zoonotic and emerging diseases

Question 1

who coined “zoonosis”

Answer 1

-rudolf virchow
-father of pathology
-famous for the cellular theory of disease

Question 2

Zoonosis definition

Answer 2

-any infectious disease that may be transmitted from animals to man or man to animals
-a disease communicable from animals to human under natural conditions

Question 3

zooanthroponosis

Answer 3

transmission: man to animal
ex. herpes

Question 4

anthropozoonosis

Answer 4

transmission: animal to man
ex. rabies

Question 5

Emerging disease

Answer 5

-diseases of infectious origin whose incidence in humans has increased in the last 2 decades or threatens to increase in the near future

Question 6

emerging disease agents categories

Answer 6

1. previously known agents in a new geographic location
2. known agent presenting in previously unsusceptible species
3. previously unknown agent detected for the first time - always been present just never identified
   -ex. ebola

Question 7

how many known human pathogens

Answer 7

1415

Question 8

how many human pathogens w animal origin

Answer 8

878

Question 9

how many pathogen present in domestic livestock

Answer 9

616

Question 10

how many pathogen in domestic carnivores

Answer 10

-317
-90% can infect more than one species

Question 11

how many pathogens in widlife

Answer 11

no effort to cateogrize pathogens in wildlife

Question 12

determinants of emerging diseases (6)

Answer 12

1.human demographics and behaviour
2.technology and industry
3. international [local] travel and commerce
4.microbial adaptation and change
5. disruption [changes] of public health measures
6. economic land use and development

Question 13

human demographics and behaviour

Answer 13

-GROWING POPULATION
-diet
-outdoor recreation
-urbanization, urban decay
-war, poverty
-child care facilities
-sexual behaviour
-drug use
-terrorism

Question 14

technology and industry

Answer 14

-livestock transportation
-irrigation
-GLOBALIZATION OF TRADE
-food processing
-water sanitization

Question 15

economic land use and dev

Answer 15

-deforestation/reforestation
-intensive/extensive farming
-waste disposal
-natural disaster

Question 16

international travel and commerce

Answer 16

• long distance air travel: globalization, trade
• local and regional travel
  -mvmnts of animal species ex. migratory birds - knows no borders

Question 17

microbial adaptation and change

Answer 17

• new agent or known agent that has adapted to environment or host
  -resistance to antimicrobial therapy
• transferring pathogenicity factors from one species to another

Question 18

disruption of public health measure

Answer 18

-medical improvements (favourable 3rd generation antibioics vs unfavourable immunosuppressive)
-reduced prevention and disease surveillance programs (economic costs: 3rd world countries)
-availability of trained personnel

Question 19

how does disease popagate/get maintained

Answer 19

-defined by R0 (mus tbe equal or greater than 1)

Question 20

how is disease maintained

Answer 20

• each new host has to be source of infection for at least one other host to maintain disease in population

Question 21

how is disease propagated

Answer 21

• each new host has to be source of infection for more than one other host to propagate disease in population

Question 22

disease propagation and magnitude of disease outbreak

Answer 22

-depends on spatial and temporal factors
-population density, timepoint and duration of contact, host susceptibility, transmissibility of agent, agent virulence and host infectiousness

Question 23

disease propagation and magnitude of disease outbreak

Answer 23

• spatial components: distance btwn infectious individual, terrain, soils, vegetation, climate, topography
  -temporal components: infected host may move across space/distance prior to contact with susceptible individual (latent or prelatent period, death of host)

Question 24

avian influenza

Answer 24

-bird flu
-fowl plague
-zoonotic and contagious

Question 25

influenza

Answer 25

- orthomyxovirus -three types =type A: most virulent (can be in multiple species) =type B (humans) =type c (humans and swine)

Question 26

influenza A

Answer 26

-affects man, pigs, horses, dogs and birds -most virulent -classified on surface antigens (hemagluttinin or neuraminidase)

Question 27

hemagluttinin antigen

Answer 27

-bind the virus to the cell -classified as H or HA -16 types

Question 28

neuraminidase antigen

Answer 28

-cleave neuraminic acid from mucin allowing viral release from the cell -classified as N or NA -9 types

Question 29

influenza in circulation among people

Answer 29

-H1N1 -H1N2 -H3N2

Question 30

low pathogenic virus

Answer 30

-very mild illness in poultry and rarely affects man (most within this category) -all low path influenza viruses has the potential to convert into high path influenza viruses

Question 31

high pathogenic virus

Answer 31

high mortality in ducks and poultry and can be severe to fatal disease in man (H7N7, H5N1)

Question 32

Influenza B

Answer 32

- mainly affects people - symptoms are less severe -seasonal vaccine: 2 strains of influenza A and 1 strain of influenza B

Question 33

Influenza C

Answer 33

-human and swine -rare occurence -mild symptoms -most seropositive by age 15

Question 34

fowl plague

Answer 34

- highly infectious - mortality near 100% -death 2-12 days after clinical signs

Question 35

fowl plague effects

Answer 35

-swollen feet: congestion and edema -lung: congestion, hemorrhage, and edema -epicardial petechial hemorrhage -intestiinal hemorrhage: peyes patches -proventicular hemorrhages

Question 36

fowl plague clinical signs

Answer 36

- sudden death - drop in egg production -cns signs -swollen combs cyanotic (blue) -respirator signs

Question 37

influenza costs

Answer 37

-avian flu hong kong: 3.8mill usd and euth 1.2m birds -SEA: 100 mill birds destroyed -EU: netherlands 33% of all birds destroyed -USA: 17M birds destroyed costed 65m dola and eggs price rose by 30%

Question 38

influenza pig problem

Answer 38

-pigs acts as bioreactor and vessel for pathogen mutation

Question 39

swine flu

Answer 39

-H1N1 -avian influenza will bind to glycosides (a-2-3 galactose sialic linkages on tracheal epithelium) -pigs generate poor antibody response -humans and pigs have phylogenetically internal protein genes and human influenza easily infects pigs -can cause lots of mutations

Question 40

swine flu clinical signs

Answer 40

-depression -anorexia -pyrexia (fever) -cough -muscular weakness -mucous discharge from conjunctiva, nose

Question 41

emerging zoonotic diseases

Answer 41

-spanish flu -influenza (avian, swine)

Question 42

spanish flu effect

Answer 42

-more deaths than WW-I -interstitial pneumonia -

Question 43

spanish flu treatment

Answer 43

-supportive -antiviral -vaccinations -quarantine -slaugher hosts

Question 44

conclusions abt emerging disease

Answer 44

- emerging zoonotic diseases among most important human public health risks -new environments= possibilities of exposure, dissemination of novel agents