Clinical use
Identification of patients with previous exposure to Blastomyces.
Background
Blastomycosis is an infection caused by a dimorphic fungus called Blastomyces, which is found in the environment, particularly in moist soil and in decomposing matter such as wood and leaves. Most cases are seen in or associated with travel to North America, particularly in the mid-western, south-central, and south-eastern states, in areas surrounding the Ohio and Mississippi River valleys, the Great Lakes and the Saint Lawrence River. Cases have also been identified in Mexico, Central and South America, India, and the Middle East. Infection is acquired after breathing in microscopic fungal spores for the air. Although most people who breathe in the spores don’t become unwell, some people may develop symptoms like fever and cough. When infection develops it presents as a systemic pyogranulomatous infection involving the lungs, which can be asymptomatic or can manifest as acute or chronic pneumonia. Hematogenous dissemination can also occur, with spread to other organs.
Specimen requirments
Serum/clotted blood (Yellow top)
Turnaround time
3-12 days
Restrictions and limitations
There is a high degree of cross-reactivity of serology assays with other dimorphic fungi such as Histoplasma, if infection is suspected, then tissue culture and histopathology can provide a definite diagnosis.
Please note Blastomyces is a hazard group 3 pathogen, if tissue/fluid samples are sent to the laboratory and Blastomyces is in the differential diagnosis, then this should be clearly identified on the sample request form. There is a danger of infection risk to laboratory staff from these samples.
Analysing laboratory
PHE Mycology Reference Laboratory, National Infection Services, PHE South West Laboratory, Science, Quarter, Southmead Hospital, Bristol, BS10 5NB