Brainscape's Knowledge GenomeTM

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


See full index

IMED2001 > Lecture 3 transmission of infection and principles of disease > Flashcards

Lecture 3 transmission of infection and principles of disease Flashcards

1
Q

Where are the portals of exit?

A

identical to entry

Exiting can be through coughing, sneezing, saliva, sputum

Pathogens also leave via blood, vaginal secretions, semen, urine, and faeces

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

Pregnant women and babies infection note:

A

Unique interactions between mother and the foetus

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

What affects spread of infection?

A

Reservoirs (places where pathogens grow and accumulate)

Mechanisms of transmission (ways pathogens move)

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

What are some potential reservoirs for pathogens?

A

Humans

Other animals

Non-living reservoirs such as water food and soil

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

How can humans and other animals be as reservoirs?

A

Sick people show symptomsa and are easy to identify but difficult when symptoms are yet to develop or have ceased

Carriers of infection can transmit disease but show no symptoms

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

How can non-living reservoirs move disease around?

A

Water is a necessity and can hold pathogens

Leading to high levels of faecal contamination in water can lead to infections spreading via faecal oral route

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

How can infection be spread?

A

Contact

Vehicle

Vector

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

What are the types of contact transmission?

A

Direct (touching)

Indirect (touching something someone else touched)

Droplets (airborne)

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

What is a commonly touched item that causes infectious disease transmission called?

A

A fomite

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

What are some pathogens transmitted through direct contact?

A

Staph

Hep A

Smallpox

STIs

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

What are some examples of indirect contact transmission?

A

Sharing of needles HIV

Snotty tissue transmission

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

What pathogens are often transmitted by droplets?

A

Influenza and whooping cough

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

What factors are important to droplet transmission?

A

Distance (short distance more likely to transmit)

Size (large droplets fall to the ground quickly smaller droplets stay airborne for a while)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is vehicle transmission?

A

Can involve pathogens riding along on air food water and this enters body and transmits infection

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

How is air used as a vehicle?

A

Spores can float in air

Dust can use air as a vehicle containing huge numbers of pathogens

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

What is vector transmission?

A

using an organism as an intermediary such as an insect which carries infection

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

What are the types of vector transmission?

A

Mechanical (pathogens on vector’s body passively brushed off onto host)

Biological (pathogens are within vector transmission through bite)

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

What are some vector organisms?

A

Fleas

Ticks

flies

mosquitos

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

Do pathogens use vector to replicate?

A

Some pathogens multiply in vector and arrive at new host lin larger numbers making establishment of infection more likely (less virulent pathogens still establish infection as a result)

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

What are zoonotic disease?

A

diseases that require an animal intermediary.

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

How are zoonotic diseases typically transferred?

A

Usually through direct contact with humans but can be through indirect contact as well as is the case with waste material of litter box, fur, feathers, infected materials, etc

It can also be transmitted by vectors from animals to humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are 3 methods to control transmission of diseases?

A

Isolation

Quarantine

Vector control

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

How is isolation typically carried out?

A

Prevent infected individuals from contact with general population

7 categories of isolation

Patients usually are isolated in hospital

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

What are the limitations of isolation?

A

Don’t always know when individual is infected such as

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How is quarantine carried out?

A

Separate those exposed from the population

Quarantine should last as long as incubation period of disease

Once symptoms subside quarantine is lifted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the limitations of quarantine?

A

Very difficult to enforce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How is vector control carried out?

A

Killing vectors or using repellants

Mosquito nets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the difference between vector and vehicle transmission?

A

Vector transmission is generally living organism

Vehicle is non-living

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Difference between indirect transmission and vehicle transmission:

A

Time between pathogen landing on intermediate item and it being transmitted. Sometimes categories overlap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What factors affect disease transmission?

A

Age

Gender

Lifestyle

Occupation

Emotional state

Climate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does age affect disease transmission?

A

Disease levels tend to increase with age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How does gender affect disease transmission?

A

Some more prevalent in one gender than others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How does lifestyle affect disease transmission?

A

poor nutrition can decrease immuno-competence in host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does occupation affect disease transmission?

A

More infections in health care workers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How does emotional state affect disease transmission?

A

vulnerable emotional state can decrease immune competence in host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How does climate affect disease transmission?

A

Greater incidence of respiratory illness in colder climates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is immunocompetence?

A

Ability of host to mount defence

38
Q

What happens if host defences are compromised?

A

Potential for infectious diseases increases

39
Q

Which group of people are more vulnerable to infections?

A

People with AIDS or genetic insufficiency diseases

People doing chemo

Surgical transplant and burn patients

Premature newborns

Elderly

Patients on artificial ventilators with cannulas and catheters

40
Q

What is neutropenia?

A

Lower neutrophil numbers in blood.

41
Q

What are neutrophils?

A

Form of primary phagocytic defence and important component of innate immune system

42
Q

What are the most common causes of profound neutropenia?

A

Administration of cytotoxic chemotherapy

Cancer of other diseases with damaged bone marrow

Congenital disorders with poor bone marrow function

Viral infections

Autoimmune disorders that destroy bone marrow cells

Overwhelming infections that use neutrophils faster than they can be made

43
Q

What kind of infections take advantage of neutropenia?

A

Bacterial and fungal infections

Often associated with surgical procedures and catheterisation

44
Q

Why are transplant recipients immunocompromised?

A

Immunity is lowered to prevent rejection of the organ.

45
Q

How are infections treated in organ transplat patients?

A

Broad spectrum antibiotics

46
Q

Why are burn victims more immunocompromised?

A

Loss of large areas of primary physical barrier results in greater chance of infection

47
Q

What bacteria is most problematic for burn patients?

A

Pseudomonas aeruginosa

48
Q

Where can opportunistic pathogens arise from?

A

Normal flora in our bodies

49
Q

How can opportunistic infections arise?

A

Movement of opportunistic organisms from one area to another where It can be pathogenic as is the case with UTIs and in cases where flora is compromised by antibiotics

50
Q

What are nosocomial infections?

A

hospital infections and are usually associated with intravenous applications

51
Q

What must hospitals consider regarding nosocomial infections?

A

Source of infection

Mode of transmission

Susceptibility of patient to infection

Prevention and control

52
Q

What are the most common sites of the sites of nosocomial infections?

A

Urinary tract

Respiratory tract

Surgical wounds

53
Q

What are the most common sources of infections within hospital environment?

A

Other patients

Hospital staff

Visitors

Unsanitary conditions

Water supplies

Respiratory equipment

Catheters

54
Q

What are the most common pathogens in nosocomial infections?

A

E. Coli

Enterococcus species

Staph (+MRSA and VRSA)

Clostridium difficile

Pseudomonas aeruginosa

Many are antibiotic resistant

55
Q

What are the measures put in place to prevent spread of disease in hospitals?

A

PPE

Washing hands with antiseptic before and after

Cleaning spills of blood or contaminated fluids

56
Q

What must hospital programs address regarding nosocomial infections?

A

Surveillance of nosocomial infections

On-site microbiology lab and standard isolation procedures

Standardised procedures for use of catheters and hospital equipment

Proper decontamination and sanitary procedures

Mandatory nosocomial-disease education programs

Infection-control specialist on staff

57
Q

What is the difference between incidence and prevalence?

A

Incidence is the number of new cases

Prevalence is the total number of people infected within a specific population at any given times

(Prevalence is always a larger number because some people will not be newly infected at that given time)

58
Q

What is the difference between morbidity and mortality?

A

Morbidity refers to the number of individuals affected by the disease

Mortality is the number of deaths

59
Q

What is the morbidity rate?

A

Number of people affected during a set period divided by total population

60
Q

What is mortality rate?

A

Number of people died due to specific disease during a set period of time divided by total population

61
Q

How do epidemiological studies classify diseases?

A

Sporadic (occurring in random manner)

Endemic (disease constantly in population in low numbers)

Epidemic (incidence of disease suddenly higher than expected morbidity and mortality rates may increase and could eventually become a worldwide problem)

Pandemic (worldwide epidemic)

62
Q

What is a common source epidemic?

A

Arises from contact with contaminated substance that affects large number of people and subsides quickly when contamination dealt with (eg. listeria in rockmelon)

63
Q

What is a propagated epidemic?

A

Epidemic that is amplified by person to person contact and remains in population for a long time and is more difficult to deal with that common source outbreak

64
Q

What is herd immunology?

A

When majority of population is immune there are few potential hosts and disease essentially disappears.

(This is why vaccines are so effective)

65
Q

What are notifiable diseases?

A

Diseases that must be reported to the health department of local and state governments.

66
Q

Why are urinary nosocomial infections most common?

A

Due to catheters

67
Q

What is the aetiology of a disease?

A

Cause of a disease

68
Q

How can a disease be proven to be a disease?

How can a microorganism be said to cause a disease?

A

Koch’s postulates

69
Q

What happens with cultures that cant be grown in pure culture?

A

Syphilis (treponema pallidum)

Mycobacterium leprae (leprosy)

Viruses and rickettsial organisms

70
Q

What are the 5 stages of a disease?

A

Incubation period (no signs or symptoms)

Prodromal period (vague general symptoms)

Illness (most severe signs and symptoms)

Decline (declining signs and symptoms

Convalescence (no signs and symptoms)

71
Q

How long is the incubation?

A

Incubation period varies with virulence of pathogen

72
Q

What is a possible problem that could arise after decline?

A

Secondary infections

73
Q

What are some non-communicable diseases?

A

CVD

Stroke

diabetes

etc

74
Q

What is the difference between communicable and contagious?

A

Communicable refers to diseases that can potentially be transmitted and if they are easily spread they are said to be contagious

75
Q

What are the 4 categories of disease duration?

A

Acute (develops quickly lasts short time)

Chronic (develops slowly lasts long tim)

Sub-acute (insidious onset (6 - 12 months) almost always fatal

Latent (remains in host after symptoms disappear can come back years later)

76
Q

What does duration of disease depend on?

A

Overall health of the host

77
Q

What are persistent bacterial infections?

A

Pathogenic bacteria capable of maintaining infections in hosts even in presence of inflammatory specific antimicrobial mechanisms and a good immune response.

78
Q

How are persistent bacterial infections treated?

A

Specific anti-microbial therapy

79
Q

What is the scope of an infection?

A

scope is whether infection is localized (contained/walled off)

Systemic (moved away from starting point)

80
Q

What is bacteraemia?

A

Bacteria in blood

81
Q

What is septicaemia?

A

Bacteria growing in blood

82
Q

What is toxaemia?

A

Toxins in blood

83
Q

What is viraemia?

A

Viruses in blood

84
Q

What are the 3 types of infection?

A

Primary (initial infection has acute onset of symptoms)

Subclinical (No symptoms visible and are carriers)

Secondary (People weakened from primary infection and ill again)

85
Q

What is toxic shock?

A

Massive leakage of plasma from circulatory system causing massive drop in BP.

86
Q

What causes toxic shock?

A

Neutrophils come in contact with M proteins on bacterial surface

87
Q

What percentage of people that are affected by toxic shock die?

A

It is fatal for 30 - 70% of patients

88
Q

What is sepsis?

A

Presence of pathogen/toxin in blood

89
Q

What are the 2 forms of sepsis?

A

severe and acute

90
Q

What is severe sepsis?

A

Sytemic inflammation and organ dysfunction

Causes abnormal temperature, HR, Respiratory rate, and WBC count

Elevated number of liver enzymes

Kills slowly over period of weeks with minimal tissue inflammation or damage

91
Q

What is acute septic shock?

A

Sudden onset causes death in 24-48 hours

Widespread tissue inflammation and cell damage

IMED2001 (44 decks)

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