That microorganisms emerge and re-emerge is not new. This has been occurring since the beginning of time. New bacterial and viral pathogens emerge either from an unrecognized ecological environment to thrust itself upon man (e.g. AIDS, Ebola) or following scientific discovery of a new strain of a previously defined pathogen (e.g. Hepatitis C).

Common bacterial pathogens (e.g. gonorrhea, malaria, enterococcus, pneumococcus, tuberculosis, staphylococcus, and streptococcus) have become resistant to many of the antibiotics used over the past 20 years and leave the medical community with no effective treatment for a growing list of infectious diseases.

As pathogens strengthen their hold, broaden their reach, and pierce our defenses, our vulnerability is extending to the most mundane activities. Questions arise such as - Is my tap water safe to drink? Is the food I ordered in a restaurant safe to eat? Are my children likely to be bitten by disease-carrying insects or ticks while playing in the yard? Does my sex partner have an infection that might be passed on to me? Is it safe to vacation in a tropical country? Is the coughing person next to me on the subway or airplane spreading a deadly strain of influenza or tuberculosis?