What are the risk factors for Coccidioidomycosis (Valley fever)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Article Review Status
Submitted
Under Review
Approved

Last updated: June 16, 2025 • View editorial policy

From the Guidelines

Risk factors for coccidioidomycosis (Valley fever) include living in or traveling to endemic areas, particularly the southwestern United States and parts of Mexico, Central and South America, as well as occupations or activities that involve soil disruption, which increase exposure risk, as noted in the 2016 Infectious Diseases Society of America (IDSA) clinical practice guideline for the treatment of coccidioidomycosis 1.

Key Risk Factors

  • Living in or traveling to endemic areas, such as the southwestern United States (Arizona, California, Nevada, New Mexico, Utah, and Texas) and parts of Mexico, Central and South America
  • Occupations or activities that involve soil disruption, such as construction, agriculture, archaeology, and military training
  • Seasonal factors, with higher risk during dry periods following rainy seasons when fungal spores become airborne
  • Certain populations face greater risk of severe disease, including: + Pregnant women + Adults over 60 + Individuals with weakened immune systems (due to HIV/AIDS, organ transplants, or medications like corticosteroids) + People with diabetes + Those of Filipino, African, Mexican, Native American, or Hispanic descent ### Environmental Conditions
  • Environmental conditions like dust storms can significantly increase exposure
  • The fungus Coccidioides lives in soil, and infection occurs when people breathe in airborne spores, which explains why activities disturbing soil in endemic regions pose such significant risk, as highlighted in the 2016 IDSA guideline 1 and supported by earlier studies 2, 3.

Importance of Understanding Risk Factors

Understanding these risk factors is important for prevention, early diagnosis, and treatment of Valley fever, as emphasized in various guidelines and studies, including the 2016 IDSA guideline 1 and other relevant research 4, 5, 6, 7.

From the Research

Risk Factors for Coccidioidomycosis

The risk factors for Coccidioidomycosis (Valley fever) include:

  • Immunosuppressive therapy and infection with the human immunodeficiency virus (HIV) 8
  • Cellular immunodeficiencies, such as those found in transplant recipients and individuals with HIV 9
  • Pregnancy 9
  • Non-Caucasian races, especially African Americans and Filipinos 9
  • Residence or travel to endemic areas, including the southwestern United States, Mexico, and Central and South America 9, 10
  • Occupational exposure to soil disturbance, such as construction or agriculture 11
  • Participation in recreational activities that disturb soil, such as off-roading or hiking 9

Population-Specific Risk Factors

Certain populations are at higher risk for developing severe or disseminated Coccidioidomycosis, including:

  • Immunocompromised individuals, such as those with HIV or undergoing immunosuppressive therapy 8, 12
  • Pregnant women 9
  • Older adults 12
  • Individuals with underlying medical conditions, such as diabetes or heart disease 12

Environmental Risk Factors

Environmental factors that increase the risk of Coccidioidomycosis include:

  • Soil disturbance, such as construction or earth-moving activities 11
  • Dust storms or other events that disturb soil and release arthroconidia into the air 9
  • Climate change, which may alter the distribution and prevalence of Coccidioides spp. 9

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Coccidioidomycosis: clinical update.

Reviews of infectious diseases, 1989

Research

Coccidioidomycosis: A Contemporary Review.

Infectious diseases and therapy, 2022

Research

A point-source outbreak of Coccidioidomycosis among a highway construction crew.

Journal of occupational and environmental hygiene, 2018

Research

Coccidioidomycosis.

Infectious disease clinics of North America, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.