Virology Question

This is due Monday November 17. Answers may be sent by e-mail to mhunt@med.sc.edu

Two viruses which have been in the news a lot recently are West Nile virus and the virus which causes Severe Acute Respiratory Syndrome. The questions below do not require a lot of literature research beyond what has been mentioned in lectures, although you do need to know how SARS is transmitted. The www.cdc.gov site is a great resource. In the case of SARS I would particularly recommend their home page on SARS (http://www.cdc.gov/ncidod/sars/). There is a link from there to the ‘What everyone should know‘ page. There is a link on that page to ‘Frequently asked questions on SARS’.

1. WNV and SARS outbreaks have both occurred in North America recently. The public health authorities in many countries world-wide have responded to SARS by imposing some kind of isolation/quarantine procedures; however, this has not been the case for WNV. Please suggest epidemiological reason(s) for the different approaches to the two viral diseases.

2. The hope of the approach used in the case of SARS was that the spread of the infection in the human population would be slowed or halted. Even if it were only slowed, it would give at least give authorities time. How could having some extra time before the next wave of SARS (should it occur) help?

3. Can you suggest any reasons why the incidence of previously unknown viruses, or of previously known viruses in new areas, seems to have been increasing in the last 20 to 30 years?

4. There is concern about what will happen if we have an outbreak of SARS which coincides with a severe influenza season – why is this?