Wilderness Medical Society

Press Releases

Wilderness Medicine Magazine (June 13, 2008)

Exposure to Wilderness Water Increases Risk of Contracting Waterborne Illnesses

A new article published in Wilderness & Environmental Medicine discusses the pitfalls of being exposed to water found in the wilderness.

Although wilderness water may appear to be clean and safe to drink, it is likely that ingesting it will result in illness caused by such pathogens as bacteria, viruses, protozoa, and parasites. Other methods of disease transmission include contact with the skin or mucous, the inhalation of aerosolized water, the ingestion of food, skin/soft-tissue or eye injury, the bite of insects, and human-to-human contact.

This report documents the factors that determine the risk of contracting a waterborne illness and explains that knowledge of the source of water exposure, length of symptoms, and incubation period for diseases will greatly assist in making an accurate diagnosis. A table presents some of the more common pathogens and their mode of transmission and symptoms.

Also presented are methods for disinfecting water found in the wilderness, including their advantages and disadvantages. For example, boiling water is the most reliable method of destroying pathogens; however, it is inconvenient and time consuming. In addition, chlorine dioxide is effective against all microorganisms, but to date this method has not been adequately tested in the field.

It is important that those involved in wilderness activities be knowledgeable about pathogens, waterborne disease symptoms, and methods of water disinfection in order to minimize the risk of contracting a waterborne illness.

To read the entire study, visit: http://wms.org/pubs/Wild Water Everywhere.pdf

Wilderness Medicine is the official quarterly magazine of the Wilderness Medical Society and is dedicated to providing valuable information to medical and allied health professionals. Since 1984 the magazine has published articles on all aspects of wilderness medicine.

[Wild Water Everywhere, But Is It Safe to Drink (or Play in)? Better Safe Than on the Run from Waterborne Illnesses in the Wild; Wilderness Medicine], 2008, Vol. 25(3):8-11.

WEM Journal Vol 19 Issue 2 (March 31, 2008)

[The “Worldwide Shortage” of Antisnake Venom: Is the Only Right Answer “Produce More” Or Is It Also “Use It Smarter?”; Wilderness & Environmental Medicine], 2007; Vol. 19(2):XXX-XXX

New model addresses perceived worldwide shortage of antisnake venom

Despite the rhetoric that there is a worldwide shortage of antisnake venom, evidence suggests that there is overuse of the current resources, according to a new paper. In the concept paper, a model is presented that could better enable policy makers to assess the amount and utilization of antisnake venom in their areas. The paper is published in the latest issue of Wilderness and Environmental Medicine.

The current argument for increasing the supply side of the antisnake venom (ASV) usage equation focuses almost entirely on providing more and better quality ASV. However, there is evidence that there is overuse of ASV on the demand side that could fulfill some of the perceived shortfalls, but this is not being considered in the debate, according to paper author Ian Simpson of the Pakistan Medical Research Council. To assess the adequacy of the current ASV supply, it is useful to reconsider the relationship between supply and demand, Simpson says.

According to WHO published statistics, the two countries with the largest annual snakebite mortality in the world are India, with 50,000, and Pakistan, with 20,000. Together these two countries constitute approximately 55 to 85 percent of overall world snakebite mortality. An extensive review of the situation regarding supply and demand in these two countries led to the development of a model that can determine the actual supply/demand of ASV. The model assesses ASV usage according to two criteria: risk and wastage. The actual usage of ASV is segmented in the model into the following main areas:

victims who receive too little ASV (high-risk/low-wastage)

victims who receive ASV either unnecessarily or in too great a quantity (low-risk/high-wastage)

victims who receive ASV that is not effective (high-risk/low-wastage)

victims who receive ASV according to effective local protocols (low-risk/low-wastage)

The current proposition—there is a shortage of ASV and the solution is to simply produce more—addresses only a small part of the high-risk/low-wastage group and does not address the two high-wastage groups. Until the high-wastage groups are recognized, resolved with training and local protocols, and moved into the low-risk/low-wastage group, the true requirement for ASV worldwide cannot be assessed.

WEM Journal Vol 19 Issue 1 (March 14, 2008)

[Adaptation to High Altitude in Sherpas: Association with the Insertion/Deletion Polymorphism in the Angiotensin-Converting Enzyme Gene; Wilderness and Environmental Medicine], 2008; Vol. 19(1):22-29

Sherpa gene may aid ability to adapt to high-altitude environment

Well known for their physical strength at high altitudes, Sherpas were the subject of a new study that tried to genetically uncover why this population experiences little acute or chronic mountain sickness. The team of researchers in the study focused specifically on examining the angiotension-converting enzyme (ACE) gene. The study is published in the latest issue of Wilderness and Environmental Medicine.

Among the nearly 140 million people residing at altitudes over 2,500 m above sea level worldwide, Sherpas are a minority ethnic population that has permanently resided for almost 500 years along the Himalayan region of Nepal. Due to their location and well-known physical strength at high altitudes, Sherpas play key roles in expeditions to Mount Everest and other famous peaks. Since the beginning of the last century, when Sherpas were first employed by British expedition teams to Mount Everest, their extraordinary mountaineering prowess and hardiness have brought them recognition in mountaineering circles.

For the study, the team of researchers enrolled 105 Sherpa volunteers in Namche Bazaar (3,440 m) and 111 non-Sherpa Nepalese volunteers in Kathmandu Valley (1,330 m) in Nepal. Information about high-altitude exposure and physiological phenotypes was obtained through fieldwork investigation.

The researchers’ findings suggest that the overrepresented I allele of the ACE gene in Sherpas might be one of the fundamental genetic factors responsible for maintaining physiological low-altitude ACE activity at high altitude. They suspect this may have an advantageous physiological role in Sherpas’ ability to adapt in a high-altitude environment.

Wilderness and Environmental Medicine is a peer-reviewed quarterly medical journal published by the Wilderness Medical Society.

Wilderness Medicine Magazine (February 27, 2008)

[Got Heat? Dealing with Hypothermia and Frostbite; Wilderness Medicine], 2008; Vol. 25;1:16-17.

Dealing with hypothermia, frostbite

As the winter weather chugs along, taking the time to brush up on how to deal with hypothermia and frostbite could make all the difference. In a new article from Wilderness Medicine, those two conditions as well as prevention strategies are offered to those who must brave the cold.

Hypothermia, the result of the inability to overcome heat loss by the generation and conservation of body heat, can be acute or chronic. Acute signifies a sudden drop of core body temperature, and chronic hypothermia is when there is a gradual drop in core temperature. Surprising to some, chronic hypothermia is more common, often occurring in ambient temperatures between 30 and 50 degrees.

More important than the classification is the recognition of the signs and symptoms. An easy way to remember this is by remembering the “umbles”—mumbling, grumbling, fumbling, and stumbling—that represent the intellectual and physical impairments often observed. Hypothermia can be further divided into mild, moderate, or severe hypothermia. Patients with mild hypothermia will be able to rewarm themselves as long as the symptoms are recognized and treated appropriately. Patients with moderate and severe hypothermia will not be able to rewarm themselves, and the application of any external sources of heat, including body-to-body rewarming, will likely be inadequate, so they should be evacuated to a medical facility immediately.

Hypothermia can be difficult to manage, but is much easier to prevent. The following prevention strategies are recommended:

Stay well hydrated

Maintain a good energy level

Dress appropriately

Plan ahead

Recognize the signs and symptoms

Whereas hypothermia involves a reduction of the core temperature, frostbite is a local process and is the result of actual freezing of the cells and soft tissues. Risk factors for frostbite include freezing temperatures, high wind and altitude, tobacco and drug use, contact with heat-conducting materials such as metal, and a previous history of frostbite.

Like hypothermia, frostbite can occur in varying degrees. The degree of severity—superficial, partial-thickness, or full-thickness frostbite (the most severe)—determines the course of action that needs to be taken. Treatment for superficial and partial-thickness frostbite may begin in the field; however, refreezing after the area has been thawed has been shown to cause much more extensive damage. Especially with partial- and full-thickness frostbite, care is needed in a medical facility.

Frostbite is often seen in high-risk types of activities such as high-altitude mountaineering but can also occur in unplanned situations closer to home. It is important to recognize the loss of sensation or an inability to move the affected area and seek immediate ways to reverse the situation.

WEM Journal Vol 18 Issue 4 (November 13, 2007)

[Venomous Snakebite in Mountainous Terrain: Prevention and Management; Wilderness and Environmental Medicine], 2007; Vol. 18(4):281-287.

Wilderness leaders must show broad understanding of medical treatment

Organizations that provide group wilderness and adventure experiences—mountaineering, rock climbing, river running, sea kayaking, and canoeing—are responsible for managing the risk of their courses. The leaders and medical providers of these trips must be prepared to anticipate and manage medical problems that might arise. A new study examined the medical incidents of the National Outdoor Leadership School (NOLS) that occurred within a three-year period, finding low and declining rates of medical incidents. The study is published in the latest issue of Wilderness and Environmental Medicine.

The study examined medical incidents that occurred on wilderness-based courses from September 1, 2002 to August 31, 2005. Injuries occurred at a rate of 1.18 per 1,000 program days and illnesses at a rate of 1.08 per 1,000 program days. No fatalities occurred during the time period. Athletic injuries (like sprains and strains) and gastrointestinal illnesses were the most common medical incidents. Hypothermia, seizures, appendicitis, heat stroke, and pregnancy complications occurred but with low frequency. Fractures, dental emergencies, tick fever, athletic injuries, and non-specific body pains were the conditions most frequently requiring evacuation.

The rate of medical incidents on NOLS courses declined during the 1990s and has remained relatively steady apart from a slight increase in 2004 and 2005. Athletic injuries continue to be a difficulty as they frequently result in evacuation even though their ultimate outcome is usually benign. Evacuation decisions should be made considering both the potential severity of the medical condition as well as patient comfort. Wilderness medical personnel must be familiar with a diverse range of medical conditions in order to provide optimal care.