Environmental Detection of Coccidioides: Challenges and Opportunities

Abstract

Valley fever (coccidioidomycosis) is an infection posing a significant human health risk, resulting from the soil-dwelling fungi Coccidioides. Although incidence and mortality from coccidioidomycosis are underreported in the United States, and this underreporting may impact public health policy in numerous jurisdictions, its incidence is rising. Underreporting may stem from diagnostic and testing difficulties, insufficient environmental sampling for pathogen detection to determine endemicity, and a shortage of data on Coccidioides dispersion. As climate change creates increasingly arid locations in the US favorable for Coccidioides proliferation, determining its total endemicity becomes more difficult. This literature review examining published research from 2000 to 2025 revealed a paucity of publications examining the endemicity of Coccidioides and research gaps in detection methods, including limited studies on the reliability of sampling for geographical and temporal variations, challenges in assessing various sample materials, poorly defined storage conditions, and the lack of precise, less restrictive, cost-effective laboratory procedures. Addressing these challenges requires interdisciplinary collaboration among Coccidioides researchers, wildlife experts, atmospheric and climate scientists, and policymakers. If these obstacles are solved, standardized approaches for identifying Coccidioides, classified by climate zones and ecoregions, could be developed, saving financial resources, labor, and time for future researchers studying the environmental drivers of coccidioidomycosis.

1. Introduction

Coccidioidomycosis is a potentially serious infection caused by inhaling the arthroconidia (asexual spores formed by fragmentation of hyphae) of the soilborne fungi Coccidioides immitis or Coccidioides posadasii [1], also known as Valley fever or cocci [2], California fever, desert rheumatism, and San Joaquin Valley fever [3]. This illness is endemic and poses a significant public health risk in southwestern North America, specifically the USA states of Arizona, California, Nevada, New Mexico, Texas, and Utah, and northern Mexico [4,5], as well as certain regions of South America [6].

Symptoms of coccidioidomycosis infection are typically nonspecific and include extreme weariness, olfactory and gustatory loss, fever, cough, headaches, rash, muscular discomfort, and joint pain [2]. These manifestations can occur commonly across both immunocompetent and immunocompromised patients. However, immunocompromised individuals face significantly higher risks of developing severe complications, including respiratory failure due to severe pneumonia, bronchopleural fistulas requiring surgical intervention, pulmonary nodules, and disseminated infection with potential septicemia [7]. It has been reported that this disease causes roughly 20% and perhaps as much as 29% of all cases of community-acquired pneumonia in endemic locations [7]. Between 1999 and 2021, around 10,000 to 20,000 cases of coccidioidomycosis were reported annually in the United States, with approximately 200 fatalities each year [8]. However, the actual incidence of coccidioidomycosis in the United States is suspected to be strongly underestimated [2] and death counts may be severely underestimated [5], because Valley fever’s symptoms mimic those of many other respiratory diseases, complicating and challenging the ability to make a diagnosis [2,4,5]. Although hospitalization data likely underestimate the true burden of coccidioidomycosis, they are still likely indicative of actual disease trends [5]. These trends indicate a strong increase in the incidence of coccidioidomycosis, as evidenced by multiple studies and data [9,10,11]. Coccidioides can infect a wide range of species, including companion animals, livestock, wildlife, and captive non-native animals [12,13].

As of 2025, not every U.S. state or county reports cases of Valley fever, despite its recognition as a major health problem in the United States since the 1930s [14]. Coccidioidomycosis is one of those diseases whose reporting has a greater influence on the health policy of the state [15,16]. A cross-sectional investigation indicated that the estimated national burden of symptomatic coccidioidomycosis in 2019 was 10 to 18 times higher than the cases reported via national surveillance [17]. A lack of sufficient environmental monitoring to identify Coccidioides species and determine their occurrence could be one reason why certain states or counties do not have reportability status. Furthermore, it is expected that some portions of the United States will become drier due to continued climate change [18,19,20,21]. This, in turn, may enable Coccidioides to spread over a larger area [22], making it difficult to quantify their endemicity and necessitating a more extensive evaluation of Coccidioides under environmental conditions.

Given the gravity of coccidioidomycosis, numerous reviews have focused on the disease and its effects on human health [23,24,25,26]. One such review [26] offers an in-depth examination of the challenges and opportunities associated with coccidioidomycosis diagnostics in clinical and laboratory settings. However, a deficiency exists in the literature reviews concerning environmental studies of Coccidioides, and our objective is to contribute to alleviating this gap.

2. Methodology

The objective of this literature review is to examine the prevailing issues related to the detection of Coccidioides in environmental contexts and propose viable solutions to these concerns. For our evaluation, we aggregated recent articles on environmental detection of Coccidioides from 2000 to 2025 by utilizing the keywords “detection of Coccidioides in soils” or “detection of Coccidioides in dust” in the Google Scholar search engine. We selected only original research publications on the environmental detection of Coccidioides from our search. Following selection, the papers were examined, and their research aims, sample locations, sampling seasons, and laboratory methods for Coccidioides detection were charted or aggregated to evaluate trends or research gaps.

3. Results and Discussion

3.1. Expanding the Search for Coccidioides in Soils and Dusts of “Non-Endemic” Areas

The acquisition of samples from regions where Coccidioides is known to be endemic is the focus of the majority of academic articles published on the detection of Coccidioides in soil and air samples (

Table 1. Sampling locations for Coccidioides detection identified in scholarly literature.

Study	Year	Sampling Areas (States)	Remarks
Cairns et al. [27]	2000	Baja California, Mexico	Endemic
Greene et al. [28]	2000	California and Nevada–Arizona border, USA	Endemic
Cordeiro et al. [29]	2006	Ceará, Brazil	Endemic
Mandel et al. [30]	2007	Arizona, USA	Endemic
De Macêdo et al. [31]	2011	Piauí, Brazil	Endemic
Baptista-Rosas et al. [32]	2012	Baja California, Mexico	Endemic
Barker et al. [33]	2012	Arizona, USA	Endemic
Lauer et al. [34]	2012	California, USA	Endemic
Lauer et al. [35]	2014	California, USA	Endemic
Johnson et al. [36]	2014	Utah, USA	Screening for Coccidioides in Dinosaur National Monument soils
Litvintseva et al. [37]	2015	Washington, USA	Verifying the existence of C. immitis in the soil of Washington State
Vargas-Gastelum et al. [38]	2015	Baja California, Mexico	Endemic
Chow et al. [39]	2016	Arizona, USA	Endemic
Colson et al. [40]	2017	California, USA	Endemic
Clifford et al. [41]	2017	Washington, USA	Investigating additional locations in central Washington State
Alvarado et al. [42]	2018	Falcon and Lara, Venezuela	Endemic
Bowers et al. [43]	2019	Arizona, USA	Endemic
Kollath et al. [44]	2020	Arizona, USA	The fungus was found at two previously undiscovered sites in northern Arizona
Gade et al. [45]	2020	Arizona, USA	Endemic
Lauer et al. [46]	2020	California, USA	Endemic
Lauer et al. [47]	2020	California, USA	Endemic
Chow et al. [48]	2021	Washington, USA	Endemic
Mead et al. [49]	2022	Arizona, USA	Northern Arizona soils contain Coccidioides, which is believed to be less common than in southern Arizona
Ramsey et al. [50]	2023	Arizona, USA	Endemic
Wagner et al. [51]	2023	California, USA	Endemic
Kollath et al. [52]	2023	Arizona, USA	Endemic
Lauer et al. [53]	2023	California, USA	Endemic
Porter et al. [54]	2024	Arizona, USA	Endemic
Head et al. [55]	2024	California, USA	Endemic
Segovia Mota [56]	2024	Baja California, Mexico	Endemic
Radosevich et al. [57]	2025	California, USA	Endemic
Radosevich et al. [58]	2025	California, USA	Endemic

). These endemic localities are defined as those that have previously tested positive for Coccidioides in soil/dust samples, have patients with coccidioidomycosis, or have experienced recent outbreaks of the disease.

However, scholarly research has not sufficiently examined the potential prevalence of Coccidioides in regions that are currently classified as non-endemic. The absence of such studies by the research community may lead to the exclusion of locations where Coccidioides may be present, resulting in a non-reportable status of the disease in those specific states or counties. The outcomes of diseases that the state does not consider reportable may be substantially worse due to a lack of public health research and awareness. This situation is particularly relevant in the context of Valley fever and Coccidioides in the United States [15,16,17].

It must be noted that most of the studies listed (Table 1) did not aim to identify new or nonindigenous locations to determine the presence or absence of Coccidioides. Instead, their main objectives were to assess the effectiveness of the methods they employed, such as sample collection processes and assays for detection of pathogens or other relevant aims (

Table 2. Primary objectives of research for environmental Coccidioides detection.

Study	Year	Primary Research Objectives
Cairns et al. [27]	2000	Evaluating the coccidioidomycosis outbreak in individuals coming from an endemic zone
Greene et al. [28]	2000	The efficacy of soil isolation and molecular identification of Coccidioides immitis
Cordeiro et al. [29]	2006	Identifying the ecological and phenotypic traits of Coccidioides spp. in Northeast Brazil
Mandel et al. [30]	2007	Examining evidence for sexual reproduction and gene acquisition through genomic and demographic analyses of the mating type loci in Coccidioides species
De Macêdo et al. [31]	2011	Identification of C. posadasii in soil samples associated with coccidioidomycosis outbreaks
Baptista-Rosas et al. [32]	2012	Molecular detection of Coccidioides spp. in Baja California environmental samples to link Valley fever to soil and climate
Barker et al. [33]	2012	Identification and phylogenetic examination of Coccidioides posadasii in soil samples from Arizona
Lauer et al. [34]	2012	Multiplex polymerase chain reaction (PCR)’s efficacy in detecting Coccidioides immitis
Lauer et al. [35]	2014	Effectiveness of integrating satellite imagery, soil type data, and multiplex PCR for predicting and identifying growth areas of C. immitis
Johnson et al. [36]	2014	Detection of Coccidioides immitis and Coccidioides posadasii DNA in soil samples obtained from Dinosaur National Monument, Utah
Litvintseva et al. [37]	2015	Discovery of Coccidioides in Washington State soils associated with recent human infections
Vargas-Gastelum et al. [38]	2015	The use of 454 pyrosequencing to uncover the effects of seasonal fluctuations on fungal diversity in a semi-arid ecosystem
Chow et al. [39]	2016	Efficiency of air sampling and molecular detection methods for environmental monitoring of Coccidioides
Colson et al. [40]	2017	Examining the relationship between growing coccidioidomycosis cases in California’s Antelope Valley, 1999–2014, and large-scale land development and fugitive dust
Clifford et al. [41]	2017	Investigating the distribution of Coccidioides immitis in south central Washington State
Alvarado et al. [42]	2018	Using molecular identification of Coccidioides spp. in soil samples from endemic Venezuela, comparing soil-derived Coccidioides ITS2 PCR amplicons from high-throughput sequencing with clinical-derived sequences from GENBANK and comparing the mycobiome of low-positive and high-positive sites to find fungal communities connected to Coccidioides prevalence
Bowers et al. [43]	2019	Direct identification of Coccidioides in Arizona soils via CocciEnv qPCR assay
Kollath et al. [44]	2020	Examining the influence of animal burrows on the ecology and distribution of Coccidioides spp. in Arizona soils
Gade et al. [45]	2020	Developing a unique airborne Coccidioides detection method and using it to study arthroconidia distribution in Phoenix, Arizona
Lauer et al. [46]	2020	Assessing environmental risk determinants and exposure routes of Valley fever inferred from field observations in California
Lauer et al. [47]	2020	Identifying Coccidioides in a seismically affected region of the USA
Chow et al. [48]	2021	Variables affecting the distribution of Coccidioides immitis in soil, Washington State, 2016
Mead et al. [49]	2022	Examination of the host, pathogen, and environment utilizing a disease triangle framework concerning coccidioidomycosis in Northern Arizona
Ramsey et al. [50]	2023	Investigating the correlation between Coccidioides posadasii and biological soil crusts
Wagner et al. [51]	2023	Identification of Coccidioides in various land management regions and its association with temporal variables and soil fungal communities
Kollath et al. [52]	2023	Employing naturally occurring soil microorganisms in Arizona to suppress the proliferation of Coccidioides spp.
Lauer et al. [53]	2023	Assessing the risk of exposure to Coccidioides spp. in the Temblor Special Recreation Management Area (SRMA), Kern County, California
Porter et al. [54]	2024	Assessing the exposure risk of aerosolized Coccidioides in a city endemic to Valley fever
Head et al. [55]	2024	Examining the influence of small mammals and their burrows on the distribution of Coccidioides in soil
Segovia Mota [56]	2024	Examining the distribution of Coccidioides spp. in Baja California soils via droplet digital PCR
Radosevich et al. [57]	2025	Characterizing the soil microbial community associated with Coccidioides immitis
Radosevich et al. [58]	2025	Identification of airborne Coccidioides spores with lightweight portable air samplers mounted on unmanned aerial vehicles in California’s Central Valley

). While it is crucial to develop efficient detection protocols for Coccidioides in the environment, which are currently lacking in full establishment, it is also essential to investigate the potential occurrence of Coccidioides in previously unsampled locations utilizing contemporary approaches.

There is one example in the USA of active surveillance for Coccidioides in an area where it was not known to occur, and that was motivated by the appearance of a disease cluster. In 2010, the Washington State Department of Health documented three cases of coccidioidomycosis in the eastern part of the state, an area that was not previously recognized as a place where the disease is endemic [59]. Three people who were diagnosed with coccidioidomycosis were exposed to Coccidioides while performing different activities in that region, such as cycling, playing or digging in natural vegetation, being in an all-terrain vehicle crash on a dirt track, and working in construction [60]. Subsequently, three counties in Washington State implemented the requirement to report the condition in 2011 [60]. Follow-up investigations [37,48] identified the presence of Coccidioides in soils in Washington State. It was suggested that the Coccidioides cases found in south-central Washington come from local soil that was contaminated via the travel, death and burial of an ancient human or domesticated animal from the central California region of endemicity to Washington State [61]. It is crucial to note that the recognition of Coccidioides endemic areas in Washington State would not have been feasible without human exposure to the fungus, the subsequent development of coccidioidomycosis, and the following detection of Coccidioides in soil samples. Outside the USA, in Mexico, the Pacific littoral and central regions (stretching southeast to Michoacán) are endemic [62]; but, other nonendemic southern states, including Campeche, Quintana Roo, Morelos, and Oaxaca, have recorded a rise in coccidioidomycosis incidence. However, it has to be established whether this upward trend is attributable to migration or evolving epidemiology [63].

Moreover, coccidioidomycosis is highly underdiagnosed [64] since most persons exposed to Coccidioides arthroconidia are asymptomatic or have limited or mild symptoms and do not seek or require medical attention [65], and misdiagnosis of coccidioidomycosis in humans is common [2,66]. This is especially true in counties or states where coccidioidomycosis is not reported, which means medical professionals may not know much about the disease and may not pay as much attention to patients’ symptoms related to this infection. Clinical indications of Valley fever might appear years after a visitor has been exposed in an endemic location [67], making it more difficult to determine where a patient’s encounter with Coccidioides occurred. Given the foregoing, it is safe to conclude that evaluating coccidioidomycosis endemicity should not be based just on patient illness condition. Therefore, disease surveillance should prioritize Coccidioides researchers’ efforts to gather environmental samples from places outside or near endemic areas in order to assess the true extent of the disease’s overall prevalence.

Due to the vast areas of dry and arid terrain in the Western Hemisphere, finding the complete range of endemism for Coccidioides would be quite a challenge. Consequently, the search for Coccidioides in additional regions should be prioritized.

Table 3. Coccidioides status in the United States based on endemicity and reportability.

State	Endemic	Reportable	State	Endemic	Reportable	State	Endemic	Reportable
Alabama	×	√	Kentucky	×	√	North Dakota	×	√
Alaska	×	×	Louisiana	×	√	Ohio	×	√
Arizona	√	√	Maine	×	×	Oklahoma	×	×
Arkansas	×	√	Maryland	×	√	Oregon	×	√
California	√	√	Massachusetts	×	×	Pennsylvania	×	×
Colorado	×	√	Michigan	×	√	Rhode Island	×	√
Connecticut	×	×	Minnesota	×	√	South Carolina	×	×
Delaware	×	√	Mississippi	×	×	South Dakota	×	√
District of Columbia	×	√	Missouri	×	√	Tennessee	×	×
Florida	×	×	Montana	×	√	Texas	√	×
Georgia	×	×	Nebraska	×	√	Utah	√	√
Hawaii	×	×	Nevada	√	√	Vermont	×	×
Idaho	×	×	New Hampshire	×	√	Virginia	×	×
Illinois	×	×	New Jersey	×	×	Washington	√	√
Indiana	×	√	New Mexico	√	√	West Virginia	×	×
Iowa	×	×	New York	×	×	Wisconsin	×	√
Kansas	×	√	North Carolina	×	×	Wyoming	×	√

Note: The bold states indicate that coccidioidomycosis is not endemic, but it is still reportable. The green color signifies reportable endemic states. The red color represents an endemic state, but the disease is not reportable. The blue color indicates non-endemic states bordering endemic states, but the disease is not reportable [14]. Italic states represent future endemic extensions according to climate niche models [22].

shows that this is especially reasonable for the United States when considering the reportability status of Valley fever in the various U.S. states and their closeness to endemic areas of the fungi that cause it. It is expected that the effects of climate change in the USA could lead to a rise in the prevalence of Coccidioides [68,69,70]. Climate models and their projections can now be considered in the process of sampling new areas for the fungus that causes Valley fever. For example, the endemic zone in the USA may extend northward into the states of North Dakota, South Dakota, Montana, Wyoming, and Idaho, according to the climate niche model proposed by Gorris et al. [22]. Therefore, it would be reasonable to include these areas in soil sampling efforts to detect the presence of Coccidioides.

Texas requires particular attention concerning the study of environmental Coccidioides [16]. Soils in western and central Texas, characterized by desert and semi-arid conditions [71], are particularly conducive to the proliferation of Coccidioides, as corroborated by niche [72] and habitat suitability [73] maps for this organism. The state is deemed endemic because skin testing [74] and evidence [75,76,77,78] have confirmed the presence of Coccidioides and regular diagnosis of coccidioidomycosis. However, it is likely that the absence of contemporary research on the extent of occurrence of Coccidioides in Texas soils and reliance on outdated data contribute to Texas not attaining reportability status [14].

3.2. Sampling in Private Lands

For soil or air testing aimed at pathogen identification to determine endemicity or other goals, researchers must pinpoint all relevant areas, including both public and private properties. Although acquiring authorization for scientific study on public land is often relatively uncomplicated, researchers may have difficulties in accessing and receiving consent for private property, which could impede their ability to gather samples. Numerous endemic locations of Coccidioides are situated on private property; for instance, Texas, recognized as one of the endemic zones for Coccidioides, possesses the largest concentration of private property in the United States (over 95%). Difficulties in sampling on private property arise partially from landowners’ apprehensions regarding disturbances during scientific research and the potential for their land to gain an undesirable image and/or lose value or utility if diseases/pathogens are discovered. This concern is particularly significant for landowners with livestock, as the discovery of pathogens could harm their reputation and result in economic losses. Policymakers must ensure that landowners are sufficiently informed and educated about Coccidioides, as its identification will provide greater long-term advantages compared to unexamined ones.

3.3. Sampling with Respect to Seasonal Variations

Environmental factors are thought to be a major reason for the seasonal and yearly changes in the number of cases of coccidioidomycosis infection in humans as related to the fungi’s life cycle [70,79,80,81,82]. Modeling the abiotic conditions that influence the disease dynamics has led to the prevalent “grow and blow” hypothesis, in which under wet conditions the Coccidioides fungus proliferates in soil as mycelia, and when the soil dries, its arthroconidia are produced and released into the air when soil disturbance occurs [81], which can lead to human exposure [83,84,85]. Although the disease patterns support this hypothesis, the actual biological process has not been studied extensively [81]. There is currently no definitive and ecologically coherent connection established between the environment and the rates of coccidioidomycosis. This uncertainty is likely due to the noisy nature of the case data and its limited coverage over a significant period of time.

Another important consideration is the climatic zone. Head et al. [80] suggested that the lifespan of Coccidioides is affected by region-specific constraints. In colder and wetter climates, the limiting variables may include inadequate heat to lyse the mycelia into individual arthroconidia, insufficient soil desiccation to promote dust emissions, or excessive moisture hindering growth. Conversely, in arid locations, inadequate precipitation may limit growth and suppress proliferation. This concept may clarify the observed rise in incidence rates in California, particularly in counties with higher humidity and milder temperatures, such as those around the central coastal region, compared to the arid counties of the southern San Joaquin Valley. Consequently, a direct method for identifying the fungus in the soil and elucidating its spatial and temporal variations has not yet been established.

Some investigations have considered collecting samples according to the “grow and blow” hypothesis, which involves sampling post-rainy season when desert soils desiccate and arthroconidia would be discharged by Coccidioides, hence increasing the likelihood of pathogen presence in their samples. Other investigations may lack a specific emphasis on seasonality during sample collection, or they may not address or include such aspects in their publications (

Table 4. Sampling months or seasons for environmental Coccidioides detection.

Study	Year	Sampling Seasons	Remarks
Cairns et al. [27]	2000	No particular reference
Greene et al. [28]	2000	Approximately 4–6 weeks after the last rainfall in spring and fall	Highest precipitation occurs in winter
Cordeiro et al. [29]	2006	No particular reference
Mandel et al. [30]	2007	No particular reference
De Macêdo et al. [31]	2011	No particular reference
Baptista-Rosas et al. [32]	2012	2–3 months following the seasonal rains	Highest precipitation occurs in winter
Barker et al. [33]	2012	No particular reference
Lauer et al. [34]	2012	Monthly
Lauer et al. [35]	2014	Monthly
Johnson et al. [36]	2014	No particular reference
Litvintseva et al. [37]	2015	Fall and spring	Highest precipitation occurs in winter
Vargas-Gastelum et al. [38]	2015	Winter and summer	Highest precipitation occurs in winter
Chow et al. [39]	2016	Fall	Summer and winter precipitation follow a bimodal pattern
Colson et al. [40]	2017	Spring	Highest precipitation occurs in winter
Clifford et al. [41]	2017	No particular reference
Alvarado et al. [42]	2018	Venezuela’s dry seasons
Bowers et al. [43]	2019	Fall and spring	Summer and winter precipitation follow a bimodal pattern
Kollath et al. [44]	2020	Spring and summer (pre- and post-monsoon)	Summer and winter precipitation follow a bimodal pattern
Gade et al. [45]	2020	Summer and fall	Summer and winter precipitation follow a bimodal pattern
Lauer et al. [46]	2020	Winter, spring/summer and fall
Lauer et al. [47]	2020	Summer	Highest precipitation occurs in winter
Chow et al. [48]	2021	Autumn	Highest precipitation occurs in winter
Mead et al. [49]	2022	No particular reference
Ramsey et al. [50]	2023	Pre- and post-winter	Summer and winter precipitation follow a bimodal pattern
Wagner et al. [51]	2023	Monthly
Kollath et al. [52]	2023	No particular reference
Lauer et al. [53]	2023	Spring, summer and fall	Highest precipitation occurs in winter
Porter et al. [54]	2024	Summer and fall, 2016 and winter, 2018 through summer, 2019
Head et al. [55]	2024	Spring, summer, and fall	Highest precipitation occurs in winter
Segovia Mota [56]	2024	Dry season
Radosevich et al. [57]	2025	Fall	Highest precipitation occurs in winter
Radosevich et al. [58]	2025	Spring	Highest precipitation occurs in winter

).

Regardless of the circumstances, the issue of addressing appropriate seasonality of the Coccidioides life cycle for each ecoregion while considering distinct variables in field soil sampling for Coccidioides remains unresolved. Environmental Coccidioides researchers can fill in some gaps in their knowledge by collecting more samples of soil for detection of Coccidioides (both species) across a wider range of locations and seasons and by reconnaissance for Coccidioides in soil under a wider range of physical conditions. Characterizing the relevant environmental factors in the field is a vital consideration. For instance, the soil type from which samples were extracted, temperature and humidity levels, and the presence of specific plant species are all pertinent. Another strategy is ex situ, which involves managing laboratory operations as closely as possible to replicate field variables such as soil moisture, artificial precipitation, ambient humidity and aridity, temperature, airflow, etc., and then assessing them. Acquiring metadata on the Coccidioides life cycle would facilitate the identification of environmental correlations, as it is often absent from numerous sampling efforts. Furthermore, this information could enhance Coccidioides distribution models.

3.4. Sampling Medium

Another important consideration is the type of environmental samples that researchers should collect to detect Coccidioides: soil or air. Identifying Coccidioides is comparatively more straightforward in soil samples than in air samples [39]. The detection of Coccidioides in the atmosphere is regarded as a challenging endeavor due to the small size of the fungal spores, their apparently uneven distribution in space and time, and the necessity for specialized air sampling methodologies to effectively capture them [45]. As of now, only a limited number of studies have successfully identified Coccidioides in air samples [39,45,54,58], and the methodologies employed in current studies may not be appropriate for large-scale detection efforts [39,86,87]. Nevertheless, the analysis of air samples for cocci is of paramount importance, as it facilitates a more profound understanding of the distribution of Coccidioides and its dispersal patterns within dryland ecosystems where dust storms are prevalent and the potential role of windblown dust in the transmission of coccidioidomycosis [88]. To enhance the efficacy of identification techniques for Coccidioides from airborne sources, researchers in this field could collaborate with aerosol scientists and engineers skilled in the design of air sampling devices to improve the design of their protocols.

3.5. Biotic and Geographic Factors Influencing the Site of Sample Collection

Animals can improve soil quality and act as a crucial stimulus for the proliferation of certain infections [89,90]. Numerous researchers have proposed that animals infected with the disease, such as bats, armadillos, and rodents, may play a role in the life cycle of Coccidioides and serve as reservoirs for the fungus [55,91,92,93]. For decades, researchers have proposed that animal carcasses may serve as a substrate for the dissemination of Coccidioides in the soil [1,94,95,96]. Fungus-positive isolates were demonstrated to be found in proximity to animal burrows [33,90,91,97] and isolates from soil devoid of animal presence yielded negative results for the fungus [28]. Coccidioides are believed to be more proficient at surviving within an animal host than in their natural environments. The explanation for these findings is that Coccidioides has a greater number of genes that interact with the host than those related to its survival in its natural habitat [98]. Thus, the life cycle of Coccidioides in its native setting (soil, air) may be short due to a strong preference for the animal host, enabling Coccidioides to remain in the environment for a restricted period. Consequently, the probability of detecting these species in soil inside their hosts’ habitats is heightened, as it may contain animal remnants. Therefore, natural wildlife habitats with substantial populations of burrowing animals should be prioritized for soil sampling to detect Coccidioides. Our literature assessment indicates the necessity of selecting soil located adjacent to or within animal burrows or areas where animals are actively excavating [28,29,31,32,35,36,37,38,39,40,43,44,46,47,49,50,51,52,53,55,56,57,58].

The Southwestern North American deserts encompass a vast region of the United States and Mexico, characterized by diverse soil types, temperatures, biodiversity, and species abundance, with Coccidioides being endemic over most of this area. In principle, regions with the highest incidence of Coccidioides are more likely to harbor the most susceptible burrowing animal populations, which, through a host–pathogen relationship with Coccidioides, facilitate its dispersion in the soil. Although some studies have been undertaken [12,99,100], there is still little research on the unique sensitivity of various species of burrowing animals to Coccidioides infection. Subsequent research should focus on assessing Coccidioides’ sensitivity levels in relation to animal species in a specific ecosystem, particularly burrowing ones, which may aid researchers in predicting potential Coccidioides-containing areas. This analysis could be performed with the help of wildlife experts to find out which burrowing species and subspecies have the most significant impact on the quality and quantity of nearby soils concerning Coccidioides.

It is also important for researchers to take into account various types of land use and management to detect the presence of Coccidioides. This includes agricultural cropland, which, though not the dominant land use, is widespread in the Southwest region of the United States. Studies have shown that agricultural fields are less appropriate for the growth of Coccidioides in comparison to soils that have not been developed previously for human land use [51]. A previous investigation [101] states that Coccidioides necessitates specific soil conditions, including xerophytic plant communities and particular soil types, such as sandy, alkaline soils rich in salts and organic matter, as well as soils abundant in certain minerals, including iron, calcium, and manganese. Moreover, Coccidioides immitis and Coccidioides posadasii exhibited preferences for distinct soil characteristics for habitation [102].

However, in agricultural contexts, various crops necessitate distinct soil amendments; consequently, agricultural soils may not have the proper balance of nutrients and conditions for the optimal growth of Coccidioides. Furthermore, agricultural and farming areas lack burrowing animals; Coccidioides only rarely affect livestock such as cattle, sheep, and pigs [103,104]; and livestock carcasses will be disposed of in a timely manner in agriculturally used land, leading to an absence of carcasses that could promote the dissemination of Coccidioides in the soil. Hence, typical agricultural and farming environments appear to lack the appropriate biotic and abiotic conditions for the proliferation of Coccidioides. Therefore, considering the mentioned findings, researchers may exclude agricultural and farming environments when sampling for Coccidioides detection. Nevertheless, a question remains regarding the proliferation of burrowing animals in the pockets of unmanaged soils adjacent to agricultural contexts, which may draw these species due to the abundant food resources offered by agricultural settings. Therefore, areas at the convergence of agricultural lands and undeveloped regions necessitate additional examination. It is important to mention that the San Joaquin Valley in California (the source of the common name for the disease, Valley fever), a major agricultural region, is known to have one of the highest incidences of Valley fever cases [105]. Consequently, further research is required, with the assistance of wildlife experts, to ascertain the prevalence of Coccidioides-sensitive burrowing animals and their ecological role in unused lands and wildlife areas in proximity to agricultural regions and fields over time. These areas are extensively distributed across the western and midwestern United States, which exhibit a higher human population density compared to entirely undeveloped regions.

Nonetheless, one should not be content with merely identifying Coccidioides in their typical environments because these pathogens demonstrate considerable plasticity. Fisher et al. [101] acknowledged the capacity of this fungus to flourish in nearly all types of desert soil, including those with low pH levels, and its ability to withstand air and soil temperatures ranging from −40.0 °C to 48.8 °C and −6.5 °C to 60.5 °C, respectively. A previous study indicated that Coccidioides spp. spores remained viable for six months at temperatures ranging from −15 °C to 37 °C and for over a week at 50 °C [106]. Therefore, considering the aforementioned variables, we should not restrict the search for Coccidioides to its currently known environments.

3.6. Climate, Environmental Change, Natural Hazards, and Coccidioides

Over the past twelve thousand years or so since the end of the last glacial period, the climate of southwestern North America has changed multiple times, becoming hotter and drier. Anthropogenic desertification may also be increasing the aridity of the Southwest as a result of fire suppression efforts, unregulated grazing, temperature fluctuations, soil erosion, and greenhouse-effect-caused climate warming [18,107]. Therefore, organisms that live in deserts, like Coccidioides, may spread into more recently desertified habitats [22]. Nonetheless, one could contend that the proliferation of deserts will not directly influence the spread of Coccidioides unless there is a corresponding rise in wildlife habitats and a corresponding shift in soil conditions to those more favorable for the preservation of Coccidioides. Although any climate-triggered changes in pre-existing ecosystems and soils would take at least many decades and probably longer and could also be affected by encroaching urbanization or other anthropogenic developments, researchers studying Coccidioides, particularly in relation to its endemicity, should interact with climate scientists and wildlife specialists to enhance their investigations into prospective areas for Coccidioides detection.

Not only does climate change cause desertification, it has other more immediate consequences as well. Wildfires [108,109] and dust storms [110,111,112] are among the various natural hazards that are associated with climate change in the Southwest and could be associated with coccidioidomycosis. Research indicates that climate change is largely responsible for the escalation of fire conditions in the western United States [113]. As temperatures increase, the drying of organic matter intensifies, leading to heightened fuel aridity and a subsequent rise in the frequency of wildfires in the western United States, as demonstrated by Abatzoglou et al. [114]. It has been demonstrated that increased wildfire activity relates to an increase in the incidence of coccidioidomycosis in California [115,116,117], a hotspot for Coccidioides infection. However, the mechanism remains incompletely understood [118]. It could be due to soil disturbance and exposure by personnel associated with firefighting [116] or the lofting of viable spores in wildfire smoke, which has been demonstrated for other fungi [119,120]. Another phenomenon exacerbated by climate change is the rise in dust storms, which have been linked to outbreaks of Coccidioides [110,121,122]. Nevertheless, the exact role of windblown dust in Valley fever infection is unclear, and there are conflicting analyses. Comrie [123] provided a review of previous research and an analysis of the relationship between dust storms and coccidioidomycosis, suggesting that there is no credible evidence indicating that all or the majority of dust storms consistently result in subsequent rises in coccidioidomycosis cases. However, other researchers [88,124] raised questions about the methodology used in that study [123] and suggested that a relationship between dust events and coccidioidomycosis may remain. Therefore, prompt further investigation is necessary to precisely ascertain the conditions under which the transmission of Valley fever may be associated with windblown dust.

Other natural hazards have also been associated with Valley fever cases. Landslides associated with earthquakes in the San Gabriel Mountains of California were later correlated with outbreaks of coccidioidomycosis [125,126,127]. Due to the discovery of Coccidioides in soils in the Indian Wells Valley, California, following two significant earthquakes in 2019 in that region of the Mojave Desert near the cities of Ridgecrest and Trona, which produced a sizable dust plume that lasted for days, Lauer et al. [47] recommended that the public and healthcare personnel in the San Joaquin Valley and the Mojave Desert be informed of the potential dangers of pathogen exposure during and after earthquakes. The aforementioned referenced studies reveal that our understanding of the correlation between climate-related and geophysical natural hazards and coccidioidomycosis outbreaks is limited, often yielding conflicting findings. In this field, Coccidioides researchers who want to focus on collecting soil samples after natural disasters should consider consulting with local meteorologists or climatologists, as these experts seem to be crucial for understanding the recent weather conditions, which may be related to the Coccidioides life cycle or dispersion, leading to a better understanding of the intersection of Coccidioides and natural disasters.

3.7. Sample Storage

Alterations in the microbial flora may occur after collecting soil samples from the designated regions. These modifications may be attributed to variations in storage conditions compared to those in the field [128]. Consequently, without adequate storage, the results of analysis may differ from those obtained in the field. Therefore, for researchers studying Coccidioides, it is essential to maintain appropriate storage conditions for samples to ensure that their analytical results reflect qualitatively and quantitatively those obtained from the field. The best way to analyze samples is to do so promptly after they have been collected [129,130]. However, laboratory examination may not always be possible without first storing environmental samples for an extended period. In other situations, storage is unavoidable, at the very least for the time it takes to transfer materials from the field to the laboratory or send samples to an organization for evaluation. Thus, samples need to be transferred or stored in a way that minimizes or stops microbial metabolism and other chemical activities as much as feasible. Presently, techniques for sample preservation utilize several temperature configurations. Coolers with cold packs are employed while transporting samples from the field to the laboratory [131]. Laboratory preservation often takes place at 4 °C for short-term storage [132], −20 °C for long-term storage [133,134], −80 °C with dry ice [135,136,137], and −196 °C with liquid nitrogen for extended long-term storage [138]. Although maintaining samples at 4 °C and −20 °C is feasible and affordable by almost every laboratory, sustaining −80 °C and −196 °C is expensive, notwithstanding their enhanced effectiveness in metabolic inhibition. However, freezing conditions for soil preservation may yield unintended consequences, such as harm to cold-sensitive microbes, osmotic stress, and the formation of ice crystals that can damage microbial cells and potentially induce cell lysis [139]. Researchers have discovered that the freeze–thawing cycle can kill soil microorganisms [140,141,142]. On the other hand, cold storage at 4 °C, unlike freezing, does not cause osmotic stress or cell lysis via ice crystal formation. As a result of the scholarly justifications above, it appears that high-cost, super-low temperature maintenance may not always produce the best outcomes. This phenomenon is particularly worrying with Coccidioides storage, since soil in its endemic habitats may seldom reach freezing temperatures; hence, Coccidioides species may lack adaptability for freezing tolerance. Thus, Coccidioides researchers should exercise caution when designing their plans, and if they intend to store their samples for an extended period of time, slow thawing, such as transferring soil from ultra-low temperatures to relatively higher temperatures in a refrigerator for some time before thawing at room temperature, may be preferred over direct thawing at room temperature.

Although the terms “soil” and “dust” are used interchangeably in this work, the effects of storing these two types of materials differ, particularly when freezing. For example, soil has a more complex matrix (organic materials, physical structure, etc.) that can provide some protection to microbes when frozen. Dust, on the other hand, is more homogeneous and potentially more vulnerable to damage, and with its larger surface area-to-volume ratio, it may produce more ice crystals upon freezing, potentially harming microbial cells. Given that Coccidioides are organisms that inhabit desert environments, it is crucial to consider the aforementioned factors when preserving samples for environmental detection. Furthermore, it has been shown that Coccidioides immitis favors organic-rich soil and dust, which are abundant in the Mediterranean climate zone of California, in contrast to Coccidioides posadasii, which is found primarily in more arid places [143]. Consequently, researchers should also consider such species differences in their work. Researchers may utilize desiccation, ethanol, or commercial preservatives as substitutes for freezing soil samples for transport or laboratory storage [144]. These technologies can be advantageous in remote regions where dependable access to electricity is challenging. Nonetheless, the impact of desiccation methods on pre-existing desiccated dust and the subsequent Coccidioides population is a separate area of investigation.

Due to recent technological advancements, scientists often employ molecular biology methods to identify Coccidioides in environmental samples (

Table 5. Laboratory methods for environmental detection of Coccidioides.

Study	Year	Techniques Used for Coccidioides Detection
Cairns et al. [27]	2000	Mice inoculation and culture
Greene et al. [28]	2000	Culture, PCR amplification utilizing ITS-specific markers, multiplex PCR, and microsatellite typing
Cordeiro et al. [29]	2006	Culture and mice inoculation
Mandel et al. [30]	2007	Mice inoculation, PCR amplification with Coccidioides-specific primers, and species determination via microsatellite primers
De Macêdo et al. [31]	2011	Mice inoculation, PCR and semi-nested PCR for cultured microorganisms and soil
Baptista-Rosas et al. [32]	2012	Nested PCR method
Barker et al. [33]	2012	Mice inoculation, plating, and PCR using Coccidioides-specific primers (direct or with a nested reaction)
Lauer et al. [34]	2012	Multiplex PCR
Lauer et al. [35]	2014	Multiplex PCR
Johnson et al. [36]	2014	Endpoint nested PCR
Litvintseva et al. [37]	2015	CocciDx real-time PCR assay and culture
Vargas-Gastelum et al. [38]	2015	Nested PCR
Chow et al. [39]	2016	Single-tube (ST) nested qPCR, generation of droplets and droplet digital PCR (ddPCR)
Colson et al. [40]	2017	Nested PCR
Clifford et al. [41]	2017	Real-time PCR assay
Alvarado et al. [42]	2018	Plating, mice inoculation, and CocciEnv qPCR assay
Bowers et al. [43]	2019	CocciDx, CocciEnv qPCR assay and Sanger sequencing
Kollath et al. [44]	2020	CocciDx and CocciEnv qPCR assay
Gade et al. [45]	2020	Single-tube (ST) nested qPCR assay
Lauer et al. [46]	2020	Nested PCR
Lauer et al. [47]	2020	Nested PCR
Chow et al. [48]	2021	TaqMan-based single-tube (ST) nested qPCR assay, culture and ITS sequencing
Mead et al. [49]	2022	CocciDx and CocciEnv qPCR assay
Ramsey et al. [50]	2023	qPCR assay
Wagner et al. [51]	2023	CocciEnv qPCR assay
Kollath et al. [52]	2023	qPCR assay
Lauer et al. [53]	2023	Nested PCR
Porter et al. [54]	2024	A single-tube nested real-time PCR test based on the CocciEnv real-time PCR target
Head et al. [55]	2024	CocciEnv qPCR assay
Segovia Mota [56]	2024	ddPCR
Radosevich et al. [57]	2025	CocciEnv qPCR assay
Radosevich et al. [58]	2025	CocciEnv qPCR assay

). However, some of those techniques may add an extra layer of sample preservation: DNA extracts from soil before polymerase chain reaction (PCR) analysis. The most often employed temperature configurations for the preservation of DNA extracts are −20 °C and −80 °C. −80 °C is considered the standard for DNA preservation [145]. Nonetheless, it has been noted that even at low temperatures, DNA progressively deteriorates with time [146]. Consequently, after a prolonged duration, PCR may be conducted on a diminished quantity of DNA, which may not accurately represent the true composition of microbial flora or may contain significantly reduced levels of target pathogenic DNA. This is particularly relevant for investigating Coccidioides detection, as they are located in dryland soils that may harbor a limited quantity of microbial DNA. Consequently, researchers must prioritize retaining adequate DNA amounts in extracts for PCR analysis during long-term storage, ensuring that even with potential degradation over time, sufficient DNA remains for effective PCR analysis. This can be achieved by optimizing DNA extraction protocols to yield a substantial quantity of DNA. For dryland soils with minimal organic matter and other nutrients and a low concentration of DNA, modifying the protocol may be necessary. For example, many Coccidioides researchers are presently considering Qiagen™’s soil DNA extraction tools [32,34,35,36,38,39,40,42,43,44,45,46,47,48,49,50,51,53,54,55,56,57,58], which can extract DNA from any soil type [147,148]. Researchers employing those tools or similar ones can consolidate multiple loads into a single MB spin column from two or more samples per site during the supernatant loading onto MB spin column phase, thereby enhancing the DNA concentration in the final tube. Alternatively, they may reduce the final elution volume or implement both strategies to optimize DNA yield.

3.8. Laboratory Methods for Environmental Detection of Coccidioides

A variety of methods, from traditional culture techniques to advanced molecular biology, have been developed for the environmental detection of Coccidioides [28]. Prior to the advent of molecular technology, the sole method for detecting Coccidioides in a culture involved cultivating the fungus from soil by traditional plating procedures or utilizing infected mice predominantly [28]. Historically, the identification of Coccidioides was labor-intensive, exhibited a low success rate [149,150,151], and often produced suspicious results. In a small area extremely endemic for Coccidioides in California, a researcher observed soil recovery rates ranging from only 0% to 43% over an 8-year period [152].

It appears from our literature assessment that, at least for environmental Coccidioides detection, researchers are gradually shifting away from technology based on culture and towards molecular biology (Table 5). It is possible that the numerous shortcomings of culturing approaches are accountable for the change in this tendency. For example, plating technologies have various drawbacks, including the need for a large number of plates in a biosafety level 3 laboratory, limited pathogen yields [28], and the overgrowth of other fungi that outcompete Coccidioides in plates [28,33]. Using mammals as subjects has numerous drawbacks, such as the need for frequent and costly animal feeding and the fact that some people may have moral objections to using animals in research [153,154]. Nevertheless, there are additional drawbacks for detecting Coccidioides using mammals as hosts. For example, infectious arthroconidia must be present for mice to pass through, but they only develop at specific points in the life cycle of Coccidioides; thus, the success rate is limited. Furthermore, this technique isolates only the certain strains of Coccidioides that cause disease in the mice. If there are nonpathogenic strains of this organism, then the distribution of the organism in the environment will not be revealed by mouse passage [43].

While molecular technology bypasses the obstacles inherent with culture procedures, it is not without its constraints. Next-generation sequencing (NGS) offers considerable promise as a molecular tool for Coccidioides detection because of its widespread usage in analyzing the diversity and composition of microbial communities in various environmental samples [155,156,157,158,159]. Researchers have used it to identify Coccidioides [160] and other fungi in paraffin-embedded and formalin-fixed tissue [161]. The ability to distinguish between C. immitis and C. posadasii is not possible with most traditional diagnostic methods but is possible with molecular techniques such as NGS [26]. Nonetheless, concerns about the sensitivity of current NGS technologies exist [162]. Another limitation of NGS is the expensive equipment that many laboratories lack, as well as the necessity for skilled bioinformaticians [163]; hence, numerous genomic agencies have emerged to undertake related research activities.

Multiplex PCR techniques are another molecular tool used to detect Coccidioides in environmental settings. Using two primer pairs, a noteworthy modification of this PCR method was created and utilized to identify C. immitis in soil samples [28]. In conjunction with primer pair RDS478/RDS482 (18S ribosomal gene, 650 bp), the C. immitis-specific primer pair ITSC1A/ITS C2 (18S ribosomal Internal Transcribed Spacer (ITS 1) region, 223 bp) was employed. These techniques were further successfully applied [34,35] to identify Coccidioides in California soils. Multiplex PCR possesses various advantageous characteristics, such as internal controls, indicators of template quantity and quality, and decreased time and reagent costs [164]. Multiplex PCR, however, is susceptible to contamination [165] and is marked by substantial initial expenses and the requirement for specialized training, which can hinder its adoption, particularly in low-resource environments [166].

To enhance sensitivity (amplifying low-abundance targets) and selectivity (minimizing the amplification of non-specific DNA sequences), Coccidioides researchers utilized nested PCR procedures, which involve two sets of primers in consecutive processes [31,32,33,36,38,39,40,45,46,47,48,53,54]. Although detecting Coccidioides with two sets of primers is more sensitive and specific, there are a few downsides to using two sets of primers: the process takes longer and requires the use of more reagents. A much higher risk of contamination also exists when PCR products are transferred between the two rounds. Additionally, specialized equipment is required, such as thermocyclers that can perform two-stage amplifications.

In recent years, the predominant and trending approaches for detecting Coccidioides are real-time quantitative PCR (qPCR), exemplified by CocciDx and CocciEnv (Table 5), which were developed by the Translational Genomics Research Institute (TGen) [43,167]. qPCR circumvents numerous issues associated with the previously stated PCR techniques. For instance, because of the closed system of qPCR, the likelihood of contamination is diminished compared to classical PCR, where post-amplification procedures may introduce contaminants. Due to its real-time amplification monitoring capabilities, qPCR is significantly more rapid than nested PCR. Post-amplification, procedures such as gel electrophoresis become unnecessary, thereby conserving time and effort. qPCR is recognized for its reliability and robustness, ensuring consistent results. Nonetheless, the distinctiveness of qPCR lies in its provision of precise measurements of target DNA concentrations via quantitative data. Furthermore, multiple real-time PCR assays utilizing LightCycler and TaqMan chemistries were established to distinguish C. immitis from C. posadasii [168,169].

While qPCR is increasingly favored for the direct detection of Coccidioides in environmental samples, it possesses several limitations that must be addressed to enhance its efficacy for regular analysis. Soil samples obtained for Coccidioides detection may include PCR inhibitors, which can disrupt the PCR process [170], and Sanger sequencing is necessary to ensure that qPCR procedures do not produce false-positive results [39]. This will incur additional costs for already expensive operations due to costly machinery and reagents. In this case, funding entities should support and research institutes should work to develop standardized qPCR methods for Coccidioides detection, similar to the practices of numerous genomic agencies currently conducting routine next-generation sequencing (NGS) and related activities upon receiving samples from various institutions or individuals. This may yield substantial cost reductions by processing a considerable volume of materials concurrently. It may also aid researchers by reducing labor, overcoming difficulties in obtaining required materials, consolidating necessary equipment in a single laboratory, and locating expertise.

4. Conclusions

Our literature review suggests that Coccidioides research in the environmental (as opposed to biomedical) context needs higher prioritization. Significant advances have been made in diagnostic and clinical domains for Valley fever in recent years, but environmental detection of the fungi that cause it is not as well developed. An acceleration of environmental investigations of Coccidioides endemicity and the conditions under which these fungi flourish is needed due to the rise in Valley fever case counts in recent decades and expected future increase in prevalence of coccidioidomycosis in southwest North America. Climate experts predict a future increase in Coccidioides endemic range and occurrence, while the medical and public health community suspects the real number of cases and fatalities is higher than documented due to underreporting and misinterpretation. Comprehending the endemic characteristics of Coccidioides and associated environmental factors is essential for educating residents to adopt appropriate precautions when outdoors or faced with natural disasters that could precipitate an outbreak of the disease, particularly given the absence of a vaccine for this infection.

Our assessment of the last 25 years of environmental Coccidioides research indicates that numerous uncertainties and knowledge gaps remain. These encompass identifying Coccidioides in regions currently considered nonendemic, selecting suitable sites for sampling, determining optimal sample collection times (during wet and dry seasons), storage protocols, and effective laboratory methodologies.

In order to address these issues, we propose a number of multidisciplinary actions and recommendations.

• Federal and state public health agencies should augment funding and assistance for researchers to search for Coccidioides in environments currently considered non-endemic.
• These organizations should encourage soil sampling for Coccidioides on private and public land by creating integrated networks that promote efficient communication for sample collection.
• Researchers studying Coccidioides should collaborate with aerosol scientists and engineers to develop air sampling technologies designed for the detection of Coccidioides.
• Researchers investigating Coccidioides should engage with wildlife specialists to identify the most susceptible species that host this fungus.
• Environmental and climate scientists should gather environmental metadata related to Coccidiodes occurrence and ensure its open accessibility.
• Biochemists can aid in researching appropriate preservation methods for soil samples related to Coccidioides viability and DNA retention.
• Researchers should collaborate across multiple laboratories to develop best practices for successful analysis.

If these advancements are implemented, we think they will significantly assist the Coccidioides research community in gaining enhanced insights into these enigmatic fungi’s detection in the environment, thus aiding in the prevention of human infections through increased awareness and facilitating patient care through modifications in medical policy.