New tests have recently been developed to diagnose Invasive Aspergillosis. These tests are for the detection of an Aspergillus protein in blood and for the detection of Aspergillus DNA in blood. Available data suggests that these new tests make an early diagnosis and seem to be able to monitor responses to treatment. However no study has been reported to date which demonstrates that the use of these tests can impact on important patient outcomes. This trial is being performed to determine whether the use of the new diagnostic tests to guide antifungal therapy will help improve treatment of Invasive Aspergillosis, reduce drug toxicity and reduce the death rate in the high-risk patients as compared with the current standard method of diagnosis and treatment with EAFT.