Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

virology > lecture 11 > Flashcards

lecture 11 Flashcards

1
Q

virus epidemiology

A

-study of determinants, frequency, dynamics, and distribution of viral disease in populations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why study epidemiology in viral diseases

A
  • risk of infection/disease in animal or animal population is determined by:
  • -characteristics of virus (genetic variation from evolution)
  • -host and host population (passive, innate, and acquired resistance)
  • -behavioral, environmental, and ecological factors that affect virus transmission from one host to another
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

role of epidemiology in viral diseases

A
  • identify/clarify role of viruses in etiology of diseases
  • understand interaction of viruses with environmental determinants of disease
  • determining factors affecting host susceptibility
  • unraveling modes of viral disease transmission
  • studying impacts of viral disease on health, economy, and society
  • studying role of infectious pathogens in the pathogenesis of chronic non-communicable diseases such as oncogenic viruses in cancer
  • large scale testing of vaccines and drugs (clinical trials)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how knowing epidemiology helps

A
  • advance our understanding of nature of disease
  • alerting and directing disease treatment, control, and prevention activities
  • providing early warning systems and tracking disease
  • assessment of economic and social impacts of disease
  • assessment of efficacy and cost of disease control and prevention programs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

case fatality rate

A
  • based on outcome of disease in population

- number (%) of deaths among clinically ill animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

mortality rate

A
  • based on outcome of disease in population

- number (%) of animals in a population that die from a specific disease over a specific period of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

morbidity rate

A
  • based on outcome of disease in population
  • percentage of animals in a population that develop clinical signs attributable to a particular virus over a defined period of time (commonly the duration of an outbreak)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

factors based on duration and/or frequency of occurrence

A
  • incidence

- prevalence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

incidence

A

-number of new cases that occur in a population over a specified period of time
=number of cases x10^n/population at risk in a specified period of time
-measure of occurrence of infection or disease in a population over time
-especially useful for describing diseases of short duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

prevalence

A

-number of occurrences of disease (old and new cases), infection, or related attributes (antibodies) in a population, at a particular point in time
=number of casesx10^n/population at risk
-at a particular time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

sporadic viral disease

A

-occurring occasionally, singly, or in scattered instances, and in a irregular or haphazard manner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

enzootic viral diseases (endemic in humans)

A

-constant present of a viral disease within a given geographic area or population group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

epizootic viral diseases (epidemic in humans)

A
  • occurrence of more cases of viral diseases than expected in a given area or among a specific group of people/animals over a particular period of time
  • refers to peaks in disease incidence that exceed the endemic/enzootic baseline or expected incidence of disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

panzootic viral diseases (pandemic in humans)

A

-virus epidemic occurring over a very wide area (several countries or continents) and usually affecting a large proportion of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

asymptomatic carrier

A
  • animals that have contracted an infectious viral disease but display no clinical symptoms
  • shed virus, transmit disease to others
  • shedding of virus may be continuous or intermittent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

contagious disease

A

-disease spread from one person or organism to another by direct or indirect contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

period of contagiousness

A

-refers to time during which an infected animal sheds virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

exotic disease

A

-disease not known to occur in a particular country or geographical area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

serioepidemiolgy

A

-simply denotes use of serological data as the basis of epidemiological investigation, as determined by diagnostic serological techniques

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

molecular epidemiology of viruses

A

-use of molecular biological data as the basis of epidemiological investigation of viral diseases

21
Q

horizontal transmission of viruses

A
  • contact transmission
  • vector transmission
  • vehicle borne transmission
  • iatrogenic transmission
  • nosocomial infection
22
Q

horizontal transmission

A
  • spread of infectious agent from one person/animal or group to another person/animal or group
  • most viruses transmitted this way
23
Q

contact (horizontal) transmission

A

-spread of infectious agent by direct or indirect (intermediate object) transmission

24
Q

direct (horizontal)-

contact virus transmission

A
  • involves actual physical contact between infected animal and susceptible animal (licking, rubbing, biting) also includes sexual contact
  • droplet transmission: transmission of virus in droplet nuclei (saliva or mucus) that travels less than one meter to source of susceptible host
25
Q

indirect (horizontal) contact transmission

A

-occurs via fomites (inanimate object/substance contaminated with infectious agent and capable of transmitting it), such as shared eating containers, bedding, dander, restraint devices, vehicles, clothing, improperly sterilized surgical equipment, or improperly sterilized syringes/needles

26
Q

indirect-contact (horizontal) transmission- airborne

A

-spread of infectious agents by droplet nuclei in dust that travels more than one meter, sometimes for miles, from the infected to susceptible host

27
Q

vector transmission

A
  • can be mechanical or biological transmission

- arthropods can carry virus

28
Q

mechanical transmission

A

-passive transport of the infectious agent on the feet or other body parts of the arthropod vector

29
Q

biological transmission

A

-infectious agent undergoes either a necessary part of its life cycle, or multiplication in the vector before transmission to susceptible host

30
Q

arboviruses

A

class of viruses transmitted to humans by arthropods such as mosquitoes and ticks

31
Q

types of transmission cycles

A
  • enzootic cycle (sylvatic or jungle cycle)
  • epizootic cycle (rural cycle)
  • urban cycle
32
Q

enzootic cycle (sylvatic or jungle cycle)

A

natural transmission of virus between wild animals/birds (vertebrate hosts) and primary insect vectors

33
Q

epizootic cycle (rural cycle)

A

-virus transmitted between non-wild or domestic animals and the primary or accessory insect vectors

34
Q

urban cycle

A

virus cycles between humans and insect vectors

35
Q

amplifying host

A

-in which the level of virus can become high enough that an insect vector such as a mosquito that feeds on it will probably become infectious

36
Q

dead end host/incidental host

A
  • host from which infectious agents are not transmitted to other susceptible hosts
  • they do not develop sufficient viremia to be picked up by insect vectors
37
Q

common-vehicle transmission

A

includes fecal contamination of food and water supples (fecal-oral transmission) and virus-contaminated meat or bone products
-can contaminate meat or meat products

38
Q

iatrogenic transmission

A
  • infection transferred during medical or surgical practice
  • can happen by: introduction of pathogens by contaminated instruments (non-sterile surgical instruments, syringes) or contaminated body surface (inadequate handwashing)
  • example: spread of equine infectious anemia virus via multiple-use syringes and needles
  • introduction of pathogen through contaminated prophylactic or therapeutic preparations
39
Q

nosocomial transmission

A
  • occurs when an animal is in a vet hospital or clinic

- hospital acquired infection

40
Q

vertical transmission

A

-usually used to describe infection that is transferred from dam to embryo or fetus, or newborn before, during, or shortly after parturition (colostrum, milk, or fecal contamination of teats)

41
Q

zoonosis

A

used to describe infections that are transmissible from animals to humans

42
Q

example of physical stability of a virus

A

-viruses that are transmitted by the respiratory route have low environmental stability, whereas those transmitted by fecal-oral route have higher stability

43
Q

herd immunity

A

-form of immunity that occurs when the vaccination of a significant large portion of a population (or herd) provides a measure of protection for individuals who have not developed immunity

44
Q

incubation period

A
  • interval between infection and the onset of clinical signs

- in many diseases there is a period during which animals are infectious before they become sick

45
Q

predromal period

A
  • first signs and feelings of illness after incubation period
  • period of early symptoms of disease occurring after the incubation period and just before the appearance of the characteristic symptoms of the disease
46
Q

acute period

A
  • when disease is at its height

- severe clinical signs

47
Q

decline period

A

-period when clinical signs begin to subside

48
Q

convalescent period

A

the body gradually returns to pre-diseased state and health is restored

virology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions