envenomings in the amazon: How venomics contributes to the knowledge of snake biology and clinical toxinology.

Bothrops atrox snakes are mostly endemic of the Amazon rainforest and is certainly the South American pit viper responsible for most of the snakebites in the region. The composition of B. atrox venom is significantly known and has been used to trace the relevance of the venom phenotype for snake biology and for the impacts in the clinics of human patients involved in accidents by B. atrox. However, in spite of the wide distribution and the great medical relevance of B. atrox snakes, B. atrox taxonomy is not fully resolved and the impacts of the lack of taxonomic resolution on the studies focused on venom or envenoming are currently unknown. B. atrox venom presents different degrees of compositional variability and is generally coagulotoxic, inducing systemic hematological disturbances and local tissue damage in snakebite patients. Antivenoms are the effective therapy for attenuating the clinical signs. This review brings a comprehensive discussion of the literature concerning B. atrox snakes encompassing from snake taxonomy, diet and venom composition, towards clinical aspects of snakebite patients and efficacy of the antivenoms. This discussion is highly supported by the contributions that venomics and antivenomics added for the advancement of knowledge of B. atrox snakes, their venoms and the treatment of accidents they evoke.

"Bad things come in small packages": predicting venom-induced coagulopathy in Bothrops atrox bites using snake ontogenetic parameters.

Introduction: Snake venom composition shows significant inter- and intra-species variation. In the case of the viperid species Bothrops atrox, responsible for the majority of snakebites in the Amazon region, geographical and ontogenetic variables affect venom composition, with ecological and medical implications. Previous studies had shown that venom from neonate and juvenile Bothrops specimens have a higher in vitro coagulant activity. The aim of this investigation was to assess the association of clinical outcomes, such as venom-induced coagulopathy and local complications, with B. atrox ontogenetic variables.Methods: This study explored the relationship between some clinical parameters in patients suffering envenomations by B. atrox in the Amazon and several morphometric parameters of the snake specimens causing the bites.Results: There were 248 specimens confirmed as agents of envenomation, mostly female snakes (70.5%) and classified as juveniles (62.7%). Patients bitten by neonates compared to adult snakes [OR = 2.70 (95%CI 1.15-6.37); p = .021] and by snakes with white tail tip [OR = 1.98 (95%CI 1.15-3.41); p = .013] were more likely to develop coagulopathy. Time from patient admission to the unclottable blood reversion was not affected by the snake gender (p = .214) or age (p = .254). Patients bitten by neonate (p = .024) or juvenile snakes (p < .0001) presented a lower frequency of moderate to severe edema, as compared to those bitten by adult snakes. In agreement with experimental observations, patients bitten by neonates and by snakes with a white tail tip were more likely to develop coagulopathy than those bitten by adult snakes. In contrast, envenomations by adult snakes were associated with a higher incidence of severe local edema.Conclusion: Despite these variations, no difference was observed in the time needed to recover blood clotting in these patients after Bothrops antivenom administration.