BSC 546 Final Exam Review questions and answers

Describe antigenic shift and antigenic drift and which causes isolated epidemics vs pandemics. Antigenic Drift - repeated minor antigenic changes' retains some resemblance to prevailing strains (Types A and B); able to cause isolated epidemics.1 Antigenic Shift - major change in one or both surface antigens; no serologic relationship with prevailing strain (only Type A) ; able to cause pandemics. Segmented genome of influenza 1. Genome is segmented - Genetic reassortment can occur when a host cell is infected simultaneously with viruses of two different parent strains 2. This mechanism probably accounts for generation of pandemic strain of Influenza A, periodically Polio A highly contagious infectious disease of the spinal cord caused by a filterable virus. Treated by salk and sabine vaccines, attacks motor neuron and cranial nerves in spinal and bulbar polio respectively. RSV An important cause of otitis media (ear infection) in young children, is prevented with palivizumab