Cryptococcus neoformans is an opportunistic fungal pathogen with global distribution. Immunocompromised populations are most at risk. Infections begin in the lungs where fungal spores are inhaled and either lie dormant or proliferate if met with an insufficient immune response. Pulmonary proliferation is followed by escape to the bloodstream and dissemination to the brain. C. neoformans in the bloodstream are poorly understood. We do not know how many fungi are there or how they disseminate. Do they travel as free fungi or do they move within ‘Trojan horse’ immune cells? We intend to answer these questions with techniques including microscopy/flow cytometry/and enzyme immunoassays.