Volume 24, Number 2—February 2018
Synopsis
Ecologic Features of Plague Outbreak Areas, Democratic Republic of the Congo, 2004–2014
Table 2
Variable | Estimate | SE | t value | p. value |
---|---|---|---|---|
Area |
0.0005266 |
0.000142 |
3.709 |
<0.001 |
Ecosystem† | ||||
Tropical | 9.598 | 0.02713 | 353.8 | <0.001 |
Dry tropical | −0.87697 | 0.01066 | −82.29 | <0.001 |
Equatorial | −5.7475 | 0.1096 | −52.44 | <0.001 |
Tropical mountain |
0.5238 |
0.006693 |
78.26 |
<0.001 |
Elevation, m | ||||
Mean | 0.07305 | 0.001006 | 72.62 | <0.001 |
SD |
−0.1236 |
0.002218 |
−55.75 |
<0.001 |
MODIS‡ | ||||
Water | −217.2609 | 1.0011 | −217.00 | <0.001 |
Evergreen needleleaf forest | −18590.00 | 2116.00 | −8.786 | <0.001 |
Evergreen broadleaf forest | 3.152 | 0.04331 | 72.78 | <0.001 |
Deciduous broadleaf forest | 908.7303 | 1.5165 | 599.2 | <0.001 |
Mixed forest | 25.4324 | 0.5472 | 46.48 | <0.001 |
Closed shrublands | 10081.9545 | 63.4111 | 159.0 | <0.001 |
Woody savannas | 3.9340 | 0.0521 | 75.51 | <0.001 |
Savannas | −51.0000 | 1.1043 | −46.18 | <0.001 |
Grasslands | −139.8523 | 2.7516 | −50.83 | <0.001 |
Permanent wetlands | −40.8106 | 0.2148 | −190.0 | <0.001 |
Croplands | −7.9310 | 0.2875 | −27.58 | <0.001 |
Urban and built-up | 96.1737 | 0.7640 | 125.9 | <0.001 |
Cropland/natural vegetation | 1.9249 | 0.0241 | 79.88 | <0.001 |
Snow and ice | 5639.5053 | 106.2298 | 53.09 | <0.001 |
Barren/sparsely vegetated |
17639.579 |
97.10 |
−181.7 |
<0.001 |
Mean rain accumulation, mm, TRMM3B43§ | 0.5343 | 0.005531 | 96.61 | <0.001 |
*Environmental variables with p<0.2. These variables were kept for multivariate analysis. Negative estimates represent variables protective against plague, positive estimates represent variables increasing plague risk.
†Ecoclimatic zones defined by the Food and Agriculture Organization of the United Nations (http://www.fao.org/ag/AGAInfo/programmes/documents/livatl2/africaezmaps.htm). These ecosystems are built incorporating repeated measures of Normalized Difference Vegetation Index, temperature, rainfall, length of growing period, and elevation.
‡Moderate Resolution Imaging Spectroradiometer (https://lpdaac.usgs.gov/dataset_discovery/modis/modis_products_table/mcd12q1).
§Tropical Rainfall Measure Mission 3B43 version 7 (http://disc.sci.gsfc.nasa.gov/precipitation/documentation/TRMM_README/TRMM_3B43_readme.shtml).