Application of Remote Sensing and GIS to the 2001 Screwworm Fly Outbreak in Chiapas, Mexico
Introduction
On the 29th of September the first case
of screwworm was collected from the umbilical wound of a calf in Berriozabal
municipality approximately 27 km northwest of the screwworm rearing facility in
Tuxtla Gutierrez, Mexico. An
additional 55 positive cases were collected from the area with the last case
collected on December 4th, 2001.This is the best-documented outbreak
to occur in the history of the screwworm eradication program. Previous outbreaks of screwworm
occurred in 1993 and 1992 in Mexico and before that in the southern United
States. With the advancement of
remote sensing and GIS technologies there is a great opportunity to learn more
about how a screwworm outbreak will spread elsewhere.
Map of Favorable Screwworm Habitats
and Positive Screwworm Cases
We identified favorable screwworm habitats on a March 2001 Landsat TM image. The green color on the map indicates areas of favorable screwworm habitat. The red dots are positive cases of screwworm. We used the satellite image analysis to help identify areas to locate to ground release chambers of sterile screwworm flies. The blue triangles represent the ground release chambers. The purple dots are ground release chambers located at the Screwworm Rearing Facility in Tuxtla Gutierrez, Mexico.
Study and Analysis of Data in Progress
We are continuing the study and analysis of the outbreak by collecting
data on land use, air temperature and precipitation and animal host density.
Pamela Phillips, Remote Sensing Specialist,
USDA-ARS, Screwworm Research Unit
page last edited 23 July 2002
