Pathogen Details, Meaning Pathogen Article and Explanation Guide

Pathogen Guide, Meaning , Facts, Information and Description

A pathogen is a biological agent that can cause disease to its host. A synonym of pathogen is "infectious agent". The term "pathogen" is most often used for agents that disrupt the normal physiology of a multicellular animal or plant. However, pathogens can infect unicellular organisms from all of the biological kingdoms (see Viruses, below).

Table of contents

1 Overview
2 Vaccines
3 Antibiotics
4 Threat of pathogens
5 Notable pathogens

5.1 Bacteria
5.2 Viruseses
5.3 Subviral pathogens
5.4 Protozoa
5.5 Fungi
5.6 Parasites

6 See also
7 External links

Overview

The human body has many natural defenses against some of the more 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 or HIV, or by antibiotics being taken to kill other pathogens,) pathogenic bacteria that was being held at bay can proliferate and cause harm to the host. Such cases are called opportunistic infections

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 life on Earth, and can be particularly devastating to its human inhabitants.

Vaccines

To this day, only one virus has been declared entirely eradicated from the planet - Variola virus, which causes Smallpox, through the use of vaccination. A massive undertaking to eradicate polio through vaccination is in progress, but in some developing countries large amounts of people still have no access to the vaccine. In recent years, some Western families have opted against vaccinating their children for either religious reasons or because of mistrust in the effectiveness or safety of vaccination. (This dropoff in vaccination has been said to have contributed to the sharp rise in recent measles cases in the United Kingdom.)

Antibiotics

Many antibiotics are effective against pathogenic bacteria, however, their widespread and sometimes poorly advised use is giving rise to antibiotic resistance. (In some places, particularly in the West, prescription of antibiotics is sometimes issued when the underlying cause of illness is actual viral, in which case the body's normal microbiota are bathed in antibiotics, and thus some bacteria "learn" to develop their own defenses against them.) Increasing availability of anti-bacterial soaps and cleaners may also be contributing to this phenomenon.

Threat of pathogens

Some pathogens (such as Yersinia pestis, which caused the Black Plague, and the aforementioned Variola virus) have been found responsible for massive amounts of casualties and have had numerous effects on afflicted groups. Of particular note in modern times is HIV/AIDS, which is known to have infected several million humans globally, threatening entire populations in certain parts of the world, as well as the recently emerged Severe Acute Respiratory Syndrome, or SARS.