I can confirm that testing for aspergillosis is not part of a routine blood test; did they just do blood counts (CBC) or did they also do an advanced chem panel (ALT, Amylase, AST, BUN, Creat, Ca, Chol, CO2, CPK, GGT, Glu, LDH, Lipase, Phos, Potassium, Sodium, TP, Trig, Uric Acid)?
There is no definitive test for aspergillosis, but a culture is often taken to check for the fungus (taken from the respiratory tract). It, combined with other general testing, is used to come to a diagnosis.
An antibody test using a blood sample has also been developed, but it is not very accurate because it is 'too sensitive'.