There are five major types of infectious agents: bacteria, viruses, fungi, protozoa, and helminths. In addition, a new class of infectious agents, the prions, has recently been recognized. A brief review of the general characteristics of each of these agents and examples of some diseases they cause follows.Click to see full answer. Moreover, what are the 5 major types of infectious agents?A variety of microorganisms can cause disease. Pathogenic organisms are of five main types: viruses, bacteria, fungi, protozoa, and worms. Some common pathogens in each group are listed in the column on the right. Infectious agents can grow in various body compartments, as shown schematically in Fig.Furthermore, what are sources of infectious agents? Infectious diseases can be caused by: Bacteria. These one-cell organisms are responsible for illnesses such as strep throat, urinary tract infections and tuberculosis. Viruses. Even smaller than bacteria, viruses cause a multitude of diseases ranging from the common cold to AIDS. Fungi. Parasites. In respect to this, what are the 4 types of infectious diseases? Types of infection include bacterial, fungal, viral, protozoan, parasitic, and prion disease. They are classified by the type of organism causing the infection. Infections can range from mild inflammation in one person to an epidemic.Is a virus an infectious agent?Viruses are tiny infectious agents that replicate only in the living cells of other organisms. Viruses have a very simple structure consisting of genetic material in the form of DNA or RNA? within a protein? capsule.