Infectious Complications Following Snakebite by Bothrops lanceolatus in Martinique: A Case Series

A Nationwide Study on the Risks of Complications and Healthcare Costs of Snakebite Envenomation in Taiwan

In Taiwan, six medically important venomous snakes, Trimeresurus stejnegeri stejnegeri, Protobothrops mucrosquamatus, Deinagkistrodon acutus, Daboia siamensis, Naja atra, and Bungarus multicinctus, are found. However, comprehensive research on the complications and associated healthcare costs of snakebite envenomation (SBE) is lacking. We retrospectively analyzed pertinent information from the Taiwan National Health Insurance Research Database dated January 2002 to December 2014. We investigated the risk factors for complications and their impact on healthcare costs. Among the 12,542 patients with SBE, those from N. atra or B. multicinctus were more likely to experience wound infections and neurological complications than were those from T. s. stejnegeri or P. mucrosquamatus. In addition, being female, being elderly, and having a Charlson Comorbidity Index equal to or greater than 3 points were associated with an increased likelihood of wound infections and psychological complications. The annual national economic burden averaged US$1,083,624, with an average healthcare cost of US$1,129 per SBE. Snakebite envenomations from N. atra or B. multicinctus, as well as various complications, resulted in significantly higher costs. It is crucial to comprehend the risk factors for complications and their role in increasing expenses to provide insight for tailored healthcare interventions, mitigate complications, and reduce the economic burdens associated with SBEs.

Snakebite-Associated Infections: A Systematic Review and Meta-Analysis

Snakebites still constitute a significant public health problem in developing countries and are considered a neglected tropical condition by the WHO. Snake accidents are associated with substantial morbidity and mortality and may produce secondary complications, such as severe infections. The objective of this systematic review was to determine the prevalence of snakebite infections and characterize the bacteria isolated from these infections. A systematic literature review in five databases was carried out to assess the prevalence of snakebite infection. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence and 95% CIs. Cochran's Q test and the I2 statistic were used to assess between-study heterogeneity. The pooled prevalence of infection due to snakebite was 27.0% (95% CI: 22.0-32.0%), with high heterogeneity among studies (I2 = 99.7%). The prevalence was higher in Asia (32%) than in the Americas (21%). Snakebite infections required surgical interventions in 68% (95% CI: 37.0-98.0%). The leading group of pathogens identified corresponded to Gram-negative bacteria (63%), particularly Morganella morganii (32%), but also, Gram-positive cocci (40%), especially Enterococcus spp. (23%) and Staphylococcus aureus (15%). However, multiple other pathogens, including anaerobes, were found. A high prevalence of snakebite-associated infection has been described, primarily due to M. morganii, with the corresponding implications for empirical therapy. Rational use of antimicrobials is recommended, and this should guide initial empirical treatment. Moreover, isolation and identification of the possible bacteria present in snakebite wounds is recommended in all cases to confirm or rule out associated infection.

Use of Antibiotics following Snakebite in the Era of Antimicrobial Stewardship

Even though there are guidelines for the management of snakebite envenoming (SBE), the use of antibiotics in this pathology remains controversial. The aim of this study is to provide a narrative review of the literature and recommendations based on the best available evidence regarding antibiotic use in SBE. We performed a narrative review of relevant literature regarding SBE and antibiotic use as prophylaxis or treatment. A total of 26 articles were included. There is wide use of antibiotics in SBE; nevertheless, infection was not necessarily documented. The antibiotics used varied according to the study, from beta lactams to lincosamide and nitroimidazoles, and from monotherapy to combined antimicrobials. The most common recommendations were to manage skin and soft tissue infections and avoid infectious complications, but these suggestions are not necessarily based on bacteriological findings. Prophylactic use of antibiotics in SBE is discouraged in most studies. Antibiotic prescription in SBE should be based on the susceptibility of microorganisms isolated from the affected tissue or identified in snakes' oral cavities. Antibiotics should be reserved only for patients with a demonstrated infection, or those at a high risk of developing an infection, i.e., presenting severe local envenoming, local signs of infection, or those with incorrect manipulation of wounds. Prospective studies are needed to correlate microbiological findings at the wound site and the response to antibiotic use.

The Incidence of Infection Complicating Snakebites in Tropical Australia: Implications for Clinical Management and Antimicrobial Prophylaxis

Objective

To define the incidence of infection following snakebite in tropical Australia and the resulting implications for the routine prescription of prophylactic antibiotics.

Methods

A retrospective study of all individuals presenting to Cairns Hospital, a tertiary referral hospital in tropical Australia, after a snakebite between December 2013 and October 2020.

Results

There were 732 hospitalisations, 720 (98.4%) patients presented within 8 hours of the snakebite, and 29/732 (4.0%) were envenomated. Envenomated patients were more likely to receive empirical antibiotics than nonenvenomated patients (8/29 (27.6%) versus 14/703 (2.0%), p < 0.001), although this was frequently as a bundle of care for critically ill individuals. Superficial skin infection was diagnosed by clinicians in 6/732 (0.8%) patients during their hospitalisation; infection was diagnosed more commonly in envenomated than in nonenvenomated patients (3/29 (10.3%) versus 3/703 (0.4%), p = 0.001). All 3 envenomated individuals diagnosed with infection were believed to have taipan (genus Oxyuranus) bites. Five (83%) of the six patients diagnosed with infection had received empirical antibiotics at presentation; only 1/710 (0.1%) patients who received no antibiotics developed a (superficial) infection.

Conclusion

Infection is a very uncommon complication of snakebite in tropical Australia. Individuals bitten by snakes in tropical Australia should not routinely receive antibiotic prophylaxis.

Antibiotic susceptibility of cultivable microbiota from the oral cavity of captive Bothrops atrox and Bothrops lanceolatus: Implications for the treatment of snakebite-associated infections in the French departments of America

INTRODUCTION

Secondary infection is a frequent complication after bites by Bothrops atroxin French Guiana or B. lanceolatus in Martinique. Knowledge of the bacteria present in snake mouths is a valuable aid for determining probabilistic antibiotherapy after Bothrops bite. The objectives of this study were to describe the cultivable bacteria of the oral microbiota of the specimens of B. atrox and B. lanceolatus kept in captivity, and to study their susceptibility to antibiotics.

METHODS

Fifteen B. atrox and 15 B. lanceolatus were sampled. Bacterial cultures were performed and each morphotype on plates was identified using MALDI-TOF mass spectrometry. Antibiotic susceptibility was studied using the agar disk diffusion method, with possible determination of the MICs.

RESULTS

One hundred and twenty-two isolates were identified: 52 isolates and 13 species in B. atrox, 70 isolates and 23 species in B. lanceolatus. The main species were Providencia rettgeri, Morganella morganii, Pseudomonas aeruginosa, Staphylococcus xylosus, and Paeniclostridium sordellii (only in B. lanceolatus mouths). For B. atrox, 96% of isolates were susceptible to piperacillin/tazobactam, cefepime, imipenem and meropenem, 94% to ciprofloxacin and 76% to cefotaxime and ceftriaxone. For B. lanceolatus, 97% of isolates were susceptible to meropenem, 96% to cefepime, 93% to imipenem and piperacillin/tazobactam, 80% to ciprofloxacin, and 75% to cefotaxime and ceftriaxone. Many isolates were resistant towards amoxicillin/clavulanate.

CONCLUSION

Among currently recommended antibiotics, cefepime and piperacillin/tazobactam seem more suitable than cefotaxime or ceftriaxone in the event of a Bothrops bite. Ciprofloxacin may also be considered for B. atrox.

The Effectiveness of Antibiotics in Managing Bacterial Infections on Bite Sites following Snakebite Envenomation

Snakebite envenomation (SBE) is a life-threatening medical emergency with a high mortality rate. Common secondary complications following SBE, such as wound infections, are significant due to their impact on worsening local tissue damage and causing systemic infection. Antivenoms are not effective to treat wound infections following SBE. Moreover, in several rural clinical settings, broad-spectrum antibiotics are often used without clear guidelines or based on limited laboratory data, resulting in undesirable side effects and exacerbated treatment costs. Therefore, robust antibiotic strategies should be developed to tackle this critical issue. Currently, there is limited information available on the bacterial profiles of SBE-induced infections and antibiotic susceptibility. Hence, it is essential to improve the knowledge of bacterial profiles and their antibiotic sensitivity in SBE victims to develop better treatment strategies. This study aimed to address this issue by examining the bacterial profiles of SBE victims with a specific focus on Russell's viper envenomation. The most frequently found bacteria in the bites of SBE victims were Staphylococcus aureus, Klebsiella sp., Escherichia coli, and Pseudomonas aeruginosa. Linezolid, clindamycin, colistin, meropenem, and amikacin were some of the most effective antibiotics for commonly grown bacteria in SBE victims. Similarly, ciprofloxacin, ampicillin, amoxiclave, cefixime, and tetracyclin were the least effective antibiotics for common bacteria found in the wound swabs of SBE victims. These data provide robust guidance for infection management following SBE and offer useful insights to aid in designing effective treatment protocols for SBE with serious wound infections in rural areas where laboratory facilities may not be readily available.

Epidemiology of secondary infection after snakebites in center-west Brazil

BACKGROUND

Snakebites represent a significant health problem in tropical countries, with an annual incidence of 2.7 million cases worldwide. The incidence of secondary infections after snake bites is also high and is usually caused by bacteria from the oral cavity of snakes. Morganella morganii has been identified as an important cause of infections and has been guiding antibiotic therapy in several regions of Brazil and the world.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a retrospective cross-sectional evaluation of snakebites in hospitalized patients between January 2018 and November 2019 and selected those with secondary infection in their medical records. During the period, 326 cases of snakebites were treated, and 155 (47.5%) of them eventually had secondary infections. However, only seven patients underwent culture of soft tissue fragments, in which three cases were negative culture results, while Aeromonas hydrophila was identified in four cases. Of these, 75% were resistant to ampicillin/sulbactam, 50% had intermediate sensitivity to imipenem, and 25% had intermediate sensitivity to piperacillin/tazobactam. Trimethoprim/sulfamethoxazole (TMP-SMX) was not tested on any strain. Of the 155 cases that progressed to secondary infections, 48.4% (75) were empirically treated with amoxicillin/clavulanate, 41.9% (65) with TMP-SMX, and 32 (22%) of these 144 cases required a change to a second regimen, and 10 of these 32 patients required a third therapeutic regimen.

CONCLUSION

Wild animals act as reservoirs of resistant bacteria because their oral cavity favors biofilm formation, which explains the finding of A. hydrophila with a reduced sensitivity profile in this study. This fact is essential for the appropriate choice of empirical antibiotic therapy.

Characteristics of Snakebite-Related Infection in French Guiana

Wound infection is frequently reported following snakebite (SB). This study is retrospective. It was conducted in the emergency department and the Intensive Care Unit (ICU) of Cayenne General Hospital between 1 January 2016 and 31 July 2021. We included 172 consecutive patients hospitalized for SB envenoming. All patients were monitored for wound infection. Sixty-three patients received antibiotics at admission (36.6%). The main antibiotic used was amoxicillin–clavulanate (92.1%). Wound infection was recorded in 55 cases (32%). It was 19% in grade 1, 35% in grade 2, and 53% in grade 3. It included abscess (69.1%), necrotizing fasciitis (16.4%), and cellulitis (21.8%). The time from SB to wound infection was 6 days (IQR: 3–8). The main isolated microorganisms were A. hydrophila and M. morganii (37.5% and 18.8% of isolated organisms). Surgery was required in 48 patients (28.1%), and a necrosectomy was performed on 16 of them (33.3%). The independent factors associated with snakebite-associated infection were necrosis (p < 0.001, OR 13.15, 95% CI: 4.04–42.84), thrombocytopenia (p = 0.002, OR: 3.37, 95% CI: 1.59–7.16), and rhabdomyolysis (p = 0.046, OR: 2.29, 95% CI: 1.02–5.19). In conclusion, wound infection following SB is frequent, mainly in grade 2 and 3 envenomed patients, especially those with necrosis, thrombocytopenia, and rhabdomyolysis. The main involved bacteria are A. hydrophila and M. morganii.

Case Report: Anaphylactoid Shock Associated with Snakebite Envenoming in Portugal

Although rare in Portugal, snakebite envenoming entails severe morbidity and mortality. We present the case of a 65-year-old woman bitten on her leg in a northern coastal region in Portugal, on a walk during the COVID-19 pandemic lockdown. Despite first looking for help at the nearest pharmacy, she developed anaphylactoid shock and was promptly driven to a tertiary hospital, where antivenom was administered in a timely manner under close monitoring. Prophylactic antibiotics were started and maintained based on elevated inflammatory markers and signs of wound inflammation. She evolved favorably, with rapid weaning of vasopressors and resolution of end-organ dysfunction. This case highlights the importance of prompt recognition and describes crucial steps in envenomation management in a country where snakebite is infrequent, but potentially fatal.

Les envenimations vipérines en Guyane française

L’OMS classe l’envenimation vipérine comme pathologie négligée. Elle représente un problème de santé publique associé à des taux de mortalité et de morbidité importants. Notre objectif est de faire une mise au point sur les données récentes de la littérature sur l’épidémiologie et la prise en charge de l’envenimation vipérine en Guyane française. La Guyane est un département français presque entièrement recouvert par une forêt tropicale. Elle abrite une herpétofaune très riche comportant notamment les espèces du genre Bothrops (famille des Viperidae) qui provoquent le plus grand nombre de morsures et d’envenimations. La gestion des envenimations vipérines représente un défi de santé publique. En effet, la plupart des envenimations se produisent dans des zones rurales éloignées où l’accès aux soins est le plus compliqué, avec la présence d’un personnel médical peu formé à la prise en charge et l’indisponibilité de l’antivenin, ce qui constitue une véritable perte de chance pour les patients. En conclusion, dans un contexte d’efforts mondiaux visant à réduire l’impact des envenimations vipérines, la coopération internationale et l’engagement des autorités locales de santé et de la société civile sont nécessaires. En Guyane, la mise en place d’une véritable filière de soins et la mise à disposition de l’antivenin dans les structures sanitaires les plus isolées constitueraient un réel progrès sanitaire.

Critical care medicine in the French Territories in the Americas: Current situation and prospects

Hospitals in the French Territories in the Americas (FTA) work according to international and French standards. This paper aims to describe different aspects of critical care in the FTA. For this, we reviewed official information about population size and intensive care unit (ICU) bed capacity in the FTA and literature on FTA ICU specificities. Persons living in or visiting the FTA are exposed to specific risks, mainly severe road traffic injuries, envenoming, stab or ballistic wounds, and emergent tropical infectious diseases. These diseases may require specific knowledge and critical care management. However, there are not enough ICU beds in the FTA. Indeed, there are 7.2 ICU beds/100 000 population in Guadeloupe, 7.2 in Martinique, and 4.5 in French Guiana. In addition, seriously ill patients in remote areas regularly have to be transferred, most often by helicopter, resulting in a delay in admission to intensive care. The COVID-19 crisis has shown that the health care system in the FTA is unready to face such an epidemic and that intensive care bed capacity must be increased. In conclusion, the critical care sector in the FTA requires upgrading of infrastructure, human resources, and equipment as well as enhancement of multidisciplinary care. Also needed are promotion of training, research, and regional and international medical and scientific cooperation.

An investigation of conventional microbial culture for the Naja atra bite wound, and the comparison between culture-based 16S Sanger sequencing and 16S metagenomics of the snake oropharyngeal bacterial microbiota

Naja atra is a major venomous snake found in Taiwan. The bite of this snake causes extensive wound necrosis or necrotizing soft tissue infection. Conventional microbial culture-based techniques may fail to identify potential human pathogens and render antibiotics ineffective in the management of wound infection. Therefore, we evaluated 16S Sanger sequencing and next-generation sequencing (NGS) to identify bacterial species in the oropharynx of N. atra. Using conventional microbial culture methods and the VITEK 2 system, we isolated nine species from snakebite wounds. On the basis of the 16S Sanger sequencing of bacterial clones from agar plates, we identified 18 bacterial species in the oropharynx of N. atra, including Morganella morganii, Proteus vulgaris, and Proteus mirabilis, which were also present in the infected bite wound. Using NGS of 16S metagenomics, we uncovered more than 286 bacterial species in the oropharynx of N. atra. In addition, the bacterial species identified using 16S Sanger sequencing accounted for only 2% of those identified through NGS of 16S metagenomics. The bacterial microbiota of the oropharynx of N. atra were modeled better using NGS of 16S metagenomics compared to microbial culture-based techniques. Stenotrophomonas maltophilia, Acinetobacter baumannii, and Proteus penneri were also identified in the NGS of 16S metagenomics. Understanding the bacterial microbiota that are native to the oropharynx of N. atra, in addition to the bite wound, may have additional therapeutic implications regarding empiric antibiotic selection for managing N. atra bites.

Naja atra bites induce extensive wound necrotizing soft tissue infections in a substantial proportion of patients. Empiric antibiotic administration in snakebite patients is a common practice, but clinical reports indicate that this treatment was ineffective in preventing secondary infection given that the microbiota of the infected wound and oropharynx of the culprit snake were not properly established. In this study, only 9 species were detected in cobra bites using a conventional microbial culture method and the VITEK 2 system, whereas 18 species were detected in the cobra oropharynx using microbial culture-based 16S Sanger sequencing. Among these, Morganella morganii, Proteus vulgaris, and Proteus mirabilis were identified as common bacteria. Compared to microbial culture-based 16S Sanger sequencing, NGS-based 16S metagenomic sequencing detected more than 286 bacterial species. Stenotrophomonas maltophilia, Acinetobacter baumannii, and Proteus penneri only appeared with 16S metagenomic sequencing. These results suggest that NGS-based 16S metagenomic sequencing is a better tool for uncovering the bacterial microbiota of the N. atra oropharynx, which may help in developing a proper therapeutic strategy for patients with N. atra bites.

Wound Infections from Taiwan Cobra (Naja atra) Bites: Determining Bacteriology, Antibiotic Susceptibility, and the Use of Antibiotics-A Cobra BITE Study

Wound necrosis and secondary infection are common complications after Naja atra bites. Clinical tools to evaluate the infection risk after Taiwan cobra bites are lacking. In this Cobra BITE study, we investigated the prevalence of wound infection, bacteriology, and corresponding antibiotic usage in patients presenting with Taiwan cobra snakebites. Patients with wound infection lacking tissue necrosis were included in developing Cobra BITE score utilizing univariate and multiple logistic regression, as patients with wound necrosis require antibiotics for infection treatment. 8,295,497 emergency department visits occurred in the span of this study, with 195 of those patients being diagnosed as having cobra bites. Of these patients, 23 had wound necrosis, and 30 had wound infection, resulting in a wound infection rate of 27.2% (53/195). Enterococcus faecalis and Morganella morganii were the main bacteria identified in the culture report regardless of whether patients’ wounds had necrosis. As per our Cobra BITE score, the three factors predicting secondary wound infection after cobra bites are hospital admission, a white blood cell count (in 103/µL) × by neu-trophil-lymphocyte ratio value of ≥114.23, and the use of antivenin medication. The area under the receiver operating characteristic curve for the Cobra BITE score system was 0.88; ideal sensitivity and specificity were 0.89 and 0.76. This scoring system enables the assessment of wound infections after N. atra bites, and it could be modified and improved in the future for other Naja spp. bites.

Clinical Features and Management of Snakebite Envenoming in French Guiana

The management of snakebite (SB) envenoming in French Guiana (FG) is based on symptomatic measures and antivenom (AV) administration (Antivipmyn Tri®; Instituto Bioclon-Mexico). Our study aimed to assess clinical manifestations, the efficacy, and safety of Antivipmyn Tri® in the management of SB. Our study is a prospective observational work. It was conducted in the Intensive Care Unit (ICU) of Cayenne General Hospital between 1 January 2016 and 31 December 2019. We included all patients hospitalized for SB envenoming. Our study contained three groups (without AV, three vials, and six vials Antivipmyn Tri®). During the study period, 133 patients were included. The main clinical symptoms were edema (98.5%), pain (97.7%), systemic hemorrhage (18%), blister (14.3%), and local hemorrhage (14.3%). AV was prescribed for 83 patients (62.3%), and 17 of them (20%) developed early adverse reactions. Biological parameters at admission showed defibrinogenation in 124 cases (93.2%), International Normalized Ratio (INR) > 2 in 104 cases (78.2%), and partial thromboplastin time (PTT) > 1.5 in 74 cases (55.6%). The time from SB to AV was 9:00 (5:22-20:40). The median time from SB to achieve a normal dosage of fibrinogen was 47:00 vs. 25:30, that of Factor II was 24:55 vs. 15:10, that of Factor V was 31:42 vs. 19:42, and that of Factor VIII was 21:30 vs. 10:20 in patients without and with AV, respectively, (p < 0.001 for all factors). Patients receiving Antivipmyn Tri® showed a reduction in the time to return to normal clotting tests, as compared to those who did not. We suggest assessing other antivenoms available in the region to compare their efficacy and safety with Antivipmyn Tri® in FG.

Wound Infections of Snakebites from the Venomous Protobothrops mucrosquamatus and Viridovipera stejnegeri in Taiwan: Bacteriology, Antibiotic Susceptibility, and Predicting the Need for Antibiotics-A BITE Study

Snakebites from Taiwan habus (Protobothrops mucrosquamatus) and green bamboo vipers (Viridovipera stejnegeri) account for two-thirds of all venomous snakebites in Taiwan. While there has been ongoing optimization of antivenin therapy, the proper management of superimposed bacterial wound infections is not well studied. In this Bacteriology of Infections in Taiwanese snake Envenomation (BITE) study, we investigated the prevalence of wound infection, bacteriology, and corresponding antibiotic usage in patients presenting with snakebites from these two snakes. We further developed a BITE score to evaluate the probability of wound infections and guide antibiotic usage in this patient population. All snakebite victims who presented to the emergency departments of seven training and research hospitals and received at least one vial of freeze-dried hemorrhagic antivenin between January 2001 and January 2017 were identified. Patient biodata, laboratory investigation results, and treatment modalities were retrieved. We developed our BITE score via univariate and multiple logistic regression analyses. The receiver operating characteristic (ROC) curve was plotted to evaluate the predictive performance of the BITE score. Out of 8,295,497 emergency department visits, 726 patients presented with snakebites from a Taiwan habu or a green bamboo viper. The wound infection rate was 22.45%, with seven positive wound cultures, including six polymicrobial infections. Morganella morganii, Enterococcus spp., Bacteroides fragilis, and Aeromonas hydrophila were most frequently cultured. There were no positive blood cultures. A total of 33.0% (n = 106) of snakebite patients who received prophylactic antibiotics nevertheless developed wound infections, while 44.8% (n = 73) of wound infection patients were satisfactorily treated with one of the following antibiotics: amoxicillin/clavulanic acid, oxacillin, cefazolin, and ampicillin/sulbactam. With the addition of gentamicin, the success of antibiotic therapy increased by up to 66.54%. The prognostic factors for the secondary bacterial infection of snakebites were white blood cell counts, the neutrophil lymphocyte ratio, and the need for hospital admission. The area under the ROC curve for the BITE score was 0.839. At the optimal cut-off point of 5, the BITE score had a 79.58% accuracy, 82.31% sensitivity, and 79.71% specificity when predicting infection in snakebite patients. Our BITE score may help with antibiotic stewardship by guiding appropriate antibiotic use in patients presenting with snakebites. It may also be employed in further studies into antibiotic prophylaxis in snakebite patients for the prevention of superimposed bacterial wound infections.

Antibiotic therapy for snakebite envenoming

There are numerous conflicting recommendations available on the use of antibiotics following snakebite. The present letter to the editor presents some recommendations based on recent studies, and aims to stimulate debate on this topic.