Wilderness & Environmental Medicine

To report the injuries and illnesses encountered by wilderness hikers in Hawaii Volcanoes National Park attempting to hike to active lava flows and to investigate the roles that demographics, prior hiking experience, hiking behavior, and preparedness play in hiker vulnerability to injury and illness.

During an 8-week period, daily on-site exit interviews of lava hikers were conducted by a uniformed park ranger and park volunteer. Information about the hiker's home residence, wilderness hiking experience, preparedness, health status, and health problems encountered during the hike was collected from a total of 804 hikers.

A high rate of injury and illness was found among the study population. Scrapes and abrasions (59%), blisters (51%), and muscle strains and sprains (47%) were the most common injuries. Dehydration (77%) and respiratory irritation (46%) were the most common illnesses. Lower extremities were the most common site of injuries, and beginning hikers were the most vulnerable to injury and illness. Many hikers were inexperienced tourists willing to disregard warning signs and enter high-risk areas.

Hawaii Volcanoes National Park is one of 22 US national park units with volcanic resources. The injuries and illnesses reported by the study group identify the impact that this type of environment can have on the safety of wilderness users in areas with similar resources. Recreating in remote and severe areas has inherent risks, but the high rate of injuries and illnesses sustained by the hikers of this study can potentially be reduced through the development of more direct risk management methods.

The main goal was to explore the different toxin properties (proteolytic, hemorrhagic, and neurotoxic) of Leptodeira annulata ashmeadii Duvernoy's gland secretion (DGS).

To separate and characterize the different proteins present in L annulata ashmeadii DGS, 20% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was run. To partially purify the proteolytic activity, Mono Q2 column ion-exchange chromatography was used. Hemorrhagic activity was analyzed in chicken embryos and mice (skin and peritoneum). Neurotoxic disorders were analyzed in mice inoculated with L annulata ashmeadii DGS.

The approximate relative mass of 21 protein bands was determined using the Multi-Analyst PC version 1.1 (Bio-Rad) program. L annulata ashmeadii DGS proved to have proteolytic, hemorrhagic, and neurotoxic activities.

Given the properties of the secretions of its Duvernoy's gland, L annulata ashmeadii should be added to the list of venomous colubrids.

To calculate the incidence and prevalence of altitude illness (acute mountain sickness [AMS], high altitude pulmonary edema, and high altitude cerebral edema) during an expedition length adventure race and to determine factors contributing to its development as well as identify cases requiring medical treatment, withdrawal from the event, or both.

The Primal Quest Expedition Length Adventure Race was held in Colorado in July 2002. Sixty-two coed teams of four participated in the event. It began at an altitude of over 9500 feet, ascended to an altitude over 13 500 feet with a cumulative elevation gain of 69 400 feet, of which 40 000 feet occurred in the first 12 hours of the event. There was 138 800 total feet of altitude change during the event. All racers underwent a prerace medical assessment 24 hours before the start of the race and completed an Environmental Systems Questionnaire version 3-R (ESQ 3-R). Onsite medical staff provided treatment during the event. A standard medical encounter form was used to record all patient encounters including a presumed diagnosis and disposition.

At the start of the race, the prevalence of altitude illness was 4.5%. The incidence of altitude illness requiring medical treatment during the race was 14.1% (AMS, 33 [13.3%]; high altitude pulmonary edema, 2 [.81%]) resulting in 4 (14.3%) of the 28 medical withdrawals from the race. There was no correlation between home altitude, prerace ESQ scores, and successful completion of the race.

Altitude illness occurs among participants in expedition length adventure races and contributes significantly to withdrawal from the event.

To find out the nutritional status of sea-level residents acclimated to an altitude of 3660 m with respect to vitamin and nutrient requirements while consuming fresh and tinned rations.

Initially, high altitude acclimatized human subjects (n = 40) were evaluated for their general nutritional status along with energy intake and expenditure and physical fitness score while they were on fresh rations. Thereafter, subjects were fed tinned rations in two groups of 20 each. Of the two groups, one group had vitamin supplementation and the other was without any vitamin supplementation for 30 days. Thereafter, all the variables were studied once again.

Daily total energy intake when subjects consumed fresh and tinned rations was 19.087 ± 0.347 MJ and 19.417 ± 0.342 MJ, respectively, whereas the total energy expenditure was 15.705 ± 1.054 MJ per day for both the groups. After consuming tinned rations for 30 days, the placebo group showed a significant (P < .01) decrease in levels of plasma vitamin A and erythrocyte transketolase activity (a marker of thiamin status) in comparison to the status when subjects were on fresh rations. However, levels of these variables were well within acceptable range. Subjects maintained their body weights and physical fitness scores. No clinical deficiency was seen after consuming tinned rations for 30 days.

The study indicates that no additional vitamin supplementation is required at high altitude after acclimatization when consuming fresh rations and at least for 30 days when consuming tinned rations.

To evaluate the protective effects of a jellyfish sting inhibitor formulated in sunscreen lotion vs conventional sunscreen against Chrysaora fuscescens and Chiropsalmus quadrumanus jellyfish.

Twenty-four healthy subjects at 2 research sites were randomly assigned to receive the jellyfish sting inhibitor (Nidaria Technology Ltd, Jordan Valley, Israel) to one forearm and conventional sunscreen to the other arm in a blinded fashion. Subjects were stung with jellyfish tentacles on each forearm for up to 60 seconds. Erythema and pain were assessed at 15-minute intervals over a 2-hour period.

In the C fuscescens group, all 12 arms pretreated with conventional sunscreen demonstrated erythema, and all subjects noted subjective discomfort. In contrast, no arm pretreated with the jellyfish sting inhibitor had objective skin changes (P < .01). Two subjects noted minimal discomfort in the arm treated with the sting inhibitor (P < .01). In the C quadrumanus group, discomfort was reported in 3 of the 12 inhibitor-treated arms compared with 10 of the 12 placebo-treated arms (P < .05). Erythema was noted on 1 arm treated with the inhibitor and 9 arms treated with the placebo (P < .01).

The jellyfish sting inhibitor prevented sting symptoms of C fuscescens jellyfish in 10 of 12 subjects and diminished the pain of the jellyfish sting in the remaining 2 subjects. The jellyfish sting inhibitor also inhibited the more severe sting of the C quadrumanus jellyfish in the majority of subjects. The jellyfish sting inhibitor does not eliminate the sting from C fuscescens or C quadrumanus jellyfish but significantly reduces the frequency and severity of stings.