Figure 2.

The life cycle of Balamuthia mandrillaris. Balamuthia mandrillaris is an opportunistic pathogen that is found in soil (a) and freshwater (b) that can occasionally infect humans. It exists either as dormant cysts or vegetative trophozoites that divide asexually through mitosis. The trophozoites and cysts can gain entry into the body either through a cutaneous wound or nasal passages (1). On entry through the skin (2), the amebae can reach the lungs through the blood. On entry through the nasal passages, the amebae can enter either the CNS through migration along the olfactory neuroepithelium (3) or migrate to the lower respiratory tract (4). Following hematogenous spread from the lungs, the amebae can invade the central nervous system (5) by crossing the blood–brain barrier causing granulomatous amebic encephalitis or spread to other tissues causing disseminated disease, or skin lesions