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| Water-borne Cryptosporidiosis
Much progress has been made in all aspects of this highly integrated project.
Climate downscaling from the Max Planck GCM is complete for the mid-Atlantic region, and
we have successfully calibrated a hydrological run-off model for a watershed in Lancaster
County. The historical analysis of extreme precipitation and water-borne disease outbreaks
in the US since 1940 is almost complete. A positive temporal and spatial correlation
was found between heavy precipitation and disease occurrence, with strongest correlation
in the Fall season. In preparation for modeling cryptosporidiosis risk under climate
change, livestock operations within the 100 year floodplain of a major creek in Lancaster
County were sampled for cryptosporidium oocysts; in field manure more than half of the
samples tested positive. We have now obtained drinking water treatment facility data and
will finalize the full risk model (from rainfall and run-off, to cryptosporidium oocyst
loads at the drinking water facilities). Run-off modeling to determine changes in salinity
of the Chesapeake Bay is progressing. Economic analysis for baseline costs of
cryptosporidiosis cases has been completed. |
More Information: Climate
Change may Impact Waterborne Diseases
| Cholera
In Peru, 11 patients have been identified as probably the first indicator cases,
occurring from late October, 1990 to January, 1991. In addition to SST satellite
data from 1991, we have obtained SST data for 1997 and SeaWifs data for algal blooms in
1998. In the Chesapeake Bay, preliminary analysis shows a strong correlation between
warmer water temperature and the presence of Vibrio cholerae. |
| Hantavirus
Both stages of the Hantavirus/El Niño analysis have been completed and first stage
submitted for publication. We were able to accurately predict high risk areas for
Hantavirus Pulmonary Syndrome based on satellite generated risk maps of land cover.
Predicted risk was also concordant with vegetative growth determined by the normalized
difference vegetative index (NDVI), supporting the hypothesis that heavy rainfall from El
Niño in 1992 were associated with higher rodent populations that triggered the Hantavirus
outbreak in 1993. |
| Dengue and Dengue Hemorrhagic Fever
The dengue fever transmission model (DENSiM) has been improved to better account
for water container temperature and water height, important to larval mosquito development
rates (Chen et al. 1998). Full model parameterization has been completed at all study
sites (Brownsville, New Orleans, and Puerto Rico), and model runs are being made using
incremental temperature changes to assess potential thresholds key to any future climate
analysis. Matrices of the downscaled
climate runs have recently been completed for input
into the DENSiM model. |
| Lyme Disease
We have classified landcover for the mid-Atlantic region by use of remote satellite
sensing. We have tuned the USDA Lyme disease simulation model to better account for
humidity and temperature and we will apply our recently developed spatial modeling of tick
abundance using generalized linear mixed models for more accurate risk prediction, given a
GIS of landcover. |
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