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Volume 24, Number 10—October 2018

Mapping Histoplasma capsulatum Exposure, United States

Amelia W. Maiga, Stephen DeppenComments to Author , Beth Koontz Scaffidi, John Baddley, Melinda C. Aldrich, Robert S. Dittus, and Eric L. Grogan
Author affiliations: Vanderbilt University Medical Center, Nashville, Tennessee, USA (A.W. Maiga, S. Deppen, M.C. Aldrich, R.S. Dittus, E.L. Grogan); Tennessee Valley Healthcare System Veterans Hospital, Nashville (A.W. Maiga, R.S. Dittus); Vanderbilt University, Nashville (B.K. Scaffidi); University of Alabama at Birmingham, Birmingham, Alabama, USA (J. Baddley)

Main Article


Scoring of 3 soil characteristics used for Histoplasma site suitability map*

Assigned value Land cover class (70% weight)† Meters from water (20% weight) Soil pH (10% weight)
9 Cultivated crops, >20% vegetation 0–222 7.2–7.6
8 Pasture or hay, >20% vegetation 222–444 7.0–7.2 or 7.6–7.8
7 Open water, woody wetlands, >20% vegetation; or emergent herbaceous wetlands, >80% vegetation 444–666 6.7–7
6 Deciduous, evergreen or mixed forest, >20% vegetation 666–888 6.4–6.7 or 7.8–8.0
5 Dwarf scrub or shrub/scrub, >20% vegetation; or grassland used for grazing, >80% vegetation 888–1,110 6.0–6.4
4 Developed, open space such as lawns, <20% impervious 1,110–1,332 5.6–6.0 or >8
3 Developed, low and medium intensity, 20% to 79% impervious 1,332–1,555 5.1–5.6
2 Barren land such as rock, sand, or clay, <15% vegetation 1,555–1,777 >4.5 and <5.1
1 Developed, high intensity, >80% impervious 1,777–1,999 <4.5

*A value of 9 represents the most suitable environment for H. capsulatum. The overall weighted score was calculated as follows: an area of evergreen forest, located 1,000 meters from water, with a soil pH of 7.7 would have a suitability score of (6 × 0.7) + (5 × 0.2) + (8 × 0.1) = 6.
†Excluded classes include perennial ice/snow and Alaska-only vegetation types.

Main Article

Page created: September 12, 2018
Page updated: September 12, 2018
Page reviewed: September 12, 2018
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.