CLINICAL MEDICINE

Detailed explanation-1: -Infectious diseases are caused by pathogens, which include bacteria, fungi, protozoa, worms, viruses, and even infectious proteins called prions.

Detailed explanation-2: -What is a pathogen? A pathogen is defined as an organism causing disease to its host, with the severity of the disease symptoms referred to as virulence. Pathogens are taxonomically widely diverse and comprise viruses and bacteria as well as unicellular and multicellular eukaryotes.

Detailed explanation-3: -Pathogenic organisms are of five main types: viruses, bacteria, fungi, protozoa, and worms.

Detailed explanation-4: -Pathogens include viruses, bacteria, fungi, and parasites that invade the body and can cause health issues. Anthrax, HIV, Epstein-Barr virus, and the Zika virus, among many others are examples of pathogens that cause serious diseases.

Detailed explanation-5: -Classical examples of intracellular pathogens are Brucella abortus, Listeria monocytogenes, Chlamydia trachomatis, Coxiella burnetii, Mycobacterium tuberculosis, Salmonella enterica, and typical infectious diseases caused by them include brucellosis, listeriosis, tuberculosis, and salmonellosis (Pamer, 2008).