1 - The Complexity of Health

Question 1

What is a zoonotic disease

Answer 1

disease or infection that is naturally transmissible from vertebrate animals to humans or humans to animals

Question 2

What is one health

Answer 2

Managing threats at the interface between ecosystem health, animal health and human health
Health of people,animals and the ecosystem of which we are a part, are interconnected.

Question 3

How many dengue deaths per year? Who?

Answer 3

22,000
primarily children

Question 4

How is dengue transmitted? How many serotypes?

Answer 4

Mosquito borne
4 serotypes

Question 5

What are the mosquito control methods to prevent dengue?

Answer 5

Release of genetically modified mosquitoes to control population

Stop warming temperatures

Question 6

Why is dengue vaccine development difficult?

Answer 6

Because of the multiple serotypes

Question 7

Two categories of dengue, describe symptoms.

Answer 7

Dengue fever: higher fever, headache, eye pain, joint/muscle pain, nausea, vomiting, loss of appetite, lasts ~1 week

Dengue hemorrhagic fever: previous symptoms, plus bleeding (red patches, bleeding from nose, mouth, gums, vomiting blood), black tar stool, belly pain, shock

Question 8

Hemorrhagic dengue results from…

Answer 8

secondary dengue infection with a different serotype

Question 9

Types of mosquitoes that transmit dengue

Answer 9

Aedes aegypti
Aedes albopictus

Question 10

What diseases does Aedes aegypti transmit? Where does it originate? Where does it breed

Answer 10

Dengue, chikungunya, yellow fever, zika
Originated in Africa
Breeds in man-made containers (water storage, old tires)

Question 11

How was aedes aegypti nearly eradicated?

Answer 11

By DDT in 1950s and 60s in Latin America

Question 12

What diseases does Aedes albopictus transmit? Where is it native to

Answer 12

Dengue, chikungunya, yellow fever, zika
Native to southeast asia

Question 13

Aedes albopictus feeds on… What makes dangerous in North America?

Answer 13

Humans and other mammals

Invasive, cold hardy

Question 14

Role of the structural vs nonstructural proteins in the dengue genome

Answer 14

Structural are the viral coat, deliver RNA to target cell
Nonstructural produce new viruses

Question 15

Recovery from first dengue infection leads to…

Answer 15

lifelong immunity against that serotype
partial and transient protection against subsequent infection by other three serotypes

Question 16

Dengue vaccines are only effective if

Answer 16

they induce a protective immune response against all dengue viruses simultaneously (multi-valent)

Question 17

What was the issue with the Dengvaxia vaccine?

Answer 17

Seronegative children given Dengvaxia were at significant risk of severe dengue infection
If children had never had dengue and were given the vaccine, their next infection was likely to be hemorrhagic dengue

Question 18

Protective efficiency of Dengvaxia

Answer 18

DENV1: 50%
DENV2: 42%
DENV3: 74%
DENV4: 77%

Question 19

Four ways to combat mosquitoes

Answer 19

• reduce habitat
• insecticide
• genetic manipulation: population control (transgenic mosquitos)
• genetic manipulation: population replacement (Wolbachia)

Question 20

Example of genetically engineering mosquitoes to control populations

Answer 20

OX513A
Male that, when mates with females, causes death in offspring
Late-acting dominant lethal gene

Question 21

How many species of vultures? They are…

Answer 21

23 (14 endangered)

Obligate scavengers

Question 22

Declines in vulture populations causing…

Answer 22

• increase in mammalian scavengers
• increase in carcass decomp times
• increase in pathogens (usually destroyed in vulture GI tract)

Question 23

Why are vulture numbers declining in Africa and Asia

Answer 23

• Diclofenac
• livestock poisoning
• ivory poaching
• traditional medicine (killed for body parts)

Question 24

What is felled livestock poisoning

Answer 24

Livestock killed by predators are poisoned by herders to kill the predators
Vultures are inadvertently poisoned

Question 25

What is Diclofenac? What is it used for in India

Answer 25

Non-steroidal anti-inflammatory drug used to treat mild-to-moderate pain, inflammation, arthritis, swelling, stiffness, joint pain

In India, cattle are considered sacred, and there are many old cattle. Used to treat lameness

Question 26

How does Diclofenac kill vultures?

Answer 26

Remains in tissue of cattle upon death
When vultures feed on carcasses, are poisoned and suffer from liver failure

Question 27

How has vulture decline caused rabies in India?

Answer 27

Higher carcass availability has led to increase in feral dog populations, and human rabies deaths

Question 28

Anthrax affects mostly what animals?

Answer 28

Herbivores (livestock: beef, bison, dairy, sheep, goats, horses)

Question 29

What animals are resistant to anthrax? Who is it not common in?

Answer 29

Carnivores are resistant

Rare in birds

Question 30

How does an anthrax infection occur in animals

Answer 30

Ingesting spores from soil

Question 31

How long do anthrax spores survive

Answer 31

In the environment for years to decades

Question 32

How do humans get anthrax?

Answer 32

Handling animal products “Woolsorters’ disease”

Meat

Question 33

Is anthrax contagious

Answer 33

No, not in people or animals
Small risk of direct infection from the lesions on another person’s body

Question 34

How to deal with anthrax

Answer 34

Effective vaccines
Antibiotic treatments

Question 35

Four routes of anthrax infection

Answer 35

Cutaneous
Gastrointestinal
Inhalation (Pulmonary)
Injection

Question 36

What is cutaneous anthrax

Answer 36

Handling infected animals or products e.g. butchering, skinning, dissecting, handling hides, wool, hair

> 90% if human cases, but 80% survival without treatment

Question 37

What is gastrointestinal anthax

Answer 37

Consumption of raw or undercooked meat
50% survival without treatment

Question 38

What is inhalation (pulmonary) anthrax

Answer 38

Wool mills, slaughterhouses, tanneries

10-15% survival (without treatment)
60% survival (with treatment)

Question 39

What is injection anthrax

Answer 39

Drug users (heroin packed inside animal hides)
Europe 2009-2010

Question 40

What is the agent causing anthrax?

Answer 40

Bacillus anthracis
Gram positive, rod-shaped bacteria

Question 41

Two different forms of Bacillus anthracis

Answer 41

Rod shaped during vegetative cycle in host (low O2 env)

Sporulates when exposed to air (requires O2 for sporulation) when in environment; resistant to inactivation

Question 42

What was discovered at London’s King Cross Station in 2002?

Answer 42

Anthrax spores identified in sample of plaster

Horse hair used to bind plaster, but was stopped ~100 years prior (environmentally stable!)

Question 43

Age of anthrax spores identified in South Africa

Answer 43

~200 years old

Question 44

Where is Anthrax a real problem?

Answer 44

India and regions of Africa

Continuous problem in Western China

Sporadic outbreaks in Europe and NA

Question 45

Recap anthrax outbreaks in Canada

Answer 45

Last human case was Sask 2006

A few animal cases per year

Alberta 2022 - 31 cattle and 3 bison in Northern AB

Question 46

Recap the anthrax outbreak in Siberia in 2016

Answer 46

Western Siberia, first outbreak since 1941

~2500 reindeer died of disease
~100 ppl hospitalized
One human death (11 year old boy)

Question 47

Why did anthrax appear suddenly in Siberia

Answer 47

Decline in reindeer vaccination rates (program stopped because pop was increasing without any cases)

Heatwave in 2016; melting permafrost released 75 year old anthrax spores