Module 5 Flashcards
(167 cards)
1
Q
What are infectious agents?
A
Organisms capable of producing infections or causing an infectious disease by invading the human body
2
Q
What are the 4 classes of microbes?
A
bacteria, viruses, fungi, parasites
3
Q
What are bacteria?
A
unicellular prokaryotes (usually with a cell wall)
4
Q
What are viruses?
A
obligate microbes that must invade a most to replicate. Encapsulated by a protein coat and can infect all forms of life
5
Q
What are fungi?
A
uni/multicellular eukaryotes with thick walls of complex carbohydrates. Can cause superficial infections or invade
6
Q
What are parasites?
A
eukaryotes that cause disease in the host
7
Q
What is the microbiome?
A
Collection of microbes that live symbiotically in/on humans particularly on the skin and mucous membranes
8
Q
What does the microbiome do?
A
help perform vital functions such as digestion, inflammation prevention, vitamin production, infection protection, etc..)
9
Q
When do microbes become pathogens?
A
When there is imbalance between good and bad microbes (called opportunistic or potential pathogens)
10
Q
What are microbes that are always pathogenic called?
A
pathogens
11
Q
What is the immune response/immunity?
A
Chemical, physical, cellular barrier to remove and prevent entrance of foreign pathogens
12
Q
What is innate immunity?
A
An instant, non-specific first line of defence designed to prevent the spread and movement of pathogens?
13
Q
What are physical innate barriers?
A
skin and mucous membrane
14
Q
What are chemical innate barriers?
A
enzymes in saliva and tears
15
Q
What are cellular innate barriers?
A
immune cells that cause inflammation/engulf viruses and bacteria
16
Q
What is the adaptive immune system?
A
a strong line of defence specific to the invader that searches for antigens, takes several days to activate, and has a memory function
17
Q
What symptoms can the adaptive immune system cause?
A
redness, swelling, pus, pain
18
Q
What are the stages of how.a pathogen causes an infectious disease?
A
entry, invasion and colonization, evasion of immune system, infection
19
Q
What is the entry stage?
A
pathogen enters body (SARS enters through oral or nasal passages)
20
Q
What is the invasion and colonization stage?
A
pathogen attaches itself to human cells (SARS uses spike protein to bind to ACE2 receptors)
21
Q
What is the evasion of immune response step?
A
different pathogens have different methods (SARS delays adaptive immune response)
22
Q
What is the infection step?
A
Pathogen reproduces, replicates, spreads (SARS hijacks machinery)
23
Q
What are the conditions for establishing an infectious disease?
A
there must be a reservoir, a mode of transmission, and opportunistic conditions
24
Q
What is a reservoir?
A
sites where pathogens can persist for long periods of time (biological or environmental)
25
What is a mode of transmission?
direct contact, droplets, air, spores, vectors, or vehicles
26
What are opportunistic conditions
factors which promote microbes of normal flora to become pathogenic and others to evade immune system such as stress, surgery, old-age
27
How can infectious disease be prevented?
eliminating resevoirs, enhanced barriers, distributed vaccines, develop targeted medecines
28
What is the chickenpox vaccine programme?
routine immunization since 2004 reduced chickenpox, highly-contagious viral disease, prevalence by 100x.
29
Why are vaccines good?
most powerful, cost-efficient protection`
30
What is herd immunity?
when a sig. portion of pop is vaxxed, those at risk have a lower chance of contracting the disease
31
How are infectious diseases a form of colonization?
introduced to pops with no immnunity, causing pop decimation, resulting in loss of groups or oral histories. Used as a control mechanism
32
What is smallpox?
an viral infectious disease with a 30% mortality rate transmitted by saliva, surfaces, and the open sores of the infected
33
Who was Jeffrey Amherst?
A British commander who used smallpox blankets as biological warfare against Indigenous populations by sending them as false peace treaties
34
When was smallpox eradicated?
1980
35
What is the incidence of infectious disease among FN compared to others?
higher
36
What is Strep throat?
A bacterial infection that can be treated with one week of antibiotics
37
Who was Brody Meekis?
A 5yo boy of Sandy Lake FN who died of strep throat. Nursing station was poorly staffed and medical transport was unreliable, with inadequately trained care workers
38
What is TB?
An infectious bacterial disease
39
What was the impact of TB on FN groups?
settlers caused epidemic, spread rapidly due to crowding on reserves, in residential schools and Indian hospitals. Highest even mortality rate reported in a human population
40
What are bacteria (detailed)?
Among the first lifeforms to exist, every individual is home to 1e12, and grouped by structure of cell wall. gram positive and gram negative
41
What is gram-positive?
thick peptidoglycan wall
42
What is gram negative?
Thin peptidoglycan wall surrounded by an outermembrane
43
What maintains the internal pressure of bacterial cytoplasm?
The bacterial cell envelope (cell wall and plasma membrane)
44
Why are bacterial cell walls good targets for eukaryotes?
They are not present in Eukaryotes
45
What are antimicrobials?
Any natural/synthetic agent that can stop the growth of/kill microorganisms
46
What are antibiotics?
small molecules used as medication or produced by microorganisms that can stop the growth of/kill microorganisms
47
What are bacteriostatic antibiotics?
inhibit growth with help of immune system (not used in life threatening infection)
48
What are bactericidal antibiotics?
kill susceptible bacteria without immune system help
49
What are broad-spectrum antibiotics?
antibiotics that target a wide range of bacteria
50
What are narrow-range antibiotics?
antibiotics that target a small group of bacteria
51
What are the types of antibiotic targets?
cell wall synthesis inhibitors, Metabolic pathway disruptors, nucleic acid synthesis inhibitors, cell membrane disruptors, and protein synthesis inhibitors
52
What are cell wall synthesis inhibitors?
Disrupt cell wall formation, making bacteria susceptible to environmental changes. May be specific to G+/G- bacteria
53
What is an example of a cell wall synthesis inhibitor?
Penicillin which permanently binds to an enzyme that crosslinks peptidoglycans, causing death by osmotic rupture
54
What are metabolic pathway disruptors?
disrupt pathways not found in human cells such as folate synthesis usually through enzyme inhibition. Generally needs two inhibitors to be bactercidal
55
What is cotrimoxazole?
A combination of two bacteriostatic antibiotics (sulfamethoxazole and trimethoprim) that affect folate synthesis
56
What are nucleic acid synthesis inhibitors?
Inhibit gyrase, a non eukaryotic topoisomerase, leading to DNA unraveling, degradation, and cell death
57
What are flouroquinalones?
A type of nucleic acid synthesis inhibitors
58
What are cell membrane disruptors?
Act on cell membrane and are rarely used as human and bacterial cell membranes are similar, so the side effects are much more serious
59
What is daptomycin?
A cell membrane disruptor that creates leaks in the plasma membrane, altering electrochemical gradients. It also impair mitochondrial function in mammalian cells
60
What are protein synthesis inhibitors?
inhibit translation of mRNA by targeting different sites on ribosomes
61
What is doxycycline?
A protein synthesis inhibitor. A single dose is used to prevent Lyme disease after a tick bite.
62
Why are protein synthesis inhibitors safe?
Bacterial and human ribosomes are very different
63
What are the antibiotic resistance pathways?
altering targets, restricting target access, developing drug specific enzymes
64
What is altering targets?
mutation alter the target of the drug, or a new enzyme takes over the function
65
What is restricting target access?
drug cannot enter cell or is pumped back out immediately upon entry
66
What is developing drug-specific enzymes?
enzyme to destroy/modify antibiotic
67
What are the steps of antibiotic resistance?
Infection, treatment, proliferation, gene transfer
68
What is the infection stage?
host is infected, some bacteria are drug-resistant
69
What is the treatment stage?
Antibiotic kill all except drug-resistance bacteria
70
What is the proliferation stage?
drug-resistant bacteria proliferate
71
What is the gene-transfer stage?
genetics can be passed to drug-susceptible bacteria
72
What is the gene transfer stage?
Genetics can be passed between bacteria
73
What is horizontal gene transfer?
Where resistance genes are spread between individuals
74
What are he types of horizontal gene transfer?
transformation, conjugation, transduction
75
What is transformation?
extracellular DNA is taken up by bacterium and incorporated into its genome
76
What is conjugation?
cell-cell contact with plasmid gene transfer
77
What is transduction?
transfer of genes through infection with bacteriophage
78
What is selective pressure?
Resistance only maintained if antibiotic stimulus is maintained?
79
Why does selective pressure occur?
Because there is a metabolic cost to maintaining resistance
80
Who is Andre?
A 56yo male in a motor vehicle accident who was put in ICU semi-conscious from brain trauma, and with an open fracture on his right leg. Central line put in for taking blood, meds, nutrients and fluids
81
What were surveillance cultures taken for?
methicillin-resistant-S-aureaus (MRSA), and carbapenem-resistant-orgnisms (CPO)
82
What are MRSA?
S Aureus cause skin and soft-tissue infection and can be treated with antibiotics, however MRSA options are more limited
83
What are CPO?
resistance to multiple-all classes of bacteria
84
How has MRSA become a problem?
prevalence doubled in the 21st century, causing severe complications and death. rigorous programs established to relieve burden
85
When was penicillin developed?
The 1950s
86
How did S aureus develop resistance to penicillin?
through beta-lactamase, an enzyme that destroyed penicillin?
87
When was methicillin developed?
1959
88
How did S aureus develop resistance to methicillin?
by altering the penicillin binding protein
89
What happened 3 days after Andre's accident?
decreased BP, fever, increased WBC count, blood samples were taken, + for MRSA, put on IV vancomycin
90
What was causing Andre's infection?
contaminated central line
91
What can vancomycin result in?
VR enterococci (extremely common) or VRSA (extremely rare for now)
92
What is multidrug resistance?
resistance to multiple types of antibiotics
93
What are examples of multi drug resistance?
CPOs, extended spectrum beta lactanase (resistant to all beta lactam antibiotics)
94
What was Andre's prognosis?
no further signs of infection, injury healed, discharged
95
How has MRSA prevalence changed?
increased globally
96
What evidence is there for global antibiotic resistance?
2800 beta lactamases identified (10x increase) and global spread of carbapenem resistance
97
Where are antibiotics most overused?
hospitals and agri/aquaculture
98
How do hospitals overuse antibiotics?
non-prescription/unregulated sale in low-middle income countries, and some hospitals rely on pharmaceutical sales for revenue
99
How do agri/aquaculture overuse antibiotics?
used for animal health maintenance. Majority of antibiotics used worldwide are used for this purpose
100
What are the burdens of antibiotic resistance?
increased incidence and mortality rate, increased treatment cost and duration
101
What are the main initiatives for preventing antibiotic resistance?
surveillance, stewardship, research/innovation, and infection prevention/control
102
How does surveillance work?
continuous monitoring of antibiotic use and resistance
103
How does stewardship work?
appropriate/careful use of microbiotics across all industries and sectors
104
How does research and innovation work?
continuous research and development for antibiotic discovery
105
How does infection prevention and control work?
strict adherence to hygiene, sanitation, and infection control
106
How are antibiotics regulated in high income countries?
EU banned antibiotics in food production in 2006, med schools and associations limited prescription through guidelines and physician education, physicians are banned from taking gifts from countries and drug advertisements are limited, statistics are kept, screening and isolation in care settings
107
How are antibiotics used in low-middle income countries?
no regulation, lower ethics, and poor quality of drugs
108
How are AR organisms controlled in KGH?
screening, if + then separate room, enhanced cleaning, dedicated equipment, and PPE/hygiene for workers
109
What is antibiotic stewardship board?
group who create policies and procedures on antibiotics, audit and feedback, and standardize treatment protocols
110
What spectrum should be used to treat antibiotics?
the most narrow
111
What are some of the difficulties in antibiotic development?
target selection, screening, testing, etc...
112
What are viruses (detailed)?
Obligate infectious agents with a protective outer layer and a genome
113
What is a virion?
A viral particle containing the minimum to repilcate
114
What is the structure of a virus?
Single or double stranded DNA or RNA genome surrounded by a capsid and with viral proteins to interact with a host
115
What must viruses do?
replicate
116
How do viruses replicate?
attach to host receptor protein, use host cellular machinery, release new virions
117
What was the 1918 pandemic?
Influenza pandemic with 3 waves (2nd was worst) that eventually became the regular flu season
118
What are pandemics and epidemics rooted in?
viral and bacterial outbreaks
119
What are epidemics?
widespread occurrence of infectious disease in a community for a period of time
120
What are pandemics?
widespread occurrence of infectious disease worldwide or over a large area for a period of time
121
What was the death toll of 1918?
50-100m people died
122
How much of the world contracted influenza?
1/3
123
What was the origin of the virus?
unknown
124
Why did increased death in young adults occur?
possibly from immune over activation leading to secondary pneumonia and tissue damage
125
How did the government handle influenza?
no federal quarantine, municipal and provincial gov. prohibited gatherings and isolated the sick, however Canada was still incapacitated
126
How did influenza spread through Canada?
Entered through QC, Montreal, and Halifax, movement of troops spread it west
127
When was the department of health formed?
1919
128
What were the impacts of health inequalities is 1918?
no social safety net, and treatment was for those who could afford it. Many worked through illness for money and children would work if parents died. Many couldn't maintain fires and froze to death in the winter. Increased death rates in FN communites
129
What percentage of FN communities in the PNW died when exposed to influenza?
30-95%
130
How did the Shishmaref protect themselves?
stationed guards south, not letting anyone in or out
131
What is COVID-19?
A respiratory disease characterized by fever cough and fatigue
132
What is the coronavirus family?
spherical, enveloped viruses with ssRNA and spike proteins on the envelope
133
What are the stages of infection of SARS-CoV-2?
entry, attatchment, replication, release, and infection
134
What is the entry stage of SARS?
enters through nasal/oral cavities and travels to lungs
135
What is the attachment stage of SARS?
spike protein attaches to ACE2 receptors
136
What is the replication stage of SARS?
hijacks machinery of host cell to replicate
137
What is the release stage of SARS?
new virions bud out of host
138
What is the infection stage of SARS?
virions infect other tissues/organisms
139
What tissues can SARS infect?
lung, respiratory tract, nasal, heart, eyes, liver, bladder, kidney, pancreas, brain, prostate, testis, placenta
140
What are the symptoms of SARS infection?
dry cough, tiredness, fever, brain fog, loss of smell and taste
141
What is the quaternary structure of the spike protein?
trimer
142
What covers the surface of the spike protein?
glycans which hide virus from antibodies
143
What happens when spike protein binds?
shape change, and then protease cleavage, allowing for fusion with host cell membrane
144
What is a variant under monitoring?
A variant with genetic changes that are suspected to affect virus characteristics and early signals of growth advantage, but no evidence of phenotypic or epidemiological impact or if transmission in two or more countries in a 2-4 week period
145
What is a variant of interest?
A variant that is predicted or known to affect virus characteristics and increasing number of cases with a growth advantage relative to other variants, suggesting increasing risk
146
What is a variant of concern
meets definition of variant of interest and meets one of the following criteria:
detrimental change in clinical disease severity
decrease in effectiveness of vaccines
decrease in ability for health systems to provide care
147
What are methods of infection control for COVID-19?
2m distancing, closure of activities with close contact, masking, washing of hands and surfaces, quarantine for symptoms/close contact, tracing
148
What are the similarities between 1918 and COVID-19?
Sudden onset with multiple waves, mutations, healthcare overwhelmed
149
What aided the fight against covid?
Biotech and modern controls
150
What was the cost of COVID-19?
structural health inequalities, lack infrastructure, service barriers, service gaps in Indigenous communities
151
What are the types of vaccines?
Viral vector, mRNA, Whole Virus, Protein Subunit, and Virus-like particles
152
What are viral vector vaccines?
harmless virus to deliver gene sequences (ex. adeovirus delivers gene sequence for spike protein) Astrazeneca, Jansses
153
What are mRNA vaccines?
synthetic portion of mRNA which codes for a piece of protein (ex. harmless piece of spike protein) Moderna, Pfizer
154
What are whole-virus vaccines?
attenuated weakened version of virus (inactivated SARS-CoV-2 viral particles) Sinovac Bharat
155
What are protein subunit vaccines?
harmless pieces of virus (ex. modified spike protein) novavax, Anhui
156
What are virus-like particle vaccines?
Biotech used to grow particles with surface antigens on them (spike protein) ex. Medicago
157
What was the vaccination strategy for COVID-19?
most at risk first, First Nations early, based on age, high levels of vaccination, major impact on rates and severity, mRNA vaxx is constantly updated
158
How are new screening methods being developed?
increased tech and understanding, with new biomarker discovery and next gen sequencing techniques
159
How must new drugs be developed?
for rare diseases, for bacteria, for new diseases
160
How should health care disparities be treated?
They should be evaluated and considered in patient care
161
What are the difficulties for Indigenous med school applicants?
difficulty financial fro travel, testing and schooling
162
What do aboriginal patient navigators do?
help address racism, discrimination and inadequate care in the hospital
163
Why is patient communication important?
enhances outcomes in the long term
164
What factors are involved in Indigenous health promotion?
protective factors, prevention, spirituality
165
What are protective factors?
self-government, land control, control over cultural activities
166
What are prevention factors?
community based approaches, gatekeeper training, peer support groups
167
What spirituality factors?
concepts of well-being and spiritual practices (powwows, sweetgrass ceremonies, and sweat lodges)
