Uncommon Parasitic Infections

Occasionally, humans could be exposed to rare and uncommon parasitic infections. Although most of these infections are asymptomatic, in certain instances, these uncommon parasites result in the development of serious or even lethal diseases. Parasites causing uncommon human infections could be: (a) Nonhuman species of some parasites (humans act as paratenic or incidental hosts). These parasites fail to complete their normal life cycle in humans; instead, their early developmental stages migrate in host tissues leading to serious diseases. (b) Parasites that could infect both humans and animals (human acts as natural host or dead-end host). (c) Free-living parasites in the environment (they are usually nonpathogenic except when they accidentally infect humans). The above-mentioned parasites could cause the following clinical conditions: