21. Parasitic Infections
Parasites are things that live in other organisms and rely on them for survival. A parasite cannot live, grow, or replicate in the absence of a host. As a result, while a parasite seldom kills its host, it can spread infections, some of which are lethal. The properties of parasites vary greatly. Many are imperceptible to the naked eye, such in the malarial parasite, yet some worm parasites can grow to be more than 35 centimeters in length. Parasites do not cause disease, but they can transmit it. The consequences of various parasites vary.
Recommended For You
