Safety of fluconazole in kidney transplant recipients for prevention of coccidioidomycosis

Coccidioides is an endemic fungus that causes infections ranging from mild respiratory illness to life-threatening disease, and immunocompromised hosts such as solid organ transplant recipients are at higher risk for disseminated infection and mortality. Our center administers fluconazole prophylaxis to kidney transplant recipients residing in geographic areas with higher incidences of coccidioidomycosis. However, because drug-drug interactions occur between triazoles and immunosuppressants used in transplant medicine, we undertook a study to ascertain whether fluconazole prophylaxis was associated with any important safety outcomes in kidney transplant recipients. This retrospective study evaluated patients who had undergone kidney transplantation between 2016 and 2019. Data on patient demographics, transplant-related clinical information, use of fluconazole prophylaxis (200 mg daily for 6-12 months post-transplant), and patient outcomes were obtained. The primary outcome was mean estimated glomerular filtration rate (eGFR) at 12 months, comparing those who received fluconazole prophylaxis to those who did not. Secondary outcomes included mean eGFR at 3 months, 6 months, and 9 months post-transplant, patient survival, biopsy-proven graft rejection, graft loss, or a new requirement for post-transplant dialysis, all within 12 months post-transplant. The mean eGFR at 12 months was similar between both groups, with 66.4 ml/min/1.73 m² in the fluconazole prophylaxis group vs. 64.3 ml/min/1.73 m² in the non-fluconazole prophylaxis group (P = 0.55). Secondary outcomes were similar across both groups. Multivariable linear regression found no significant association between fluconazole use and graft function. Fluconazole prophylaxis for prevention of coccidioidomycosis was not associated with adverse graft outcomes in kidney transplant recipients.

Comparison of coccidioidal complement fixation and quantitative immunodiffusion serology at a reference laboratory

The incidence of coccidioidomycosis continues to increase. The diagnosis frequently relies on non-invasive diagnostic testing with immunodiffusion and complement fixation (CF) testing the current gold standard. A direct comparison of quantitative immunodiffusion and CF for IgG antibodies has not been previously reported. In a comparison of 368 samples, there was close concordance observed (360/368 = 97.8%) (P-value < .001). These tests can be considerably interchangeable in the reference laboratory setting.

The dog as a sentinel and animal model for coccidioidomycosis

Coccidioidomycosis is a potentially fatal fungal disease of humans and animals that follows inhalation of Coccidioides spp. arthroconidia in the environment. The disease in dogs resembles that in people, and because dogs may be at increased risk of exposure due to their proximity to the ground and digging behavior, they are valuable models for the disease in humans. Dogs have been sentinels for identification of new regions of endemicity in Washington and Texas. Canine serosurveillance has also been used to predict variables associated with environmental presence of Coccidioides spp. Expansion of the endemic region of coccidioidomycosis with climate change-along with predicted population increases and increased development in the southwest United States-may result in 45.4 million additional people at risk of infection by 2090. Here we provide an overview of the value of dogs as sentinels for the disease and encourage the routine reporting of coccidioidomycosis cases in dogs to public health agencies. We also highlight the value of dogs as naturally occurring models for studying novel treatment options and preventatives, such as a novel live avirulent coccidioidomycosis vaccine.

Invasive Fungal Infections and Oomycoses in Cats: 1. Diagnostic approach

CLINICAL RELEVANCE

In contrast to superficial fungal infections, such as dermatophytosis, invasive fungal infections (IFIs) are characterised by penetration of tissues by fungal elements. Disease can spread locally within a region or can disseminate haematogenously or via the lymphatics. The environment is the most common reservoir of infection. Since fungal spores are airborne, indoor cats are also susceptible to IFIs. Some environmental fungi are ubiquitous and present globally, while others are endemic or hyperendemic within specific geographic regions. Zoonotic pathogens include Microsporum canis, Sporothrix schenckii and Sporothrix brasiliensis.

AIM

In the first of a two-part article series, the approach to the investigation of feline IFIs and oomycoses is reviewed. As well as tips for diagnosis, and information on the ecological niche and distribution of fungal pathogens, the review covers clinical presentation of the most common IFIs, including cryptococcosis, histoplasmosis, blastomycosis, coccidioidomycosis, sporotrichosis, phaeohyphomycosis, aspergillosis and dermatophytic pseudomycetoma, as well as the oomycoses pythiosis, lagenidiosis and paralagenidiosis. In Part 2, the spectrum of activity, mechanisms of action, pharmacokinetic and pharmacodynamic properties and adverse effects of antifungal drugs are reviewed, and the treatment and prognosis for specific IFIs and oomycoses are discussed.

EVIDENCE BASE

The review draws on published evidence and the authors' combined expertise in feline medicine, mycology, dermatology, clinical pathology and anatomical pathology.

Invasive fungal infections and oomycoses in cats 2. Antifungal therapy

CLINICAL RELEVANCE

Invasive fungal infections (IFIs) and oomycoses (hereafter termed invasive fungal-like infections [IFLIs]) are characterised by penetration of tissues by fungal elements. The environment is the most common reservoir of infection. IFIs and IFLIs can be frustrating to treat because long treatment times are usually required and, even after attaining clinical cure, there may be a risk of relapse. Owner compliance with medication administration and recheck examinations can also decline over time. In addition, some antifungal drugs are expensive, have variable interpatient pharmacokinetic properties, can only be administered parenterally and/or have common adverse effects (AEs). Despite these limitations, treatment can be very rewarding, especially when an otherwise progressive and fatal disease is cured.

AIM

In the second of a two-part article series, the spectrum of activity, mechanisms of action, pharmacokinetic and pharmacodynamic properties, and AEs of antifungal drugs are reviewed, and the treatment and prognosis of specific IFIs/IFLIs - dermatophytic pseudomycetoma, cryptococcosis, sino-orbital aspergillosis, coccidioidomycosis, histoplasmosis, sporotrichosis, phaeohyphomycosis, mucormycosis and oomycosis - are discussed. Part 1 reviewed the diagnostic approach to IFIs and IFLIs.

EVIDENCE BASE

Information on antifungal drugs is drawn from pharmacokinetic studies in cats. Where such studies have not been performed, data from 'preclinical' animals (non-human studies) and human studies are reviewed. The review also draws on the wider published evidence and the authors' combined expertise in feline medicine, mycology, dermatology, clinical pathology and anatomical pathology.

ABBREVIATIONS FOR ANTIFUNGAL DRUGS

AMB (amphotericin B); FC (flucytosine); FCZ (fluconazole); ISA (isavuconazole); ITZ (itraconazole); KCZ (ketoconazole); PCZ (posaconazole); TRB (terbinafine); VCZ (voriconazole).

Novel Presentation of Coccidioidomycosis with Myriad Free-Floating Proteinaceous Spheres in the Pericardial Sac of a Southern Sea Otter (Enhydra lutris nereis)

A southern sea otter (Enhydra lutris nereis) stranded dead in central California, USA, with a distended pericardial sac containing thousands of free-floating proteinaceous masses. Serology, fungal culture, PCR, and sequencing confirmed the etiology of this novel lesion as Coccidioides immitis. Range expansion of this zoonotic pathogen is predicted with climate change.

Diagnostic delays in cutaneous coccidioidomycosis: A report from Central California

Cutaneous Coccidioidomycosis (CC) infection can present with a wide variety of clinical presentations and is well known as a 'great imitator'. We performed a retrospective analysis of patients with CC in a large referral center in Central Valley, California, from 2010 to 2022 using the ICD9 and ICD10 codes for coccidioidomycosis and CC. We identified 40 patients with CC during the study period. The mean age of the study population was 43 years (with standard deviation of 14.08). Among these, 60% were men and 40% women. The appearance of the lesions varied from ulcers, plaques, nodules, blisters, cellulitis, and abscesses. The most common site of CC lesions was in the lower extremities (42.5%), followed by upper extremities (30%), chest and abdomen, head and neck (25% each). Only 22.5% of the 40 cases were diagnosed as CC and 15% were diagnosed as erythema nodosum. Rest were diagnosed initially as bacterial cellulitis in 37.5%, tinea in 7.5%, and others in 12.5%. There was resolution of the cutaneous lesions in all patients with antifungal treatment. The mean time of diagnosis from onset of symptoms on an average was 12 weeks (8-16 weeks) in our study with 75% cases initially misdiagnosed. Comprehensive knowledge about the manifestations and evaluation of CC among primary care providers and emergency room physicians is essential to prevent delays in diagnosis and treatment.

Coccidioides spp. exposure among military working dogs in endemic regions of the United States

Coccidioidomycosis is a fungal disease in arid regions of the United States that is predicted to expand with climate change. Cases in military personnel and military working dogs (MWDs) impact personnel readiness and result in healthcare costs. To examine Coccidioides exposure among MWDs, 276 banked serum samples were retrieved from dogs housed in California, Texas, Arizona, New Mexico, Nevada, and Utah. Using gel immunodiffusion, six (2.1%) specimens were IgG-positive and three (1.1%) were equivocally IgM-positive. The IgG-positive samples were from Arizona (2 [prevalence 8.0%]) and California (4 [3.7%]). These data will guide future efforts to study MWDs as sentinels for human coccidioidomycosis.

Temporal tracheobronchial lymphadenopathy resolution is affected by initial severity and poorly correlated to serologic antibody testing in dogs with pulmonary coccidioidomycosis

OBJECTIVE

To determine associations between antibody serologic tests and tracheobronchial lymphadenopathy (TBL) in dogs with pulmonary coccidioidomycosis and identify variables associated with time to resolution of TBL.

ANIMALS

32 client owned dogs with newly diagnosed pulmonary coccidioidomycosis from October 2020 to February 2021.

METHODS

Prospective cohort study. Thoracic radiographs and anti-Coccidioides spp antibody serology were performed at baseline and once every 3 months until remission or for a maximum of 12 months. Radiographic tracheobronchial lymph node height, length, and area were measured and recorded as ratios via comparison with the length of the T4 vertebral body (LT4) and length of the manubrium. Severity of TBL was also subjectively categorized as mild, moderate, or severe.

RESULTS

Tracheobronchial lymphadenopathy was identified in 81% (26/32; 95% CI, 64% to 93%) of dogs. There was no relevant association between TBL presence or severity and antibody serology results. Tracheobronchial lymphadenopathy resolved in 72% (n = 18) of dogs at the 3-month evaluation. The median time to resolution of TBL after initiation of fluconazole was 96 days (range, 72 to 386 days). Univariate analysis identified increasing TBL severity (hazard ratio, 0.40; 95% CI, 0.19 to 0.84; P = .02) and length:LT4 ratio (hazard ratio, 0.41; 95% CI, 0.20 to 0.82; P = .01) as variables associated with reduced probability of resolution of TBL.

CLINICAL RELEVANCE

Antibody serologic test results are not clinically useful to predict TBL presence or severity in dogs with pulmonary coccidioidomycosis, and larger tracheobronchial lymph nodes are more likely to take longer to resolve. Resolution of TBL occurs in most dogs within 3 to 6 months after fluconazole administration.

Coccidioides species antifungal susceptibility testing: Experience from a large healthcare system in the endemic region

The clinical utility of Coccidioides species antifungal susceptibility testing (AST) remains unclear. This study describes the clinical course of eight patients with severe or chronic coccidioidomycosis and subsequent Coccidioides AST. We present the clinical manifestations, antifungal treatment regimens, and clinical outcomes for these patients.

Natural history of pulmonary coccidioidomycosis: Further examination of the VA-Armed Forces Database

There are still many limitations related to the understanding of the natural history of differing forms of coccidioidomycosis (CM), including characterizing the spectrum of pulmonary disease. The historical Veterans Administration-Armed Forces database, recorded primarily before the advent of antifungal therapy, presents an opportunity to characterize the natural history of pulmonary CM. We performed a retrospective cohort study of 342 armed forces service members who were diagnosed with pulmonary CM at VA facilities between 1955 to 1958, followed through 1966, who did not receive antifungal therapy. Patients were grouped by predominant pulmonary finding on chest radiographs. The all-cause mortality was low for all patients (4.6%). Cavities had a median size of 3-3.9 cm (IQR: 2-2.9-4-4.9 cm), with heterogeneous wall thickness and no fluid level, while nodules had a median size of 1-1.19 cm (Interquartile range [IQR] 1-1.9-2-2.9 cm) and sharp borders. The majority of cavities were chronic (85.6%), and just under half were found incidentally. Median complement fixation titers in both the nodular and cavitary groups were negative, with higher titers in the cavitary group overall. This retrospective cohort study of non-disseminated coccidioidomycosis, the largest to date, sheds light on the natural history, serologic markers, and radiologic characteristics of this understudied disease. These findings have implications for the evaluation and management of CM.

Soil and climactic predictors of canine coccidioidomycosis seroprevalence in Washington State: An ecological cross-sectional study

Coccidioidomycosis is a predominantly respiratory infection of animals and humans caused by soil-dwelling fungi. Long known to be endemic to North American deserts, locally acquired human cases first emerged in Washington State in 2010. To inform development of an environmental niche map, we conducted an ecological cross-sectional study of the association between soil and climactic variables and canine seroprevalence in Washington State, at the zip code tabulation area level. Soil predictors included soil texture (per cent sand, silt and clay), pH, electrical conductivity and water storage capacity; climactic predictors included mean annual air temperature and liquid precipitation. Clustering was evaluated with Moran's I, and four modelling approaches were adopted a priori: two models without any smoothing (logistic regression and quasi-logistic regression) and two smoothing models (non-spatial and spatial smoothing). No evidence was found for clustering, and both smoothing models resulted in marked attenuation of all coefficients. Temperature was found to have a positive effect in the non-smoothing models (prevalence odds ratio, logistic model: 1.70, 95% confidence interval 1.02, 2.84). While no other significant associations were found, there was suggestive evidence of a positive effect for pH. Despite the limitations inherent to the ecological and cross-sectional nature of these data, these findings provide insight for the development of an environmental niche map in Washington State and demonstrate the utility of using data from an animal sentinel to predict human disease risk.

Autochthonous Transmission of Coccidioides in Animals, Washington, USA

We report 5 cases of coccidioidomycosis in animals that were acquired within Washington, USA, and provide further evidence for the environmental endemicity of Coccidioides immitis within the state. Veterinarians should consider coccidioidomycosis in animals with compatible clinical signs that reside in, or have traveled to, south central Washington.

Coccidioidomycosis in an Indoor-housed Rhesus Macaque (Macaca mulatta)

Coccidioides spp. are saprophytic, dimorphic fungi that are endemic to arid climates, are capable of infecting many species, and result in diverse clinical presentations. An indoor-housed laboratory rhesus macaque presented with weight loss and decreased activity and appetite. During the diagnostic evaluation, a bronchiolar-alveolar pattern in the cranial lung lobes, consistent with bronchopneumonia, was noted on radiographs. Given the poor prognosis, the macaque was euthanized. Confirming the radiographic assessment, gross necropsy findings included multifocal to coalescing areas of consolidation in the right and left cranial lung lobes. Microscopically, the consolidated regions were consistent with a pyogranulomatous bronchopneumonia and contained round, nonbudding, fungal yeast structures considered to be morphologically consistent with Coccidioides immitis. Culture and colony morphology results were confirmed through additional diagnostic testing. Sequencing of the D1-D2 domain of the 28S large ribosomal subunit positively matched with a known sequence specific to C. immitis. Serology for Coccidioides spp. by both latex agglutination (IgM) and immunodiffusion (IgG) was positive. In this rhesus macaque, the concordant results from histology, culture, DNA sequencing, and serology were collectively used to confirm the diagnosis of coccidioidomycosis. This animal likely acquired a latent pulmonary infection with Coccidioides months prior to arrival, when housed outdoors in a Coccidioides-endemic area. The nonspecific clinical presentation in this macaque, coupled with the recent history of indoor housing and lag between clinical presentation and outdoor housing, can make similar diagnostic cases challenging and highlights the need for awareness regarding animal source when making an accurate diagnosis in an institutional laboratory setting.

Enzymes as feed additive to aid in responses against Eimeria species in coccidia-vaccinated broilers fed corn-soybean meal diets with different protein levels

This research aimed to evaluate the effects of adding a combination of exogenous enzymes to starter diets varying in protein content and fed to broilers vaccinated at day of hatch with live oocysts and then challenged with mixed Eimeria spp. Five hundred four 1-d-old male Cobb-500 chickens were distributed in 72 cages. The design consisted of 12 treatments. Three anticoccidial control programs [ionophore (IO), coccidian vaccine (COV), and coccidia-vaccine + enzymes (COV + EC)] were evaluated under 3 CP levels (19, 21, and 23%), and 3 unmedicated-uninfected (UU) negative controls were included for each one of the protein levels. All chickens except those in unmedicated-uninfected negative controls were infected at 17 d of age with a mixed oral inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Live performance, lesion scores, oocyst counts, and samples for gut microflora profiles were evaluated 7 d postinfection. Ileal digestibility of amino acids (IDAA) was determined 8 d postinfection. Microbial communities (MC) were analyzed by G + C%, microbial numbers were counted by flow cytometry, and IgA concentrations were measured by ELISA. The lowest CP diets had poorer (P < or = 0.001) BW gain and feed conversion ratio in the preinfection period. Coccidia-vaccinated broilers had lower performance than the ones fed ionophore diets during pre- and postchallenge periods. Intestinal lesion scores were affected (P < or = 0.05) by anticoccidial control programs, but responses changed according to gut section. Feed additives or vaccination had no effect (P > or = 0.05) on IDAA, and diets with 23% CP had the lowest (P < or = 0.001) IDAA. Coccidial infection had no effect on MC numbers in the ileum but reduced MC numbers in ceca and suppressed ileal IgA production. The COV + EC treatment modulated MC during mixed coccidiosis infection but did not significantly improve chicken performance. Results indicated that feed enzymes may be used to modulate the gut microflora of cocci-vaccinated broiler chickens.

Holocene coccidioidomycosis: Valley Fever in early Holocene bison (Bison antiquus)

Early Holocene bison mandibles (Bison antiquus) from Nebraska, ca. 8500 y ago, were examined with a variety of modern histotechnological procedures and staining techniques. A pathological, anatomical diagnosis of moderately severe, locally extensive, mandibular osteomyelitis with intralesional spherules morphologically consistent with fungal pathogens in the genus Coccidioides was made. The modern distribution of the organisms in North America is restricted to the arid Southwest. This implies either the fossil home range of the fungi was larger than it is today or fossil bison migrated between endemic and nonendemic foci during the early Holocene.

Comparative aspects of coccidioidomycosis in animals and humans

Coccidioides spp. appear capable of infecting all mammals and at least some reptiles. Development of disease as a result of infection is species-dependent. Dogs seem to have a susceptibility similar to that of humans, with subclinical infections, mild-to-severe primary pulmonary disease, and disseminated disease. Whereas central nervous system disease in humans is typically meningitis, brain disease in dogs and cats takes the form of granulomatous parenchymal masses. Osteomyelitis is the most common form of disseminated disease in the dog, while skin lesions predominate in the cat. Orally administered azole antifungal agents are the backbone of therapy in animals as they are in humans.

Diagnosis and treatment of ocular coccidioidomycosis in a female captive chimpanzee (Pan troglodytes): a case study

We report here the first documented case of ocular coccidioidomycosis in a chimpanzee (Pan troglodytes). In 1996, a 12-year-old female chimpanzee was undergoing treatment with an experimental triazole, BayR3783, for coccidioidomycosis when she was diagnosed with severe conjunctivitis in the right eye. Subsequent development of a coccidioidal granuloma of the ventral conjunctiva and anterior uvea was noted over the next several months, distorting the lens, iris, pupil, and sclera and progressing to uveitis. Treatment with BayR3783 and subconjunctival injections of triamcinolone were successful in reducing the ocular mass, but extensive damage was done to the lens and cornea. This case study provides an interesting comparison to ocular coccidioidomycosis cases observed in both humans and canines.

Comparison of Coccidioides immitis serological antibody titres between forms of clinical coccidioidomycosis in horses

A retrospective study was performed to determine if there is an association between serological Coccidioides immitis antibody titres (IgG) and form/severity of coccidioidal disease in horses, and to identify trends in survival and treatment success based on the form of the disease. Data were obtained on horses with positive serological titres tested at the Coccidioidomycosis Serology Laboratory, School of Medicine, University of California, Davis from 1981 to 2004. Thirty-nine cases in which a diagnosis of coccidioidomycosis had been made were selected for inclusion. Six distinct categories were identified including abortion (n=6), miliary/interstitial pneumonia (n=6), pneumonia with thoracic effusion (pleural or pericardial) (n=11), disseminated (n=10), osteomyelitis (n=3) and external abscessation (n=3) both without pulmonary disease. Statistical differences in titre distribution were found between the abortion category and the pulmonary category (P=0.003), the abortion category and pneumonia with thoracic effusion (P=0.001), the abortion category and disseminated disease (P=0.001), and the pulmonary form and pneumonia with effusion (P=0.001). The other categories had overlapping titre results. Higher serological antibody titres seemed to be associated with a poorer prognosis for survival. Categories with the highest titres, disseminated (geometric mean titre=104) and pneumonia with thoracic effusion (geometric mean titre=226), were overwhelmingly fatal (19/21 known deaths) due to severe clinical disease. The categories with lower titres, abortion (geometric mean titre=4), bone involvement only (geometric mean titre=13) and cutaneous (geometric mean titre=5), had a better survival rate (10/12 known survivors) and less severe clinical disease. Measurement of serological titre may be a useful diagnostic aid in establishing form and severity of disease and thus inform prognosis.

DISSEMINATED COCCIDIOIDOMYCOSIS IN A CAPTIVE INDOCHINESE TIGER (PANTHERA TIGRIS CORBETTI) WITH CHRONIC RENAL DISEASE

A 19-yr-old, 78.2-kg captive female Indochinese tiger (Panthera tigris corbetti) from the El Paso Zoo (El Paso, Texas, USA) with chronic renal disease was euthanized after a 10-day course of anorexia, depression, progressive rear limb weakness, muscle fasciculations, and head tremors. Postmortem findings included pericardial effusion, generalized lymphadenopathy, glomerulosclerosis, glomerular atrophy with membranous glomerulonephropathy, and pancreatic adenocarcinoma. Pyogranulomatous pneumonia, pericarditis, and lymphadenitis were associated with fungal spherules histomorphologically consistent with Coccidioides immitis. Rising antibodies to C. immitis were detected on samples obtained perimortem and 2 mo before euthanasia. Retrospective serology was negative for two additional Indochinese tigers, two Iranian leopards (Panthera pardus saxicolor), two jaguars (Panthera onca), two bobcats (Lynx rufus texensis), two ocelots (Leopardus pardalis), and three Amur leopards (Panthera pardus orientalis) housed at the zoo over an 8-yr period. Despite being located within the endemic region for C. immitis, this is only the second case of coccidioidomycosis reported from this institution.

Treatment of Coccidioides immitis pneumonia in two horses with fluconazole

Pulmonary coccidioidomycosis in horses can often lead to severe systemic disease and its treatment has previously been expensive and has carried a poor prognosis. This paper describes the successful treatment of two horses with pulmonary coccidioidomycosis with a fluconazole product produced by a compounding pharmacy.

Isolation of Cokeromyces recurvatus, initially misidentified as Coccidioides immitis, from peritoneal fluid in a cat with jejunal perforation

Cokeromyces recurvatus, a zygomycete, was isolated by fungal culture from the peritoneal fluid of a cat with jejunal perforation secondary to intestinal lymphosarcoma. This organism has not been recovered previously from a veterinary patient. The tissue form of C. recurvatus is morphologically similar to those of Coccidioides immitis and Paracoccidioides brasiliensis and may be misdiagnosed as 1 of these organisms on the basis of cytologic or histopathologic specimens, particularly in geographic regions where these organisms are not endemic.

Coccidioidomycosis: A Diagnostic Challenge

Coccidioidomycosis is a systemic fungal infection acquired endemically in the southwestern United States. Clinical disease is quite common in the dog; though less frequently recognized in the cat, disease is often severe at the time of diagnosis. Diagnosis can be a challenge because serology, while specific, is not very sensitive and quantitative titration of antibodies does not correlate entirely with clinical disease in dogs. Radiographs, serum biochemistry tests and complete blood counts are beneficial additions to the database when establishing a diagnosis; cytology, histopathology, and culture are definitive when available. Advanced imaging can detect central nervous system and subtle skeletal lesions. Disease can occur in most organs of the body and may prove a diagnostic challenge requiring several modalities. Coccidioidomycosis may need to be considered both in animals in the endemic region and in those with a travel history through it.

Fungal Infections of the Central Nervous System in the Dog and Cat

Fungal infections of the central nervous system (CNS) in dogs and cats are uncommon. The purpose of this paper is to review the clinical signs, diagnostic tests, and therapeutic options of fungal infections of the CNS in the dog and cat. Clinical signs are dependent on lesion location and are often multifocal. Extraneural involvement is common. Antemortem diagnosis can be difficult and is definitively made via cytology, biopsy, or culture of an affected organ or cerebrospinal fluid (CSF). Magnetic resonance imaging can support a diagnosis and may assist in therapeutic decisions. Fungal serology can support a diagnosis when direct visualization of the organism is not possible. Long-term azole maintenance therapy is suggested to enhance survival and prevent relapse. Serial cerebrospinal fluid evaluation and magnetic resonance imaging may identify early relapse.

Posaconazole therapy for systemic coccidioidomycosis in a chimpanzee (Pan troglodytes): a case report

Systemic coccidioidomycosis was diagnosed in a 4-year-old male chimpanzee (Pan troglodytes) with ascites and failure to thrive. Physical examination, laboratory and radiological studies, and exploratory laparotomy showed signs of systemic fungal infection that included penetration into the central nervous system (CNS). Serum and cerebrospinal fluid (CSF) titres, along with ascites cytology findings, confirmed the presence of Coccidioides immitis. However, the organism could not be cultured from the CSF. Treatment with fluconazole 10 mg kg(-1) daily for 6 months was not associated with clinical improvement. Subsequent treatment with posaconazole 50 mg kg(-1) daily for approximately 24 months resulted in negative serum titres and improved clinical status. Illness not directly related to the C. immitis infection caused the chimpanzee's deterioration and eventual killing. Histological examination performed during necropsy provided no evidence of coccidioidomycosis; however, a positive C. immitis serum antibody titre was noted. The successful suppression of coccidioidomycosis observed in this chimpanzee suggests that posaconazole may have a role in the treatment of CNS infections caused by susceptible fungi.

Subtotal pericardectomy and epicardial excision for treatment of coccidioidomycosis-induced effusive-constrictive pericarditis in dogs: 17 cases (1999-2003)

OBJECTIVE

To determine the history, clinicopathologic findings, and results of surgery for effusive-constrictive pericarditis associated with Coccidioides immitis infection in dogs.

DESIGN

Retrospective study.

ANIMALS

17 client-owned dogs that underwent a subtotal pericardectomy and epicardial excision.

PROCEDURE

Hospital records from May 1999 to June 2003 were reviewed. Data collected included history, clinicopathologic findings, treatments, and outcome. Follow-up information was obtained via recheck examination and by use of standardized telephone interviews with referring veterinarians and owners.

RESULTS

All dogs were of large breeds, and most were male (mean age, 4.66 years). Ten dogs had no prior history of C. immitis infection, and 7 dogs had chronic infection with C. immitis. Having a chronic C. immitis infection reduced the odds of survival, compared with no previous infection. All dogs had clinical signs of right-sided heart failure. All dogs had serum titers (range, 1:8 to 1:256) for antibodies against C. immitis prior to surgery, and titers were not significantly associated with outcome. Predominant echocardiographic findings were thickened pericardium, reduced right ventricular filling, and pleural or pericardial effusion. All dogs underwent a subtotal pericardectomy and epicardial excision and had fibrosing pyogranulomatous pericarditis in biopsy specimens obtained during surgery. The perioperative mortality rate was 23.5%, and the 2-year postdischarge survival rate was 82%.

CONCLUSIONS AND CLINICAL RELEVANCE

Surgical treatment via subtotal pericardectomy and epicardial excision is successful at relieving right-sided heart failure in dogs with effusive-constrictive pericarditis secondary to C. immitis infection, but long-term treatment with antifungal agents may still be required.

Incidence of coccidioides infection among dogs residing in a region in which the organism is endemic

OBJECTIVE

To determine the incidence of Coccidioides infection among dogs residing in a region in which the organism is endemic (Pima and Maricopa counties, Arizona) and estimate the rate of clinical illness.

DESIGN

Community-based longitudinal and cross-sectional studies.

ANIMALS

124 healthy 4- to 6-month-old seronegative puppies (longitudinal study) and 381 4- to 18-month-old dogs with unknown serostatus (cross-sectional study).

PROCEDURE

Dogs in the longitudinal study were tested at 6-month intervals for at least 1 year for anticoccidioidal antibodies. Dogs that became ill were evaluated for coccidioidomycosis. Dogs in the cross-sectional study were tested for anticoccidioidal antibodies once, and clinical abnormalities were recorded.

RESULTS

28 of the 104 (27%) dogs that completed the longitudinal study developed anticoccidioidal antibodies. Thirty-two of the 381 (8%) dogs in the cross-sectional study had anticoccidioidal antibodies. Five seropositive dogs in the longitudinal study and 13 seropositive dogs in the cross-sectional study had clinical signs of disease. The remaining seropositive dogs were otherwise healthy and were classified as subclinically infected. Survival analysis indicated that the cumulative probability of infection by 2 years of age was 28%, and the cumulative probability of clinical infection by 2 years of age was 6%. Titers for clinically and subclinically infected dogs overlapped.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that young dogs living in the study area had a high likelihood of becoming infected with Coccidioides spp, but few developed clinical illness. Serologic testing alone was insufficient for a diagnosis of clinical disease because of the overlap in titers between clinically and subclinically infected dogs.

Risk factors associated with Coccidioides infection in dogs

OBJECTIVE

To evaluate potential risk factors for Coccidioides infection among dogs living in a region in which the organism is endemic (Pima and Maricopa counties, Arizona).

DESIGN

Community-based longitudinal and cross-sectional studies.

ANIMALS

104 healthy 4- to 6-month-old puppies (longitudinal study) and 381 4- to 18-month-old dogs with unknown serostatus (cross-sectional study).

PROCEDURE

Dogs in the longitudinal study were tested 3 times at 6-month intervals for anticoccidioidal antibodies; dogs in the cross-sectional study were tested only once. Owners of all dogs completed a questionnaire on potential environmental exposures.

RESULTS

In the longitudinal study, the relative risk of infection for dogs that were outdoors during the day was 4.9 times the risk for dogs that were kept indoors. Seropositive dogs in the cross-sectional study were 6.2 times as likely to have access to > 1 acre to roam as were seronegative dogs. Logistic regression analysis indicated that the odds of infection increased with age (odds ratio [OR], 1.1), amount of roaming space (OR, 2.4), and walking in the desert (OR, 2.2). Walking on sidewalks had a protective effect (OR, 0.4).

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that in regions in which the organism is endemic, dogs that spend more time outdoors or have more land in which to roam are at greater risk of infection with Coccidioides spp.

Seroprevalence of antibodies against Coccidioides immitis in healthy horses

OBJECTIVE

To determine the seroprevalence of antibodies against Coccidioides immitis in healthy horses residing in an area in which the organism is endemic.

DESIGN

Prospective study.

ANIMALS

197 healthy horses (in which coccidioidomycosis had not been previously diagnosed) that resided in an area of Arizona in which coccidioidomycosis is endemic.

PROCEDURE

Of the horses evaluated at the Arizona Equine Medical and Surgical Center during a 6-month period, 197 with no clinical signs of coccidioidomycosis were randomly selected for inclusion in the study; sera were evaluated for IgM and IgG antibodies against C immitis via an immunodiffusion assay (IgG-positive samples were assessed quantitatively). Within 6 months, recheck titer evaluations were attempted for all seropositive horses.

RESULTS

Serum antibodies against C immitis were detected in 8 of 197 horses (seroprevalence, 4.06%). Results of serologic assays were positive for IgG antibodies and negative for IgM antibodies in 7 horses and positive for both IgG and IgM antibodies in 1 horse; reciprocal serum IgG antibody titers were low (none > 8). Follow-up serologic data were obtained from 5 horses; compared with initial findings, horses had become seronegative or titers were unchanged or decreased. Duration of residence in the area was significantly shorter for seropositive horses than for seronegative horses.

CONCLUSIONS AND CLINICAL RELEVANCE

Serum antibodies against C immitis may rarely be detected in healthy horses residing in an area in which the disease is endemic; any horse with a detectable serum antibody titer should be reevaluated after an interval of at least 3 weeks.

Draining skin lesion from a desert Poodle

A 16-month-old intact female Poodle in Arizona had a history of intermittent coughing of a few weeks duration. Coccidiomycosis antibody screening test results were negative for immunoglobulin (Ig) M, but were positive (1:64) for IgG. Fine needle aspiration specimens of a draining lesion on the right palmar front foot contained large numbers of neutrophils, many of which contained bacteria, and lower numbers of macrophages. A few small structures also were observed, 2-5 microm in diameter with thin, nonstaining capsules and small, round to oval densely aggregated, eccentric nuclei. Cytologic findings were consistent with septic pyogranulomatous inflammation with Coccidiodes immitis endospores. Fungal culture of a sample from the draining lesion yielded white growth with barrel-shaped arthroconidia. Identification of the organism as C immitis was confirmed by a commercial DNA probe test. Although coccidioidomycosis often is diagnosed by microscopic identification of C immitis spherules in cytologic specimens, in this case only endospores, which are released from mature spherules, were observed. In cases of suspected coccidiodomycosis, the unique morphology of endospores may be useful in making a cytologic diagnosis.

Coccidioidomycosis in Przewalski's horses (Equus przewalskii)

Coccidioidomycosis is a rare, often subclinical infection in domestic animals caused by the fungus Coccidioides immitis. Because of an apparent high incidence of coccidioidomycosis in Przewalski's horses (Equus przewalskii) housed at a single facility, necropsy records and biomaterials from animals that died between 1984 and 2000 were reviewed (n = 30, 15 males, 15 females). Coccidioidomycosis was the leading cause of death (33%) in this population with lesions in the lungs and tracheobronchial lymph nodes of all animals and variable involvement of the skeletal muscle, heart, kidney, liver, skin, brain, spinal cord, spleen, as well as other regional lymph nodes. At the time of death, affected horses tended to be younger than unaffected animals, were from multiple lineages, and males were over represented. During the same time period, no other exotic equids (n = 76) housed at the same facility were diagnosed with coccidioidomycosis, suggesting that environmental factors are not the sole cause of the high incidence in E. przewalskii. Numbers of the lymphocyte subsets (CD3, CD4, CD5, CD8, CD21+ cells) quantified by flow cytometry were similar between Przewalski's horses and domestic horses (Equus caballus). Although responses of lymphocyte blastogenesis assays were similar between Przewalski's (n = 5) and domestic horses (n = 5) in response to the T cell mitogen concanavalin A, lymphocytes from two of the Przewalski's horses failed to proliferate in response to Coccidioides. One of these horses had systemic disease and the second developed coccidioidomycosis 2 yr later. These results suggest that the immune system of some Przewalski's horses fails to respond appropriately to Coccidioides.

Update on canine and feline fungal diseases

Systemic fungal diseases cause significant morbidity and mortality in dogs and cats. Blastomycosis, histoplasmosis, coccidiomycosis, and cryptococcosis represent the four most common systemic fungal diseases. Young adult, large breed dogs generally are predisposed; cats usually do not have predictable predispositions. Intact cell-mediated immunity is essential to initial resistance to infection and response to treatment in animals. Several body systems can be affected. Diagnosis can be confirmed on the basis of clinical signs and demonstration of the causative organism. Serology is helpful with coccidiomycosis and cryptococcosis. Treatment is complicated by limited availability of fungicidal antimicrobials and the necessity of long-term treatment with expensive drugs.

Clinical, clinicopathologic, and radiographic findings in dogs with coccidioidomycosis: 24 cases (1995-2000)

OBJECTIVE

To determine clinical, clinicopathologic, and radiographic abnormalities in dogs with coccidioidomycosis.

DESIGN

Retrospective case series.

ANIMALS

24 dogs.

PROCEDURE

Clinical information and results of clinicopathologic testing were obtained from medical records. Thoracic radiographs were reviewed to characterize abnormalities.

RESULTS

Dogs ranged from 1 to 10 years old at the time of diagnosis, with 12 dogs being between 1 and 3 years old. Historical complaints included cough, lameness, signs of head or neck pain, and difficulty breathing. Mild anemia, neutrophilia, and monocytosis were common. All dogs had hypoalbuminemia, and 8 of 15 had hyperglobulinemia. Thoracic radiographs of 19 dogs were reviewed. Pulmonary infiltrates were seen in 13 dogs, with an interstitial pattern of infiltration being most common. Hilar lymphadenopathy was seen radiographically in 10 dogs. Serum from 20 dogs was tested for antibodies against Coccidioides immitis. One dog was positive for IgM antibodies, 5 were positive for IgM and IgG antibodies, and 14 were positive for IgG antibodies. Quantitative IgG titers measured in 14 dogs ranged from 1:2 to 1:128 (median and mode, 1:32). In 6 dogs, histologic examination of biopsy samples revealed fungal spherules ranging from 8 to 70 microm in diameter.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that in dogs, coccidioidomycosis may be associated with a wide spectrum of nonspecific respiratory and musculoskeletal abnormalities. The chronic nature of the disease makes diagnosis difficult, even in regions in which the organism is endemic.

Multicentric lymphoma and disseminated coccidioidomycosis in a dog

An 11-year-old, spayed female Alaskan malamute with a history of coccidioidal osteomyelitis was evaluated for inappetance and lethargy. Findings included generalized lymphadenopathy, pale mucous membranes, tachycardia, and labored breathing. Laboratory findings and radiographic imaging were consistent with generalized lymphoma and disseminated coccidioidomycosis. Treatment consisted of antibiotics, chemotherapeutic agents, and antifungals.

Pulmonary coccidioidomycosis in a neonatal foal

A 13-day-old foal with profound tachypnoea and respiratory distress was examined. Thoracic radiographs revealed a severe, diffuse miliary pattern, and the foal was markedly hypoxaemic. It failed to improve with empirical treatment, and was euthanased. Lesions associated with Coccidioides immitis infection were identified at postmortem examination, and were limited to the lower respiratory tract.

Coccidioides immitis isolated from armadillos (Dasypus novemcinctus) in the state of Piauí, northeast Brazil

Natural infection of armadillos with Coccidioides immitis was studied in the state of Piauí, northeast of Brazil, endemic for coccidioidomycosis. In 1998, 26 nine-banded armadillos (Dasypus novemcinctus) were captured in 4 different counties. The animals were sacrificed under deep anesthesia with ether. At necropsy fragments of spleen, liver, lungs and heart were homogenized and seeded onto Sabouraud dextrose agar with and without cycloheximide (BBL, USA). Part of each organ was also processed for histological examination. Suspected colonies of filamentous fungi observed after the second week of incubation at room temperature, exhibiting barrel-shaped arthroconidia alternating with empty spaces, were inoculated intraperitoneally into mice. Three armadillos proved to be infected with C. immitis. Mice inoculated with suspected colonies obtained from homogenized spleen of three and liver of two armadillos developed disseminated coccidioidomycosis and immature and mature spherules of C. immitis were disclosed in several organs. For the first time armadillos (D. novemcinctus) were found naturally infected with C. immitis, adding new data on the ecology and on a possible role of these ancestral mammals in the evolutionary life cycle of this fungus.

Constrictive pericarditis secondary to Coccidioides immitis infection in a dog

A 4-year-old castrated male mixed-breed dog with a history of coccidioidomycosis was referred for evaluation of abdominal and pleural effusion. Results of radiography, ultrasonography, cytologic evaluation of thoracic fluid, and serologic testing supported a diagnosis of constrictive pericarditis secondary to infection with Coccidioides immitis. Aggressive treatment for presumptive coccidioidomycosis was begun, but the dog's condition continued to deteriorate, and the dog was euthanatized. At necropsy, the pericardium was thicker than normal and fibrotic and adhered to the epicardium. Microscopically, the pericardium and 1 section of epicardium contained lymphoplasmacytic infiltrates with a few macrophages and neutrophils. Coccidioides immitis was cultured from pericardial fluid. A search of records from the Arizona Veterinary Diagnostic Laboratory for 1988 through 1998 revealed that of 46 dogs in which a diagnosis of coccidioidomycosis was confirmed at necropsy, 13 had involvement of the heart or pericardium.

Canine systemic fungal infections

The principal route of infection for the disseminated fungal diseases discussed in this article is inhalation. In some cases, direct wound contamination and ingestion may also have an important role in the pathogenesis of the disease, especially in histoplasmosis. Another common theme of these diseases is the response of the immune system. If the inoculum is small and the animal is not immunocompromised, the infection may be limited to the respiratory tract and may resolve with few or no clinical signs. Dogs are usually presented to the veterinarian when the fungus has disseminated throughout the body via the circulatory or lymphatic systems, thus causing clinical signs secondary to specific organ infection. Draining skin tracts and lymphadenopathy occur in several of the diseases. The ocular location that is frequently affected is the choroid, where the organisms cause cell-mediated chorioretinitis. Early detection of these changes is important for saving vision and for diagnosing the systemic nature of the disease. Treatment is often effective, especially early in the disease, although it is expensive and long-term, with many animals needing over a year of treatment. Sometimes the treatment must continue lifelong. Ocular disease may not respond to treatment even when respiratory and other organ system clinical signs are rapidly improving. This isolation of the eye is similar to that of the CNS and requires regular monitoring of ocular disease, especially in the fundus, to ensure that systemic drugs are penetrating into the eye. Once the disease progresses to the anterior segment, the ocular prognosis worsens. Better penetration of the blood-retinal and blood-aqueous barriers may be achieved with fluconazole when compared with the other antifungal drugs. Secondary inflammatory ocular disease must also be monitored and treated appropriately to prevent scarring, which may cause vision loss or glaucoma.

Feline systemic fungal infections

Systemic fungal diseases are important diagnostic considerations in all sick cats, particularly in cats with ocular symptoms. The most common ocular manifestation of these diseases is posterior uveitis (choroiditis); however, anterior uveitis is sometimes present and is usually secondary to the inflammation in the posterior segment. Occasionally, adnexal diseases such as blepharitis, inflammation of the nictitating membrane, and ocular discharge may be present in cats with systemic mycoses. The prognosis for cats with systemic fungal diseases has changed with the advent of the triazole antifungal drugs. In the past, the prognosis was guarded to poor for survival of the cat. Today, with prolonged antifungal therapy, many cats recover completely from their disease. The prognosis for return of vision for eyes affected with systemic fungal disease is still guarded. Often, even if the infection is controlled systemically, the retina is severely damaged and may remain nonfunctional.

Peritoneal coccidioidomycosis in a mountain lion in California

An adult mountain lion (Felis concolor) from the vicinity of Weldon, California (USA) was necropsied following euthanasia due to emaciation and proximity to semi-rural housing. There were spherules consistent with Coccidioides immitis within peritoneal surfaces with granulomatous inflammation and fungi consistent with C. immitis were cultured from abdominal fluid. This is the first reported case of coccidioidomycosis in a wild mountain lion.

Inflammatory diseases of the central nervous system in dogs

Inflammatory diseases of the central nervous system (CNS) are important causes of seizures in dogs. Specific diseases include canine distemper, rabies, cryptococcosis, coccidioidomycosis, toxoplasmosis, neosporosis, Rocky Mountain spotted fever, ehrlichiosis, granulomatous meningoencephalomyelitis, and pug dog encephalitis. Inflammatory disorders should be considered when a dog with seizures has persistent neurological deficits, suffers an onset of seizures at less than 1 or greater than 5 years of age, or exhibits signs of systemic illness. A thorough history, examination, and analysis of cerebrospinal fluid are important in the diagnosis of inflammatory diseases. However, even with extensive diagnostic testing, a specific etiology is identified in less than two thirds of dogs with inflammatory diseases of the CNS.

Coccidioidomycosis in a bottlenose dolphin

A stranded bottlenose dolphin (Tursiops truncatus gilli) succumbed to a pulmonary infection of Coccidioides immitis. The dolphin initially presented with mild inspiratory dyspnea that rapidly worsened over 48 hr to include buoyancy abnormalities and finally death. At necropsy, caseous nodules were observed throughout the lungs and perihilar lymph nodes. On histological examination of tissues, double walled organisms containing endospores characteristic of C. immitis were observed in lung, perihilar lymph nodes, and brain. Pyogranulomatous infiltrates were observed in the lung and perihilar lymph nodes only. A DNA Gen-Probe test performed on a purified isolate confirmed infection by C. immitis. Serum was positive for antibodies to C. immitis at a titer of 1:128 and was negative for all known marine morbilliviruses. Although there have been reports of C. immitis infections in free ranging marine wildlife, including California sea lions (Zalophus californianus) and sea otters (Enhydra lutris), this is the first reported case of coccidioidomycosis in a cetacean.

Disseminated coccidioidomycosis in a mandrill baboon (Mandrillus sphinx): a case report

A case of disseminated coccidioidomycosis caused by a dimorphic fungus Coccidioides immitis in a mandrill baboon (Mandrillus sphinx) was diagnosed following radiography, ultrasound-guided aspiration of thoracic lesions, and aspiration cytology of skeletal lesions of the left sixth rib. The diagnosis was confirmed by fungal culture and serum quantitative immunodiffusion for antibodies against C. immitis.

Granulomatous meningitis caused by Coccidioides immitis in a dog

Granulomatous meningitis attributable to Coccidioides immitis was diagnosed on postmortem examination in a 4-year-old Border Collie. Clinical signs included CNS disease, aspiration pneumonia secondary to a megaesophagus, and otitis externa. Central nervous system signs included central vestibular and cranial nerve dysfunction. Cerebellar and medullary infiltrates seen on histologic examination affected cranial nerves VIII, IX, and X. Despite extensive diagnostics, diagnosis was not made antemortem. Analysis of CSF suggested suppurative meningitis, but bacteriologic culture results were negative. Coccidioides endospores were identified on reexamination of brain tissue. The clinical course of disease and rate of Coccidioides immitis infection is variable. Causative agents of granulomatous or inflammatory CNS disease may include fungal infection more often than is currently suspected.

Immunological and chemical characterization of glycoproteins in IEF fractions of Blastomyces dermatitidis yeast lysate antigen

After isoelectric focusing (IEF), fractions of a Blastomyces dermatitidis yeast lysate antigen were analysed for the presence of glycoproteins that may lead to cross-reactivity in immunoassays for the diagnosis of blastomycosis. Five major glycoproteins were apparent, two of which showed cross-reactivity when used in Western blots with sera obtained from dogs with histoplasmosis and coccidioidomycosis. These five glycoproteins were characterized for linkage to the proteins using N-glycosidase F (NGF) and for their lectin binding properties. The cross-reactive 235- and 160-kDa glycoproteins were found to possess mainly O-linked, high-mannose-type carbohydrates, and periodate-mediated oxidation of these molecules eliminated cross-reactivity observed with heterologous sera. Thus, the periodate-treated IEF antigens described here may be useful in solid-phase enzyme immunoassays for the diagnosis of blastomycosis.

Primary cutaneous coccidioidomycosis and subsequent drug eruption to itraconazole in a dog

Three weeks after traveling to Arizona, a 13-month-old, female Labrador retriever developed draining tracts in the right hind limb. Primary cutaneous coccidioidomycosis was diagnosed. Initial treatment with itraconazole resulted in exacerbation of clinical signs. Histopathology was suggestive of a cutaneous drug eruption. Discontinuation of the itraconazole caused resolution of the drug eruption. Successful treatment of the fungal infection was achieved using ketoconazole.