Infectious disease - Wikipedia, the free encyclopedia

Infectious disease - Wikipedia, the free encyclopedia: "An infectious disease is a clinically evident disease that damages or injures the host that results from the presence of one or more pathogenic microbial agents, including viruses, bacteria, fungi, protozoa, multicellular parasites, and aberrant proteins known as prions. These pathogens can cause diseases in both animals and plants. Transmission of an infectious disease may occur through several pathways; including through contact with infected individuals, by water, food, airborne inhalation, or through vector-borne spread.[1] A contagious disease (also called a communicable disease) is an infectious disease that is capable of being transmitted from one person or species to another.[2] Contagious diseases are often spread through direct contact with an individual, contact with the bodily fluids of infected individuals, or with objects that the infected individual has contaminated. The term infectivity describes the ability of an organism to enter, survive and multiply in the host, while the infectiousness of a disease indicates the comparative ease with which the disease is transmitted to other hosts.[3] An infection however, is not synonymous with an infectious disease, as an infection may not cause clinical symptoms or impair host function.[1]"