What term is used to describe tiny living organisms that can cause infectious diseases?

The term that best describes tiny living organisms capable of causing infectious diseases is pathogens. While "germs" is a colloquial term often used interchangeably with pathogens, it does not strictly define the specific types of organisms involved. Pathogens encompass a broader category, including bacteria, viruses, fungi, and parasites, all of which can lead to infections.

Bacteria and viruses are specific types of pathogens, but the term "pathogen" captures the full range of microorganisms that can cause illness. Therefore, while "germs" is commonly understood, using "pathogens" provides a more scientifically accurate description of these infectious agents.