In terms of weather, both unusually dry weather and unusually moist weather have been cited. The seemingly contradictory data can most likely be reconciled by proposing that B. dermatitidis prospers in its natural habitats in times of moisture and moderate warmth, but that inoculum formed during these periods remains alive for some time and can be released into the air by subsequent dust formation under dry conditions. Indeed, dust per se or construction potentially linked to dust has been associated with several outbreaks The data, then, tend to link blastomycosis to all weather, climate and atmospheric conditions except freezing weather, periods of snow cover, and extended periods of hot, dry summer weather in which soil is not agitated. Gender bias
Sex is another factor inconstantly linked to contraction of blastomycosis: though many studies show more men than women affected, some show no sex-related bias. As mentioned above, most cases are in middle aged adults, but all age groups are affected, and cases in children are not uncommon. Ethnic populations
Ethnic group or race is frequently investigated in epidemiological studies of blastomycosis, but is potentially confounded by differences in residence and in quality and accessibility of medical care, factors that have not been stringently controlled for to date. In the United States, some studies show a disproportionately high incidence and/or mortality rate for blastomycosis among Black people.In Canada, some studies, but not others, indicate that First Nations people have a disproportionately high incidence of blastomycosis. Incidence in First Nations children may be unusually high.
It usually is found in the cerebrum or cerebellopontine angle. Symptoms may be acute or develop slowly over several months and depend on the location of the lesion. Ocular – This is an uncommon form of GME and is characterized by sudden blindness caused by optic neuritis. The disease is bilateral. Ocular GME is considered to be an extension of CNS disease. The blood vessels of the posterior segment of the eye and anterior uvea have the same infiltrates of inflammatory cells as the intracranial vessels. Uveitis, retinal detachment, and secondary glaucoma may be seen. Diagnosis and treatment
Cerebrospinal fluid (CSF) analysis shows a large number of white blood cells. Typically small mature lymphocytes are the majority of cells seen, with monocytes and neutrophils making up the rest. Definitive diagnosis is based on histopathology, either a brain biopsy or post-mortem evaluation (necropsy). A CT scan or MRI will show patchy, diffuse, or multifocal lesions. For a number of years, the basic treatment was some type of corticosteroid in combination with one or more immunosuppressive drugs, typically cytosine arabinoside and/or cyclosporine or other medications such as azathioprine, cyclophosphamide, or procarbazine, of which were usually added one at a time to the corticosteroid until a successful combination was found. There is evidence that treatment with radiation therapy for focal GME provides the longest periods of remission. Pug dog encephalitis
Pug dog encephalitis (PDE) is an idiopathic inflammatory disease primarily affecting the prosencephalon (forebrain and thalamus). It is also known as necrotizing meningoencephalitis.