Parasites enter the body of host (humans, plant,

animals)in the form of egg, Cyst, active or

vegetation forms as thethree Ppathogens

transmissible and infective stages, which are living

structures with potential for growth, enter a

particular anatomic site and grow within specific

location. They are able to cause disease in humans

and veterinary productions because they contain capsule, enzymes and toxins that give them virujence abiity. In plants, they colonize and harm food plant due to specific pathogenicity factors which they use such as ceff wall-degrading enzyme, toxins, errectorproteins, pyntonormones and exopolysaccharides.

The pathogen transmissible structures is an adaptation to effectively Withstand the host’s unstable ph, and body temperatures as it (host) provided the pathogens with nourishment, moist environment and extensive surface area. When a favorable environmental condition Occurs, the viable transmissible structures undergo yet another adaptation and get to its target site inside the host. In humans, on arrival at the site, they release enzymatic proteins that would degrade the host’s cell wall barrier and secret protein called effector proteins into the extracellular environment or directly into the cell to suppress host defense mechanism or cause reduction of biochemical synthesis that gives the host defense. This is known as pathogen biology which studies the

ability of pathogen or etiologic agents to recognizeand establish in their host victims to a large extent. When they release the enzymes which they

secret on cells and tissues of thelr target site, the

host now release its rich nutritive constituents to

the pathogens and make the pathogen to feed on

the host’s bodily nutrition.


Disease occurs because as pathogen feed they

discharge metabolic by-products in the form of

toxins which become harmful to the host. They

also increase in population through reproduction

which mounts pressure to nutrient availability

thereby making the host to become deficient of

certain nutritive element s such as vitamin A, iron

etc: Some stay in the intestinal tract where as

others explore the body, passing through any

Humber of body parts and often causing havoc as

they wander. They can for instance, get into joints

and eat the calcium lining the bone resuting in

arthritic tendencies to cause symptoms such as

joint and muscle aches.


They can also eat the protein coating on nerves

causing a disruption in nerve signals from the

brain. So, the molecules (vitamin A) that the

pathogens may recognize give a signal that the host can provide a home and nutrition. Pathogens

are able to cause symptoms because while in the

body they destroy cells faster than cells can De

regenerated, produce toxin substances and allergic

reactions, irritate and invade body tissues, put

pressure on the body organs causing organs

obstruction, depress immune system function while activatingbImmune system response.

The Continuous consumption of essentlal nutrients that

sustains the host by dedicated pathogens reduces

nutrients availability in the host’s body which triggers disease. symptoms.


As humans are constantly exposed to pathogens in

a polluted or brown air, Surface water, soil and

food, a new host is as well exposed to infectious

particles shed by an infected individual. The first

contact with a new host occurs through an

epithelial surface. This may be the skin or the

intestinal mucosa surface of the respiratory gastro

intestinal and urogenital tracts. Disease symptoms

Occur by the damage and toxins or by the way the

body responds to the damage and toXIns produced

by pathogens. After making contacts an infectious

agent must establish a focus inection. This involves adhering to the epitnellal surtace and then

colonizing it, or penetrating it to replicate in the

tissues. At this stage many pathogens are repelled

by immune defenses mediated by epithelia and

phagocytes. The immune systems are activated in

a response to intracellular infection to bring effectors cells and molecules to the site of an infection while preventing pathogens spread into the blood.

The pathobiology of poor sanitary facilities and condition, pollutionof surface water and consumption of infected food plant would undoubtedly promote advocacy on the need to keep and protect our territorial waters, food plants and medicinal plants provided by vegetation and landscape and ensure sustainability of life earth.

Updated: July 27, 2020 — 2:19 am

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