Veterinary Science and Microbiology

VSC438 Ecology of Infectious Disease

Viruses

Dr. Jim Collins

 

Modern Plague, Ancient Origin - HIV: What happened?

 

Topics

Current situation

Disease discovery

The cause of “Acquired Immunodeficiency Syndrome”

Controversy….. LAV and HTLV-III,  or…. Luc Montagnier and Robert Gallo

Ecology of HIV: STD, Blood-borne, and unknown.

How do we know that HIV causes AIDS?

Origins of HIV: a Zoonosis

What is the evidence for a “Zoonotic Transmission event”

            Antibodies to the human agent in animals

            Sequence similarity of human agent (HIV) to animal agent (SIV)

Phylogenetic studies

            Geographic range of the animals with SIV to humans with HIV

            Plausible route of interspecies transmission

HIV migration

Animal Lentiviruses and their genes

HIV / SIV Clades

TH M subgroups of HIV-1

World wide differences in the mechanism of human-to-human transmission: Why?

Africa compared to the USA: the roles of simultaneous STDs and cultural practices and standards.

Pathogenic pathway: How HIV works

The unique replication strategy of Retroviridae: Integration of the genome

            (Lentiviruses are a subgroup of Retroviruses)

Quaspecies

 

Questions

1. What is the evidence that HIV came from SIVcpz?

2. From the standpoint of an RNA virus, what “allows” this to happen?

3. What is so different about the HIV epidemic in the USA and Western Europe vs. that in Africa?  Why?

 

Case: What can be done?

Eastern Europe's HIV, TB Crisis Threatens Rest of Continent

HIV infections and tuberculosis are rising rapidly in the former East Bloc, and unless action is taken to fight the infections, all of Europe is at risk of a major health crisis, according to the Red Cross and Red Crescent Conference. While Africa and Asia have the highest number of AIDS cases, the former East Bloc has the fastest growth rate.  Some 30,000 people die each year from tuberculosis in Russia, which in 2000 had a rate of 90.7 cases per 100,000 people, double the European average.  And this could spell problems for Western Europe, which is being flooded with impoverished East Europeans migrating to Western Europe to seek jobs.  Europe is standing in front of a creeping crisis with millions of people under threat of death from the rapidly rising number of HIV infections combined with tuberculosis.