August 2001: Volume 43, Number 8 The Evolution of New Bacterial
Pathogens by Kelly A. Reynolds, MSPH, Ph.D. Photographs, figures
and/or graphics that may illustrate this article are visible in
the printed version of the article only. To receive a copy,
please make a request at firstname.lastname@example.org. Be sure
to include the article title, author(s) name(s), the issue, your
name and your fax number or full address in the email. We all
know that new pathogens continue to emerge, but where do they
come from? How can a previously unknown organism suddenly
surface and wreak havoc on public health? A number of factors
contribute to the emergence of a new pathogen. They include: • A
pathogen may be previously unrecognized, undetectable or
undiagnosed but prevalent in the community for some time; • A
pathogen may have always been present but harmful only to a
specific group of individuals, such as the immunocompromised; •
A pathogen may be transmitted by a new exposure route, or • A
pathogen may truly be a new