Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

ze1lb1o > Pathogenese > Flashcards

Pathogenese Flashcards

(61 cards)

Start Studying
1
Q

When is a germ classified as pathogen?

A

as soon as a germ can lead to disease

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

Define endemic and give an example

A

disease which occus within a defined area for an indefinite time periode and without having the tendence to spread –> rabies

low morbidity, spatial but no temporal limitation

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

define epidemic

A

massed occurance of a dangerous infectios disease with a temporal and spatial limitation while having a high index of minifestation –> FMDV in UK 2001

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

definde pandemic and give an example

A

spreading of an epidemic across whole countries or continents
–> widespread diesease without spatial limitation in a certain time period
–> SARS CoV-2

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

what is morbidity?

A

number of sick hosts * 100 / number of hosts at risk in %

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

what is mortality?

A

number of hosts which died from the viurs * 100 / total number of hosts at risk

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

what is lethality?

A

nmber of deaths * 100 / number of hosts with symptoms (infected)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is incidence?

A

number of new cases of illness within a certain time period

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

what is prevalence?

A

number of all existing infection cases * 100 / size of population

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

what is seroprevalece

A

number of antibody positive individuals * 100 / size of population

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

Which body surfaces are involved in virus entry and excretion?

A

infection through body surfaces:
- conjunctiva
- respiratory tract
- alimentary tract
- urogenital tract
- anus

parenteral inoculation
- arthropod
- capillary
- scratch, injury
- skin

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

Which virus enters via small surface wounds?

A

human papillomavirus (HPV)

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

How is HPV transmitted? What does an infection lookmlike?

A
  • transmission by skin contact or sexually
  • chronic persistent infection of basal cells
  • development of warts through cell proliferation
  • benign lesions in genita area –> can become malignent
  • integration of the virus genome leads to transformation –> cervical carcinoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name different types of virus entry via deep wounds and example viruses

A
  • iatrogenic (by non sterile inhection needles): HIV, HBV
  • arthopods as vector: Alpha, flavi, Reo, Bunya
  • bite by virus carrier: rabies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where does rabies replicate?

A

shortly in muscle cels and then in neurons in the CNS –> transport into neurons may take several months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How can rabies be treated?

A

via vaccination:
- passive: anti rabies IgG
- active: inactivated vaccine

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

How can rabies be diagnosed

A
  • direct detection via IFA or RT-PCR in alive patients
  • direct detection via IFA, RT-PCR, Negri-bodies, virus isolation from brain tissue in dead patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are negri bodies and what do negri bodies contain (rabies infection)

A

= cytoplasmic spherical structures formed by liquid-liquid phase separation and they contain:
- TLR3 (central)
- nucleocapsid protein N (periphery)

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

name countermeasures of the respiratory tarct against viral infection

A
  • translocation of mucous layer by ciliated epithelium
  • only small particles can migrate to the alveoli
  • control by alveolar macrophages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the difference between aerosols and droplets?

A

aerosols vs droplets:
- travel more than 1 meter vs less than 1 meter
- can float in air for hours vs cannot
- can be inhaled vs cannot be inhaled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why is influenza transmission between birds and humans inefficient?

A
  • HA binds to different sialic acid residues in birds and humans
  • mucosal epithelial cells of the upper and lower respiratory tract carry different sugar residue structures on their surface
  • sugar topology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When can viruses infect gastric and intestinal areas?

A

only when virions are stable against acidic pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

which viruses that infect the gastric and intestinal area are coatedand which are not coated?

A

uncoated: Enetroviruses, Calcivirus, Reovirus

coated: enteral coronavirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why is the intestinal mucosa an effective barrier?

A
  • different pH value
  • mucus
  • phagocytes and antiboides
  • GALT (gut associated lymphoid tissue) –> e.g. Peyers Patches
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What cells do the lymph follicles in the mucosa of the GIT contain and what is their function?
M- cells --> do Transcytosis = transfer through M-cells with out degradation -->present antigens to lymphocytes which are located beneathh they sit on the luminal side
26
Which viruses replicate in M-cells and which only pass through?
no replication: Reo, Polio replication: Rotavirus
27
Which viruses have a minor host specificity and which have a high specificity?
minor: - alphaviruses - flavivirus - rabies high: - herpes - papilloma - retro - HCV, HBV
28
What is viral tropism?
preferred locations of replication in the body
29
Name example viruses which are hepatotropic, neurotropic, pneumotropic, epithelotropic, dermatotropic, lymphotropic
- hepatotropic: HAV, HBV, HCV - neurotropic: Rabies, FSME - pneumotropic: Influenza - epithelotropic: Papilloma - dermatotropic: Parapoxvirus - lymphotropic: Eppstein Barr Virus
30
What determines host specificity and tissue tropism? Give examples
1. receptor: CD155 in Polio 2. cellular factors of viral replication (cellular transcription factor): liver specific enhancers in HBV 3. cellular factors of virus maturation: proteases in Influenza
31
which tryptase cleaves HA in Infleunza extracellularly?
Clara
32
What is often crucial for susceptibility and virus spread?
Polarity of cells
33
How are viruses spread within the body?
1. replication at the site of entry 2. primary viremia 3. sites of repöication (e.g muscle, spleem, liver...) 4. secondary viremia 5. sites of replication (brain, skin, kidney, lung, GIT etc) 6. Transmission to other hosts via 5.
34
How can the infection and exit site in epithelial cells (polarity) be tested in the lab?
- cell culture in a membrane coated chamber - selective release of viruses into the media above or under the cells
35
Which viruses infect the apical site of epithelial cells?
- SARS - Influenza - West Nil Virus
36
Which viruses infect the basolateral site of epithelial cells?
- marburg virus - crimean congo - VSV
37
Which virus infects the basolateral surface and is released from the apical site?
reovirus
38
What happens after viruses are released from the basolateral site?
- viruses reach the lymphatic system - reach lymp nodes - antigen presentation in lymphnodes or virus replication takes place
39
What is primary viremia?
- direct virus infection of the host - without clinical symptoms
40
What is secondary viremia?
- after virus replication in infected organs a huge number of viruses is released - mostly accompanied by clinical symptoms
41
How can viruses exist in the blood?
- non associated - adsorbed to cell, erythrocytes, platelets - intracellular
42
How can viruses escape from the capilary lumen?
- fenestrae - trafficking lymphocyte or monocyte - transcytosis - replication in endothelial cells
43
How can the CNS be invaded?
1. Transfer from the blood to the CNS 2. infection of peripheral neurons --> migration to the CNS via axonal transport
44
what is the consequence of the separation of blood circulation of mother and fetus in ruminants and swine?
if the mother is infected and produces antibodies against it, they doi not reach the fetus and because the fetus has no own innate immunsystem it stays infected --> diaplacental infections
45
How can viruses be excreted?
local infection: virus excretion often via the same way as invasion, only reverse direction systemic infection: virus excreted from one or multiple sites
46
what is pathogenicity?
feature of a microorganism to cling to the host, replicate inside a host sepcies and thereby cause an infectious disease
47
what is virulence?
quantitative statement about the grade of disease causing features
48
How is virulence quantified?
LD50 value: slightly virulent: 10^6 virions moderate virulent: 5*10^3 virions highly virulent: 5 virions
49
What causes differences in virulence?
virulence based on genetics of pathogen and host --> changes in virulence based on mutations - point mutation - insertion, deletion - recombination - reassortment
50
what is host resistance?
- unspecifc defence against pathogens - can be divided into susceptibility (host can be infected) and sensitivity (extent of disease after infection)
51
what determines susceptibility and sensitivity?
susceptibility: genetically determinded (receptors, factors of target cells) sensitivity: physiologically determinded (age, immunosuppresion, hormonal status, nutritional condition)
52
What leads to host resistance? Give examples
absence of essential factors: - Polio: mouse have no receptor for human poliovirus - HIV: CCR delta 32 variant in chemokine receptor gene - Norovirus: FUT2 gene homozygous negative individuals resistent
53
What is the reason for a disease?
1. direct damaging of tissues and organs: cytopathic effect 2. immuno pathological
54
Do cytopathic effect correlate in vitro and in vivo?
no
55
what benefits secondary infections?
viral immune suppresion
56
Which viruses damage the immune system?
- HIV - Pestivirus - Parvovirus - measles
57
Name types of persisting infections and examples
1. chronic infectiosn: HCV 2. latent infections: herpes 3. slow infections: measles 4. transforming infections : DNA viruses
58
what is the difference between acute and persitent infections?
persistent infections are temporally unlimited
59
is infection always detectavle during latency and chronic infections? Why?
latency: during latency no infectious virus can be detected --_> viral nucleic acid is present as a episome chronic: infectious virus always detectable --> permanent virus secretion
60
What is the relationship between the immune system and acute, latent and persisting chronic infections?
acute: IFN block, cell lysis latent: not providing a targetm infection of immune privileged cells chronic: always IFN block, inducing immune tolerance or immune evasion
61
How can viral diseases be communicated?
- horizontal: direct physical contact, indirect contact (nnedles, clothes), transmission by an agent (food, water), transmission via air, live vectors - vertical (in temporal and factual context of birth): virus integrated DNA copies in germ cells, diaplacental, perinatal

ze1lb1o (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions