A Study of the Safety and Efficacy of Posaconazole Versus Voriconazole for the Treatment of Invasive Aspergillosis (MK-5592-069)

Inclusion Criteria: * Weight \>40 kg (88 lb) and ≤150 kg (330 lb); if between 13 and 14 years of age must weigh \>= 50 kg (110 lb) * Must meet the criteria for proven, probable, or possible IA as per 2008 European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) disease definitions at the time of randomization. Proven IA will include those participants with the demonstration of fungal elements (by cytology, microscopy, or culture) in diseased tissue (sterile sampling). Probable IA includes participants with at least 1 host factor, clinical criteria, as well as mycological criteria including both direct and indirect methods. Possible IA includes participants with at least 1 host factor and clinical criteria but without mycological criteria. A modification to the 2008 EORTC/MSG criteria regarding risk factors has been made to allow for the inclusion of participants with any duration of neutropenia as an acceptable inclusion host factor. * If with possible IA at time of randomization must be willing or be in process of an ongoing diagnostic work up which is anticipated to result in a mycological diagnosis of proven or probable IA postrandomization. * Must have a central line (e.g., central venous catheter, peripherally-inserted central catheter, etc.) in place or planned to be in place prior to beginning IV study therapy. If without central…