The Disease Ecology, Epidemiology, Clinical Manifestations, Management, Prevention, and Control of Increasing Human Infections with Animal Orthopoxviruses.

Zoonotic orthopoxvirus outbreaks have occurred repeatedly worldwide, including monkeypox in Africa and the United States, cowpox in Europe, camelpox in the Middle East and India, buffalopox in India, vaccinia in South America, and novel emerging orthopoxvirus infections in the United States, Europe, Asia, and South America. Waning smallpox immunity may increase the potential for animal-to-human transmission followed by further community transmission person-to-person (as demonstrated by monkeypox and buffalopox outbreaks) and by contact with fomites (as demonstrated by camelpox, cowpox, and, possibly, Alaskapox). The objectives of this review are to describe the disease ecology, epidemiology, clinical manifestations, prevention, and control of human infections with animal orthopoxviruses and to discuss the association with diminished population herd immunity formerly induced by vaccinia vaccination against smallpox. Internet search engines were queried with key words, and case reports, case series, seroprevalence studies, and epidemiologic investigations were found for review.

Nephrotoxic Mushroom Poisoning: Global Epidemiology, Clinical Manifestations, and Management.

Because mushroom poisonings are increasing worldwide after ingestions of known, newly described, and formerly considered edible species, the objectives of this review are to describe the global epidemiology of nephrotoxic mushroom poisonings, to identify nephrotoxic mushrooms, to present a toxidromic approach to earlier diagnoses of nephrotoxic mushroom poisonings based on the onset of acute renal failure, and to compare the outcomes of renal replacement management strategies. Internet search engines were queried with the keywords to identify scientific articles on nephrotoxic mushroom poisonings and their management during the period of 1957 to the present. Although hepatotoxic, amatoxin-containing mushrooms cause most mushroom poisonings and fatalities, nephrotoxic mushrooms, most commonly Cortinarius species, can cause acute renal insufficiency and failure. Several new species of nephrotoxic mushrooms have been identified, including Amanita proxima and Tricholoma equestre in Europe and Amanita smithiana in the United States and Canada. In addition, the edible, hallucinogenic mushroom Psilocybe cubensis has been noted recently via mass spectrometry as a rare cause of acute renal insufficiency. Renal replacement therapies including hemodialysis are often indicated in the management of nephrotoxic mushroom poisonings, with renal transplantation reserved for extracorporeal treatment failures.

Regional Rodent-Borne Infectious Diseases in North America: What Wilderness Medicine Providers Need to Know.

Rodents can transmit infectious diseases directly to humans and other animals via bites and exposure to infectious salivary aerosols and excreta. Arthropods infected while blood-feeding on rodents can also transmit rodent-borne pathogens indirectly to humans and animals. Environmental events, such as wet winters, cooler summers, heavy rains, and flooding, have precipitated regional rodent-borne infectious disease outbreaks; these outbreaks are now increasing with climate change. The objectives of this review are to inform wilderness medicine providers about the environmental conditions that can precipitate rodent-borne infectious disease outbreaks; to describe the regional geographic distributions of rodent-borne infectious diseases in North America; and to recommend prophylactic treatments and effective prevention and control strategies for rodent-borne infectious diseases. To meet these objectives, Internet search engines were queried with keywords to identify scientific articles on outbreaks of the most common regional rodent-borne infectious diseases in North America. Wilderness medicine providers should maintain high levels of suspicion for regional rodent-borne diseases in patients who develop febrile illnesses after exposure to contaminated freshwater after heavy rains or floods and after swimming, rafting, or paddling in endemic areas. Public health education strategies should encourage limiting human contact with rodents; avoiding contact with or safely disposing of rodent excreta; avoiding contact with contaminated floodwaters, especially contact with open wounds; securely containing outdoor food stores; and modifying wilderness cabins and campsites to deter rodent colonization.

The Environmental Health Impact of Hurricane Katrina on New Orleans.

Hurricane Katrina caused unprecedented flood damage to New Orleans, Louisiana, and has been the costliest hurricane in US history. We analyzed the environmental and public health outcomes of Hurricane Katrina by using Internet searches to identify epidemiological, sociodemographic, and toxicological measurements provided by regulatory agencies.Atmospheric scientists have now warned that global warming will increase the proportion of stronger hurricanes (categories 4-5) by 25% to 30% compared with weaker hurricanes (categories 1-2).With the new $14.6 billion Hurricane Storm Damage Risk Reduction System providing a 100-year storm surge-defensive wall across the Southeast Louisiana coast, New Orleans will be ready for stronger storms in the future.

Effects of Tourniquets in the Development of Pain States: a Novel Clinical Pilot Study and Review of Utilization of Tissue Oximetry to Measure Neural Ischemia.

PURPOSE OF REVIEW: Approximately 20% of patients undergoing surgery develop persistent lower extremity pain following total knee arthroplasty. Animal studies have confirmed that prolonged tourniquet time increases the risk of endoneural ischemia and can mediate or modulate the development of chronic pain. The use of Near InfraRed Spectroscopy (NIRS) adjacent to nerve tissue, previously described as ONG has been shown to detect early neural compromise and has demonstrated clinical utility in carpal tunnel diagnosis. RECENT FINDINGS: In this pilot study, we recruited 10 healthy adult volunteers to undergo oxyneurography (ONG) and sensory nerve conduction testing (sNCT). We performed testing on the upper and lower extremities in each individual. The tourniquet was applied followed by measurements of sNCT and ONG as described. We observed a significant drop in the mean ONG index at 3 and 5 min following tourniquet inflation in upper and lower extremities. Similar to raw ONG values, there was significant variability in sNCT measurements, which in general increased from baseline with tourniquet inflation. In the upper extremity, there was a significant increase in sNCT with tourniquet inflation, while in the lower extremity, there was a trend towards significance. The use of ONG can be supported as a diagnostic tool to detect nerve ischemia and to potentially reduce the incidence of tourniquet-mediated or -modulated neural ischemia and reduce the development of chronic post-tourniquet pain.

Red Meat Allergies after Lone Star Tick (Amblyomma americanum) Bites.

Red meat allergies have followed tick bites on every continent except Antarctica. The sensitizing antigen is galactose-α-1,3-galactose (α-gal), an oligosaccharide constituent of nonprimate blood and meat, acquired by ticks during animal bloodfeeding. Because red meat allergy after tick bites is a worldwide phenomenon, the objectives of this review were to describe the global epidemiology of red meat allergy after tick bites and its immunological mechanisms; to identify the human risk factors for red meat allergy after tick bites; to identify the most common tick vectors of red meat allergy worldwide; to describe the clinical manifestations, diagnostic confirmation, and management of patients with red meat allergy after tick bites; and to recommend strategies for the prevention of tick bites. To meet these objectives, Internet search engines were queried with keywords to select scientific articles for review. The keywords included ticks, tick bites, allergy, anaphylaxis, and meat allergy. The study period was defined as 1980-2019. The major risk factors for red meat allergy after tick bites included male sex, non-B blood type, systemic mastocytosis, a bioprosthetic (bovine or porcine) heart valve, and preexisting allergies to gelatin or animal dander. Following confirmation by challenge testing, patients with red meat allergies should avoid red meats, foods containing gelatin, and intravenous immunotherapy with monoclonal antibodies such as cetuximab and infliximab produced in SP2/0 mouse cell lines. Red meat allergy after tick bites represents an emerging threat from tick bites in addition to infectious diseases.

The Disease Ecology, Epidemiology, Clinical Manifestations, and Management of Emerging Cryptococcus gattii Complex Infections.

Cryptococcus neoformans, a soil-dwelling fungus found worldwide, can cause cryptococcosis, an opportunistic fungal infection of the lungs and central nervous system. One former member of the C neoformans complex, Cryptococcus gattii, has caused meningitis in immunosuppressed and immunocompetent persons in endemic regions in Africa and Asia. Between 1999 and 2004, C gattii caused outbreaks of human cryptococcosis in unexpected, nonendemic, nontropical regions on Vancouver Island, Canada, and throughout the US Pacific Northwest and California. C gattii was recognized as an emerging species with several genotypes and a unique environmental relationship with trees that are often encountered in the wilderness and in landscaped parks. Because C gattii infections have a high case-fatality rate, wilderness medicine clinicians should be aware of this emerging pathogen, its disease ecology and risk factors, its expanding geographic distribution in North America, and its ability to cause fatal disease in both immunosuppressed and immunocompetent persons.

Emerging Tickborne Viral Infections: What Wilderness Medicine Providers Need to Know.

Ticks are versatile vectors of infectious diseases and transmit a broad range of pathogens, including bacteria, viruses, and parasites. Ticks harbor pathogens without infection and share pathogens with other ticks while feeding together on a host. The primary objective of this review is to identify tickborne viral pathogens in the United States, focusing on emerging pathogens. Additional objectives include describing the epidemiology of tick-transmitted viruses, identifying the most common tick vectors of viral pathogens in the United States, identifying the most common tick-transmitted viruses worldwide, and recommending effective strategies for the prevention and treatment of tickborne viral infections. Flaviviruses transmitted by ixodid ticks cause most tickborne viral infections that present clinically as either encephalitis or hemorrhagic fever. Recently, several new tickborne viruses have emerged in the United States, including Bourbon virus, Heartland virus, Powassan virus, and the severe fever with thrombocytopenia syndrome virus transmitted by a tick recently introduced from China, the Asian long-horned tick (Haemaphysalis longicornis). In most cases, there are no specific drug therapies for tickborne viral infections, and treatment is supportive. Vaccination, personal protection, landscape management, and wildlife management are all effective strategies for the primary prevention and control of tickborne viral infectious diseases.

The Disease Ecology, Epidemiology, Clinical Manifestations, and Management of Trichinellosis Linked to Consumption of Wild Animal Meat.

Historically, human trichinellosis was caused by Trichinella spiralis and transmitted to humans by consumption of undercooked domestic pork. Today, most cases of trichinellosis are caused by other Trichinella species and transmitted by consumption of raw or undercooked wild game meats. Given the increasing global prevalence of wild animal meat-linked trichinellosis, the objectives of this review are: 1) to describe the life cycle and global distribution of Trichinella worms; 2) to describe the changing epidemiology of trichinellosis; 3) to describe the clinical phases of trichinellosis; 4) to recommend the latest diagnostic tests; and 5) to recommend treatment and prevention strategies. Internet search engines were queried with keywords as subject headings to meet the objectives of this review. Although trichinellosis surveillance systems and laws regulating commercial pork production have limited T spiralis-caused trichinellosis in Europe and the United States, trichinellosis due to consumption of raw and undercooked wild boar and feral hog meat continues to occur throughout Southeast Asia. Trichinellosis due to consumption of raw or undercooked meats of other infected game, such as bear, deer, moose, and walrus, continues to occur worldwide. Only adherence to hygienic practices when preparing wild game meats and cooking wild game meats to recommended internal temperatures can prevent transmission of trichinellosis to humans. Wilderness medicine clinicians should be prepared to advise hunters and the public on the risks of game meat-linked trichinellosis and on how to diagnose and treat trichinellosis to prevent fatal complications.

Amatoxin-Containing Mushroom Poisonings: Species, Toxidromes, Treatments, and Outcomes.

Amatoxins are produced primarily by 3 species of mushrooms: Amanita, Lepiota, and Galerina. Because amatoxin poisonings are increasing, the objective of this review was to identify all amatoxin-containing mushroom species, present a toxidromic approach to earlier diagnoses, and compare the efficacies and outcomes of therapies. To meet these objectives, Internet search engines were queried with keywords to select peer-reviewed scientific articles on amatoxin-containing mushroom poisoning and management. Descriptive epidemiological analyses have documented that most mushroom poisonings are caused by unknown mushrooms, and most fatal mushroom poisonings are caused by amatoxin-containing mushrooms. Amanita species cause more fatal mushroom poisonings than other amatoxin-containing species, such as Galerina and Lepiota. Amanita phalloides is responsible for most fatalities, followed by Amanita virosa and Amanita verna. The most frequently reported fatal Lepiota ingestions are due to Lepiota brunneoincarnata, and the most frequently reported fatal Galerina species ingestions are due to Galerina marginata. With the exception of liver transplantation, the current treatment strategies for amatoxin poisoning are all supportive and have not been subjected to rigorous efficacy testing in randomized controlled trials. All patients with symptoms of late-appearing gastrointestinal toxicity with or without false recovery or quiescent periods preceding acute liver insufficiency should be referred to centers providing liver transplantation. Patients with amatoxin-induced acute liver insufficiency that does not progress to liver failure will have a more favorable survival profile with supportive care than patients with amatoxin-induced acute liver failure, about half of whom will require liver transplantation.

Environmental and Wilderness-Related Risk Factors for Histoplasmosis: More Than Bats in Caves.

INTRODUCTION: Histoplasma capsulatum is a dimorphic fungus that causes histoplasmosis, a sporadic endemic mycosis with environmental, occupational, and wilderness exposure-related risk factors. The objectives of this review are to describe these risk factors, to alert clinicians to the different presenting manifestations of histoplasmosis, and to recommend effective management and prevention strategies. METHODS: Internet search engines were queried with keywords to select articles for review over the study period, 1950 to 2018. Articles selected for review included case series, epidemiologic analyses of surveillance data, clinical and laboratory updates, immunologic investigations, and observational and longitudinal studies. Articles excluded from review included systemic mycosis reviews and clinicopathologic conference reports. RESULTS: The principal transmission mechanism of histoplasmosis is by inhalation of spores aerosolized by soil disruption, resulting in pneumonic infections ranging from asymptomatic to disseminated. Although histoplasmosis is more common in endemic regions, nonendemic regions have reported increasing autochthonous and imported cases. Immunocompromised persons are at significantly increased risks of contracting histoplasmosis. Environmental and wilderness-related risk factors for histoplasmosis include bird and bat watching, cave and cave entrance exploration, and bamboo removal and burning. Occupational risk factors for histoplasmosis include road construction, roofing, bridge and water tower work, demolition, and masonry. CONCLUSIONS: Histoplasmosis can result in considerable morbidity. Increased awareness of disease risk factors among the public and the international healthcare community will improve the timely diagnosis and treatment of histoplasmosis and prevent disease progression and dissemination.

Correction for Diaz, Paragonimiasis Acquired in the United States: Native and Nonnative Species.

Volume 26, no. 3, p. 493­504, 2013. Page 497: The snail shown in Fig. 8 is not a slender walker snail (Pomatiopsis lapidaria), as indicated in the legend of the figure, but rather a sharp hornsnail (Pleurocera acuta). The correct image (that of the slender walker snail, Pomatiopsis lapidaria; courtesy of Steve Cringan, photographer) is shown below.

Death by Propofol.

Since its introduction in 1986, propofol ( two, 6-diisopropylphenol) , an intravenous sedative-hypnotic agent, has been utilized for the induction and maintenance of general anesthesia and conscious sedation in over 80 percent of cases; largely replacing thiopental ( sodium pentothal) over a decade ago. Unrestricted as a controlled substance, propofol's abuse potential emerged quickly and was highlighted by the death of pop singer, Michael Jackson, in 2009. In order to assess the epidemiological features of fatal propofol abuse, a descriptive analysis of the scientific literature was conducted using Internet search engines. Well-documented cases of fatal propofol abuse were stratified as unintentional or accidental deaths and as intentional deaths by suicides or homicides. Continuous variables were compared for differences by unpaired, two-tailed t-tests with statistical significance indicated by p-values less than 0.05. Of 21 fatal cases of propofol abuse, 18 (86 percent ) occurred in healthcare workers, mostly anesthesiologists and nurse anesthetists (n=14, 67 percent ). One case occurred in a layman who purchased propofol on the Internet. Seventeen deaths (81 percent ) were accidental; two were suicides (9.5 percent ) and two were homicides (9.5 percent ). Blood levels in intentional death cases were significantly greater than in accidental death cases (p less than 0.0001) all of which reflected initial therapeutic induction-level doses in the ranges of 2.0-2.5 mg/kg. Though lacking in analgesic effects, the abuse of propofol by young healthcare professionals, particularly operating room workers, has been significant; and likely underreported. Propofol is a dangerous drug with an evident abuse potential which often results in fatalities.

Preparing the United States for Zika Virus: Pre-emptive Vector Control and Personal Protection.

Discovered in 1947 in a monkey in the Zika forest of Uganda, Zika virus was dismissed as a cause of a mild illness that was confined to Africa and Southeast Asia and transmitted by Aedes mosquitoes. In 2007, Zika virus appeared outside of its endemic borders in an outbreak on the South Pacific Island of Yap. In 2013, Zika virus was associated with a major neurological complication, Guillain-Barré syndrome, in a larger outbreak in the French Polynesian Islands. From the South Pacific, Zika invaded Brazil in 2015 and caused another severe neurological complication, fetal microcephaly. The mosquito-borne transmission of Zika virus can be propagated by sexual transmission and, possibly, by blood transfusions, close personal contacts, and organ transplants, like other flaviviruses. Since these combined mechanisms of infectious disease transmission could result in catastrophic incidences of severe neurological diseases in adults and children, the public should know what to expect from Zika virus, how to prevent infection, and what the most likely failures in preventive measures will be. With federal research funding stalled, a Zika vaccine is far away. The only national strategies to prepare the United States for Zika virus invasion now are effective vector control measures and personal protection from mosquito bites. In addition to a basic knowledge of Aedes mosquito vectors and their biting behaviors, an understanding of simple household vector control measures, and the selection of the best chemical and physical mosquito repellents will be required to repel the Zika threat.

Chemical and Plant-Based Insect Repellents: Efficacy, Safety, and Toxicity.

Most emerging infectious diseases today are arthropod-borne and cannot be prevented by vaccinations. Because insect repellents offer important topical barriers of personal protection from arthropod-borne infectious diseases, the main objectives of this article were to describe the growing threats to public health from emerging arthropod-borne infectious diseases, to define the differences between insect repellents and insecticides, and to compare the efficacies and toxicities of chemical and plant-derived insect repellents. Internet search engines were queried with key words to identify scientific articles on the efficacy, safety, and toxicity of chemical and plant-derived topical insect repellants and insecticides to meet these objectives. Data sources reviewed included case reports; case series; observational, longitudinal, and surveillance studies; and entomological and toxicological studies. Descriptive analysis of the data sources identified the most effective application of insect repellents as a combination of topical chemical repellents, either N-diethyl-3-methylbenzamide (formerly N, N-diethyl-m-toluamide, or DEET) or picaridin, and permethrin-impregnated or other pyrethroid-impregnated clothing over topically treated skin. The insecticide-treated clothing would provide contact-level insecticidal effects and provide better, longer lasting protection against malaria-transmitting mosquitoes and ticks than topical DEET or picaridin alone. In special cases, where environmental exposures to disease-transmitting ticks, biting midges, sandflies, or blackflies are anticipated, topical insect repellents containing IR3535, picaridin, or oil of lemon eucalyptus (p-menthane-3, 8-diol or PMD) would offer better topical protection than topical DEET alone.

Poisoning by Herbs and Plants: Rapid Toxidromic Classification and Diagnosis.

The American Association of Poison Control Centers has continued to report approximately 50,000 telephone calls or 8% of incoming calls annually related to plant exposures, mostly in children. Although the frequency of plant ingestions in children is related to the presence of popular species in households, adolescents may experiment with hallucinogenic plants; and trekkers and foragers may misidentify poisonous plants as edible. Since plant exposures have continued at a constant rate, the objectives of this review were (1) to review the epidemiology of plant poisonings; and (2) to propose a rapid toxidromic classification system for highly toxic plant ingestions for field use by first responders in comparison to current classification systems. Internet search engines were queried to identify and select peer-reviewed articles on plant poisonings using the key words in order to classify plant poisonings into four specific toxidromes: cardiotoxic, neurotoxic, cytotoxic, and gastrointestinal-hepatotoxic. A simple toxidromic classification system of plant poisonings may permit rapid diagnoses of highly toxic versus less toxic and nontoxic plant ingestions both in households and outdoors; direct earlier management of potentially serious poisonings; and reduce costly inpatient evaluations for inconsequential plant ingestions. The current textbook classification schemes for plant poisonings were complex in comparison to the rapid classification system; and were based on chemical nomenclatures and pharmacological effects, and not on clearly presenting toxidromes. Validation of the rapid toxidromic classification system as compared to existing chemical classification systems for plant poisonings will require future adoption and implementation of the toxidromic system by its intended users.

Tickborne Coinfections in the United States.

Unlike mosquitoes, ticks transmit the broadest range of pathogens, including bacteria, viruses, and parasites. Ticks have capitalized on many competitive advantages offered to them by changes in climate and human lifestyle and a greater abundance of wild animal reservoir hosts no longer effectively controlled. As a result, tick-transmitted coinfections are increasing today with both recognized and newly discovered pathogens that complicate differential diagnosis and antimicrobial treatment. Without the support of immunological and molecular diagnostic techniques, usually only available at federal and some state laboratories, the initial differential diagnosis of tickborne coinfections is complicated and antimicrobial therapy may not cover coinfections. Therefore, the objectives of this review were to identify the newly emerging tickborne pathogens in the United States, to describe the evolving epidemiology of tick-transmitted coinfections, to design a decision tree analysis approach to the clinical diagnosis and management of tickborne coinfections, and to recommend effective strategies for the control and personal prevention of tickborne diseases. Clinicians should suspect tickborne coinfections in returning travelers and vacationers with clinical and immunological evidence of multiple infecting agents, especially in cases of unusual presentation or severity, prolonged duration, or nonresponse to single antibiotic therapy, typically with doxycycline. Decision tree models based on pathogen prevalence rates in ticks and their zoonotic reservoirs may assist clinicians in diagnosing tickborne coinfections and guiding initial antimicrobial therapy.