Serology of coccidioidomycosis

Coccidioidomycosis during pregnancy: a review and recommendations for management

Pregnancy is an established risk factor for the development of severe and disseminated coccidioidomycosis, particularly when infection is acquired during the later stages of gestation. Although recent studies suggest that the incidence of symptomatic coccidioidomycosis during pregnancy is decreasing and that outcome has improved, management is complicated by the observations that azole antifungal agents can be teratogenic when given to some women, particularly at high doses, early in pregnancy. This article summarizes the data on these issues and offers guidance on the management of coccidioidomycosis during pregnancy.

The utility of fine needle aspiration for diagnosis of extrapulmonary coccidioidomycosis: a case report and discussion

Coccidioidomycosis typically presents as pneumonia, but rarely manifests as extrapulmonary disease. We describe a case of coccidioidal infection that presented as a neck mass and was diagnosed by fine needle aspiration (FNA). Initial clinical suspicion was for mycobacterial infection. Several modalities are available for the detection of Coccidioides species, but culture has been the mainstay of diagnosis. FNA provides a relatively noninvasive and effective modality for tissue-based diagnosis based on characteristic histological findings. It allows the additional advantage of early on-site identification, allowing for triage of the specimen, notification of laboratory staff and prompt initiation of treatment. The case herein described is intended to demonstrate an atypical presentation of extrapulmonary coccidioidomycosis and highlight the utility of FNA for diagnosis of such lesions. Clinicians should be aware of the unique advantages of FNA for evaluation of lesions of infectious etiology.

Vaccine immunity to coccidioidomycosis occurs by early activation of three signal pathways of T helper cell response (Th1, Th2, and Th17)

We have previously reported that C57BL/6 mice vaccinated with a live, attenuated mutant of Coccidioides posadasii, referred to as the ΔT vaccine, are fully protected against pulmonary coccidioidomycosis. This model was used here to explore the nature of vaccine immunity during the initial 2-week period after intranasal challenge. Elevated neutrophil and eosinophil infiltration into the lungs of nonvaccinated mice contrasted with markedly reduced recruitment of these cells in vaccinated animals. The numbers of lung-infiltrated macrophages and dendritic cells showed a progressive increase in vaccinated mice and corresponded with reduction of the lung infection. Concentrations of selected inflammatory cytokines and chemokines were initially higher in lung homogenates of vaccinated mice but then generally decreased at 14 days postchallenge in correlation with containment of the organism and apparent dampening of the inflammation of host tissue. Profiles of cytokines detected in lung homogenates of ΔT-vaccinated mice were indicative of a mixed T helper 1 (Th1)-, Th2-, and Th17-type immune response, a conclusion which was supported by detection of lung infiltration of activated T cells with the respective CD4(+) gamma interferon (IFN-γ)(+), CD4(+) interleukin-5 (IL-5)(+), and CD4(+) IL-17A(+) phenotypes. While Th1 and Th2 immunity was separately dispensed of by genetic manipulation without loss of ΔT vaccine-mediated protection, loss of functional Th17 cells resulted in increased susceptibility to infection in immunized mice. Characterization of the early events of protective immunity to Coccidioides infection in vaccinated mice contributes to the identification of surrogates of immune defense and provides potential insights into the design of immunotherapeutic protocols for treatment of coccidioidomycosis.

What's Behind the Increasing Rates of Coccidioidomycosis in Arizona and California?

The number of cases of symptomatic coccidioidomycosis reported in the endemic regions of California and Arizona has increased over the past two decades. In California, the southern San Joaquin Valley has seen a dramatic increase, with rates of symptomatic illness of more than 150 per 100,000 of population in Kern County. In Arizona, almost 5,000 cases are now reported yearly. In contrast to California, the coccidioidal endemic region in Arizona is also the most populous region of the state, and Arizona now accounts for 60% of all cases reported in the United States. Reasons for these increases appear to be multifactorial. Possible etiologies include climate change, changes in local exposure, an increase in the number of individuals susceptible to infection living in the endemic region, and increased testing and reporting. None of these factors are mutually exclusive and none has been clearly established as the etiology for the increase.

The public health impact of coccidioidomycosis in Arizona and California

The numbers of reported cases of coccidioidomycosis in Arizona and California have risen dramatically over the past decade, with a 97.8% and 91.1% increase in incidence rates from 2001 to 2006 in the two states, respectively. Of those cases with reported race/ethnicity information, Black/African Americans in Arizona and Hispanics and African/Americans in California experienced a disproportionately higher frequency of disease compared to other racial/ethnic groups. Lack of early diagnosis continues to be a problem, particularly in suspect community-acquired pneumonia, underscoring the need for more rapid and sensitive tests. Similarly, the inability of currently available therapeutics to reduce the duration and morbidity of this disease underscores the need for improved therapeutics and a preventive vaccine.

Coccidioidomycosis: knowledge, attitudes, and practices among healthcare providers--Arizona, 2007

Coccidioidomycosis presumably causes ≤ 33% of community-acquired pneumonias cases, although < 15% of the patients are tested for coccidioidomycosis. We assessed healthcare providers' knowledge, attitudes, and practices regarding coccidioidomycosis diagnosis and treatment in Arizona. A survey was mailed to 7,608 eligible healthcare providers licensed by the Arizona medical, osteopathic, and nursing boards in October and December 2007. We used weights to adjust for non-response and multivariate logistic regression models to identify predictors of ≥ 70% correct regarding knowledge and treatment practices. Of 1,823 (24%) respondents, 53% were physicians, 52% were male, and the mean age was 51 years. Approximately 50% reported confidence in their ability to treat coccidioidomycosis, and 21% correctly answered all four treatment questions. Predictors of ≥ 70% correct concerning knowledge and treatment practices included always counseling patients after diagnosis (adjusted odds ratio [AOR]=4.4; 95% confidence interval [CI]: 2.8-7.1); specializing in infectious diseases (AOR=2.4; 95% CI: 1.0-5.7); and having received coccidioidomycosis continuing medical education (CME) in the last year (AOR=1.8; 95% CI: 1.2-2.6). These findings demonstrate that coccidioidomycosis CME improves knowledge of disease diagnosis and management, underscoring the need for a comprehensive coccidioidomycosis education campaign for healthcare providers in Arizona.

A risk factor study of coccidioidomycosis by controlling differential misclassifications of exposure and susceptibility using a landscape ecology approach

State-reported coccidioidomycosis cases in Arizona have dramatically increased since 1997, raising concerns about a possible epidemic, its cause, and associated risk factors, including spatio-temporal differences in susceptibility and exposure. This stratified, two-stage, cross-sectional study evaluates inherent, socio-economic, and environmental risk factors of coccidioidomycosis from information collected during an address-based telephone survey of 5460 households containing 14,105 individuals in greater Tucson, Arizona. Three geomorphic and two demographic strata controlled for differences in group-level exposures and susceptibility, and assured recruitment of a minority population. Logistic regression of self-reported cases indicates that location of residence by geomorphic and demographic strata was a risk factor that confounded the associations of coccidioidomycosis with age, race-ethnicity, and educational attainment. The risk due to age is more evenly distributed across the population than bivariate results when individual- and group-level exposure and susceptibility factors are controlled. Similarly the association for being Hispanic decreased from strong bivariate 0.28 odds ratio to a weak multivariate 0.75. Location of residence confounded the risk due to race-ethnicity and was an effect modifier of risk due to age. Differential misclassification of exposure to Coccidioides spores and susceptibility to coccidioidomycosis was reduced through landscape stratification by demographics and geomorphic types. Landscape epidemiological studies of diseases with strong environmental and demographic determinants can reduce residual confounding and account for spatial and temporal differences between neighborhoods and at broader scales.

Conventional and molecular diagnostic testing for the acute neurologic patient

OBJECTIVE

The aim of this review is to describe and evaluate both conventional and molecular diagnostic testing utilized in dogs and cats with acute neurologic diseases. Various types of polymerase chain reaction (PCR) are explored along with novel molecular diagnostic testing that ultimately may prove useful in the critical care setting.

DATA SOURCES

PUBMED was searched to obtain relevant references material using keywords: 'canine OR feline meningitis AND meningoencephalitis,''feline infectious peritonitis,''canine distemper,''canine OR feline AND toxoplasma,''canine neospora,''canine OR feline AND rickettsia,''granulomatous meningoencephalitis,''steroid responsive meningitis arteritis,''necrotizing encephalitis,''novel neurodiagnostics,''canine OR feline AND CNS borrelia,''canine OR feline AND CNS bartonella,''canine OR feline AND CNS fungal,''nested OR multiplex OR degenerate OR consensus OR CODEHOP AND PCR.' Research findings from the authors' laboratory and current veterinary textbooks also were utilized.

HUMAN DATA SYNTHESIS

Molecular diagnostic testing including conventional, real-time, and consensus and degenerate PCR and microarray analysis are utilized routinely for the antemortem diagnosis of infectious meningoencephalitis (ME) in humans. Recently, PCR using consensus degenerate hybrid primers (CODEHOP) has been used to identify and characterize a number of novel human viruses.

VETERINARY DATA SYNTHESIS

Molecular diagnostic testing such as conventional and real-time PCR aid in the diagnosis of several important central nervous system infectious agents including canine distemper virus, Toxoplasma gondii, Neospora caninum, rickettsial species, and others. Recently, broadly reactive consensus and degenerate PCR reactions have been applied to canine ME including assays for rickettsial organisms, Borrelia spp. and Bartonella spp., and various viral families.

CONCLUSIONS

In the acute neurologic patient, there are several key infectious diseases that can be pursued by a combination of conventional and molecular diagnostic testing. It is important that the clinician understands the utility, as well as the limitations, of the various neurodiagnostic tests that are available.

The diagnosis of coccidioidomycosis

Until recently, culture, microscopy, and serology have been the available methods for the diagnosis of coccidioidomycosis. While Coccidioides is frequently isolated by culture, special precautions must be taken because of the risk of laboratory infection and because Coccidioides is on the Select Agent list. Serology is useful but the sensitivity remains lower than desired. A commercially available test for coccidioidal galactomannan antigenuria now exists and appears useful for immunocompromised hosts with severe disease. Polymerase chain reaction assays targeting specific coccidioidal genes have demonstrated utility but are not commercially available. Moreover, their sensitivity and the best sample type remain unestablished.

Current status and future perspectives on molecular and serological methods in diagnostic mycology

Invasive fungal infections are an important cause of infectious morbidity. Nonculture-based methods are increasingly used for rapid, accurate diagnosis to improve patient outcomes. New and existing DNA amplification platforms have high sensitivity and specificity for direct detection and identification of fungi in clinical specimens. Since laboratories are increasingly reliant on DNA sequencing for fungal identification, measures to improve sequence interpretation should support validation of reference isolates and quality control in public gene repositories. Novel technologies (e.g., isothermal and PNA FISH methods), platforms enabling high-throughput analyses (e.g., DNA microarrays and Luminex® xMAP™) and/or commercial PCR assays warrant further evaluation for routine diagnostic use. Notwithstanding the advantages of molecular tests, serological assays remain clinically useful for patient management. The serum Aspergillus galactomannan test has been incorporated into diagnostic algorithms of invasive aspergillosis. Both the galactomannan and the serum β-D-glucan test have value for diagnosing infection and monitoring therapeutic response.

Point-source outbreak of coccidioidomycosis in construction workers

Coccidioidomycosis results from inhaling spores of the fungus Coccidioides spp. in soil or airborne dust in endemic areas. We investigated an outbreak of coccidioidomycosis in a 12-person civilian construction crew that excavated soil during an underground pipe installation on Camp Roberts Military Base, California in October 2007. Ten (83.3%) workers developed symptoms of coccidioidomycosis; eight (66.7%) had serologically confirmed disease, seven had abnormal chest radiographs, and one developed disseminated infection; none used respiratory protection. A diagnosis of coccidioidomycosis in an eleventh worker followed his exposure to the outbreak site in 2008. Although episodic clusters of infections have occurred at Camp Roberts, the general area is not associated with the high disease rates found in California's San Joaquin Valley. Measures to minimize exposure to airborne spores during soil-disrupting activities should be taken before work begins in any coccidioides-endemic area, including regions with only historic evidence of disease activity.

The spectrum and presentation of disseminated coccidioidomycosis

PURPOSE

Extrapulmonary dissemination of Coccidioides species is associated with significant morbidity and mortality. The clinical manifestations vary widely according to the host, the severity of illness, and location of dissemination. The morbidity and mortality can be reduced by early recognition and treatment, which in turn depends on understanding the spectrum and presentation of disease.

METHODS

We performed a retrospective analysis of 150 cases with extrapulmonary nonmeningeal disease seen from 1996 to 2007 at a referral medical center in an endemic region.

RESULTS

Hematogenous dissemination was associated with high mortality and occurred primarily in immunocompromised patients, but only 30% of patients with more limited forms of dissemination were immunocompromised. In keeping with prior studies, there was a preponderance of males (nearly 2:1) and people of African or Asian (especially Pacific Islanders) descent. In contrast, Hispanics and diabetics were not at increased risk. Serology was frequently negative in immunocompromised patients, but the diagnosis could be established by isolation of the organism in culture, or in histologic or cytologic specimens.

CONCLUSIONS

Although coccidioidomycosis is a great imitator, the diagnosis can usually be made readily if a high level of suspicion is maintained and appropriate diagnostic testing is performed. In most patients, that will include serologic testing in addition to cultures and histology or cytology of appropriate samples.

Voriconazole use for endemic fungal infections

In a retrospective review of 24 patients with histoplasmosis, blastomycosis, or coccidioidomycosis treated with voriconazole (most for salvage therapy), the outcome was favorable (improved or stable) for 22 (95.8%) within 2 months of starting voriconazole and for 20 (83.3%) at the last follow-up. Prospective studies are required to determine its role in the treatment of endemic mycoses.

Coccidioidomycosis in elderly persons

BACKGROUND

Coccidioidomycosis is a fungal infection acquired via inhalation of airborne fungal arthrospores of Coccidioides species in regions of endemicity in the deserts of the southwestern United States and northern Mexico. In recent years, the incidence of coccidioidomycosis has increased in areas of endemicity, and previous studies have found the highest incidence of coccidioidal infection in Arizona among persons in older age groups.

METHODS

We conducted a retrospective review of data for all patients with coccidioidomycosis who were treated at our institution that compared clinical manifestations of coccidioidomycosis in patients aged >or=60 years with those in patients aged <60 years.

RESULTS

We compared 210 patients aged >or=60 years with 186 patients aged <60 years. No significant differences were observed with regard to manifestations of coccidioidomycosis, even after adjustment for comorbid conditions, excluding immunosuppression. Regardless of age, when coccidioidal illnesses in immunosuppressed patients were compared with those in nonimmunosuppressed patients, immunosuppressed patients were significantly more likely to have extrapulmonary dissemination of infection, to require hospitalization, and to have progressive infection or to die of coccidioidomycosis. Univariate logistic regression identified immunosuppression as the only marker that increased risk of extrapulmonary dissemination of infection (odds ratio, 2.13;P=.05), hospitalization (odds ratio, 2.68; P<.001), and death (odds ratio, 8.39; P<.001). Multivariate analysis revealed that neither age nor an interaction of age and immunosuppression had a significant impact on coccidioidal manifestations.

CONCLUSIONS

Coccidioidomycosis is a serious illness in all patients, but its different manifestations in older-aged persons, compared with those in younger-aged persons, may be related to immunosuppression rather than age alone.

Coccidioidomycosis in dogs and cats: a review

The dimorphic fungi Coccidioides immitis and Coccidioides posadasii are the causative agents of coccidioidomycosis. Dogs and cats residing in and visiting endemic areas are at risk of exposure to infectious arthrospores. The primary infection is pulmonary and frequently results in chronic cough. Disseminated disease is common and causes cutaneous, osseous, cardiac, ocular, nervous system, or other organ disease. Radiographic changes include a variable degree of interstitial pulmonary infiltration, hilar lymphadenopathy, and osseous lesions. Serological titers support the diagnosis, but definitive diagnosis relies on identification of Coccidioides in cytological or tissue samples. Coccidioidomycosis should be considered in any dog or cat that has been potentially exposed during the previous 3 years and is presented with chronic illness, respiratory signs, lameness, lymphadenopathy, nonhealing cutaneous lesions, or neurological, ocular, or cardiac abnormalities.

Testing for coccidioidomycosis among patients with community-acquired pneumonia

Lack of testing may lead to underdiagnosis and underestimates of disease prevalence.

Coccidioidomycosis is a common cause of community-acquired pneumonia (CAP) in disease-endemic areas. Because testing rates influence interpretation of reportable-disease data and quality of CAP patient care, we determined the proportion of CAP patients who were tested for Coccidioides spp., identified testing predictors, and determined the proportion of tested patients who had positive coccidioidomycosis results. Cohort studies to determine the proportion of ambulatory CAP patients who were tested in 2 healthcare systems in metropolitan Phoenix found testing rates of 2% and 13%. A case-control study identified significant predictors of testing to be age >18 years, rash, chest pain, and symptoms for >14 days. Serologic testing confirmed coccidioidomycosis in 9 (15%) of 60 tested patients, suggesting that the proportion of CAP caused by coccidioidomycosis was substantial. However, because Coccidioides spp. testing among CAP patients was infrequent, reportable-disease data, which rely on positive diagnostic test results, greatly underestimate the true disease prevalence.

Exudative pleurisy of coccidioidomycosis: a case report and review of the literature

Introduction

Community-acquired pneumonia is the most common manifestation in primary coccidioides infections (Coccidioides immitis, C. posadasii). It is essential that this endemic dimorphic fungus be considered in order to proceed with the most appropriate diagnostic tools and therapy.

Case presentation

We present a rare case of primary pleural coccidioides and a review of the current literature for optimal diagnostic methods and therapeutic strategies.

Conclusion

With increased domestic and international travel, coccidioidomycosis will likely be encountered in nonendemic regions. Recognition by physicians is critical for a timely diagnosis and therapy. Tissue culture can assist in the diagnosis and polymerase chain reaction analysis shows potential as a possible addition.

Fungal Infections

The incidence of invasive fungal infections has increased dramatically over the past two decades, mostly due to an increase in the number of immunocompromised patients.1–4 Patients who undergo chemotherapy for a variety of diseases, patients with organ transplants, and patients with the acquired immune deficiency syndrome have contributed most to the increase in fungal infections.5 The actual incidence of invasive fungal infections in transplant patients ranges from 15% to 25% in bone marrow transplant recipients to 5% to 42% in solid organ transplant recipients.6,7 The most frequently encountered are Aspergillus species, followed by Cryptococcus and Candida species. Fungal infections are also associated with a higher mortality than either bacterial or viral infections in these patient populations. This is because of the limited number of available therapies, dose-limiting toxicities of the antifungal drugs, fewer symptoms due to lack of inflammatory response, and the lack of sensitive tests to aid in the diagnosis of invasive fungal infections.1 A study of patients with fungal infections admitted to a university-affiliated hospital indicated that community-acquired infections are becoming a serious problem; 67% of the 140 patients had community-acquired fungal pneumonia.8

Virulence mechanisms of coccidioides

Coccidioides is a fungal respiratory pathogen of humans that can cause disease in both immunosuppressed and immunocompetent individuals. We describe here three mechanisms by which the pathogen survives in the hostile host environment: production of a dominant spherule outer wall glycoprotein (SOWgp) that modulates host immune response and results in compromised cell-mediated immunity to coccidioidal infection, depletion of SOWgp presentation on the surface of endospores, which prevents host recognition of the pathogen when the fungal cells are most vulnerable to phagocytic defenses, and induction of elevated production of host arginase I and coccidioidal urease, which contribute to tissue damage at sites of infection. Arginase I competes with inducible nitric oxide synthase (iNOS) in macrophages for the common substrate, L-arginine, and thereby reduces nitric oxide (NO) production and increases the synthesis of host orinithine and urea. Host-derived L-ornithine may promote pathogen growth and proliferation by providing a pool of the monoamine, which could be taken up and used for synthesis of polyamines via metabolic pathways of the parasitic cells. We have shown that high concentrations of Coccidioides- and host-derived urea at infection sites in the presence of urease produced and released by the pathogen, results in secretion of ammonia and contributes to alkalinization of the microenvironment. We propose that ammonia and enzymatically active urease released from spherules during the parasitic cycle of Coccidioides exacerbate the severity of coccidioidal infection by contributing to a compromised immune response to infection and damage of host tissue at foci of infection.

The Prevention of Recrudescent Coccidioidomycosis After Solid Organ Transplantation

BACKGROUND

Coccidioidomycosis is an endemic fungal infection of the southwestern United States that causes considerable morbidity and mortality in transplant recipients, often as the result of reactivated infection.

METHODS

A retrospective review of the medical records of 47 patients with prior coccidioidomycosis who underwent solid organ transplantation (18 liver, 24 kidney, 3 pancreas, and 2 combined organ) at our tertiary care academic medical center.

RESULTS

Of 47 transplant recipients with a history of coccidioidomycosis, 44 had quiescent infection at transplantation. Of the three with active coccidioidomycosis at transplantation, two were taking azole prophylaxis and had no further coccidioidal infection after transplantation. One of the three had positive serologic findings identified only on the day of transplantation, and prophylaxis was initiated a few hours after surgery along with immunosuppression; nevertheless, the treatment course was complicated by disseminated coccidioidomycosis. Seven patients did not initiate or self-discontinued prophylaxis; one patient who discontinued prophylaxis experienced recurrent pulmonary infection.

CONCLUSIONS

For patients undergoing transplantation in an area endemic for coccidioidomycosis, we recommend routine evaluation for evidence of prior infection and initiation of azole prophylaxis. For our patients with quiescent infection, azoles suppressed any recrudescent coccidioidomycosis after transplantation. The selection of patients who would benefit from prophylaxis and the optimal dose and duration of such prophylaxis should be studied further.

The role of IL-10 in genetic susceptibility to coccidioidomycosis on mice

Epidemiological and clinical studies have confirmed that coccidioidomycosis is more severe in African American and Filipino patients than in Caucasians, suggesting a genetic basis for susceptibility in humans. We discovered that inbred strains of mice also vary greatly in their susceptibility to Coccidioides immitis infections, and although resistance is the dominant phenotype, it is a multigenic trait in mice. We found a strong direct correlation between susceptibility in mice and the amount of IL-10 made in response to infection. We then showed that IL-10-deficient mice are much more resistant to infection than the parent C57BL/6 strain. Finally, we showed that genetically resistant mice that are transgenic for IL-10 and so overproduce that cytokine are more susceptible to C. immitis. This is in part due to suppression of NOS2 expression by IL-10.

Safety, antigenicity, and efficacy of a recombinant coccidioidomycosis vaccine in cynomolgus macaques (Macaca fascicularis)

The safety, immunogenicity and efficacy of recombinant Ag2/PRA106 + CSA chimeric fusion protein (CFP) vaccine in ISS/Montanide adjuvant-administered intramuscular (IM) was assessed in adult female cynomolgus macaques challenged with Coccidioides posadasii. Animals received three immunizations with either 5 microg CFP, 50-microg CFP, or adjuvant alone and were challenged 4 weeks following the final immunization. Although significant antibody response was produced in response to vaccination, there were no discernable adverse effects, suggesting that the vaccine was well tolerated. Upon intratracheal challenge, all animals showed evidence of disease. Two animals that received 5-microg doses of CFP were euthanatized prior to the study's end because of severe symptoms. Animals vaccinated with 50-microg doses of CFP showed evidence of enhanced sensitization compared to adjuvant controls and animals vaccinated with 5-microg doses of CFP. This was based on higher serum anti-CFP titers, enhanced secretion of interferon-gamma (IFN-gamma) from stimulated bronchoalveolar lavage mononuclear cells (BALMC), reduced pulmonary radiologic findings following intratracheal challenge, reduced terminal complement fixation titers, and reduced necropsy findings. Overall the vaccine was well tolerated, induced sensitization, and resulted in a protective response when given at the higher 50-microg dose. Additional experiments may be needed to optimize the vaccination and to confer greater protection against lethal challenge.

Laboratory Aspects in the Diagnosis of Coccidioidomycosis

Coccidioides immitis and Coccidioides posadasii, the two recognized causes of coccidioidomycosis, may be detected by direct microscopy, culture, and serologic documentation. Two useful stains include the Grocott methenamine silver (GMS) and the calcofluor white (CFW). Other useful stains used in histopathologic studies include hematoxylin-eosin (H&E) and periodic acid Schiff (PAS). Nucleic acid amplification tests (NAATs) have been introduced for detection of Coccidioides spp. in specimens, but are not yet commercially available. Isolation of Coccidioides spp. by culture is not difficult as many fungal as well as routine bacteriologic media are available. For the safe isolation of Coccidioides spp., the laboratory should maintain a biological safety level 2 or 3. Identification of Coccidioides spp. uses the organisms' phenotypic or genotypic characteristics. Phenotypic identification to genus level may be achieved by visualization of spherules in specimens and/or by the presence of arthroconidia in culture. Isolates may be confirmed as Coccidioides spp. by molecular probes. Separation of species into C. immitis and C. posadasii is best achieved by specialized molecular techniques which are not normally available in routine clinical laboratories. Humoral antibodies can be used for the diagnosis and prognosis of coccidioidomycosis. Although positive serologic results may be helpful in the diagnosis of coccidioidomycosis, negative serologic results cannot be used to rule out the disease. Enzyme immunoassays (EIA) and immunodiffusion methods are commonly used for detection of both IgM and IgG antibody groups. Sequential complement fixation (CF) studies for IgG class of antibody are useful for the prognosis of coccidioidomycosis.

State-of-the-Art Treatment of Coccidioidomycosis Skeletal Infections

Coccidioidomycosis is a fungal infection endemic to the southwestern United States. Typically a respiratory illness, coccidioidomycosis can rarely present as extrapulmonary infection. Skeletal coccidioidomycosis occurs in 20% to 50% of disseminated infections. Skeletal coccidioidomycosis is a chronic and progressive infection that eventually results in bone destruction and loss of function and often involves adjacent structures, such as joints, muscles, and tendons and other soft tissues. Sinus tract formation may occur. This infection may be multifocal. Although radiographs, white blood cell count scans, and other imaging methods identify and define relevant abnormalities, histopathologic examination with culture of the involved bone is the only means to confirm the diagnosis. Serologic testing is adjunctive, and complement fixation titers can be evaluated serially to assess response to treatment. A number of studies addressing the efficacy of various antifungal agents have been performed, and the results of these studies as they pertain to skeletal coccidioidomycosis are summarized herein. Among the various studies, response rates ranged from 23% to 100%, but relapse was common. A combination of medical therapy-often, itraconazole or fluconazole-and surgical débridement is often needed to control skeletal coccidioidomycosis. Early diagnosis and treatment are critical to avoid long-term problems with chronically infected bones and joints. Anatomical issues, diagnostic studies, and data related to treatment of this form of extrapulmonary coccidioidomycosis are reviewed in this article.

Coccidioidomycosis in California State Correctional Institutions

Coccidioidomycosis (CM) has been recognized in inmates of California State prisons since 1919, where it has been diagnosed in inmates of various correctional facilities inside and outside the known endemic areas. In recent years construction of new prisons within endemic areas has led to an increase in the number of cases of CM. In 2005 and 2006, the Pleasant Valley State Prison (PVSP) near Coalinga and Avenal State Prison (ASP) near Avenal on the western side of the San Joaquin Valley have been particularly affected. In 2005, our serologic testing yielded 150 new cases from PVSP and 30 from ASP. The incidence rate in 2005 for PVSP (population approximately 5,000) was at least 3,000 per 100,000, and this will be exceeded in 2006. Some cases diagnosed in early 2006 likely were infections that were acquired in 2005. Some cases are medically managed on site, but very ill inmates have had care in nonprison facilities. Precise numbers of patients who were hospitalized were not made available to the author. Estimates of the cost per patient have varied from $8,000 in the 1990s to $30,000 more recently. Thus, this disease has important medical, demographic, and financial implications for the state.

Serologic testing for symptomatic coccidioidomycosis in immunocompetent and immunosuppressed hosts

Serologic studies are an important diagnostic tool in the clinical evaluation and follow-up of persons with coccidioidomycosis. Numerous types of serologic tests are available, including immunodiffusion, enzyme immunoassay, and complement fixation. We conducted a retrospective review of the results of 1,797 serologic tests spanning 12 months from the onset of coccidioidomycosis in 298 immunocompetent and 62 immunosuppressed persons with symptomatic infection. Using the onset of symptoms as a reference point, we plotted the positive or negative serologic results over time for both groups. Compared with the immunocompetent group, immunosuppressed persons had lower rates of seropositivity for every type of test during the first year after onset of symptoms for coccidioidomycosis, although many results did not achieve statistical significance. Combining the results of these tests increased the sensitivity of the serologic evaluation in immunocompromised patients. Immunosuppressed persons have the ability to mount a serologic response to coccidioidomycosis, but in some circumstances, multiple methods may be required to improve detection.

Detection of Coccidioides species in clinical specimens by real-time PCR

Coccidioides spp. are dimorphic fungal pathogens endemic to the semiarid regions of North, Central, and South America. Currently, direct smear and culture are the most common means of identifying Coccidioides spp. While these methods offer relatively sensitive and specific means of detecting Coccidioides spp., growth in culture may take up to 3 weeks, potentially delaying the diagnosis and initiation of appropriate antifungal therapy. In addition, growth of the organism represents a significant safety risk to laboratory personnel. The need for a rapid and safe means of diagnosing coccidioidomycosis prompted us to develop a real-time PCR assay to detect Coccidioides spp. directly from clinical specimens. Primers and fluorescent resonance energy transfer (FRET) probes were designed to target the internal transcribed spacer 2 region of Coccidioides. The assay's limit of detection is below 50 targets per reaction. An analysis of 40 Coccidioides sp. clinical isolates grown in culture demonstrated 100% sensitivity of the assay. A cross-reactivity panel containing fungi, bacteria, mycobacteria, and viruses was tested and demonstrated 100% specificity for Coccidioides spp. An analysis of 266 respiratory specimens by LightCycler PCR demonstrated 100% sensitivity and 98.4% specificity for Coccidioides spp. compared with culture. Analysis of 66 fresh tissue specimens yielded 92.9% sensitivity and 98.1% specificity versus those of the culture method. The sensitivity of the assay testing 148 paraffin-embedded tissue samples is 73.4%. A rapid method for the detection of Coccidioides spp. directly from clinical material will greatly assist in the timely diagnosis and treatment of patients, while at the same time decreasing the risk of accidental exposure to laboratory personnel.

Coccidioidomycosis in patients with diabetes mellitus

PURPOSE

The study reviewed the interrelationships of diabetes mellitus and coccidioidomycosis.

SUBJECTS AND METHODS

We conducted a retrospective review of the medical records of immunocompetent patients with coccidioidomycosis who were treated at our academic medical institution between January 1, 1999, and October 31, 2003, to compare those with and without diabetes mellitus and to determine whether glycemia correlates with the course of illness.

RESULTS

Of 329 immunocompetent patients with coccidioidomycosis, 44 had diabetes (4 type 1 and 40 type 2) and were divided into 2 groups: those with serum glucose concentrations of less than 12.2 mmol/L (220 mg/dL) and those with glucose concentrations of greater than or equal to 12.2 mmol/L (220 mg/dL). Persons with diabetes in either glucose group were more likely than those without diabetes to have cavitary lung disease (relative risk, 2.94; P<.001) and relapsed infection. However, only the diabetes group with serum glucose concentrations greater than or equal to 12.2 mmol/L (220 mg/dL) were more likely to have disseminated infection (relative risk, 2.8; P=.05) and to require treatment (relative risk, 9.85; P=.005), but their infection was less likely to resolve (relative risk, 0.24; P=.002).

CONCLUSION

Because glycemia strongly correlated with clinical characteristics of coccidioidomycosis in this cohort, we recommend routine measurement of serum glucose in persons with coccidioidomycosis to identify patients with an increased risk of complicated infection. Future studies should evaluate the efficacy of tight glycemic control on the outcome of coccidioidal infection.

Coccidioidomycosis

The difficulties in managing this potentially horrific disease, with its myriad manifestations, are immense, because host factors dramatically impact outcome. Coccidioidomycosis should warrant great respect among clinicians, because, even with dramatic improvements in therapies, outcomes remain poor. Although there have been outstanding successes with these new therapies, tragic losses after years of immense patient suffering still occur. Coccidioidomycosis is a geographically restricted fungus but is one that inflicts tremendous suffering on affected patients. In addition, because of travel and the influx of susceptible hosts, dramatic increases in patients at risk for infection are seen throughout the southwest United States. The extended-spectrum azoles, such as posaconazole and voriconazole, may prove to be more efficacious in the treatment of coccidioidomycosis than prior agents, including amphotericin B, fluconazole, and itraconazole. Additional resources are needed to conduct randomised, controlled clinical trials for the treatment of this disease.

Unusual presentations of coccidioidomycosis: a case series and review of the literature

Coccidioidomycosis is an emerging fungal infection of the southwestern United States. Although Coccidioides species infections are usually asymptomatic or result in a mild, flu-like illness, disseminated disease may occur in 1% of cases. While extrapulmonary disease usually involves the skin, central nervous system, bones, or joints, coccidioidomycosis is a great imitator, with the ability to infect any tissue or organ. Cases may be diagnosed outside of endemic areas, hence providers worldwide should be aware of the broad range of manifestations of coccidioidomycosis. We present a case series of unusual presentations of coccidioidomycosis including serous cavity infections with cases of pericarditis, empyema, and peritonitis, as well as unusual abscesses involving the retropharyngeal space and gluteal musculature. We provide a complete review of the literature and summarize the clinical presentations, diagnoses, and treatments of these rare forms of disseminated coccidioidomycosis.

Coccidioidomycosis as a common cause of community-acquired pneumonia

The early manifestations of coccidioidomycosis (valley fever) are similar to those of other causes of community-acquired pneumonia (CAP). Without specific etiologic testing, the true frequency of valley fever may be underestimated by public health statistics. Therefore, we conducted a prospective observational study of adults with recent onset of a lower respiratory tract syndrome. Valley fever was serologically confirmed in 16 (29%) of 55 persons (95% confidence interval 16%–44%). Antimicrobial medications were used in 81% of persons with valley fever. Symptomatic differences at the time of enrollment had insufficient predictive value for valley fever to guide clinicians without specific laboratory tests. Thus, valley fever is a common cause of CAP after exposure in a disease-endemic region. If CAP develops in persons who travel or reside in Coccidioides-endemic regions, diagnostic evaluation should routinely include laboratory evaluation for this organism.

High levels of interleukin-10 impair resistance to pulmonary coccidioidomycosis in mice in part through control of nitric oxide synthase 2 expression

We have shown previously that there is a direct correlation between IL-10 levels and susceptibility to Coccidioides immitis peritonitis in C57BL/6 (B6), DBA/2, and BXD recombinant inbred mice. We now show that B6 mice are also more susceptible to C. immitis pneumonia and that interleukin-10 (IL-10)-deficient (IL-10-/-) B6 mice are more resistant to C. immitis pneumonia. In addition, we established that high levels of IL-10 are sufficient to make genetically resistant mice susceptible to both C. immitis peritonitis and pneumonia by infecting h.IL-10 transgenic mice. Infected h.IL-10 transgenic mice express lower levels of gamma interferon, IL-12 p40, and inducible nitric oxide synthetase 2 (NOS2) mRNA in their lungs, implicating inducible NOS as a defense mechanism in this disease. We treated DBA/2 mice with aminoguanidine, and they became more susceptible to C. immitis peritonitis and pneumonia. We conclude that high levels of IL-10 are both necessary and sufficient to make mice susceptible to C. immitis, regardless of the genetic background of the mice, and that IL-10 impairs resistance to C. immitis in part by suppressing NO synthesis.

Protein expression profiling of Coccidioides posadasii by two-dimensional differential in-gel electrophoresis and evaluation of a newly recognized peroxisomal matrix protein as a recombinant vaccine candidate

Coccidioides posadasii and Coccidioides immitis are dimorphic, soil-dwelling pathogenic ascomycetes endemic to the southwestern United States. Infection can result from inhalation of a very few arthroconidia, but following natural infection, long-lived immunity is the norm. Previous work in the field has shown that spherule-derived vaccines afford more protection than those from mycelia. We have used two-dimensional differential in-gel electrophoresis coupled with nano-high-performance liquid chromatography-tandem mass spectrometry to directly assess both absolute abundance and differential expression of proteins in the spherule and the mycelial phases of C. posadasii with the intent to identify potential vaccine candidates. Peptides derived from 40 protein spots were analyzed and a probable identity was assigned to each. One spherule-abundant protein, identified as Pmp1, showed homology to allergens from Aspergillus fumigatus and other fungi, all of which exhibit similarity to yeast thiol peroxidases. Recombinant Pmp1 was reactive with serum from individuals with both acute and protracted disease, and evoked protection in two murine models of infection with C. posadasii. These results demonstrate the utility of proteomic analysis as a point of discovery for protective antigens for possible inclusion in a vaccine candidate to prevent coccidioidomycosis.

Improved protection of mice against lethal respiratory infection with Coccidioides posadasii using two recombinant antigens expressed as a single protein

Two recombinant antigens which individually protect mice from lethal intranasal infection were studied in combination, either as a mixture of two separately expressed proteins or as a single chimeric expression product. Mice vaccinated with either combination survived longer than mice given single antigens. Immunized mice also exhibited specific IgG immunoglobulins and yielded splenocytes which produced interferon-gamma in response to either antigen. The chimeric antigen has the practical advantage of offering enhanced protection from multiple components without increasing production costs.