Epidemiology of Viral Diseases Flashcards
Virus epidemiology is the study of ________
Determinants, Dynamics, Distribution, and frequency of viral diseases in populations
(DDDF)
The risk of infection and/or disease in an animal or animal population is determined by:
- Characteristics of virus
- The host and host population
- Behavioral, environmental, and ecological factors that affect transmission
What is the role of viral epidemiology?
- Understand etiology of diseases
- Determine factors affecting host susceptibility
- Modes of transmission
- Impacts of viruses on health, economy, and society
- Study non infectious and infectious diseases
- Large scale testing of vaccines and drugs
What benefits comes from epidemiology of viruses?
- Understand nature of diseases
- Able to direct treatments, control, and prevention
- Early warning signs, able to track disease
- Assess social and economic impacts of disease
- Assess efficiency and cost of disease control and prevention
What is case fatality rate?
of death among clinically sick animals (not among entire population!!!)
Ex: # of sick animals is 25, number of dead animals is 10 (10/25 x 100)
What is mortality rate?
of animals in a population that die from a disease over a period of time
What is morbidity rate?
of animals in a population that develop CS attributable to a particular virus over time
What is incidence rate?
a measure of the occurance of infection or disease in a population over time
Ex: a year or a month
- helps determines frequency or duration of a disease
What is prevelance?
The # of occurances of a disease (OLD AND NEW CASES) in a population at a particular point in time
- helps determine frequency and duration of a disease
What is a sporadic viral disease?
Disease that occurs occasionally, singly, or in scattered instances
or in irregular and haphazard manner
What is an enzootic/endemic viral disease?
Constant presence of a viral disease within a given geographic area or population group
Ex: up north, alot of lyme dz bc alot of ticks
What is an epizootic/epidemic viral disease?
viral disease that occurs in more cases than expected in a given area or among a specific group
peaks in a disease incidence that exceeds the expected incidence
What is a pandemic / panzootic viral disease?
Occurs over a very wide area (several countries or continents)
affects a large proportion of the population
Types of asymptomatic carriers?
- Incubatory acute carriers
- Convalescent chronic carriers
- Inapparent carriers
What is an incubatory acute carrier?
animal that sheds virus during incubation period of the disease
What is a convalescent chronic carrier?
Animal that sheds a virus during recovery of a disease
What is a inapparent carrier?
Carrier state may exist in an animal with an infection that is inapparent throughout its course
What is an exotic disease?
a disease not known to occur in a particular country or area