Module 7: Infectious Disease Flashcards
(226 cards)
1
Q
What is a disease?
A
Any process or condition that adversely affects the normal functioning of a living thing
2
Q
What is an infectious disease?
A
Any disease caused by another organism or an infective agent known as pathogens
3
Q
What are pathogens?
A
Any agent which causes disease in an organism
4
Q
What distinguishes a prion?
A
Non living, defective form of protein molecules which do not contain genetic material
5
Q
What are examples of diseases caused by prions?
A
Mad cow disease, Creutzfeldt - Jacob disease
6
Q
What distinguishes a virus?
A
Non living, non cellular that requires a living host to replicate and contains genetic material
7
Q
What are examples of diseases caused by viruses?
A
Hepatitis B, Aids, Smallpox
8
Q
What distinguishes a bacteria?
A
Living, unicellular, prokaryotic cell which has a cell wall
9
Q
What are examples of diseases caused by bacteria?
A
Tuberculosis, Anthrox
10
Q
What distinguishes a protozoa?
A
Living, unicellular eukaryotic cell
11
Q
What are examples of diseases caused by protozoa?
A
Malaria, Giardiasis
12
Q
What distinguishes a fungi?
A
Living, eukaryotic unicellular or multicellular organism with cell walls
13
Q
What are examples of diseases caused by fungi?
A
Tinea, Thrush
14
Q
What distinguishes a macro parasite?
A
Living, eukaryotic multicellular organism visible to the naked eye
15
Q
What are ectoparasites?
A
External parasites
16
Q
What are endoparasites?
A
Internal parasites
17
Q
What are examples of macro parasites?
A
Tapeworm, paralysis tick
18
Q
How do bacteria reporduce?
A
Via an asexual process known as binary fission
19
Q
What is binary fission?
A
A single cell dividing into two identical cells
20
Q
What are the four most common shapes of bacteria?
A
Coccus, spirillum, bacillus and vibrio
21
Q
What do coccus bacteria look like?
A
Spherical
22
Q
What do spirillum bacteria look like?
A
Spiral
23
Q
What do bacillus bacteria look like?
A
Rod shaped
24
Q
What do vibrio bacteria look like?
A
Common shaped (ununiform tear drops)
25
How do bacteria cause disease?
By producing toxins and chemicals harmful to the host
26
How can transmission of disease occur?
Directly, indirectly or through a vector
27
What is an endospore?
A tough waterproof external layer on some bacteria
28
Why are endospores problematic?
They can lay dormant for years and can resist heat, chemicals and desiccation
29
What does saprophytic in context with fungi mean?
That they live on dead plant and animal material
30
What is mould composed of?
They are composed of hyphae, which spreads to form mycelium
31
What is mycelium?
The main fungal body
32
What is hyphae?
Microscopic tublur filaments
33
How can fungi reproduce?
Asexually by budding or sexually
34
What is a fungal cutaneous infection?
Infection of the outer skin layer
35
What is a fungal subcutaneous infection?
Infection beneath the skin surface
36
What is a fungal systemic infection?
Infection affecting internal organs
37
How can fungi by transmitted?
Directly or indirectly
38
How can protozoa be transmitted?
Directly, indirectly and by vectors
39
How do protozoa reproduce?
By binary fission
40
What are the four main classifications of Protozoa?
- Flagellates
- Ciliates
- Amoebae
- Sporozoa
41
What are flagellates?
Protozoa which have a whip like tail known as flagellum
42
What are ciliates?
Protozoa which have many hair like projections known as cilia
43
What are amoebaes?
Protozoa which use projections of cytoplasm to move around
44
What are sporozoa?
Protozoa which can not move and reproduce by releasing spores
45
What are some examples of endoparasites?
Flatworms, tapeworms and roundworms
46
What are some examples of ectoparasites?
Leeches, ticks and flees
47
What are helminths?
A parasitic worm
48
What are worms generally treated with?
Anthelmintics
49
How do helminths reproduce?
By releasing eggs
50
What are athropods?
Are invertebrates that have an exoskeleton and segmented body
51
What are some examples of anthropods?
Fleas, ticks, lice, mites, mosquitoes
52
What is a capsid?
It is a protective coat that encloses the genetic material in a virus
53
What can be found on the protein coat of virsus?
Chemicals which helps attachment to cells
54
What are prions?
Abnormal proteins causing degenerative diseases
55
How do prions cause disease?
By inducing abnormal folding patterns in normal proteins
56
Why are diseases caused by prions called spongiform?
They leave the brain filled with tiny holes like a sponge
57
How are prions transmitted?
By ingesting infected tissue, inheritance and it can be spontaneous
58
What are the three stages of chain of infection?
A host susceptible to disease
A disease causing pathogen
A mode of transmission
59
What is direct contact?
Transmission through physical contact between host and organisms
60
What is horizontal transmission?
Spread in the same generation
61
What is vertical transmission?
Spread from parents to offspring
62
What are some examples of direct contact?
Kissing, touching and biting
63
What is indirect contact?
Transmission when there is no direct contact between host and organisms
64
What is a formite?
An object or material that carries pathogens
65
What are some examples of indirect contact?
Coughing, sneezing, touching infected surfaces, contaminated food or water
66
What is vector transmission?
Transmisson through arthropods
67
What are some examples of vectors?
Mosquitos, sandflies, ticks
68
What are clusters of fungi and bacteria known as?
Colonies
69
What are the two conditions required for bacterial and fungal culture?
Nutrient agar and 30*C
70
What do bacterial colonies look like?
Tend to be smooth, glossy and coloured
71
What do fungal colonies look like?
Tend to be fury and large
72
How did people think disease was caused in the past?
BY spontaneous generation
73
Who developed the agar plate technique?
Koch
74
What did Koch do extensive studies on?
Anthrax
75
What did koch conclude?
That disease is caused by micro-organisms
76
What are the four criteria for Koch's postulates?
1. The same pathogen must be present in every diseased host
2. Pathogen must be isolated and then cultured
3. When sample is exposed to a host they must develop the same symptoms
4. Pathogen must be isolated from second host and must be same as first
77
What did Louis Pasteur discover whilst researching fermentation?
Different organisms were responsible for fermentation and souring of alcohol
78
What is pasteurisation?
The process of heating a liquid to destroy pathogens
79
Who proposed germ theory?
Louis Pasteur
80
What experiment did Louis Pasteur do to prove germ theory?
The swan neck experiment
81
What vaccine did Louis Pasteur develop?
Vaccine against rabies
82
Why is Australia's agriculture relatively free from many infectious diseases?
Because of the isolated nature of Australia
83
What is Panama Disease caused by?
A fungus
84
What are the signs of Panama Disease?
Yellowing and wilting of leaves and splitting of stems
85
How is Panama Disease spread?
From root to root contact and contaminated soil
86
What is footrot in sheep caused by?
A bacteria
87
What are the signs of footrot in sheep?
Abscesses between toes, lameness and weight loss
88
How is footrot in sheep spread?
Foot to foot via pasture or mud
89
What are the main factors increasing the risk of disease?
Increased mobility of human population
Climate change
Antimicrobial resistance
Loss of genetic diversity
90
Where can fungi enter plants?
Via the stomata or other openings
91
How does fungi impact plants?
Destroys conducting tissues preventing the absorption of nutrients
92
How do insects impact plants?
They can cause direct physical damage
93
Where can bacteria which effect plants be found?
Soil, weeds and seeds
94
What are the four steps for an organism to cause disease?
1. Enter the host
2. Multiply in host tissue
3. Resist or not stimulate host defence
4. Damage the host
95
What does a prion do to facilitate movement through the body?
May piggyback other proteins
96
How does a protozoa enter host cells?
Microtubule protrusion
97
How do protozoa protect themselves?
They form a vacuolar membrane providing protection from lysosome
98
How do viruses adhere to host cells?
Viral surface proteins adhere to host cell surface receptors
99
How does a virus enter the cell?
Receptor mediated endocytosis
100
What adaptations help bacteria with adhesion?
By pili and fimbriae
101
How do bacteria invade the body?
Enzymes break down cell contents
Toxins are secreted to damage host cells
102
What adaptations do bacteria have to protect itself?
Capsules resist phagocytosis
103
What adaptations do ticks have for invasion?
Specialised mouthparts which can be inserted in skin
Molecules are secreted in saliva to prevent clotting/inflammation
104
What adaptations does fungus have for invasion?
Thermotolerance
Enzymes secreted to damage cells and provide nutrients for fungus
105
What are adaptation of pathogens which are airborne?
Able to remain suspended in air for long periods
Resist drying out
Cause sneezing and coughing
106
What are adaptation of pathogens which are waterborne?
Able to colonise in water
Many can not be destroyed from boiling water
107
What are adaptations of vector borne pathogens?
Vector is not affected by pathogens
Are in digestive track/saliva for transmission
Life cycle of pathogen is synched with feeding of vector
108
What are adaptations of faeco-oral pathogens?
Pathogens very stable in all environments
Causes vomiting/diarrhoea increasing transmission
109
What are adaptations of soil-borne pathogens?
Form endospores to resist desiccation
Stable in a range of environments
110
What are adaptations of blood-borne pathogens?
Takes advantage of unique features of red blood cells
111
What are the two major types of passive defences for plants?
Physical and chemical barriers
112
What physical barriers do plants have?
Thick cuticle, cell walls and small stomata
Bark
Vertical hanging leaves reducing the risk of water pooling
113
What do chemical barriers do in plants?
Chemical compounds reduce fungal and bacterial growth
Enzymes break down pathogen-derived toxins
114
What are the three major stages of active defence in plants?
Recognition, rapid response and delayed response
115
What is pathogen recognition in plants?
Can recognise pathogens by certain physical and chemical signals
116
When does rapid response happen in plants?
In minutes to hours
117
What can happen during the rapid response in plants?
Release of hydrogen peroxide directly killing microbes
Reinforcements of cell wall
Cell death isolating the pathogen
118
When does delayed response happen in plants?
In days
119
What happens during the delayed response in plants?
Repairing wounds in bark
120
What is innate immunity?
Immunity present at birth that is none specific and includes the first and second line of defence
121
What is the first line of defence in animals?
Physical and chemical barriers
122
When does the second line of defence occur?
When the first line of defence in broken
123
What is the second line of defence in animals?
Cellular response such as inflammation
124
What is the third line of defence in animals?
Adaptive immunity which is acquired and is a specified response
125
What is an antigen?
A molecule which is recognised as foreign triggering a response
126
What does the lymphatic system consist of?
Lymph, lymph nodes and lymph vessels
127
What does the lymphatic system do?
Forms a drainage system for all parts of the body
128
What do the lymph nodes do?
FiIlter out microbes, cellular debris and cancer cells
129
What do macrophage do?
Phagocytosis of pathogens
130
What do dendrite cells do?
Trigger adaptive immune response
131
What do neutrophil do?
Are the most common white blood cell at the site of trauma/infection
132
What does the microbiome do?
Inhibits the growth and multiplication of pathogens
133
What can occur when microbiome is compromised?
Pathogen growth may not be controlled and disease can occur such as thrush
134
What can impact the microbiome?
Antibiotics
135
What are the three parts of skin?
epidermis, dermis and hypodermis
136
What is the three step process that occurs when skin is broken?
1. Inflammation
2. Proliferation --> new cells generated
3. Maturation --> cells mature creating a new barrier
137
What is the mucous membrane?
Epithelial tissue which forms a barrier from pathogens
138
What does the mucous membrane secret?
Mucus, lysozyme and immunoglobins
139
What does mucus do?
Protects the lining of the body by trapping foreign substances
140
What are sphincters?
Circular muscles that ensures one way flow through constriction and relaxation
141
How is a granuloma created?
Cells die to create a wall that prevents the infection from spreading
142
What happens to granuloma once formed?
They are destroyed by macrophages
143
When does vomiting occur?
Presence of pathogens in the stomach
144
What does diarrhoea do?
Quickly expels organisms from the intestine
145
What is inflammation?
A chemical response that helps repair wounds and pathogen destruction
146
What are some signs of inflammation?
Pain, heat, redness, swelling
147
What type of response is inflammation?
Non-specific defence mechanism
148
What is phagocytosis?
The process of phagocytes engulfing foreign particles
149
What happens to particles inside phagocytes?
They are destroyed by enzymes
150
Where do neutrophils originate from?
Bone marrow
151
What do neutrophils do?
Are the first to move to the site of infection and fight acute infections
152
Where are monocytes?
Circulating in the blood
153
What do monocytes transform into?
Macrophages and dendrite cells
154
What do macrophages and dendrite cells do?
Fight chronic infections and act as a bridge between innate and adaptive immune systems
155
What is a fever?
The bodies response to pathogens by increasing body temp
156
What is the purpose of fevers?
To limit the growth of pathogens and enhance white blood cell activity
157
Why can fevers be bad?
In temperature is too high in the brain it can lead to seizures
158
What are cytokins?
Chemical messengers which promote development and differentiation of T and B cells
159
What is an example of cytokins?
Interleukin
160
What is the humoral response effective against?
Pathogens in body fluids
161
What is the cell mediated response effective against?
Intracellular pathogens
162
What is responsible for the adaptive immune response?
T and B cells
163
What are the T and B cells responsible for?
The adaptive immune response
164
What do B cells become?
Plasma cells which produce antibodies
165
What do T cells become?
Cytotoxic T cells which destroy infected body cells
166
What is mainly responsible for the humoral response?
B cells
167
Where are B cells stored?
Lymph nodes
168
What activate B cells?
Helper T cells which release cytokines
169
What happens when a B cell is activated?
1. B cell multiplies
2. B cells differentiates into plasma cells and memory cells
170
What is the cell mediated response?
When T-cells target and destroy an entire infected host cell
171
What are the four types of T cells?
Helper T cells, cytotoxic T cells, memory T cells and suppressor T cells
172
What do helper T cells do?
Release chemical that activate cloning of cytotoxic T cells and B cells
173
What do cytotoxic T cells do?
Move to the site of infection and release chemicals that destroy infected cells
174
What do memory T cells do?
Remain in the body to respond to future infections
175
What do suppressor t cells do?
Suppress the immune response when the infection has been defeated
176
What are major local factors?
Sanitation, overcrowding, poor communication, animal husbandry and culture
177
What are global factors?
Increased movement of people globally and rise in antibiotic resistance
178
What are societal factors?
Anti vaccination campaigns
Lack of education
Poverty
Immigration
Rise of international travel
179
What is included in personal hygiene?
Keeping our body and any openings clean
180
What is included in community hygiene?
Sewage and garbage disposal, sterilisation of medical equipment and reduction of overcrowding
181
What does DAWR stand for?
Department of Agriculture and Water Resources
182
What is DAWR responsible for?
Keeping Australia relatively disease free
183
What does vaccination involve?
The introduction of the vaccine to the body
184
What is immunisation?
The process in which the body reacts to a pathogen
185
What does an immune response produce?
Memory cells
186
What is active acquired immunity?
When the immune response occurs and memory cells are created
187
What are the three things that vaccines can contain?
Pathogens that are living but attenuated or dead and toxoids
188
What are booster injections used for?
To increase memory cells
189
What is passive acquired immunity?
Introduction of antibodies which have been produced by another organism to prevent disease from developing
190
How long will passive acquired immunity last for?
A couple of months
191
What does RICE stand for in the public health campaign approach?
Resolution of WHO to find solution
Information in form of scientific studies
Coordination on all scales
Education of human population
192
What are pestacides?
Chemicals used to kill pests on plants
193
What are the three types of pesticides?
Insecticides - insects
Fungicides - fungus
Herbicides - weeds
194
Why is the use of pesticides discouraged?
As organisms can build resistance and they have great harm on the environment
195
What are alternatives to pestacides?
Natural pesticides and companion plants
196
What does genetic engineering involve?
Altering of the genetic composition of an organism
197
Why is genetic engineering used against infectious diseases?
As it makes it possible to make organisms resistant to diseases
198
What are the four main classifications of antimicrobials?
Antibiotics - Bacteria
Antivirals - Viruses
Antifungals - Fungi
Antiprotozoals - Protozoa
199
What is an example of an antibiotic?
Penicillins
200
What is an example of an antiviral?
Tamiflu
201
What is an example of an antifungal?
Fluconazole
202
What is an example of an antiprotozoals?
Doxycycline
203
What does an antiviral do?
Does not kill a virus but inhibits development in cells
204
What does an antibiotic do?
Kills or slows down the growth of bacteria
205
What is incidence?
The number of new cases occurring during a specific time
206
How is incidence calculated?
Number of new cases during time/size of population x 100
207
What is prevalence?
The proportion of the population that have the disease
208
How is prevalence calculated?
All new + previous cases during time period/population during time period x 100
209
What is smokebush?
It is a plant that indigenous people have used for healing
210
Why have scientists taken interest in smokebush?
It's properties have the potential to treat HIV
211
How does direct contact influence the spread of the disease?
Limits spread as it is limited to the transmission through touching or droplets in a one meter range
212
How does indirect contact influence the spread of the disease?
Results in disease spreading rapidly over large distances
213
How does vector transmission influence the spread of the disease?
Spreads disease according to the mobility and lifecycle of the vector, can spread pathogens across borders
214
What is a retrospective cohort study?
It uses preexisting secondary research data to examine the relationship between an exposure and an outcome
215
What is a prospective cohort study?
Follows a group of individuals over time
216
What is endemic?
Disease regularly occurring within an area or community
217
How were antibiotics used historically?
Historically, antibiotics have been very successful in the treatment of bacterial infections. During World
War II, many soldiers’ lives were saved due to the use of antibiotics to treat wounds
218
What does increased blood flow to infected areas result in?
They bring phagocytes to the site to
carry out phagocytosis, destroying the pathogen
219
What chemicals cause inflammation?
Histamines and prostaglandins
220
What does phytophthora cinnamomi cause?
Lesions in the plant which look rotten
221
What was one historical strategy of controlling the spread of disease and how effective was it?
In the 18th century they started isolating people who were unwell and quarantine of exposed people this was very effective
222
What type of protein is formed in response to a pathogen?
Antibody
223
What is the independent variable?
The one that is manipulated or changed
224
What is the dependent variable?
The variable that changes as a result of the independent variable manipulation
225
How do you remember the difference between dependent and independent variables?
The dependent variable 'depends' on the independent variable
226
What does heterotrophic mean?
An organism that cannot produce its own food
