Abstract
Blastomycosis is a serious fungal disease of dogs, humans, and occasionally other mammals caused by geographically restricted, thermally dimorphic Blastomyces species. Blastomycosis is primarily a canine disease, with approximately ten dogs diagnosed for every human case. Dogs also develop disease more rapidly, thus becoming sentinels for possible human disease. Human and canine blastomycosis may differ according to epidemiology/epizoology, clinical features, performance and use of diagnostics, and management.
You have full access to this open access chapter, Download chapter PDF
Similar content being viewed by others
Keywords
1 Introduction
Blastomycosis is a disease of mammals caused by the geographically restricted, thermally dimorphic fungi Blastomyces species. Human blastomycosis was first reported by Gilchrist in 1894 in a case of cutaneous disease first mistakenly attributed to protozoan disease (Gilchrist 1894). Four years later, Gilchrist and Stokes isolated the causative agent, a fungus they called Blastomyces dermatitidis (Gilchrist and Stokes 1898). The first case of canine blastomycosis was reported by Meyer in 1912 (Meyer 1912). Since then, blastomycosis has been recognized as a common and serious disease of people and animals in endemic/enzootic areas.
2 Ecology and Distribution
Our understanding of the ecology of Blastomyces species is incomplete due to the difficulty in isolating the fungus from the environment (Restrepo et al. 2000). Blastomycosis is acquired primarily through inhalation of airborne conidia of Blastomyces species. These are liberated from the mold phase, which is associated with moist, acidic, sandy soils enriched with decaying organic matter and animal droppings (Restrepo et al. 2000). Aerosolization of conidia is promoted by disturbances to soil that may be caused by natural phenomena or due to human or animal activities such as excavation (Bradsher 2014b). Upon inhalation, conidia undergo a temperature-dependent transformation to yeast-like cells, capable of causing local and disseminated disease (Bradsher 2014b).
The geographic range of endemicity for canine and human blastomycosis includes North America, where it primarily occurs in states and provinces along the Great Lakes, and Ohio, Mississippi, Missouri, and St. Lawrence rivers (Bradsher 2014b). Autochthonous blastomycosis has also been reported from most of Africa (Broc and Haddad 1952; Carman et al. 1989), parts of India (Randhawa et al. 1983), and the Middle East (Kuttin et al. 1978; Kingston et al. 1980). However, the etiological agent may not always be the same species between and within geographical regions. Genetic studies of large collections of B. dermatitidis isolates have identified the presence of two distinct genetic populations (Meece et al. 2011; Brown et al. 2013), leading Brown et al. (2013) to conclude the presence of a cryptic species which they called B. gilchristii . These species are indistinguishable in morphology, physiology, and in most currently applied molecular bar codes (Dukik et al. 2017). Although clinical and demographic phenotypic differences have been suggested (Meece et al. 2013), the clinical significance of distinguishing B. dermatitidis from B. gilchristii is not yet established. Geographic differences exist, and epidemiological differences (such as outbreak potential) are surmised by the fact that isolates identified as B. gilchristii predominate in northern Ontario and Wisconsin, areas with the highest reported incidence of blastomycosis (Brown et al. 2013).
On the other hand, differences have long been noted in isolates from Africa compared to those implicated in disease in North America. In fact, isolates from Africa have been observed to be slightly smaller (Kaufman et al. 1983), more difficult to convert to yeast phase (Lombardi et al. 1988), and have different antigenic expression (Kaufman et al. 1983) than isolates from North America. Moreover, clinical differences in human disease have been suggested (Vandepitte and Gatti 1972). Strikingly, no cases of animal blastomycosis have been reported from Africa (Carman et al. 1989). Recently, a new species of Blastomyces, B. percursus, was described from Israel and South Africa (Dukik et al. 2017); B. dermatitidis and B. gilchristii have also been confirmed in isolates from sub-Saharan Africa (Brown et al. 2013), and so the extent that disease is attributable to each species there and elsewhere outside of North America has not yet been defined.
Most human and animal cases of blastomycosis are sporadic or endemic/enzootic (Bradsher 2014b), although occasionally outbreaks have occurred which have informed our understanding of the ecology, attack rate, and natural history of outbreak-related B. dermatitidis infection (Klein et al. 1986; Armstrong et al. 1987; Baumgardner and Burdick 1991; Smith and Gauthier 2015). Outbreaks have involved both rural and urban exposures (Smith and Gauthier 2015). Recreational outdoor activities and especially water activities as well as exposure to excavation and construction are frequently implicated in human and canine blastomycosis (Baumgardner et al. 1995; Smith and Gauthier 2015). Proximity to waterways has been identified as a risk factor for sporadic blastomycosis in people (Baumgardner et al. 1992) and in dogs (Archer et al. 1987; Baumgardner et al. 1995; Arceneaux et al. 1998). For instance, case-control studies of canine blastomycosis in Louisiana and Wisconsin have identified residence within 400 m of a body of water to be a significant risk factor for the disease in dogs (Baumgardner et al. 1995; Arceneaux et al. 1998). In Louisiana, Arceneaux et al. found the odds of living near water was tenfold higher for dogs with blastomycosis than controls (Arceneaux et al. 1998).
Most people who develop blastomycosis are immunocompetent. Persons with immunodeficiencies who develop blastomycosis are reported to have more severe forms of the disease (Pappas et al. 1993), but the numbers of cases reported to date have been small. Persons treated with tumor necrosis factor (TNF)-α inhibitors may represent a growing cohort at risk of blastomycosis (Smith and Kauffman 2009). Individuals with diabetes mellitus appear to be at higher risk of blastomycosis (Lemos et al. 2002) and of requiring management in an intensive care unit (Kralt et al. 2009). Most animals with blastomycosis were previously healthy, although Davies and Troy reported 10% of infected cats in a small series had feline leukemia virus (Davies and Troy 1996).
Anderson et al. (2016) recently showed that people can become reinfected with Blastomyces spp.; previously, whether a second episode of blastomycosis represented reinfection and not relapse was inconclusive. These authors reported on two persons in whom blastomycosis was diagnosed and treated, only to later develop the disease again (Anderson et al. 2016). By genotyping isolates from the initial and subsequent episodes in each respective patient using 27 polymorphic microsatellite markers, they demonstrated that relapse occurred in one case (concordance between the two isolates at 27/27 loci) and reinfection occurred in the other (concordance at just 15/27 loci) (Anderson et al. 2016).
Blastomycosis is most common in dogs residing in or visiting enzootic areas (Baumgardner et al. 1995). The incidence of blastomycosis in dogs is eight to ten times that of humans (Baumgardner et al. 1995; Herrmann et al. 2011), presumably related to time spent outdoors, proximity to soil, and activities, such as digging, that may result in soil disturbances and conidial exposure. Most affected dogs are immunocompetent (Sykes and Merkel 2014). The incidence appears to be highest in young, large sporting dogs and hounds, including coonhounds, pointers, Weimaraners (Rudmann et al. 1992), golden retrievers, Labrador retrievers, and Doberman pinschers (Arceneaux et al. 1998). Sporting dogs may be more likely to be exposed due to selective use in hunting (Rudmann et al. 1992). Some but not all studies have found the disease is more common in intact males (Rudmann et al. 1992; Arceneaux et al. 1998). Blastomycosis has also been described in wild canids. For example, Nemeth et al. (2016) reviewed the database of wild animals sent to the Canadian Wildlife Health Cooperative from 1991 to 2014. Blastomycosis was diagnosed in 14 wild canids, including 11 of 149 (7.6%) red foxes (Vulpes vulpes) and 3 of 185 (1.6%) gray wolves (Canis lupus).
Feline blastomycosis is encountered 28–100 times less frequently than canine blastomycosis (Legendre 2012; Davies et al. 2013) and has been reported even among indoor-only cats (Blondin et al. 2007; Houseright et al. 2015). Blastomycosis has also been reported in captive wild felids, including lions (Panthera leo), Siberian tiger (Panthera tigris), cheetah (Acinonyx jubatus), and snow leopard (Panthera uncia) (Storms et al. 2003).
Blastomycosis has been reported in a range of domestic and captive animals including kinkajou (Potos flavus) (Harris et al. 2011), ferret (Nemeth et al. 2016), red ruffed lemur (Varecia rubra) (Rosser et al. 2016), and rhesus monkey (Macaca mulatta) (Wilkinson et al. 1999). Marine mammals reported with blastomycosis include sea lion (Zalophus californianus) (Zwick et al. 2000) and Atlantic bottlenose dolphin (Tursiops truncatus) (Cates et al. 1986). Wild, free-roaming animals (other than canids) that have developed blastomycosis include an American black bear (Ursus americanus) (Dykstra et al. 2012).
Among livestock, some cases of blastomycosis have been described in horses living in endemic areas (Wilson et al. 2006; Stewart and Cuming 2015). Blastomycosis has also been reported in an alpaca (Imai et al. 2014).
Animals do not play a role in transmission of Blastomyces spp., aside from rare cases of inoculation blastomycosis reported due to a bite (Gray and Baddour 2002; Harris et al. 2011) or percutaneous injury during autopsy of an infected animal (Gray and Baddour 2002). The concurrent or sequential infection of a person and his or her dog is common (Baumgardner et al. 1992) and likely due to a common exposure (Sarosi et al. 1979; Armstrong et al. 1987; Baumgardner et al. 1992). Even so, dogs appear to develop disease earlier (Sarosi et al. 1979). In experimental murine blastomycosis, larger inocula lead to earlier disease (Williams and Moser 1987), and it has been inferred that the shorter prepatent period in dogs reflects increased inocula from being closer to the ground (Legendre 2012). In any case, a history of blastomycosis in one’s dog should raise suspicion for the disease in a person with a compatible syndrome (Sarosi et al. 1979).
3 Clinical Signs
3.1 In Humans
Clinical signs encountered in persons with blastomycosis will depend on the organ systems involved, but clinicians should be aware of the protean nature of the disease (Bradsher 2014a). Pulmonary infection can be subclinical or can result in an acute or chronic pneumonia (Sarosi et al. 1974). Acute pulmonary blastomycosis can present with fevers, sepsis, and hypoxia, with clinical examination and radiographs consistent with focal airspace disease (Sarosi et al. 1974; Lemos et al. 2002). In other words, the disease can be indistinguishable from community-acquired (bacterial) pneumonia (Lemos et al. 2002; Bradsher 2014a; Alpern et al. 2016), and it is common for patients to receive multiple courses of antibiotics before the correct diagnosis is established (Alpern et al. 2016). Acute respiratory distress syndrome (ARDS) occurs in 8–15% of cases of symptomatic blastomycosis (Meyer et al. 1993; Vasquez et al. 1998; Lemos et al. 2001; Azar et al. 2015) and is associated with mortality rates of at least 40% (Meyer et al. 1993; Vasquez et al. 1998; Lemos et al. 2001; Azar et al. 2015; Schwartz et al. 2016). Patients with chronic pulmonary involvement may present with chronic dyspnea, cough and hemoptysis, often accompanied by constitutional symptoms. The radiographic appearance is like acute disease but with a third of patients having mass-like lesions (Patel et al. 1999). Not surprisingly, chronic blastomycosis is frequently mistaken for pulmonary malignancies or tuberculosis (Lemos et al. 2002; Bradsher 2014a).
Extrapulmonary disease occurs in ~25–40% of cases (Baumgardner et al. 1992; Lemos et al. 2002). The most common extrapulmonary site of blastomycosis is the skin, usually manifesting as ulcerative or verrucous lesions (Bradsher 2014b). Osteoarticular disease is the next most common form (Kralt et al. 2009). In a series of persons with osteoarticular blastomycosis, disease of the axial skeleton was most common, followed by long bones of the lower limb (Oppenheimer et al. 2007). Vertebral disease may rarely present with spinal cord compression syndromes (Saccente et al. 1998). As with bacterial osteomyelitis, disease of long bones most often localizes to the metaphyses (Oppenheimer et al. 2007). Arthritis is less common than osteomyelitis. It is generally monoarticular and mimics pyogenic bacterial septic arthritis (Oppenheimer et al. 2007). In males, the third most common site of extrapulmonary blastomycosis is the prostate and genitourinary system (Saccente and Woods 2010). Central nervous system disease is less common, occurring in approximately 5% of cases with extrapulmonary dissemination (Bariola et al. 2010). Patients may present with meningitis, encephalitis, or signs of a space-occupying lesion (Bush et al. 2013). Cerebrospinal fluid pleocytosis occurs and can have either lymphocytic or neutrophilic predominance (Bariola et al. 2010). Ocular involvement has been reported but it is uncommon (Lopez et al. 1994).
3.2 In Animals
Canine disease is more commonly disseminated beyond the lungs at the time of diagnosis (Legendre 2012). Chest radiographs may show focal airspace disease or a “snowstorm” pattern of reticulonodular disease (Crews et al. 2008b) (Fig. 8.1). Ocular disease is much more common in dogs than in humans, occurring in up to half of all cases (Bloom et al. 1996; Arceneaux et al. 1998). Among these, bilateral disease occurs in half (Bloom et al. 1996). Ocular disease can be localized to anterior segments, posterior segments, or, most commonly, both (i.e., endophthalmitis) (Bloom et al. 1996). Like in human disease, cutaneous involvement is common in canine blastomycosis, occurring in approximately half of infected dogs (Arceneaux et al. 1998). An example of a dog with bilateral ocular and cutaneous disease is shown in Fig. 8.2. Other common sites of extrapulmonary disease include lymphatic and osteoarticular structures (Arceneaux et al. 1998). Central nervous system disease is less common, occurring in 6% of dogs in a series (Arceneaux et al. 1998). Cardiovascular blastomycosis has been reported in nine dogs (Langlois et al. 2013; Schmiedt et al. 2015); it is extraordinarily uncommon in people.
Like the disease in humans, clinical signs commonly encountered in canine blastomycosis are nonspecific. In decreasing frequency of occurrence reported by a large study, these include fever, lymphadenopathy, harsh lung sounds, cutaneous lesions, chorioretinitis, anterior uveitis, cough, emaciation, and retinal detachment (Arceneaux et al. 1998).
Cats are often diagnosed only upon autopsy and with widespread disease (Davies and Troy 1996). In one series, clinical signs of respiratory, neurologic, and cutaneous disease were present in 59, 41, and 18% of cats, respectively (Davies and Troy 1996).
In horses, clinical signs generally include pneumonia and with reports of respiratory infection or cutaneous and subcutaneous lesions (Wilson et al. 2006; Stewart and Cuming 2015).
4 Diagnosis
4.1 Culture
Culture of Blastomyces spp. from a clinical specimen is the gold standard diagnostic for blastomycosis. Blastomyces dermatitidis /gilchristii grow on general fungal media such as Sabouraud’s dextrose agar or potato dextrose agar, incubated at 25–30 °C (Bradsher 2014b). Growth of white to buff colonies usually appears within 10–14 days but may require up to 6 weeks incubation (Bradsher 2014b). Microscopically, B. dermatitidis/gilchristii characteristically have conidiophores of varying lengths that run perpendicular to hyphae and terminate with single conidia that resemble “lollipops” (Bradsher 2014b). In contradistinction, the conidia of B. percursus appear in clusters at the end of conidiophores (Dukik et al. 2017). Traditionally, conversion of the mold to a yeast phase at 37°C was performed for confirmation of the identification, but this is rarely done today (Saccente and Woods 2010). Most microbiology laboratories confirm identification of B. dermatitidis/gilchristii with a DNA probe (AccuProbe; GenProbe Inc., San Diego, CA), but cross-reactions can occur, including with other dimorphic fungi (Saccente and Woods 2010).
The diagnostic yield of culture is surmised from a retrospective review of cases of human pulmonary blastomycosis (Martynowicz and Prakash 2002). Blastomyces dermatitidis was isolated from the first sputum sample in 75% of cases, which increased to 81% after a mean of 2.3 samples (Martynowicz and Prakash 2002); the diagnostic yield of bronchial washings was even higher. Nonetheless, the true sensitivities are likely lower since only diagnosed cases (i.e., those with at least one positive test) are included in this type of study.
Despite favorable operating characteristics, culture has important limitations. Slow turnaround times limit reliance on this test for management decision (Bradsher 2014b). In addition, occupational exposure of laboratory workers to highly infectious mycelia is a real concern (Denton et al. 1967). While culture is a standard investigation of humans suspected of blastomycosis (Bradsher 2014b), it is rarely used in veterinary practice (Legendre 2012; Sykes and Merkel 2014). In a survey of small-animal veterinary practices in Wisconsin, 80% of respondents reported that they never used culture for the diagnosis of blastomycosis (Anderson et al. 2014). Similarly, large retrospective case series of dogs with pulmonary blastomycosis from Louisiana (Arceneaux et al. 1998) and Minnesota (Crews et al. 2008a) found that fungal cultures were sent for only 17 of 115 dogs (12%) and 6 of 125 dogs (5%), respectively.
4.2 Microscopy, Cytology, and Histopathology
Microscopic examination of clinical specimens using wet smears, cytopathology, and histopathology are cornerstone diagnostic tools for blastomycosis in humans and animals (Saccente and Woods 2010). The classic appearance is of large (8–15 μm), round, multinucleate yeast-like cells with thick, double refractile walls that may have a single bud with broad bases (Guarner and Brandt 2011) (Fig. 8.3). Small yeast forms are also known to occur and may be difficult to distinguish histologically from the yeast-like cells of other dimorphic fungi (Guarner and Brandt 2011).
The most expedient test is a wet preparation using potassium hydroxide (KOH) solution, with or without staining with calcofluor white or lactophenol blue (Saccente and Woods 2010). The sensitivity of this test is poor: a study found the yield of sputum for KOH preparation in human pulmonary blastomycosis to be 25% for a single specimen (Martynowicz and Prakash 2002). Nonetheless, examination of multiple specimens often leads to the correct diagnosis. For example, in a series of 100 persons with pulmonary blastomycosis, KOH preparation of respiratory samples (invasively and noninvasively collected) led to the immediate diagnosis in 66% of cases (Patel et al. 1999).
Visualization of Blastomyces yeast-like cells is enhanced with cytologic and histopathologic preparations. Cytology stains like Papanicolaou and Wright stains can be used to identify the organism in respiratory specimens (usually sputum and bronchoalveolar lavage in humans and transtracheal lavage or transthoracic fine-needle aspirates in dogs), lymph node aspirates, and impression smears or discharge from cutaneous lesions (Martynowicz and Prakash 2002). In tissue, the yeast-like cells may first be visualized with hematoxylin and eosin, although sensitivity and specificity are greatly improved by use of fungal stains like periodic acid-Schiff (PAS) or Grocott-Gomori methenamine-silver nitrate (GMS) (Saccente and Woods 2010). The host response is characterized by mixed inflammatory reaction, predominated first by neutrophils and eventually by noncaseating granulomas (Saccente and Woods 2010).
Cytologic and histopathologic examinations are frequently used in medical and veterinary practice. These tests perform well in diagnosing blastomycosis compared to culture (Patel et al. 2010), and with faster turnaround time. Cytologic examination led to the diagnosis in 71% of cases of canine disease from Louisiana, and histopathologic examination diagnosed an additional 9% (Arceneaux et al. 1998).
4.3 Antigen and Antibody Detection
An antigen enzyme immunoassay (EIA) for B. dermatitidis galactomannan is commercially available for the diagnosis of blastomycosis in humans and animals (MiraVista Diagnostics, Indianapolis, IN, USA). In a study of 89 people with blastomycosis proven by histopathology or culture, the quantitative detection of antigenuria had a sensitivity of 90% (Connolly et al. 2012). Sensitivity was higher in patients with pulmonary disease (with or without extrapulmonary dissemination) compared to isolated extrapulmonary disease. The specificity was 99% in controls without fungal infections, but cross-reactivity occurred in 96% of controls with histoplasmosis (Connolly et al. 2012). However, another study from Marshfield, Wisconsin, evaluated antigen tests in persons with blastomycosis over a course of 10 years and found the sensitivity of antigenuria to be 76% (Frost and Novicki 2015).
The use of the antigen EIA has also been studied for the diagnosis of canine blastomycosis (Spector et al. 2008). In a study of 46 dogs with blastomycosis, the sensitivities of antigen detection in urine and blood were 93 and 87%, respectively; false-positive results occurred in 2% of controls (Spector et al. 2008). Antigen detection is commonly used by veterinarians for the diagnosis of blastomycosis: Wisconsin veterinarians reported relying on this test more than any other to diagnose the disease (Anderson et al. 2014).
There is not currently a role for serological testing for Blastomyces-specific antibodies due to poor sensitivity (Smith and Gauthier 2015). An investigational EIA for antibodies against Blastomyces adhesion-1 (BAD-1) was reported to have sensitivities and specificities of 88% and 95–99%, respectively (Richer et al. 2014). Confirmatory studies are warranted.
4.4 Nucleic Acid Detection
Nucleic acid detection is not yet a part of routine diagnostics for blastomycosis, and the role for this tool in clinical laboratories has not been defined. Theoretically, nucleic acid detection could reduce turnaround time compared with culture while obviating laboratory-associated hazard. It could also improve sensitivity compared to cytology or histopathology (Babady et al. 2011).
5 Treatment
5.1 In Humans
Clinical guidelines have been published for the management of human blastomycosis by the Infectious Diseases Society of America (IDSA) updated in 2008 (Chapman et al. 2008) and of human fungal pneumonias including blastomycosis by the American Thoracic Society (ATS) in 2011 (Limper et al. 2011). In humans, the recommended treatment for mild to moderate pulmonary or extrapulmonary blastomycosis (other than osteoarticular or CNS disease) is itraconazole 200 mg once or twice daily for 6–12 months; treatment of osteoarticular disease should be for 12 months. Moderately severe to severe pulmonary or extrapulmonary disease should be treated preferably with lipid formulation amphotericin B (3–5 mg/kg) or alternatively amphotericin deoxycholate (0.7–1.0 mg/kg) until clinical improvement, followed by de-escalation to a triazole for 6–12 months (Chapman et al. 2008). Central nervous system disease should be treated with a lipid formulation of amphotericin B (3–5 mg/kg) (for 4–6 weeks or until clinical improvement) followed by step-down to a triazole for 12 months (Chapman et al. 2008; Limper et al. 2011). Recent interest in the use of voriconazole for CNS blastomycosis has been driven by improved CSF and brain tissue penetration (Ta et al. 2009); accumulating published clinical experience provides anecdotal support for its use for this indication (Bakleh et al. 2005; Borgia et al. 2006; Bariola et al. 2010; Bush et al. 2013). Therapeutic drug monitoring is recommended for itraconazole and possibly voriconazole to ensure adequate levels are maintained (Chapman et al. 2008; Limper et al. 2011).
Acute respiratory distress syndrome due to blastomycosis occurs in 8–15% of persons with symptomatic blastomycosis (Meyer et al. 1993; Vasquez et al. 1998; Lemos et al. 2001; Azar et al. 2015), but it portends a grave prognosis with case fatality rates of at least 40% (Meyer et al. 1993; Vasquez et al. 1998; Lemos et al. 2001; Azar et al. 2015; Schwartz et al. 2016). Consequently, the roles of adjunctive, rescue therapies for ARDS caused by blastomycosis are an area of great interest, but little data. Some investigators have suggested a role for adjunctive corticosteroids considering the inflammatory cascade involved in the pathogenesis ARDS (Hough 2014). Anecdotal support has come from case reports and series (Lahm et al. 2008; Plamondon et al. 2010; Azar et al. 2015; Schwartz et al. 2016), although sufficiently powered prospective or retrospective studies are unlikely to be forthcoming (Schwartz et al. 2016). Extracorporeal membrane oxygenation (ECMO) is another promising adjunctive rescue therapy for ARDS due to blastomycosis (Dalton et al. 1999; Resch et al. 2009; Bednarczyk et al. 2015; Schwartz et al. 2016) and should be considered in centers where the capacity exists.
5.2 In Animals
Guidelines for the management of veterinary blastomycosis are currently available for cats as part of guidelines for the prevention and management of rare systemic mycoses published in 2013 by the European Advisory Board on Cat Diseases (Lloret et al. 2013). These suggest that itraconazole (10 mg/kg once daily) should be the preferred therapy for most cases, usually given for >3 months and that amphotericin B (0.25 mg/kg every 48 h to a total dose of 4–16 mg/kg) or fluconazole (2.5–10 mg/kg twice daily) are preferred for severe cases or those with CNS involvement (Lloret et al. 2013).
No guidelines currently exist for the diagnosis or management of canine blastomycosis. Randomized controlled trials do not exist to guide management decisions, but several prospective and retrospective studies of canine blastomycosis are instructive.
Legendre et al. prospectively treated 112 dogs with blastomycosis with itraconazole at doses of 5 or 10 mg/kg daily for 60 days and compared outcomes to historical controls treated with amphotericin B (at a cumulative dose of 8–9 mg/kg) in a study setting (Legendre et al. 1996). No differences were observed in outcomes between dogs treated with either of the itraconazole doses and amphotericin B: cure was achieved in 54–57% of all dogs, with disease recurring in 20–21% and death in 23–26% (Legendre et al. 1996). These observations are for the most part congruent with other reports (Arceneaux et al. 1998).
Fluconazole has been suggested by some authors as a reasonable (and cheaper) alternative to itraconazole in the treatment of canine blastomycosis (Mazepa et al. 2011). In vitro susceptibility testing on a small number of human B. dermatitidis isolates suggests fluconazole has less activity than itraconazole (Li et al. 2000; González et al. 2005). While no trial has compared these head-to-head, small single-arm trials in humans are informative. In a prospective, open-label trial of 48 persons with non-life-threatening, non-CNS blastomycosis, itraconazole (at a dose of 200–400 mg daily, for a mean of 6 months) resulted in 90% success (response with no relapse by 1 year follow-up) (Dismukes et al. 1992). In contrast, a trial of fluconazole at a dose of 400–800 mg daily (for a mean of 8.9 months) in 39 patients with non-life-threatening, non-CNS blastomycosis resulted in successful outcome in 87% (Pappas et al. 1997). Prospective trials are lacking in dogs, but Mazepa et al. (2011) retrospectively compared 36 and 31 dogs treated with fluconazole and itraconazole, respectively. The study was not powered to detect a difference in outcomes, but dogs treated with fluconazole required longer courses of therapy than those treated with itraconazole (median 183 vs 138 days, respectively). Nonetheless, costs for fluconazole were much less than for itraconazole, with median costs of $1223 and $3717, respectively (Mazepa et al. 2011). Taken together, this data suggests that fluconazole at higher doses and for longer courses may be reasonable alternatives to itraconazole for blastomycosis in animals.
For CNS and ocular disease, fluconazole achieves better penetration than itraconazole into these structures (Perfect et al. 1986; Savani et al. 1987), although both drugs were effective in animal models of non-blastomycotic fungal meningitis (Perfect et al. 1986) and endophthalmitis (Savani et al. 1987).
Adjunctive systemic corticosteroids have been suggested for ocular blastomycosis in dogs. In a retrospective study of 12 dogs with ocular involvement in 19 eyes, systemic corticosteroids were administered in addition to triazoles (Finn et al. 2007). The success rate in this series was 74% across all eyes involved, including 67% of eyes with endophthalmitis, the most common complication that generally carries a poor prognosis (Finn et al. 2007). For comparison, another retrospective study of itraconazole monotherapy for ocular blastomycosis reported favorable outcomes in just 13% of eyes with endophthalmitis (Brooks et al. 1992). In another study, amphotericin B plus ketoconazole resulted in favorable outcomes for 20% of eyes with endophthalmitis, although this improved to 43% if only non-severely affected eyes were considered (Bloom et al. 1996).
5.3 Monitoring Response to Therapy
Radiographic worsening is commonly observed soon after initiation of effective antifungal therapy for canine blastomycosis, occurring in almost a quarter of dogs (Crews et al. 2008b). However, this does not portend a worse outcome (Crews et al. 2008b) and—in the absence of other signs of clinical failure—should not alter management. For this reason, follow-up chest radiography is recommended no sooner than 4–6 weeks after therapy initiation in stable patients (Crews et al. 2008b).
Quantitative Blastomyces antigen detection by EIA has been evaluated for monitoring of remission in dogs during and after treatment for blastomycosis (Foy et al. 2014). Foy and colleagues prospectively studied 27 dogs with blastomycosis who were monitored clinically, radiographically , and with detection and quantification of Blastomyces antigen in urine and serum following discontinuation of antifungal therapy; among these, 12 dogs were also monitored from time of therapy initiation (Foy et al. 2014). The investigators found that urine antigen levels dropped dramatically within several months of initiation of antifungal therapy. Seven of 27 dogs (26%) relapsed at a median of 4 months following treatment discontinuation. Five of these had detectable antigenuria at the time of clinical relapse, but only one had rising levels of antigenuria preceding clinically detectable relapse. Moreover, persistence of positive urinary antigen at treatment discontinuation did not predict relapse: only two of seven dogs that relapsed had detectable antigenuria at that treatment discontinuation. On the other hand, five of eight of dogs with antigenuria at the end of therapy did not relapse (Foy et al. 2014). In summary, monitoring urine antigen levels during and/or after discontinuation of therapy is unlikely to add significant value to serial clinical and radiographic evaluations for most dogs with blastomycosis.
6 Prevention
A commercially available vaccine against blastomycosis does not currently exist, although the science is advancing. Wüthrich et al. (2000, 2011) developed a recombinant, live-attenuated vaccine using an avirulent, genetically engineered strain of B. dermatitidis lacking Blastomyces adhesin-1 (BAD-1 , previously called WI-1), an essential virulence factor. This vaccine has been demonstrated to be protective against experimental blastomycosis in mice (Wüthrich et al. 2000), although efficacy in dogs has not yet been established. Experimental infection and a field study of beagles and foxhounds, respectively, demonstrated acceptable safety and immunogenicity (Wüthrich et al. 2011). Adverse reactions included fever, lymphadenopathy, and draining cutaneous lesions at the site of inoculation (Wüthrich et al. 2011); these may limit use in all but highly enzootic regions.
References
Alpern JD, Bahr NC, Vazquez-Benitez G et al (2016) Diagnostic delay and antibiotic overuse in acute pulmonary blastomycosis. Open Forum Infect Dis 3:ofw078. https://doi.org/10.1093/ofid/ofw078
Anderson JL, Dieckman JL, Reed KD, Meece JK (2014) Canine blastomycosis in Wisconsin: a survey of small-animal veterinary practices. Med Mycol 52:774–779. https://doi.org/10.1093/mmy/myu051
Anderson JL, Meece JK, Hall MC, Frost HM (2016) Evidence of delayed dissemination or re-infection with Blastomyces in two immunocompetent hosts. Med Mycol Case Rep 13:9–11. https://doi.org/10.1016/j.mmcr.2016.09.002
Arceneaux KA, Taboada J, Hosgood G (1998) Blastomycosis in dogs: 115 cases (1980–1995). J Am Vet Med Assoc 213:658–664
Archer JR, Trainer DO, Schell RF (1987) Epidemiologic study of canine blastomycosis in Wisconsin. J Am Vet Med Assoc 190:1292–1295
Armstrong CW, Jenkins SR, Kaufman L et al (1987) Common-source outbreak of blastomycosis in hunters and their dogs. J Infect Dis 155:568–570
Azar MM, Assi R, Relich RF et al (2015) Blastomycosis in Indiana: clinical and epidemiologic patterns of disease gleaned from a multicenter retrospective study. Chest 148:1276–1284. https://doi.org/10.1378/chest.15-0289
Babady NE, Buckwalter SP, Hall L et al (2011) Detection of Blastomyces dermatitidis and Histoplasma capsulatum from culture isolates and clinical specimens by use of real-time PCR. J Clin Microbiol 49:3204–3208. https://doi.org/10.1128/JCM.00673-11
Bakleh M, Aksamit AJ, Tleyjeh IM, Marshall WF (2005) Successful treatment of cerebral blastomycosis with voriconazole. Clin Infect Dis 40:e69–e71. https://doi.org/10.1086/429319
Bariola JR, Perry P, Pappas PG et al (2010) Blastomycosis of the central nervous system: a multicenter review of diagnosis and treatment in the modern era. Clin Infect Dis 50:797–804. https://doi.org/10.1086/650579
Baumgardner DJ, Buggy BP, Mattson BJ et al (1992) Epidemiology of blastomycosis in a region of high endemicity in north central Wisconsin. Clin Infect Dis 15:629–635
Baumgardner DJ, Burdick JS (1991) An outbreak of human and canine blastomycosis. Rev Infect Dis 13:898–905
Baumgardner DJ, Paretsky DP, Yopp AC (1995) The epidemiology of blastomycosis in dogs: north central Wisconsin, USA. J Med Vet Mycol 33:171–176
Bednarczyk JM, Kethireddy S, White CW et al (2015) Extracorporeal membrane oxygenation for blastomycosis related acute respiratory distress syndrome: a case series. Can J Anaesth 62:807–815
Blondin N, Baumgardner DJ, Moore GE, Glickman LT (2007) Blastomycosis in indoor cats: suburban Chicago, Illinois, USA. Mycopathologia 163:59–66. https://doi.org/10.1007/s11046-006-0090-1
Bloom JD, Hamor RE, Gerding PA (1996) Ocular blastomycosis in dogs: 73 cases, 108 eyes (1985–1993). J Am Vet Med Assoc 209:1271–1274
Borgia SM, Fuller JD, Sarabia A, El-Helou P (2006) Cerebral blastomycosis: a case series incorporating voriconazole in the treatment regimen. Med Mycol 44:659–664. https://doi.org/10.1080/13693780600803870
Bradsher RW (2014a) The endemic mimic: blastomycosis an illness often misdiagnosed. Trans Am Clin Climatol Assoc 125:188–202
Bradsher RW (2014b) Blastomycosis. In: Bennett JE, Dolin R, Blaser MJ (eds) Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, 8th edn. Elsevier, Amsterdam, pp 2963–2973
Broc R, Haddad N (1952) Tumeur bronchique a Scopulariopsis americana determination precoce d’une maladie de Gilchrist. Bull Mem Soc Med Hop Paris 68:678–682
Brooks DE, Legendre AM, Gum GG et al (1992) The treatment of canine ocular blastomycosis with systemically administered itraconazole. Prog Vet Comp Ophthalmol 4:263–268
Brown EM, McTaggart LR, Zhang SX et al (2013) Phylogenetic analysis reveals a cryptic species Blastomyces gilchristii, sp. nov. within the human pathogenic fungus Blastomyces dermatitidis. PLoS One 8:e59237
Bush JW, Wuerz T, Embil JM et al (2013) Outcomes of persons with blastomycosis involving the central nervous system. Diagn Microbiol Infect Dis 76:175–181. https://doi.org/10.1016/j.diagmicrobio.2013.03.002
Carman WF, Frean JA, Crewe-Brown HH et al (1989) Blastomycosis in Africa. A review of known cases diagnosed between 1951 and 1987. Mycopathologia 107:25–32
Cates MB, Kaufman L, Grabau JH et al (1986) Blastomycosis in an Atlantic bottlenose dolphin. J Am Vet Med Assoc 189:1148–1150
Chapman SW, Dismukes WE, Proia LA et al (2008) Clinical practice guidelines for the management of blastomycosis: 2008 update by the Infectious Diseases Society of America. Clin Infect Dis 46:1801–1812
Connolly P, Hage CA, Bariola JR et al (2012) Blastomyces dermatitidis antigen detection by quantitative enzyme immunoassay. Clin Vaccine Immunol 19:53–56. https://doi.org/10.1128/CVI.05248-11
Crews LJ, Feeney DA, Jessen CR et al (2008a) Utility of diagnostic tests for and medical treatment of pulmonary blastomycosis in dogs: 125 cases (1989–2006). J Am Vet Med Assoc 232:222–227. https://doi.org/10.2460/javma.232.2.222
Crews LJ, Feeney DA, Jessen CR, Newman AB (2008b) Radiographic findings in dogs with pulmonary blastomycosis: 125 cases (1989–2006). J Am Vet Med Assoc 232:215–221. https://doi.org/10.2460/javma.232.2.215
Dalton HJ, Hertzog JH, Hannan RL et al (1999) Extracorporeal membrane oxygenation for overwhelming Blastomyces dermatitidis pneumonia. Crit Care 3:91–94
Davies C, Troy G (1996) Deep mycotic infections in cats. J Am Anim Hosp Assoc 32:380–391. https://doi.org/10.5326/15473317-32-5-380
Davies JL, Epp T, Burgess HJ (2013) Prevalence and geographic distribution of canine and feline blastomycosis in the Canadian prairies. Can Vet J 54:753–760
Denton JF, Di Salvo AF, Hirsch ML et al (1967) Laboratory-acquired North American blastomycosis. JAMA 199:935. https://doi.org/10.1001/jama.1967.03120120123030
Dismukes WE, Bradsher RW, Cloud GC et al (1992) Itraconazole therapy for blastomycosis and histoplasmosis. NIAID Mycoses Study Group. Am J Med 93:489–497
Dukik K, Muñoz JF, Jiang Y et al (2017) Novel taxa of thermally dimorphic systemic pathogens in the Ajellomycetaceae (Onygenales). Mycoses 60:297–309. https://doi.org/10.1111/myc.12601
Dykstra JA, Rogers LL, Mansfield SA et al (2012) Fatal disseminated blastomycosis in a free-ranging American black bear (Ursus americanus). J Vet Diagn Investig 24:1125–1128. https://doi.org/10.1177/1040638712461788
Finn MJ, Stiles J, Krohne SG (2007) Visual outcome in a group of dogs with ocular blastomycosis treated with systemic antifungals and systemic corticosteroids. Vet Ophthalmol 10:299–303. https://doi.org/10.1111/j.1463-5224.2007.00554.x
Foy DS, Trepanier LA, Kirsch EJ, Wheat LJ (2014) Serum and urine Blastomyces antigen concentrations as markers of clinical remission in dogs treated for systemic blastomycosis. J Vet Intern Med 28:305–310. https://doi.org/10.1111/jvim.12306
Frost HM, Novicki TJ (2015) Blastomyces antigen detection for the diagnosis and management of blastomycosis. J Clin Microbiol 53:02352–02315. https://doi.org/10.1128/JCM.02352-15
Gilchrist TC (1894) Protozoan dermatitis. J Cutan Gen Dis 12:496–499
Gilchrist TC, Stokes WR (1898) A case of pseudo-lupus vulgaris caused by a blastomyces. J Exp Med 3:53–78
González GM, Fothergill AW, Sutton DA et al (2005) In vitro activities of new and established triazoles against opportunistic filamentous and dimorphic fungi. Med Mycol 43:281–284. https://doi.org/10.1080/13693780500088416
Gray NA, Baddour LM (2002) Cutaneous inoculation blastomycosis. Clin Infect Dis 34:E44–E49. https://doi.org/10.1086/339957
Guarner J, Brandt ME (2011) Histopathologic diagnosis of fungal infections in the 21st century. Clin Microbiol Rev 24:247–280. https://doi.org/10.1128/CMR.00053-10
Harris JR, Blaney DD, Lindsley MD et al (2011) Blastomycosis in man after kinkajou bite. Emerg Infect Dis 17:268–270. https://doi.org/10.3201/eid1702.101046
Herrmann JA, Kostiuk SL, Dworkin MS, Johnson YJ (2011) Temporal and spatial distribution of blastomycosis cases among humans and dogs in Illinois (2001–2007). J Am Vet Med Assoc 239:335–343. https://doi.org/10.2460/javma.239.3.335
Hough CL (2014) Steroids for acute respiratory distress syndrome? Clin Chest Med 35:781–795
Houseright RA, Webb JL, Claus KN (2015) Pathology in practice. Blastomycosis in an indoor-only cat. J Am Vet Med Assoc 247:357–359. https://doi.org/10.2460/javma.247.4.357
Imai DM, McGreevey N, Anderson JL, Meece JK (2014) Disseminated Blastomyces dermatitidis, genetic group 2, infection in an alpaca ( Vicugna pacos). J Vet Diagn Invest 26:442–447. https://doi.org/10.1177/1040638714523773
Kaufman L, Standard PG, Weeks RJ, Padhye AA (1983) Detection of two Blastomyces dermatitidis serotypes by exoantigen analysis. J Clin Microbiol 18:110–114
Kingston M, El-Mishad MM, Ali MA (1980) Blastomycosis in Saudi Arabia. Am J Trop Med Hyg 29:464–466
Klein BS, Vergeront JM, Weeks RJ et al (1986) Isolation of Blastomyces dermatitidis in soil associated with a large outbreak of blastomycosis in Wisconsin. N Engl J Med 314:529–534
Kralt D, Light B, Cheang M et al (2009) Clinical characteristics and outcomes in patients with pulmonary blastomycosis. Mycopathologia 167:115–124
Kuttin ES, Beemer AM, Levij J et al (1978) Occurrence of Blastomyces dermatitidis in Israel. First autochthonous Middle Eastern case. Am J Trop Med Hyg 27:1203–1205
Lahm T, Neese S, Thornburg AT et al (2008) Corticosteroids for blastomycosis-induced ARDS: a report of two patients and review of the literature. Chest 133:1478–1480
Langlois DK, Pelosi A, Kruger JM (2013) Successful treatment of intracardiac and intraocular blastomycosis in a dog with combination azole therapy. J Am Anim Hosp Assoc 49:273–280. https://doi.org/10.5326/JAAHA-MS-5874
Legendre AM (2012) Blastomycosis. In: Greene CE (ed) Infectious diseases of the dog and cat, 4th edn. Elsevier, Amsterdam, pp 606–614
Legendre AM, Rohrbach BW, Toal RL et al (1996) Treatment of blastomycosis with itraconazole in 112 dogs. J Vet Intern Med 10:365–371
Lemos LB, Baliga M, Guo M (2002) Blastomycosis: the great pretender can also be an opportunist. Initial clinical diagnosis and underlying diseases in 123 patients. Ann Diagn Pathol 6:194–203
Lemos LB, Baliga M, Guo M (2001) Acute respiratory distress syndrome and blastomycosis: presentation of nine cases and review of the literature. Ann Diagn Pathol 5:1–9
Li RK, Ciblak MA, Nordoff N et al (2000) In vitro activities of voriconazole, itraconazole, and amphotericin B against Blastomyces dermatitidis, Coccidioides immitis, and Histoplasma capsulatum. Antimicrob Agents Chemother 44(6):1734. https://doi.org/10.1128/AAC.44.6.1734-1736.2000
Limper AH, Knox KS, Sarosi GA et al (2011) An official American Thoracic Society statement: treatment of fungal infections in adult pulmonary and critical care patients. Am J Respir Crit Care Med 183:96–128
Lloret A, Hartmann K, Pennisi MG et al (2013) Rare systemic mycoses in cats: blastomycosis, histoplasmosis and coccidioidomycosis: ABCD guidelines on prevention and management. J Feline Med Surg 15(7):624. https://doi.org/10.1177/1098612X13489226
Lombardi G, Padhye AA, Ajello L (1988) In vitro conversion of African isolates of Blastomyces dermatitidis to their yeast form. Mycoses 31:447–450
Lopez R, Mason JO, Parker JS, Pappas PG (1994) Intraocular blastomycosis: case report and review. Clin Infect Dis 18:805–807
Martynowicz MA, Prakash UBS (2002) Pulmonary blastomycosis: an appraisal of diagnostic techniques. Chest 121:768–773. https://doi.org/10.1378/chest.121.3.768
Mazepa ASW, Trepanier LA, Foy DS (2011) Retrospective comparison of the efficacy of fluconazole or itraconazole for the treatment of systemic blastomycosis in dogs. J Vet Intern Med 25:440–445. https://doi.org/10.1111/j.1939-1676.2011.0710.x
Meece JK, Anderson JL, Fisher MC et al (2011) Population genetic structure of clinical and environmental isolates of Blastomyces dermatitidis, based on 27 polymorphic microsatellite markers. Appl Environ Microbiol 77:5123–5131. https://doi.org/10.1128/AEM.00258-11
Meece JK, Anderson JL, Gruszka S et al (2013) Variation in clinical phenotype of human infection among genetic groups of Blastomyces dermatitidis. J Infect Dis 207:814–822. https://doi.org/10.1093/infdis/jis756
Meyer K (1912) Blastomycosis in dogs. Proc Path Soc Philadelphia 15:10
Meyer KC, McManus EJ, Maki DG (1993) Overwhelming pulmonary blastomycosis associated with the adult respiratory distress syndrome. N Engl J Med 329:1231–1236
Nemeth NM, Campbell GD, Oesterle PT et al (2016) Red fox as sentinel for Blastomyces dermatitidis, Ontario, Canada. Emerg Infect Dis 22(7):1275. https://doi.org/10.3201/eid2207.151789
Oppenheimer M, Embil JM, Black B et al (2007) Blastomycosis of bones and joints. South Med J 100:570–578. https://doi.org/10.1097/SMJ.0b013e3180487a92
Pappas PG, Bradsher RW, Kauffman CA et al (1997) Treatment of blastomycosis with higher doses of fluconazole. The National Institute of Allergy and Infectious Diseases Mycoses Study Group. Clin Infect Dis 25:200–205
Pappas PG, Threlkeld MG, Bedsole GD et al (1993) Blastomycosis in immunocompromised patients. Medicine (Baltimore) 72:311–325
Patel AJ, Gattuso P, Reddy VB (2010) Diagnosis of blastomycosis in surgical pathology and cytopathology: correlation with microbiologic culture. Am J Surg Pathol 34:256–261. https://doi.org/10.1097/PAS.0b013e3181ca48a5
Patel RG, Patel B, Petrini MF et al (1999) Clinical presentation, radiographic findings, and diagnostic methods of pulmonary blastomycosis: a review of 100 consecutive cases. South Med J 92:289–295
Perfect JR, Savani DV, Durack DT (1986) Comparison of itraconazole and fluconazole in treatment of cryptococcal meningitis and candida pyelonephritis in rabbits. Antimicrob Agents Chemother 29:579–583
Plamondon M, Lamontagne F, Allard C, Pépin J (2010) Corticosteroids as adjunctive therapy in severe blastomycosis-induced acute respiratory distress syndrome in an immunosuppressed patient. Clin Infect Dis 51:e1–e3
Randhawa HS, Khan ZU, Gaur SN (1983) Blastomyces dermatitidis in India: first report of its isolation from clinical material. Sabouraudia 21:215–221
Resch M, Kurz K, Schneider-Brachert W et al (2009) Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS) in fulminant blastomycosis in Germany. BMJ Case Rep 2009:bcr0720080392. https://doi.org/10.1136/bcr.07.2008.0392
Restrepo A, Baumgardner DJ, Bagagli E et al (2000) Clues to the presence of pathogenic fungi in certain environments. Med Mycol 38(Suppl 1):67–77
Richer SM, Smedema ML, Durkin MM et al (2014) Development of a highly sensitive and specific blastomycosis antibody enzyme immunoassay using Blastomyces dermatitidis surface protein BAD-1. Clin Vaccine Immunol 21:143–146. https://doi.org/10.1128/CVI.00597-13
Rosser MF, Lindemann DM, Barger AM et al (2016) Systemic blastomycosis in a captive red ruffed lemur (Varecia rubra). J Zoo Wildl Med 47:912–916. https://doi.org/10.1638/2016-0019.1
Rudmann DG, Coolman BR, Perez CM, Glickman LT (1992) Evaluation of risk factors for blastomycosis in dogs: 857 cases (1980–1990). J Am Vet Med Assoc 201:1754–1759
Saccente M, Abernathy RS, Pappas PG et al (1998) Vertebral blastomycosis with paravertebral abscess: report of eight cases and review of the literature. Clin Infect Dis 26:413–418
Saccente M, Woods GL (2010) Clinical and laboratory update on blastomycosis. Clin Microbiol Rev 23:367–381
Sarosi GA, Eckman MR, Davies SF, Laskey WK (1979) Canine blastomycosis as a harbinger of human disease. Ann Intern Med 91:733. https://doi.org/10.7326/0003-4819-91-5-733
Sarosi GA, Hammerman KJ, Tosh FE, Kronenberg RS (1974) Clinical features of acute pulmonary blastomycosis. N Engl J Med 290:540–543. https://doi.org/10.1056/NEJM197403072901004
Savani DV, Perfect JR, Cobo LM, Durack DT (1987) Penetration of new azole compounds into the eye and efficacy in experimental Candida endophthalmitis. Antimicrob Agents Chemother 31:6–10
Schmiedt C, Kellum H, Legendre AM et al (2015) Cardiovascular involvement in 8 dogs with blastomyces dermatitidis infection. J Vet Intern Med 20:1351–1354. https://doi.org/10.1892/0891-6640(2006)20[1351:CIIDWB]2.0.CO;2
Schwartz IS, Embil JM, Sharma A et al (2016) Management and outcomes of acute respiratory distress syndrome caused by blastomycosis: a retrospective case series. Medicine (Baltimore) 95:e3538. https://doi.org/10.1097/MD.0000000000003538
Smith JA, Gauthier G (2015) New developments in blastomycosis. Semin Respir Crit Care Med 36:715–728. https://doi.org/10.1055/s-0035-1562898
Smith JA, Kauffman CA (2009) Endemic fungal infections in patients receiving tumour necrosis factor-alpha inhibitor therapy. Drugs 69:1403–1415. https://doi.org/10.2165/00003495-200969110-00001
Spector D, Legendre AM, Wheat J et al (2008) Antigen and antibody testing for the diagnosis of blastomycosis in dogs. J Vet Intern Med 22:839–843. https://doi.org/10.1111/j.1939-1676.2008.0107.x
Stewart AJ, Cuming RS (2015) Update on fungal respiratory disease in horses. Vet Clin North Am Equine Pract 31:43–62. https://doi.org/10.1016/j.cveq.2014.11.005
Storms TN, Clyde VL, Munson L, Ramsay EC (2003) Blastomycosis in nondomestic felids. J Zoo Wildl Med 34:231–238. https://doi.org/10.1638/1042-7260(2003)034[0231:BINF]2.0.CO;2
Sykes JE, Merkel LK (2014) Blastomycosis. In: Sykes JE (ed) Canine and feline infectious diseases. Elsevier, St. Louis, pp 574–586
Ta M, Flowers SA, Rogers PD (2009) The role of voriconazole in the treatment of central nervous system blastomycosis. Ann Pharmacother 43:1696–1700. https://doi.org/10.1345/aph.1M010
Vandepitte J, Gatti F (1972) A case of North American blastomycosis in Africa. Its existence in Republic of Zaire. Ann la Société belge médecine Trop 52:467–479
Vasquez JE, Mehta JB, Agrawal R, Sarubbi FA (1998) Blastomycosis in northeast Tennessee. Chest 114:436–443
Wilkinson LM, Wallace JM, Cline JM (1999) Disseminated blastomycosis in a rhesus monkey (Macaca mulatta). Vet Pathol 36:460–462. https://doi.org/10.1354/vp.36-5-460
Williams JE, Moser SA (1987) Chronic murine pulmonary blastomycosis induced by intratracheally inoculated Blastomyces dermatitidis conidia. Am Rev Respir Dis 135:17–25. https://doi.org/10.1164/arrd.1987.135.1.17
Wilson JH, Olson EJ, Haugen EW et al (2006) Systemic blastomycosis in a horse. J Vet Diagn Investig 18:615–619. https://doi.org/10.1177/104063870601800619
Wüthrich M, Filutowicz HI, Klein BS (2000) Mutation of the WI-1 gene yields an attenuated blastomyces dermatitidis strain that induces host resistance. J Clin Investig 106:1381–1389. https://doi.org/10.1172/JCI11037
Wüthrich M, Krajaejun T, Shearn-Bochsler V et al (2011) Safety, tolerability, and immunogenicity of a recombinant, genetically engineered, live-attenuated vaccine against canine blastomycosis. Clin Vaccine Immunol 18:783–789. https://doi.org/10.1128/CVI.00560-10
Zwick LS, Briggs MB, Tunev SS et al (2000) Disseminated blastomycosis in two California sea lions (Zalophus californianus). J Zoo Wildl Med 31:211–214. https://doi.org/10.1638/1042-7260(2000)031[0211:DBITCS]2.0.CO;2
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer International Publishing AG, part of Springer Nature
About this chapter
Cite this chapter
Schwartz, I.S. (2018). Blastomycosis in Mammals. In: Seyedmousavi, S., de Hoog, G., Guillot, J., Verweij, P. (eds) Emerging and Epizootic Fungal Infections in Animals. Springer, Cham. https://doi.org/10.1007/978-3-319-72093-7_8
Download citation
DOI: https://doi.org/10.1007/978-3-319-72093-7_8
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-72091-3
Online ISBN: 978-3-319-72093-7
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)