What is a pathogen?

What is a pathogen?

• A. A microorganism that causes disease
• B. A virus only
• C. A disease-causing protein
• D. A chemical contaminant

Answer: (A)

A pathogen is an organism capable of causing disease in a host. In environmental health, this includes microscopic living things such as bacteria, viruses, fungi, and parasites that can invade and harm the body. It’s not limited to viruses or to non-living agents like proteins or chemicals. For example, bacteria like Salmonella, viruses like norovirus, and parasites like Giardia are all pathogens. A disease-causing protein (prion) isn’t a microorganism in the traditional sense, and a chemical contaminant isn’t biological at all. So the best description is a microorganism that causes disease.

A pathogen is an organism capable of causing disease in a host. In environmental health, this includes microscopic living things such as bacteria, viruses, fungi, and parasites that can invade and harm the body. It’s not limited to viruses or to non-living agents like proteins or chemicals. For example, bacteria like Salmonella, viruses like norovirus, and parasites like Giardia are all pathogens. A disease-causing protein (prion) isn’t a microorganism in the traditional sense, and a chemical contaminant isn’t biological at all. So the best description is a microorganism that causes disease.