Lecture 7. Emerging and Re-emerging Bacterial Diseases

Question 1

What is an emerging disease?

Answer 1

One that has appeared in a population for the first time, or that may have existed previously but is rapidly increasing in incidence or geographic range

Question 2

What is a re-emerging disease?

Answer 2

A disease whose incidence has increased in a defined time period and location

Question 3

What is the biggest concern regarding TB?

Answer 3

Drug-resistant forms of TB are on the rise

Question 4

How many deaths from antimicrobial resistance are caused by drug-resistant TB?

Answer 4

1 in 3

Question 5

What are factors attributed to re-emergence of infectious disease?

Answer 5

Human activity (behaviour, population movement, habitat encroachment, land use, etc.)
Climate and weather
Co-infection
Microbial adaptation and change

Question 6

What is not a re-emerging disease?

Answer 6

An outbreak or a seasonal variation

Question 7

What does transmission mean?

Answer 7

The mechanism in which a disease is spread i.e. faeco-oral, vector borne, etc.

Question 8

What does incubation period mean?

Answer 8

The time between infection and symptom onset

Question 9

What does carrier mean?

Answer 9

A person or animal without apparent disease who harbours a specific infectious agent and is capable of transmitting it to others

Question 10

What does infectivity mean?

Answer 10

The proportion of persons exposed to a causative agent who become infected by an infectious disease

Question 11

What does reservoir mean?

Answer 11

The habitat in which an infectious agent normally lives, grows and multiplies; can include human reservoirs, animals reservoirs, and environmental reservoirs

Question 12

What does zoonoses mean?

Answer 12

An infectious disease that is transmissible under from animals to humans

Question 13

What does endemic mean?

Answer 13

A disease which is constantly present in a population or geographical area

Question 14

What does epidemic mean?

Answer 14

The occurrence of more cases of disease than expected in a given area or population over a particular period of time

Question 15

What does pandemic mean?

Answer 15

Worldwide epidemic, effecting a large, widespread population simultaneously

Question 16

What causes Lyme disease?

Answer 16

Borrelia burgdorferi

Question 17

What transmits Lyme disease?

Answer 17

Zoonotic reservoir, vector borne transmission - bite of infected black legged tick

Question 18

Who is most at risk of Lyme disease?

Answer 18

White; male; age 5-14 or 50-70

Question 19

When did Lyme disease first emerge?

Answer 19

1960s and continuing to expand

Question 20

When is Lyme disease most common?

Answer 20

May-August

Question 21

What proteins do B. burgdorferi express?

Answer 21

Outer Surface protein A (OspA) - used for attachment to tick mid-gut
OspC

Question 22

Does Lyme disease have a vaccine?

Answer 22

No

Question 23

How can Lyme disease be prevented?

Answer 23

Reduce exposure to tick bites (personal protection, deer and land management, acaricides, education)

Question 24

How can Lyme disease be treated?

Answer 24

Can be treated with doxycycline if caught early

Question 25

What is the causative agent of cholera?

Answer 25

Vibrio cholerae 01 EI Tor

Question 26

How is cholera transmitted?

Answer 26

Contaminated water (and food)

Question 27

What does cholera cause?

Answer 27

Sudden and dramatic ‘rice water’ diarrhoea, due to the effect of the toxin

Question 28

How does cholera cause death?

Answer 28

Death can occur due to excretion of 0.5 to 1l/h of diarrhoea, leading rapidly to tachycardia, hypotension, and vascular collapse due to dehydration

Question 29

How many global pandemics have been caused by cholera?

Answer 29

6

Question 30

How many cases of cholera are there annually worldwide?

Answer 30

1.3-4 million (only 140,000 reported)

Question 31

What is cholera a key indicator of?

Answer 31

Lack of socio-eco development and sanitation

Question 32

What is cholera re-emergence linked to?

Answer 32

Increasing size of vulnerable populations living in unsanitary conditions (displaced persons and infrastructure breakdown)

Question 33

What is poor hygiene not cause by?

Answer 33

Class

Question 34

How can cholera be prevented?

Answer 34

With safe water and sanitation

Question 35

How can cholera be treated?

Answer 35

Cholera vaccine (Vaxchora, Dukoral, Shancho)
Rehydration therapy (Oral or intravenous; salts and mineral replacement )
Antibiotic treatment
Zinc treatment
Surveillance and rapid responses to outbreaks needed

Question 36

What caused the cholera epidemic in Haiti in 2010?

Answer 36

Nepalese government forces arrival in Haiti after the earthquake (Nepal had an outbreak just before the earthquake)

Question 37

How is Shigella spp. transmitted?

Answer 37

Food, water, reduced hygiene

Question 38

What are Shigella spp. the etiological agents of?

Answer 38

Acute invasive intestinal infections clinically manifested by watery or bloody diarrhoea

Question 39

How many people are affected by shigollosis every year?

Answer 39

At least 80 million, predominantly children

Question 40

What 4 Shigella species can cause shigellosis?

Answer 40

S. dysenteriae
S. flexneri
S. boydii
S. sonnei

Question 41

What are all Shigella species?

Answer 41

Multidrug resistant

Question 42

What is a multidrug resistance?

Answer 42

Resistance to >3 classes of antimicrobial agents