What term describes the process of increasing the number of germs in the body and their multiplication?

The process of increasing the number of germs in the body and their multiplication is accurately described as infection. An infection occurs when harmful microorganisms, such as bacteria, viruses, or fungi, invade the body, proliferate, and cause illness. This can result in a range of symptoms and health issues, depending on the type of microorganism and the body's response.

Immunity refers to the body’s ability to resist or fight off infection, often through the immune system’s defenses. Contamination typically refers to the presence of unwanted substances or microorganisms on a surface or in a substance, but it does not imply that those germs are multiplying within the body. Infestation specifically refers to the invasion of a host by larger parasites, such as worms or insects, rather than microbial infection. Therefore, the term infection is the most accurate and relevant term to describe the process in question.