Pilot Feasibility Study With Patients Who Are at High Risk For Developing Invasive Candidiasis in a Critical Care Setting (MK-0991-067)

Inclusion Criteria: * Hospitalization for a minimum of 3 days in an ICU and expectation to stay in the ICU for at least another 48 hours * Meets the following high-risk criteria: Requires mechanical ventilation at the time of study entry; and has a central venous catheter in place at the time of study entry; and is receiving broad spectrum antibiotics at the time of study entry; AND meets at least one of the following criteria: Required parenteral nutrition during the current ICU admission; or required renal dialysis during the current ICU admission; or had major surgery during or within the 7 days before the current ICU admission; or was diagnosed with pancreatitis during or within the 7 days before the current ICU admission; or required systemic steroids or other immunosuppressive agents during or within the 7 days before the current ICU admission * Meets at least one of the following criteria of suspected infection at the time of study entry or within the 24 hours before study entry: Temperature ≥38° C or ≤36° C (oral equivalent); or hypotension (systolic blood pressure of \<90 mm Hg) or significant drop in blood pressure (40 mm Hg) from the participant's normal baseline; or elevated white blood cell count of ≥12,000/mm\^3 * Candida is growing in at least one non-sterile culture site collected during the current ICU admission * Female of childbearing potential has a negative serum or urine pregnancy test before enrollment Exclusion Criteria: * Females pregnant or breast feeding * History of allergy, hypersensitivity, or any serious reaction to caspofungin or another member of the echinocandin class (e.g., micafungin, anidulafungin) * Neutropenia or expected to develop neutropenia during study therapy * Diagnosis of acquired immune deficiency syndrome (AIDS), aplastic anemia, or chronic granulomatous disease * Diagnosis of moderate or severe hepatic insufficiency * Patient not expected to survive at least 24 hours * Received systemic (IV or oral) antifungal therapy within 10 days before study entry * Active diagnosis of proven or probable invasive fungal infection (IFI) * Currently on or has received an investigational agent within 10 days before study entry * Any condition or concomitant illness which might confuse the study results or pose additional risk in administering the study therapy