Entry/Exit Portals?
Portal of exit
In order for micro organisms to survive and repeat the cycle of infection in other humans, it must have a way to exit the reservoir. Organisms can grow in moldy water, or may spread via coughing, body fluids (sex), fecal material and urine.
Mode of transmission
Direct contact with the reservoir, which includes inhalation of infectious species found in particles in the air. Indirect contact occurs when the organism is able to withstand the harsh environment outside the reservoir and still remains infective when the specific opportunity arises.
This can be contaminated food products, and inanimate objects, like toys, furniture, door knobs, or personal care products from an infected individual. There are also a variety of infections transmitted from mother to child during the birthing process or fetal development, such as AIDS, etc.
Portal of entry
They are mouth, nose, breaks in the skin, vagina, or inserted tubes or catheters.
Susceptibility of host
Organisms usually cause infections in people who are physically weak and have a suppressed immune system.
Persistent viral infections
With recurrent infections, the organism continues to damage the body which eventually results in symptoms.
As the body weakens, the individual develops weight loss and extreme fatigue. Hepatitis-B causes a lifelong infection.
