viruses & cancer + emerging and re emerging viruses

viruses & cancer

Monday, September 19, 2011

emerging and re-emerging viruses


what are emerging infections?

Newly appeared in the population

Have existed but are rapidly increasing in incidence or geographic range

from PH 301 lectures of Lilen Sarol, PhD


EXAMPLES


PROCESS OF EMERGENCE

Introduction of the agent into a new host population, originating from:

environment

another host species

variant of an existing human infection

Establishment and further dissemination within the new host population



AGENT-RELATED FACTORS

Microbial adaptation

Mutation

Natural selection

antibiotic-resistant bacteria

Evolutionary progression

Virulence factors



HOST-RELATED FACTORS

Human Susceptibility

immune status

nutrition

age

occupation, etc.

Human behavior and demographics

Affect disease dissemination



environment-related factors

(#1) Changing ecosystems / land use

Argentine, Bolivian hemorrhagic fever

changes in agriculture (grassland to maize) favoring rodent host

Hantaviruses

Ecological or environmental changes increasing contact with rodent hosts

Rift Valley fever

agriculture, irrigation




(#2) Economic development

Dengue/DHF

urbanization favoring mosquito vector

Lassa fever

urbanization favoring rodent hosts, increasing exposure

Rift Valley fever

dam buildingfrom PH 301 lectures of Lilen Sarol, PhD



(#3) Technology and industry

Hepatitis B and C

transfusions, organ transplants

Influenza (pandemic)

possibly pig-duck agriculture facilitating reassortment




(#4) International travel and commerce

Dengue/DHF

Ebola, Marburg

In Europe and US, importation of monkeys

HIV

Influenza (pandemic)

SARS



SPECIAL TOPICS IN VIROLOGY

BIOTERRORISM & DUAL RESEARCH


OUTLINE

❖ Overview: Dual-Use Research

❖ Overview: Risks

❖ Biotechnology and Bioterrorism

❖ Case Studies


Biological Research has led to the development of new drugs, treatments, and medical

advancements that have profoundly impacted our health and way of life

The General Public holds scientists and their work in high regard and trusts that they will act in the best interest of society


What is Dual-Use Research?

“Legitimate scientific work that could be misused to threaten public health or national security”


THUS: any medical advance that improves the ease of engineering,

handling, or delivering treatment has the potential to be applied by those wishing to do harm and can be considered "dual-

use


“advances in biotechnology … have the potential to create a much more dangerous biological warfare threat … engineered biological agents could be worse than any disease

known to man.” (CIA, 2003)


Case Studies


❖ Dr. Wimmer, Distinguished Professor in the Department of Molecular Genetics and Microbiology at the State University of New York (SUNY) at Stony Brook

❖ 1991: Published the chemical formula of the polio virus

❖ 2001:biochemically synthesized (deliberately) poliovirus according to its genomic sequence in the absence of a template without a DNA or RNA template, or the help of living cells

❖ 2002 published in Science

❖ DUAL USE Implications: unnecessarily demonstrating how bioterrorists could use modern scientific techniques to create dangerous pathogens

❖ POLICY: “prior to attempting synthesis of a microbial chromosome we commissioned an independent bioethical review of our proposed scientific plan.”


❖ PROS: experiments could uncover the reasons why the Spanish flu pandemic was so deadly and could offer insight into avian flu pathology and how it might become transmissible in humans.

❖ CONS:

❖ publication of the viral sequence, conditions under which the virus was handled and the threat of its escape into the environment;

❖ recreate deadly and transmissible though extinct or eradicated viruses;

❖ can be used for the design of a weapon of mass destruction; there is a risk verging on inevitability of accidental… or deliberate release of the virus.

❖ IMPACT TO PUBLIC HEALTH: advancement in tools to sequence genomes and synthesize DNA; BUT could be used to engineer biological weapons


VIDEO ON SCIENTISTS’ VIEWS


We must PREVENT such MISUSE

without IMPEDING research

PROGRESS!

“are there potential benefits to public health and safety from application or utilization of this information?”


LABORATORY ACTIVITY


Create a letter-sized POSTER to educate college students on your choice of

emerging/re-emerging infection...FOCUS on :

1. awareness2. prevention


viruses & cancer + emerging and re emerging viruses

Health & Medicine

proposed scientific

public health

related factors

genomic sequence

microbial

modern scientifictechniques

unnecessarily

distinguished