What term describes the invasion of the body by a pathogenic agent that multiplies and produces injurious effects?

The term that best describes the invasion of the body by a pathogenic agent that multiplies and produces injurious effects is Infection. Infections occur when microorganisms, such as bacteria, viruses, fungi, or parasites, enter the body, multiply, and cause harm to the host. The process can lead to various symptoms and immune responses as the body attempts to fight off the invaders.

In contrast, inflammation refers to the body's response to infection or injury, characterized by redness, heat, swelling, and pain, but it does not encompass the direct invasion or multiplication of pathogens itself. Contamination refers to the presence of an unwanted substance in a sterile environment, which may not necessarily involve active multiplication of pathogens. Inoculation typically means introducing a pathogen into a host to stimulate an immune response, rather than a natural invasion that results in symptoms. Thus, while all these terms relate to disease processes, infection specifically signifies the condition where pathogenic agents invade and replicate in the body, leading to harmful effects.