Pathogenesis factors o Microbial factors: virulence factors: chlamydia mycoplasma, influenza virus, S. Pneuomiae Mycobacteria, Pneumococccal, polypeptide pneumolysin o Host factors: hypogammaglobulimia, CD4+ T cell reduction, underlying lung disease medicine o Routes of pathogenesis: gross aspiration microaspiration, aerosolization, hematogel d spread, direct spread Microbial factors: virulence factors: chlamydia, maycoplasma, influenza virus, S. Pneuomiae, Mycobacteria, Pneumococccal, polypeptide pneumolysin.  Host factors: hypogammaglobulimia, CD4+ T cell reduction, underlying lung disease, medicine  Routes of pathogenesis: gross aspiration, microaspiration, aerosolization, hematogenous spread, direct spread