Coccidioides spp. are endemic to which region?

Coccidioides spp. are endemic to which region?

• A. Southeastern United States
• B. Northeast United States
• C. Southwestern United States, parts of Mexico and Central America
• D. Great Lakes region

Answer: (C)

Coccidioides species are classically endemic to arid, desert-like regions in the Southwest United States, with established presence in parts of Mexico and Central America. This environmental niche—hot, dry soils that become dusty—supports the organism and explains why cases cluster in areas like Arizona and the San Joaquin Valley of California, extending into neighboring states and into northern Mexico and Central America. The Great Lakes, Northeast, and Southeastern regions do not share that persistent arid ecology, so they are not typical endemic zones (though travel-associated cases can occur). This geographic pattern is what makes the Southwestern United States, parts of Mexico, and Central America the best-fit region.

Coccidioides species are classically endemic to arid, desert-like regions in the Southwest United States, with established presence in parts of Mexico and Central America. This environmental niche—hot, dry soils that become dusty—supports the organism and explains why cases cluster in areas like Arizona and the San Joaquin Valley of California, extending into neighboring states and into northern Mexico and Central America. The Great Lakes, Northeast, and Southeastern regions do not share that persistent arid ecology, so they are not typical endemic zones (though travel-associated cases can occur). This geographic pattern is what makes the Southwestern United States, parts of Mexico, and Central America the best-fit region.