The diagnostic considerations raised by immunocompromised patients with opportunistic infection continue to expand. When such patients harbor latent or persistent infection acquired in a tropical environment, the diagnostic challenge is even greater. The Infectious Disease Service at Yale-New Haven Hospital was asked to see a middle-aged man from Peru with known T-cell lymphoma who had recently completed a course of chemotherapy. He presented to the hospital with fever, petechial skin rash, pulmonary infiltrates, and neutropenia. Ultimately this case illustrated the necessity for careful evaluation of such patients, looking, in particular, for evidence of opportunistic parasitic infection.