What term is used to describe microorganisms that cause disease?

The term that is used to describe microorganisms that cause disease is "pathogens." Pathogens include a variety of organisms such as bacteria, viruses, fungi, and parasites that can lead to diseases in their hosts. Identifying these agents as pathogens helps differentiate them from other types of microbes that may not be harmful or that may even be beneficial to health, such as certain bacteria involved in digestion.

While "microbes" is a broad term that encompasses all microscopic organisms, including those that are harmless or beneficial, it does not specifically indicate disease-causing organisms. "Bacteria" and "viruses" are specific types of pathogens, but they are subsets within the broader category of pathogens. Hence, referring to them collectively as pathogens is the most accurate way to describe organisms that are known to cause disease.