Recreation reduces tick density through fine-scale risk effects on deer space-use.

Altered interactions between pathogens, their hosts and vectors have potential consequences for human disease risk. Notably, tick-borne pathogens, many of which are associated with growing deer abundance, show global increasing prevalence and pose increasing challenges for disease prevention. Human activities can largely affect the patterns of deer space-use and can therefore be potential management tools to alleviate human-wildlife conflicts. Here, we tested how deer space-use patterns are influenced by human recreational activities, and how this in turn affects the spatial distribution of the sheep tick (Ixodes ricinus), a relevant disease vector of zoonoses such as Lyme borrelioses. We compared deer dropping and questing tick density on transects near (20 m) and further away from (100 m) forest trails that were either frequently used (open for recreation) or infrequently used (closed for recreation, but used by park managers). In contrast to infrequently used trails, deer dropping density was 31% lower near (20 m) than further away from (100 m) frequently used trails. Similarly, ticks were 62% less abundant near (20 m) frequently used trails compared to further away from (100 m) these trails, while this decline in tick numbers was only 14% near infrequently used trails. The avoidance by deer of areas close to human-used trails was thus associated with a similar reduction in questing tick density near these trails. As tick abundance generally correlates to pathogen prevalence, the use of trails for recreation may reduce tick-borne disease risk for humans on and near these trails. Our study reveals an unexplored effect of human activities on ecosystems and how this knowledge could be potentially used to mitigate zoonotic disease risk.

Recent chemical exposures and blood volatile organic compound levels in a large population-based sample.

Little is known about factors that influence blood levels of volatile organic compounds in nonoccupationally exposed populations. The authors examined the possible relationship between recent self-reported chemical exposures and elevated blood volatile organic compound levels among 982 adult participants in theThird National Health and Nutrition Examination Survey. A strong dose-response effect was indicated (p < .001) for increasing lifetime pack-years of cigarettes smoked for elevated levels of toluene, styrene, and benzene. A positive dose-response effect was indicated for daily alcohol consumption with respect to elevated blood levels of 2-butanone and acetone. For volatile organic compounds typically found in 10-75% of the population, the establishment of a link with specific environmental exposures is relatively easy because there is less effect of confounding in this group. Some volatile organic compounds, however, are seen in less than 10% of the general population; finding these compounds at any level may warrant a search for a particular exposure.

DoEpi. Computer-assisted instruction in epidemiology and computing and a framework for creating new exercises.

DoEpi is a series of computer exercises and a framework for making new exercises based on the Epi Info programs for epidemiologic computing. The system contains three outbreak investigations, a research survey, four exercises in advanced Epi Info programming, and four exercises in public health surveillance. The exercises are available via the Internet (www.cdc.gov, under "Publications, Products, and Software") with provision for CME and CEU credit from the Centers for Disease Control and Prevention. They can serve as a useful adjunct to lectures and textbooks in teaching epidemiology or epidemiologic computing. A new DoEpi exercise with hypertext, low-resolution photographs, questions, answers, and an examination can be constructed in hours rather than weeks or months using an Exercise Development "wizard" provided as part of the instructor's module. Epi Info exercises with data files and customized programs require more work to construct but can be added by those with the necessary skills. DoEpi exercises can be used in a variety of ways for different curricula and students of different background levels, including those with English as a second language. Translation of DoEpi exercises into other languages is facilitated by the instructor's module, and construction of new exercises with locally suitable materials is encouraged. DoEpi is based on DOS programs to allow the widest use. The format lends itself to conversion to hypertext programs in the Microsoft Windows and Internet formats at a future date.

Archetypal healing.

With emphasis on healing versus curing, the authors draw from a wide assortment of treatment methods for psychospiritual relief of pain in the terminally ill. These archetypal methods include: life-review therapy; ministry of presence; clinical hypnosis; myths, symbols, rituals, and community; creative therapies. In life-review therapy, the ill person shares his/her life story with the provider much like the healing rituals of the ancient storyteller did in his community. In the ministry of presence, the caregiver focuses on sharing his vulnerability, not his professional skills. Clinical hypnosis emphasizes the naturalness and simplicity of accessing the unconscious along with problem areas of the hypnoclinician. Myths, symbols, rituals, and community serve as nurturing agents in the intervention of pain, while creative therapies such as music, drama, crafts, and art continue to be powerful healing instruments. Archetypal healing produces relief of pain in the caregiver, as well as the ill, with emphasis on healing versus curing.