Animal Bites and Stings Reported by United States Poison Control Centers, 2001–2005

Unintentional Pediatric Poisoning Exposures in an Emergency Department: A Comparison of Poison Control Center Referrals and Caregiver Self-Referred Visits

OBJECTIVES

The purpose of this study is to describe the demographics and clinical characteristics of patients referred to a pediatric emergency department (ED) for unintentional poisoning exposures by a poison control center (PCC) compared with patients/caregivers who self-refer.

METHODS

The electronic data warehouse at a pediatric hospital was queried from October 1, 2014, to September 30, 2015, for unintentional poisoning-related ED visits and subsequent inpatient admissions. Eligible patients aged 18 years and younger were identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes for pharmaceuticals, non-pharmaceuticalchemicals, fumes/vapors, foreign bodies, adverse food reactions, food poisoning, and bites/stings. Referral classification (PCC referral vs self-refer) was determined by PCC and hospital medical records.Descriptive statistics were used to characterize the patient demographics and ED visits by referral classification and age group. Simple and multiple logistic regression models examined the individual and combined impact of demographic and clinical characteristics on self-referral.

RESULTS

Of the 705 patients identified, 84.4% presented as caregiver/self-referred compared with PCC-referred. As compared with those who self-referred, a higher percentage of patients who contacted the PCC before ED presentation were white (93.9% [89.4-98.2%] vs 83.8% [80.7-86.7%]) and had commercial insurance (62.7% [51.5-69.5%] vs 53.0% [48.9-57.0%]). Pharmaceutical (71.9%) and chemical (14.0%) exposures were the most common exposure types for PCC-referred patients whereas foreign bodies (54.3%) were the most common for self-referred patients. The largest predictors of self-referral were age, insurance, and exposure type.

CONCLUSIONS

Among patients presenting at 1 pediatric ED, disparities with PCC utilization exist among age groups, racial identification, and poison exposure type. Educational outreach interventions are needed to ensure optimal use of the PCC services by patients, caregivers, and health care professionals.

Supervised Learning Computer Vision Benchmark for Snake Species Identification From Photographs: Implications for Herpetology and Global Health

We trained a computer vision algorithm to identify 45 species of snakes from photos and compared its performance to that of humans. Both human and algorithm performance is substantially better than randomly guessing (null probability of guessing correctly given 45 classes = 2.2%). Some species (e.g., Boa constrictor) are routinely identified with ease by both algorithm and humans, whereas other groups of species (e.g., uniform green snakes, blotched brown snakes) are routinely confused. A species complex with largely molecular species delimitation (North American ratsnakes) was the most challenging for computer vision. Humans had an edge at identifying images of poor quality or with visual artifacts. With future improvement, computer vision could play a larger role in snakebite epidemiology, particularly when combined with information about geographic location and input from human experts.

Tourniquet Use in Animal Attacks: An Analysis of News Media Reports

Background

Animal attacks pose a significant public health problem in the United States. Non-venomous animals are the leading cause of mortality in these attacks, and extremity injuries leading to hemorrhage are a common pattern. The Stop the Bleed campaign advocates for public training in bleeding control tactics and public access to bleeding control kits. Controlling life-threatening bleeding, as promoted by the Stop the Bleed campaign, may be a method to reduce preventable death in these attacks.

Methodology

We searched the Nexus Uni database, which compiles international news media articles, to collect newspaper articles in the United States between 2010 and 2019 that referenced animal attacks on humans in which a tourniquet was applied. We screened articles to assess for inclusion criteria and isolated a single report for each attack.

Results

A total of 50 individual attacks met the inclusion criteria and were included for data collection. Overall, 92% (n = 46) of the victims survived the attacks, and the average victim age was 33. California was the most common location of the attacks (n = 12, 24%), sharks caused the most attacks (n = 26, 52%), and victims most often sustained isolated extremity injuries (n = 24, 48% for arm and n = 24, 48% for leg). Laypeople applied the most tourniquets (n = 29, 58%), and appliers most frequently used improvised tourniquets (n = 30, 60%).

Conclusions

While mortality in this series was low, there are hundreds of fatalities from non-venomous animal attacks each year. Equipping and training the at-risk public to stop bleeding may save additional lives. Future Stop the Bleed efforts should improve access to public hemorrhage control equipment and expand educational outreach to people engaged in high-risk activities with animals.

A Clot Twist: Extreme Variation in Coagulotoxicity Mechanisms in Mexican Neotropical Rattlesnake Venoms

Rattlesnakes are a diverse clade of pit vipers (snake family Viperidae, subfamily Crotalinae) that consists of numerous medically significant species. We used validated in vitro assays measuring venom-induced clotting time and strength of any clots formed in human plasma and fibrinogen to assess the coagulotoxic activity of the four medically relevant Mexican rattlesnake species Crotalus culminatus, C. mictlantecuhtli, C. molossus, and C. tzabcan. We report the first evidence of true procoagulant activity by Neotropical rattlesnake venom in Crotalus culminatus. This species presented a strong ontogenetic coagulotoxicity dichotomy: neonates were strongly procoagulant via Factor X activation, whereas adults were pseudo-procoagulant in that they converted fibrinogen into weak, unstable fibrin clots that rapidly broke down, thereby likely contributing to net anticoagulation through fibrinogen depletion. The other species did not activate clotting factors or display an ontogenetic dichotomy, but depleted fibrinogen levels by cleaving fibrinogen either in a destructive (non-clotting) manner or via a pseudo-procoagulant mechanism. We also assessed the neutralization of these venoms by available antivenom and enzyme-inhibitors to provide knowledge for the design of evidence-based treatment strategies for envenomated patients. One of the most frequently used Mexican antivenoms (Bioclon Antivipmyn®) failed to neutralize the potent procoagulant toxic action of neonate C. culminatus venom, highlighting limitations in snakebite treatment for this species. However, the metalloprotease inhibitor Prinomastat substantially thwarted the procoagulant venom activity, while 2,3-dimercapto-1-propanesulfonic acid (DMPS) was much less effective. These results confirm that venom-induced Factor X activation (a procoagulant action) is driven by metalloproteases, while also suggesting Prinomastat as a more promising potential adjunct treatment than DMPS for this species (with the caveat that in vivo studies are necessary to confirm this potential clinical use). Conversely, the serine protease inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF) inhibited the direct fibrinogen cleaving actions of C. mictlantecuhtli venom, thereby revealing that the pseudo-procoagulant action is driven by kallikrein-type serine proteases. Thus, this differential ontogenetic variation in coagulotoxicity patterns poses intriguing questions. Our results underscore the need for further research into Mexican rattlesnake venom activity, and also highlights potential limitations of current antivenom treatments.

Incidence and mortality due to snakebite in the Americas

BACKGROUND

Better knowledge of the epidemiological characteristics of snakebites could help to take measures to improve their management. The incidence and mortality of snakebites in the Americas are most often estimated from medical and scientific literature, which generally lack precision and representativeness.

METHODOLOGY/PRINCIPAL FINDINGS

Authors used the notifications of snakebites treated in health centers collected by the Ministries of Health of the American countries to estimate their incidence and mortality. Data were obtained from official reports available on-line at government sites, including those of the Ministry of Health in each country and was sustained by recent literature obtained from PubMed. The average annual incidence is about 57,500 snake bites (6.2 per 100,000 population) and mortality is close to 370 deaths (0.04 per 100,000 population), that is, between one third and half of the previous estimates. The incidence of snakebites is influenced by the abundance of snakes, which is related to (i) climate and altitude, (ii) specific preferences of the snake for environments suitable for their development, and (iii) human population density. Recent literature allowed to notice that the severity of the bites depends mainly on (i) the snake responsible for the bite (species and size) and (ii) accessibility of health care, including availability of antivenoms.

CONCLUSIONS/SIGNIFICANCES

The main limitation of this study could be the reliability and accuracy of the notifications by national health services. However, the data seemed consistent considering the similarity of the incidences on each side of national boundaries while the sources are distinct. However, snakebite incidence could be underestimated due to the use of traditional medicine by the patients who escaped the reporting of cases. However, gathered data corresponded to the actual use of the health facilities, and therefore to the actual demand for antivenoms, which should make it possible to improve their management.

National estimates of noncanine bite and sting injuries treated in US Hospital Emergency Departments, 2001-2010

OBJECTIVE

Injuries resulting from contact with animals and insects are a significant public health concern. This study quantifies nonfatal bite and sting injuries by noncanine sources using data from the National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP).

METHODS

The NEISS-AIP is an ongoing nationally representative surveillance system used to monitor all types and causes of injuries treated in US hospital emergency departments (EDs). Cases were coded by trained hospital coders using information from medical records on animal and insect sources of bite and sting injuries being treated. Data were weighted to produce national annualized estimates, percentages, and rates based on the US population.

RESULTS

From 2001 to 2010 an estimated 10.1 million people visited EDs for noncanine bite and sting injuries, based on an unweighted case count of 169,010. This translates to a rate of 340.1 per 100,000 people (95% CI, 232.9-447.3). Insects accounted for 67.5% (95% CI, 45.8-89.2) of bite and sting injuries, followed by arachnids 20.8% (95% CI, 13.8-27.9). The estimated number of ED visits for bedbug bite injuries increased more than 7-fold-from 2156 visits in 2007 to 15,945 visits in 2010.

CONCLUSIONS

This study provides an update of national estimates of noncanine bite and sting injuries and describes the diversity of animal exposures based on a national sample of EDs. Treatment of nonfatal bite and sting injuries are costly to society. Direct medical and work time lost translates to an estimated $7.5 billion annually.

Epidemiological study of insect bite reactions from central India

INTRODUCTION

The physical effects of the arthropod bites on human skin receive less attention, especially in the rural areas where the per capita income is less. Ours is a rural-based hospital, the vicinity having more of plants, trees, and forests; we undertook the study to find out the relation of insect bite dermatitis in a rural area.

MATERIALS AND METHODS

The study was carried out in the Dermatology outpatient department of our institute on 100 subjects of insect bite dermatitis who were questioned retrospectively about the sequence of events besides their environmental and living conditions. They were examined thoroughly and the relevant clinical findings were noted, also taking into account the prior treatment taken by them, if any.

RESULTS AND CONCLUSIONS

It was found that insect bite dermatitis has no age or gender preponderance, and the protective factors for the same are use of full sleeve clothes and keeping the doors and windows closed at night. On the contrary, the risk factors are residence in areas of heavy insect infestation, use of perfumes and colognes, warm weather in spring and summer and the lack of protective measures. However, there was no direct association of atopy with increased risk of developing insect bite dermatitis.

Myroides odoratimimus soft tissue infection in an immunocompetent child following a pig bite: case report and literature review

Members of the genus Myroides are aerobic Gram-negative bacteria that are common in environmental sources, but are not components of the normal human microflora. Myroides organisms behave as low-grade opportunistic pathogens, causing infections in severely immunocompromised patients and rarely, in immunocompetent hosts. A case of Myroides odoratimimus cellulitis following a pig bite in an immunocompetent child is presented, and the medical literature on Myroides spp. soft tissue infections is reviewed.

Neurological effects of venomous bites and stings: snakes, spiders, and scorpions

Snake and spider bites, as well as scorpion sting envenoming, are neglected diseases affecting millions of people all over the world. Neurological complications vary according to the offending animal, and are often directly related to toxic effects of the venom, affecting the central nervous system, the neuromuscular transmission, the cardiovascular system, or the coagulation cascade. Snake bite envenoming may result in stroke or muscle paralysis. Metalloproteinases and other substances (common in vipers and colubrids) have anticoagulant or procoagulant activity, and may induce ischemic or hemorrhagic strokes. The venom of elapids is rich in neurotoxins affecting the neuromuscular transmission at either presynaptic or postsynaptic levels. The clinical picture of scorpion sting envenoming is dominated by muscle weakness associated with arterial hypertension, cardiac arrythmias, myocarditis, or pulmonary edema. These manifestations occur as the result of release of catecholamines into the bloodstream or due to direct cardiac toxicity of the venom. Cerebrovascular complications have been reported after the sting of the Indian red scorpion. Intracranial hemorrhages occur in the setting of acute increases in arterial blood pressure related to sympathetic overstimulation, and cerebral infarctions are related to either cerebral hypoperfusion, consumption coagulopathy, vasculitis, or cardiogenic brain embolism. Three main syndromes result from spider bite envenoming: latrodectism, loxoscelism, and funnel-web spider envenoming. Latrodectism is related to neurotoxins present in the venom of widow spiders. Most cases present with headache, lethargy, irritability, myalgia, tremor, fasciculation, or ataxia. Loxoscelism is caused by envenoming by spiders of the family Sicariidae. It may present with a stroke due to a severe coagulopathy. The venom of funnel-web spiders also has neurotoxins that stimulate neurotransmitter release, resulting in sensory disturbances and muscle paralysis. Proper management of the envenomed patient, including prompt transport to the hospital, correction of the hemostatic disorder, ventilatory support, and administration of antivenom, significantly reduce the risk of neurological complications which, in turn, reduce the mortality and improve the functional outcome of survivors.

An Evaluation of Snake Bites and Antivenin Use at a Regional Medical Center

Snake bites are a rare but challenging problem for surgeons. The purpose of our study was to evaluate our experience with snake bites at a regional medical center. We reviewed patients treated for snake bites from 2004 to July 2008. Demographics, clinical information, and outcomes were documented. Descriptive statistics were used, and χ2, t test, and Fisher exact test were used to compare patients based on antivenin use. A P value < 0.05 was considered significant. Over the study period, 126 patients presented to the emergency department with 44 (35%) requiring hospital admission. The average age was 38 years (range, 2 to 76 years); 66 per cent were male and 95 per cent white. Bites most commonly occurred in the summer and fall months with none from December through March. Copperhead bites accounted for 50 per cent of bites. An average of 4.8 vials of antivenin was given to 61 per cent of admitted patients with 93 per cent receiving the drug within 6 hours. Minor reactions to antivenin occurred in three patients (11%). Two patients required surgery (5%), and the readmission rate was 7 per cent. There was no known morbidity or mortality. When comparing patients who received antivenin with patients who did not, the only significant clinical variables were an increased prothrombin time (12.1 vs 11.7, respectively; P = 0.048) and a longer length of hospital stay (3 vs 1.8 days, P = 0.0006) in patients receiving antivenin. The majority of patients with snake bites can be treated with supportive care and antivenin when indicated. Antivenin use at our institution is largely based on physical findings and not related to laboratory values.

Venom variation in hemostasis of the southern Pacific rattlesnake (Crotalus oreganus helleri): isolation of hellerase

Envenomations by the southern Pacific rattlesnake (Crotalus oreganus helleri) are the most common snakebite accidents in southern California. Intraspecies venom variation may lead to unresponsiveness to antivenom therapy. Even in a known species, venom toxins are recognized as diverse in conformity with interpopulational, seasonal, ontogenetic and individual factors. Five venoms of individual C. oreganus helleri located in Riverside and San Bernardino counties of southern California were studied for their variation in their hemostatic activity. The results demonstrated that Riverside 2 and San Bernardino 1 venoms presented the highest lethal activity without hemorrhagic activity. In contrast, San Bernardino 2 and 3 venoms had the highest hemorrhagic and fibrinolytic activities with low lethal and coagulant activities. Riverside 1, Riverside 2 and San Bernardino 1 venoms presented a significant thrombin-like activity. San Bernardino 2 and 3 venoms presented an insignificant thrombin-like activity. In relation to the fibrinolytic activity, San Bernardino 3 venom was the most active on fibrin plates, which was in turn neutralized by metal chelating inhibitors. These results demonstrate the differences amongst C. oreganus helleri venoms from close localities. A metalloproteinase, hellerase, was purified by anionic and cationic exchange chromatographies from San Bernardino 3 venom. Hellerase exhibited the ability to break fibrin clots in vitro, which can be of biomedically importance in the treatment of heart attacks and strokes.

Deaths from reptile bites in the United States, 1979-2004

INTRODUCTION

Bites from reptiles cause thousands of injuries but fortunately few deaths in the U.S. each year. This article reviews deaths from reptile bites over the last 25 years.

METHODS

Mortality data was obtained using CDC WONDER to evaluate deaths that occurred from 1979 to 2004 due to reptile bites. Information on race, gender, ages, and state where death occurred is reported.

RESULTS

There were 134 deaths reported over this 25-year time period. Whites were 93.3% of the victims, and males were 79.1% of the victims. The age group reporting the most deaths was the 25 to 34 year old category. There were 17 (12.7%) victims less than 15 years of age, and 25 (18.7%) victims older than 65 years of age. Seventy-five of the fatalities (55.9%) occurred in five states.

CONCLUSIONS

An average of five deaths occurs from reptile bites each year in the U.S. White males living in the Southern part of the United States are more likely to be the victim of a fatal reptile envenomation.