Diseases and Pathogens

Pathogens

Pathogens are disease-causing or infectious microorganisms (EPA 2011, Kennedy 2012). Some of them are often found in water from sewage discharges, leaking septic tanks, or runoff from feedlots. They enter the body and cause disease every day through the air we breathe, food, water or direct personal contact. The body's immune system is able to destroy many pathogens. When it cannot, infection occurs and the person gets sick. There are different types of pathogens, but the most common are the virus, bacteria, the fungus and protozoa (EPA, Kennedy).

Most Common Types and Their Differences

Bacteria are single-celled microorganisms, which have no nucleus (DHSS 2012, Kennedy 2012). They cause many diseases, many of which can be prevented by vaccination. Bacteria do not usually kill the infected person and only weaken him a lot. These non-fatal bacteria do not spread easily. Examples of bacteria are anthrax, Escherichia coli,...
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