Infection

Four stages of progression:

1. Colonization

2. Invasion

3. Multiplication

4. Spread

1. COLONIZATION

-Infectious microorganisms exist in reservoirs e.g. environment, animals or infected humans 

-Transmitted via direct contact or indirectly by vectors (insects)

-Human to human transmission by areosolized microorganisims in droplets (coughing/sneezing)

-After deposit in reciptive enviroment- microorganism stabilizes adherence to the tissue through specific surface receptors 

2. INVASION 

-Infectious agent…