Infectious Disease Drivers
Infectious disease can be catastrophic, and sometimes lethal, to the host. Most of the disease drivers show a significant degree of host specificity.
During infection process each stage is hindered by varied defense mechanisms. When host system is open to invading pathogen, host infectivity is determined by stability and mode of transmission outside the infectious agent. Few infectious diseases like anthrax are transmitted by heat resistant spores. While others such as HIV are spread only exchange of body fluids as they are unable to survive as infectious agents outside the body.
When a microbe is profitably settled onto infection site of host, incidence of disease and infection happens and secrete toxins that transmit to other parts of the body. Extracellular parasites advance by direct extension of the focus of infection through the lymphatic and the bloodstream.