Notes from the Field: Increase in Coccidioidomycosis - Arizona, October 2017-March 2018

Coccidioides Serologic Screening Practices in Individuals With Rheumatic and Autoimmune Diseases

OBJECTIVE

We aimed to estimate Coccidioides serologic screening rates before initiation of biologic disease-modifying antirheumatic drugs including tofacitinib (b/tsDMARDs), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), and/or noninhaled corticosteroids.

METHODS

This retrospective cohort study used 2011 to 2016 US Medicare claims data and included beneficiaries with rheumatic or autoimmune disease residing in regions within Arizona, California, and Texas endemic for Coccidioides spp. with ≥1 prescription for a b/tsDMARD, csDMARD, and/or noninhaled corticosteroid. We estimated prior-year serologic screening incidence before initiating b/tsDMARDs, csDMARD, and/or noninhaled corticosteroid.

RESULTS

During 2012 to 2016, 4,331 beneficiaries filled 64,049 prescriptions for b/tsDMARDs, csDMARDs, and noninhaled corticosteroids. Arizona's estimated screening rate was 20.1% (95% confidence interval [95% CI] 14.5-25.7) in the year before prescription initiation for b/tsDMARDs, 8.1% (95% CI 6.5-9.7) before csDMARDs, and 6.9% (95% CI: 5.6-8.2) before corticosteroids. Screening rates for b/tsDMARDs (2.8%, 95% CI 0.0-6.7), csDMARDs (1.0%, 95% CI 0.0-2.0), and corticosteroids (0.8%, 95% CI: 0.4-1.1) were negligible in California and undetected in Texas. Adjusted screening rate before prescription for b/tsDMARDs in Arizona increased from 14.5% (95% CI 7.5-21.5) in 2012 to 26.7% (95% CI 17.6-35.8) in 2016. Rheumatologists prescribing b/tsDMARDs in Arizona screened more than other providers (20.9% [95% CI 13.9-27.9] vs 12.9% [95% CI 5.9-20.0]).

CONCLUSION

Coccidioides serologic screening rates among Medicare beneficiaries with rheumatic/autoimmune diseases on b/tsDMARDs, csDMARDs, and noninhaled corticosteroids was low in Coccidioides spp.-US endemic regions between 2012 and 2016. Alignment of screening recommendations and clinical practice is needed.

Understanding the exposure risk of aerosolized Coccidioides in a Valley fever endemic metropolis

Coccidioides is the fungal causative agent of Valley fever, a primarily pulmonary disease caused by inhalation of fungal arthroconidia, or spores. Although Coccidioides has been an established pathogen for 120 years and is responsible for hundreds of thousands of infections per year, little is known about when and where infectious Coccidioides arthroconidia are present within the ambient air in endemic regions. Long-term air sampling programs provide a means to investigate these characteristics across space and time. Here we present data from > 18 months of collections from 11 air sampling sites across the Phoenix, Arizona, metropolitan area. Overall, prevalence was highly variable across space and time with no obvious spatial or temporal correlations. Several high prevalence periods were identified at select sites, with no obvious spatial or temporal associations. Comparing these data with weather and environmental factor data, wind gusts and temperature were positively associated with Coccidioides detection, while soil moisture was negatively associated with Coccidioides detection. These results provide critical insights into the frequency and distribution of airborne arthroconidia and the associated risk of inhalation and potential disease that is present across space and time in a highly endemic locale.

Epidemiology of Coccidioidomycosis in the Veterans Health Administration, 2013-2022

We describe the epidemiology of coccidioidomycosis among a national cohort of Veterans. Using electronic health record data from adults tested for coccidioidomycosis between 1 January 2013 and 31 December 2022, we analyzed differences in baseline demographics (age, sex, race/ethnicity, birth country, comorbidities, residence, and Charlson Comorbidity Index score) between 4204 coccidioidomycosis-test-positive and 63,322 test-negative Veterans. Log-binomial regression models with adjusted risk ratios (aRRs) were used to evaluate risk factors associated with coccidioidomycosis including dissemination, hospitalization, and mortality. Case counts and incidence rates were highest in select counties in Arizona and California where Coccidioides is endemic. Coccidioidomycosis-positive Veterans were younger, more likely to be male, and Philippine-born. The risk factors most highly associated with being coccidioidomycosis-positive included Native Hawaiian/Pacific Islander (aRR 1.068 [95%CI: 1.039-1.098]), Asian (aRR 1.060 [95%CI: 1.037-1.083]), Black (aRR 1.029 [95%CI: 1.022-1.036]), American Indian/Alaska Native (aRR 1.026 [95%CI: 1.004-1.048]) race, and Hispanic/Latino ethnicity (aRR 1.021 [95%CI: 1.013-1.028]). Black race (aRR: 1.058 [95%CI: 1.037-1.081]) and Hispanic/Latino ethnicity (aRR 1.018 [95%CI: 1.0003-1.036]) were also associated with disseminated coccidioidomycosis, strengthening the evidence for the association of coccidioidomycosis, including severe infections, with specific racial and ethnic groups. There were no statistically significant differences in hospitalization within 45 days of testing or 30-day all-cause mortality. Improving our understanding of coccidioidomycosis risk factors is important for targeted prevention strategies and to reduce delays in diagnosis and ineffective treatment.

Climate Change and the Epidemiology of Infectious Diseases in the United States

The earth is rapidly warming, driven by increasing atmospheric carbon dioxide and other gases that result primarily from fossil fuel combustion. In addition to causing arctic ice melting and extreme weather events, climatologic factors are linked strongly to the transmission of many infectious diseases. Changes in the prevalence of infectious diseases not only reflect the impacts of temperature, humidity, and other weather-related phenomena on pathogens, vectors, and animal hosts but are also part of a complex of social and environmental factors that will be affected by climate change, including land use, migration, and vector control. Vector- and waterborne diseases and coccidioidomycosis are all likely to be affected by a warming planet; there is also potential for climate-driven impacts on emerging infectious diseases and antimicrobial resistance. Additional resources for surveillance and public health activities are urgently needed, as well as systematic education of clinicians on the health impacts of climate change.

Coccidioidomycosis in Northern Arizona: an Investigation of the Host, Pathogen, and Environment Using a Disease Triangle Approach

Coccidioides immitis and Coccidioides posadasii are the etiological agents of coccidioidomycosis (Valley fever [VF]). Disease manifestation ranges from mild pneumonia to chronic or extrapulmonary infection. If diagnosis is delayed, the risk of severe disease increases. In this report, we investigated the intersection of pathogen, host, and environment for VF cases in Northern Arizona (NAZ), where the risk of acquiring the disease is much lower than in Southern Arizona. We investigated reported cases and assessed pathogen origin by comparing genomes of NAZ clinical isolates to isolates from other regions. Lastly, we surveyed regional soils for presence of Coccidioides. We found that cases of VF increased in NAZ in 2019, and Coccidioides NAZ isolates are assigned to Arizona populations using phylogenetic inference. Importantly, we detected Coccidioides DNA in NAZ soil. Given recent climate modeling of the disease that predicts that cases will continue to increase throughout the region, and the evidence presented in this report, we propose that disease awareness outreach to clinicians throughout the western United States is crucial for improving patient outcomes, and further environmental sampling across the western U.S. is warranted.

IMPORTANCE Our work is the first description of the Valley fever disease triangle in Northern Arizona, which addresses the host, the pathogen, and the environmental source in the region. Our data suggest that the prevalence of diagnosed cases rose in 2019 in this region, and some severe cases necessitate hospitalization. We present the first evidence of Coccidioides spp. in Northern Arizona soils, suggesting that the pathogen is maintained in the local environment. Until disease prevention is an achievable option via vaccination, we predict that incidence of Valley fever will rise in the area. Therefore, enhanced awareness of and surveillance for coccidioidomycosis is vital to community health in Northern Arizona.

Real-time PCR assay for detection and differentiation of Coccidioides immitis and Coccidioides posadasii from culture and clinical specimens

Coccidioidomycosis (Valley fever) is a pulmonary and systemic fungal disease with increasing incidence and expanding endemic areas. The differentiation of etiologic agents Coccidioides immitis and C. posadasii remains problematic in the clinical laboratories as conventional PCR and satellite typing schemes are not facile. Therefore, we developed Cy5- and FAM-labeled TaqMan-probes for duplex real-time PCR assay for rapid differentiation of C. immitis and C. posadasii from culture and clinical specimens. The RRA2 gene encoding proline-rich antigen 2, specific for Coccidioides genus, was the source for the first set of primers and probe. Coccidioides immitis contig 2.2 (GenBank: AAEC02000002.1) was used to design the second set of primers and probe. The second primers/probe did not amplify the corresponding C. posadasii DNA, because of an 86-bp deletion in the contig. The assay was highly sensitive with limit of detection of 0.1 pg gDNA/PCR reaction, which was equivalent to approximately ten genome copies of C. immitis or C. posadasii. The assay was highly specific with no cross-reactivity to the wide range of fungal and bacterial pathogens. Retrospective analysis of fungal isolates and primary specimens submitted from 1995 to 2020 confirmed 168 isolates and four primary specimens as C. posadasii and 30 isolates as C. immitis from human coccidioidomycosis cases, while all eight primary samples from two animals (rhesus monkey and rhinoceros) were confirmed as C. posadasii. A preliminary analysis of cerebrospinal fluid (CSF) and pleural fluid samples showed positive correlation between serology tests and real-time PCR for two of the 15 samples. The Coccidioides spp. duplex real-time PCR will allow rapid differentiation of C. immitis and C. posadasii from clinical specimens and further augment the treatment and surveillance of coccidioidomycosis.

Recent Trends in the Epidemiology of Fungal Infections

The breadth of fungi causing human disease and the spectrum of clinical presentations associated with these infections has widened. Epidemiologic trends display dramatic shifts with expanding geographic ranges, identification of new at-risk groups, increasing prevalence of resistant infections, and emergence of novel multidrug-resistant pathogenic fungi. Certain fungi have been transmitted between patients in clinical settings. Major health events not typically associated with mycoses resulted in larger proportions of the population susceptible to secondary fungal infections. Many health care-related, environmental, and socioeconomic factors have influenced these epidemiologic shifts. This review summarizes updates to clinically significant fungal pathogens in North America.

The Consequences of Our Changing Environment on Life Threatening and Debilitating Fungal Diseases in Humans

Human activities have significantly impacted the environment and are changing our climate in ways that will have major consequences for ourselves, and endanger animal, plant and microbial life on Earth. Rising global temperatures and pollution have been highlighted as potential drivers for increases in infectious diseases. Although infrequently highlighted, fungi are amongst the leading causes of infectious disease mortality, resulting in more than 1.5 million deaths every year. In this review we evaluate the evidence linking anthropomorphic impacts with changing epidemiology of fungal disease. We highlight how the geographic footprint of endemic mycosis has expanded, how populations susceptible to fungal infection and fungal allergy may increase and how climate change may select for pathogenic traits and indirectly contribute to the emergence of drug resistance.

Fungal prostatitis due to endemic mycoses and Cryptococcus: A multicenter case series

BACKGROUND

Fungal prostatitis is exceedingly rare with mostly case reports.

METHODS

Electronic medical records at three medical centers were searched for cases of fungal prostatitis due to endemic mycoses and Cryptococcus over the preceding 10 years.

RESULTS

Seven cases were identified from 105 600 prostate biopsies within the Southern California Permanente Medical Group for an incidence of 0.0066%. An additional eight cases were identified from two other health care systems. Excluding four patients without available clinical data, 11 patients were reviewed, most of whom underwent biopsy due to elevated prostate-specific antigen. Four were asymptomatic and the remainder had nonspecific signs or symptoms. All biopsies revealed granulomatous inflammation and fungal organisms. Seven patients had coccidioidomycosis, three patients had cryptococcosis (confirmed in two cases and suspected by organism morphology in the other), and one patient had likely histoplasmosis based on organism morphology. Prolonged antifungal treatment was standard; outcomes were favorable.

CONCLUSION

Fungal prostatitis due to endemic mycoses and Cryptococcus is uncommon and associated with favorable outcomes but generally involves prolonged therapy.

Surveillance for Coccidioidomycosis - United States, 2011-2017

PROBLEM/CONDITION

Coccidioidomycosis (Valley fever) is an infection caused by the environmental fungus Coccidioides spp., which typically causes respiratory illness but also can lead to disseminated disease. This fungus typically lives in soils in warm, arid regions, including the southwestern United States.

REPORTING PERIOD

2011-2017.

DESCRIPTION OF SYSTEM

Coccidioidomycosis has been nationally notifiable since 1995 and is reportable in 26 states and the District of Columbia (DC), where laboratories and physicians notify local and state public health departments about possible coccidioidomycosis cases. Health department staff determine which cases qualify as confirmed cases according to the definition established by Council of State and Territorial Epidemiologists and voluntarily submit basic case information to CDC through the National Notifiable Diseases Surveillance System.

RESULTS

During 2011-2017, a total of 95,371 coccidioidomycosis cases from 26 states and DC were reported to CDC. The number of cases decreased from 2011 (22,634 cases) to 2014 (8,232 cases) and subsequently increased to 14,364 cases in 2017; >95% of cases were reported from Arizona and California. Reported incidence in Arizona decreased from 261 per 100,000 persons in 2011 to 101 in 2017, whereas California incidence increased from 15.7 to 18.2, and other state incidence rates stayed relatively constant. Patient demographic characteristics were largely consistent with previous years, with an overall predominance among males and among adults aged >60 years in Arizona and adults aged 40-59 years in California.

INTERPRETATION

Coccidioidomycosis remains an important national public health problem with a well-established geographic focus. The reasons for the changing trends in reported cases are unclear but might include environmental factors (e.g., temperature and precipitation), surveillance artifacts, land use changes, and changes in the population at risk for the infection.

PUBLIC HEALTH ACTION

Health care providers should consider a diagnosis of coccidioidomycosis in patients who live or work in or have traveled to areas with known geographic risk for Coccidioides and be aware that those areas might be broader than previously recognized. Coccidioidomycosis surveillance provides important information about the epidemiology of the disease but is incomplete both in terms of geographic coverage and data availability. Expanding surveillance to additional states could help identify emerging areas that pose a risk for locally acquired infections. In Arizona and California, where most cases occur, collecting systematic enhanced data, such as more detailed patient characteristics and disease severity, could help clarify the reasons behind the recent changes in incidence and identify additional opportunities for focused prevention and educational efforts.

Heat Inactivation of Coccidioides posadasii and Coccidioides immitis for Use in Lower Biosafety Containment

Introduction

The difficulty involved in obtaining sufficient intact genomic deoxyribonucleic acid (DNA) from Coccidioides spp for downstream applications using published protocols prompted the exploration of inactivating mycelia and arthroconidia using heat under biosafety level 3 containment. This was followed by optimizing DNA extraction from mycelia using various methods at lower containment.

Methods

Various exposure times and temperatures were examined to identify an effective heat inactivation procedure for arthroconidia and mycelia from both C immitis and C posadasii. Heat inactivation of mycelia was followed by DNA extraction using 2 commercially available kits, as well as a phenol:chloroform-based extraction procedure to determine DNA integrity and quantity among extraction methods using both live and heat-inactivated mycelia.

Results

Ten-minute and 30-minute exposure times at 80°C were sufficient to inactivate Coccidioides spp arthroconidia and mycelia, respectively. DNA yield between live versus heat-inactivated mycelia was similar for each extraction procedure. However, DNA obtained using phenol:chloroform was of higher quantity and integrity compared with DNA obtained using the commercially available kits, which was highly fragmented.

Conclusion

The ability to heat-inactivate Coccidioides cultures for processing at a lower level of containment greatly increased the efficiency of DNA extractions. Therefore, this is an ideal method for obtaining Coccidioides spp DNA and inactivated arthroconidia.