Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Communicable Disease Control MPH > Influenza, Pandemics & Other Respiratory Infections > Flashcards

Influenza, Pandemics & Other Respiratory Infections Flashcards

(51 cards)

Start Studying
1
Q

Where did influenza come from

A

Zoonotic

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

Genera of influenza & which are more common in humans

A

A, B, C

A&B main human pathogens

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

Subdivision of influenza A

A

Subdivided by 2 surface antigens:
- Haemagglutanin (15 subtypes)
- Neuraminidase (9 subtypes)
All 15H and 9N have been detected in birds.
E.g. H1N1

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

Why can influenza change/mutate

A

Can get gene reassortment in infections
Gene swapping can occur during co-infection with human and avian flu virus
No proof reading mechanism so prone to mutation

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

What causes seasonal flu epidemics?

A

Minor antigenic variation = antigenic drift

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

What causes flu pandemics

A

Gene re-assortment & major antigenic variation = antigenic shift

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

Where does gene re-assortment often occur for flu

A

Animal (pig) reservoir- get bird virus and human virus at same time –> viruses combine –> new virus adapted to spread rapidly in humans

Or virus straight from bird –> human (human reservoir)

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

How do humans promote zoonotic infections

A

Humans in close proximity to animals - wet/live markets etc.
Intensive farming: bringing lots of animals in close proximity to each other
Farm parks/zoos

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

Influenza A

A

Can infect pigs, cats, horses, birds, sea mammals, humans
Causes severe & extensive outbreaks and pandemics

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

Influenza B

A

Tends to cause sporadic outbreaks (schools, care homes, garrisons) that are less severe
More often seen in children
Like A - prone to mutation

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

Influenza C

A

Relatively minor disease
Mild symptoms or asymptomatic

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

Influenza transmission

A

Mainly via aerosols generated by coughs & sneezes.
Possible via hand-hand contact, other personal contact & fomites

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

Influenza infection symptoms & complications

A

Upper +/- lower respiratory tract symptoms + fever, headache, myalgia, weakness
Complications: include bacterial pneumonia, life threatening

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

People with higher risk of flu mortality

A

Underlying medical conditions
chronic cardiac & pulmonary diseases
old age
chronic metabolic diseases
chronic renal disease
immunosuppressed

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

Influenza treatment

A

Supportive care (oxygen, hydration, nutrition, maintain homeostasis, prevent/treat secondary infections)

Antivirals: reduce risk of transmission, reduce severity and duration of symptoms (only really see a difference at a population level)

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

Seasonal flu

A

Antigenic drift every year - so can infect people who were immune to last years varient.
Usually peaks December - March (northern hemisphere)
Southern hemisphere - analyses their strains to make predictions for vaccines

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

Avian Influenza - about

A

Avian pathogen but can transmit to humans.
Usually mild in birds but can mutate to 100% mortality form.
~50% death rate in humans
HIgh risk of becoming pandemic

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

How to control avian influenza

A

Cull affected birds
Biosecurity & quarantine (e.g. 5-10km around a farm)
Disinfect farms
Control poultry movement
Vaccinate workers with seasonal flu jab
Antivirals for poultry workers
PPE
Try to reduce chance of coinfection

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

What is the number 1 risk to UK

A

Pandemic flu

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

Reasons for more pandemics

A

More travel
More people
Intensive farming (more animal contact with humans & factory farming)

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

Why are we better equipped to deal with pandemics

Study These Flashcards
A
  • Better nutrition, overall healthier population
  • Better supportive care
  • Vaccination
  • Antivirals
22
Q

Infection control responses to pandemics

Study These Flashcards
A

Hand hygiene, cough etiquette
PPE
Surgical masks (for non aerosol generating procedures)
Segregation of patients
Reduce social contact
Flu surgeries (separate potentially infected patients)
Environmental cleaning
Ventillation

23
Q

Population wide interventions for pandemics

Study These Flashcards
A

Travel restrictions (slow transmission to buy time)
Restrictions of public gatherings
School closure (effectiveness depends on where infection is spreading)
Voluntary home isolation of cases
Voluntary quarantine of contacts
Screening on entry to UK

24
Q

SARS CoV Info

Study These Flashcards
A

2002
Animal origin/reservoir = bats
Intermediate hosts = civet cats
Incubation 2-7 days.
Case Fatality Rate: <24y: <1%. >50% in over 65s
No vaccine or specific treatment
Superspreading

25
SARS S&S
Fever, cough, SOB, myalgia, diarrhoea CXR shows pneumonia or respiratory distress syndrome
26
MERS CoV
2012 Presents like SARS with severe acute respiratory disease Bat origin. Intermediate host: camels Superspreading
27
Covid-19
Swiss cheese method of response (detect, test, trace, isolate, support) Will become endemic but hasn't yet. Virus survives longer in higher humidity
28
Pandemic response
Local, national & global surveillance Epidemiological surveillance Wastewater surveillance Research (reinfections, durability of immunity, long covid, population behaviour) Rapid evidence reviews Vaccine efficacy studies
29
Challenges & issues in Covid
Challenges: misinformation & disinformation, covid deniers, antivax Issues: - health literacy - epidemiological literacy (especially in politicians) - risk perception
30
Pneumonia causes
Respiratory viruses, bacterial and fungal Typical pneumonias: Strep pneumonia, klebsiella, haemophilus influenza, staph a, group A strep, moraxella, pseudomonus Atypical pneumonias: mycoplasma, legionella pneumophilia (Legionnaires), chlamydia psitacci (bird exposure), aspergillus (mouldy hay)
31
Classification of pneumonias
CAP (acute infection of lung tissue in a patient who has acquired it from the community or within 48 hours of the hospital admission) HAP (acute infection of lung tissue in a non-intubated patient that develops after 48 hours of hospitalization) HCAP (Healthcare associated): acute infection of lung tissue acquired from healthcare facilities such as nursing homes, dialysis centers, outpatient clinics, or a patient with a history of hospitalization within the past three months. VAP (Ventilator associated): A type of nosocomial infection of lung tissue that usually develops 48 hours or longer after intubation for mechanical ventilation
32
Pneumonia risk
Top 10 cause of death USA Mortality from uncomplicated disease ~3% Mortality from bacteraemic pneumonia 25% 1 million deaths globally pa in <5s Risky even for young adults 5-10% pts admitted with CAP need intensive care - Most common dangerous organisms = pneumoccocus (strep pneumonia) & legionella
33
S. pneumonia (pneumococcus)
Common secondary infection Lots of different serotypes Causes meningitis, sepsis, invasive pneumococcal disease (severe pneumonia) Also causes >50% of otitis media in children & milder pneumonia and bronchitis Most common secondary bacterial infection of influenza
34
Why do people get pneumonia
- defect in host immune defenses - particularly virulent bacteria - overwhelming inoculum - Gains entry to lower respiratory tract: inhalation of aerosolised material or aspiration of upper respiratory tract resident flora
35
Risk factors for pneumococcal disease
Reduced consciousness Serious underlying disease Factors impairing clearance of pulmonary pathogens (CF etc.) Hypoxaemia Acidosis Alcohol Toxic inhalations pulmonary oedema uraemia malnutrition steroids immunosuppressives viral infection mechanical obstruction
36
Importance of pneumonia prevention
High risk to elderly High rate of CAP Increasing resistance and multi resistant strains
37
Pneumonia prevention strategies
Infection control in hospitals Vaccination programmes (e.g. PCV13, PPV23) Stop people getting things that make them susceptible – give flu vaccine and pneumonia vaccine to elderly etc. Reduce occupational hazards (dust exposure --> wear masks etc.) Nutrition
38
Respiratory Syncytial Virus (RSV) about
Common cause of winter coughs & colds Major cause of bronchiolitis in infants Transmission: large droplets & secretions & fomites Survives on hard surfaces: 4-7 hours Incubation period: 3-5 days
39
RSV epidemics
sharp winter peaks Starts Nov/Dec lasts 4-5 months Little variability in timing or magnitude
40
At risk groups for RSV
Very young preterm babies (chronic lung disease of prematurity increases risk) Very elderly
41
Prevention/how to mitigate RSV Risk (textbook exam Q) (not just for RSV - similar measures for all respiratory viruses)
- Breast feeding - Vaccination (passive vaccine) to newborn babies during RSV season - Education & awareness - parents & elderly carers - Hygiene measures (tissue in bin after blow nose, wash hands; cover mouth when cough) - Stay away from grandchildren/grandparents when ill (especially flu) - Don't send sick kids to school - Prewarning hospital/clinics so patients can be put in different waiting rooms - Cohorting - separate infected & non infected area (for staff and pts) - Isolate in hospital - Clean rooms/environmental contamination - Ventilation - Treatment as prevention (if there is treatment)
42
Legionella/Legionnaires Disease - where is it found
Environmental pathogen Warm Stagnant water Becomes a problem when water is aerosolised - showers - taps - air conditioning (puddle of water behind AC units --> fan on) - Jacuzzis - Humidifiers Also: cooling towers in factory plants --> water condenses on temperature gradient --> sumps of legionella --> windows --> spreads Human = dead end host - can't transmit to other humans
43
Legionella prevention
Shock dosing up water towers with toxic substance that kills legionella Test water supply if suspect domestic source Maintain water temp >55 degs (building regulations) Good plumbing techniques - no dead legs Regular flushing and disinfection Adequate cleaning and chlorination
44
Legionella presentation & demographics
Incubation period: 2-10 days, typically 5-6 days Flu like illness, muscle aches, tiredness, headache, dry cough, fever, pneumonia Can progress to multi-organ failure
45
At risk groups for legionella
More common in men Over 50s Heavy smokers 10-15% mortality
46
Diagnosis and management of legionella
- detection of urinary antigen (false positive risk) - culture from respiratory specimen = gold standard - detection of legionella spp nucleic acid (e.g. by PCR) in LRT specimen Management: Abx, supportive, intensive care
47
PH investigation for legionella
Try to identify the source 10 day exposure history - healthcare setting, travel, car wash, care, domestic, workplace, - are there any other local cases (6km radius) May carry out water & environmental sampling
48
Surveillance of legionella
Not notifiable but Health Protection Team needs informing Serious environmental issue National enhanced surveillance scheme European network monitors travel associated cases
49
Legionella epidemiology UK
steadily increasing since 1980 ~500 cases 2019 1/2 travel associated 1/2 community acquired
50
Who enforces Legionella prevention & management England
Local authority environmental health officers OR health and safety executive
51

Communicable Disease Control MPH (11 decks)

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