Information AboutPathogen |
| CATEGORIES ABOUT PATHOGEN | |
| microbiology | |
| pathology | |
| soil contamination | |
| immune system | |
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There are several substrates and ''pathways'' where by pathogens can invade a host; the principal pathways have different episodic time frames, but Soil Contamination has the longest or most persistent potential for harboring a pathogen. The body contains many natural defenses against some of the common pathogens (such as '' Pneumocystis '') in the form of the human Immune System and by some "helpful" Bacteria present in the human body's Normal Flora . However, if the immune system or "good" bacteria is damaged in any way (such as by Chemotherapy , Human Immunodeficiency Virus (HIV), or Antibiotic s being taken to kill other pathogens), pathogenic bacteria that were being held at bay can proliferate and cause harm to the host. Such cases are called Opportunistic Infection s. Some pathogens (such as the bacterium '' Yersinia Pestis '', which may have caused the Black Plague , and the '' Variola '' virus) have been found to be responsible for massive amounts of casualties and have had numerous effects on afflicted groups. Of particular note in modern times is HIV, which is known to have infected several million humans globally, as well as Severe Acute Respiratory Syndrome (SARS) and the Influenza virus. Today, while many medical advances have been made to safeguard against infection by pathogens, through the use of Vaccination , Antibiotics , and Fungicide , pathogens continue to threaten human life. Social advances such as Food Safety , Hygiene , and Water Treatment have reduced the threat from some pathogens. TYPES OF PATHOGENS Below is a listing of different types of notable pathogens as categorized by their structural characteristics, and some of their known effects on infected hosts. TRANSMISSION OF PATHOGENS See Also: Transmission (medicine) One of the primary pathways by which food or water become contaminated is from the release of untreated sewage into a Drinking Water supply or onto cropland, with the result that people who eat or drink contaminated sources become infected. In Developing Countries most sewage is discharged into the environment or on cropland as of 2006; even in Developed Countries there are periodic system failures resulting in a Sanitary Sewer Overflow . This is the typical mode of transmission for the infectious agents of (at least): TRANSMISSION TO VASCULAR PLANTS In the case of terrestrial Vascular Plant s, pathogenic infection can occur by contact with foliage, and also from root uptake of soil pathogens. The latter pathway explains why some plant families such as Orchid s are more disease resistant, since they rely upon Fungal Hyphae to supply Nutrient s rather than root structures, which have larger radii for conveying certain pathogens. SEE ALSO EXTERNAL LINKS
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