Light micrograph of Candida albicans yeast cells. C. albicans is a single-celled fungus (yeast) that can cause an infection called candidiasis. Part of the normal flora, C. albicans is normally harmless and unproblematic, however infections occur when the yeast starts to multiply rapidly, causing redness and itching. It can infect the surfaces of the skin, mouth and vagina. Patients who are hospitalised or have a weakened immune system are at greater risk of developing invasive candidiasis. Invasive candidiasis occurs when the fungus enters the bloodstream (candidaemia) and spreads to one or more organs. If left untreated candidaemia can lead to death. Treatments include a range of antifungal medications.