Document: GID-3-55-1

The epizootiology of cutaneous leishmaniasis in the Negev and the Arava, Israel: The role of human activity.

WASSERBERG, G.*

Ben-Gurion University of the Negev, Beer-Sheva, 84105 Israel ¹

Abstract:
An increase in the incidence of cutaneous leishmanisis (CL) is reported in southern Israel during the last 20 years. This increase appears to be associated with human activity. The question raised is: Does this increase occurs due to entry of more people into endemic regions, or does human activity alter the environment thereby increasing the probability of infection? We are studying the elementary ecological mechanisms that could influence these epidemiological patterns. The study is being conducted in 5 sites in the Negev and Arava deserts, Israel. At each site twelve 60 by 60m plots were selected: Six in disturbed habitats, and six in natural habitats. In each plot, rodents and sand flies were trapped and environmental variables were measured. To assess the impact of human activity on the zoonotic system we compared the prevalence and densities of the reservoir Psammomys obessus, and vector Phlebotomus papatasi populations in disturbed vs. natural habitats. Infection rates of P. obessus were significantly higher in disturbed habitats than in undisturbed ones. CL in P. obessus was positively correlated with sand fly density but not with host density. Soil in disturbed habitats was significantly more humid and plants were significantly lusher than in natural habitats. Sand fly densities were correspondingly higher in disturbed habitats as well. These results suggest that an important impact of human activity, the addition of water, improves the conditions for sand fly breeding and promotes larger host populations by improving the quality of their food. So by altering the natural environment man actually brings the trouble upon himself.

Keywords: Epizootiology, Cutaneous Leishmaniasis, Sand-Rat, Sand-fly,Zoonosis, Human induced disturbance, Southern Israel

This abstract is being presented at: 3:30 PM in session:
CONSERVATION ECOLOGY