On Wednesday representatives from the Harvard School of Public Health will
be coming to talk about their research and hold an info session about the
school. Mel Larson, from the Center for Communicable Disease Dynamics
(CCDD) at HSPH, will also be present to hand out information to students,
talk about the CCDD and the opportunities they have there for the spring
and summer, and discuss resources HSPH offers students to help with their
applications.

When: Wednesday, October 22 at 5pm
Where: Kemeny 004

The information for the talk is found below:

*Phenotypic variation allows for heighted pathogen virulence*

Lauren M. Childs, Cayley Bowles, Caroline O. Buckee

Abstract: Theoretical frameworks for understanding why some pathogens cause
virulence in their hosts suggest that pathogens evolve to maximize their
reproductive number, a quantity inextricably linked to pathogen growth
within the host. Since pathogen-induced mortality is an unavoidable
consequence of increased pathogen growth and transmission, a trade-off
typically emerges, leading to maximized fitness at an intermediate
virulence. While these frameworks are a useful starting point to think
about transmission-virulence tradeoffs, they implicitly assume that each
pathogen is associated with only a single virulence phenotype encoded by
the genotype and need to be re-evaluated in the context of pathogens that
exhibit variable phenotypes in identical hosts, such as the diversity of
clinical syndromes observed in malaria infections. We develop a theoretical
model to test whether a single genotype that gives rise to multiple disease
phenotypes can account for the existence of heterogeneous disease outcomes.
We find that variation in gene-specific virulence and transmission within a
single strain can indeed contribute to its success, expanding regions of
coexistence and dominance in competition with a strain having a single
optimized virulence. Our results further demonstrate that expressing
multiple virulence phenotypes, even when one is highly virulent, can be
advantageous for a strain.


Visit http://www.math.dartmouth.edu/~siamchapter/index.html for more
information.