Dr. Yansouni -- Vector-Borne Diseases

Question 1

Vector for malaria

Answer 1

*Anopheles *mosquitoes

Question 2

Vector for Dengue

Answer 2

Aedes mosquitoes

Question 3

Vector for West Nile virus

Answer 3

*Culex *mosquitoes

Question 4

Vector for lyme disease

Answer 4

*Ixodes *ticks

Question 5

5 anopheles mosquito behaviors that determine whether they will bite or not

Answer 5

• Bite dusk to dawn
• Only females
• Inactive below 18 degrees C
• Altitude sensitive
• Do not like cities

Question 6

Only effective repellents for *anopheles *mosquito (2)

Answer 6

DEET and picaridin

Question 7

Potential geographical limits of the northern and southern hemispheres for year round survival of Aedes mosquito

Answer 7

January and July Isoforms

Question 8

Why is dengue so important to be aware of?

Answer 8

• Emerging **URBAN VECTOR-BORNE **disease (incidence x30 in last 50 yrs)
• 50 million cases/year
• 22,000 deaths/year
• Overtaking malaria as leading cause of fever in returning travellers in several places

Question 9

4 behaviors of Aedes mosquito that determine whether or not they will bite

Answer 9

• Daytime biters
• Only females
• Inactive below 18 degrees C
• Thrive in cities and elsewhere

Question 10

2 only effective repellents against Aedes mosquito

Answer 10

DEET and picaridin

Question 11

Another measure against Aedes mosquito besides spray-on repellents

Answer 11

Permethrin-treated clothes/nets/curtains

Question 12

Seasonal life cycle of ticks (5)

Answer 12

• Spring = eggs
• Summer = larva
• Spring = Nymph
• Fall = adults
• Spring = eggs

Question 13

Seasons that humans are at greatest risk of infection by ticks

Answer 13

Late spring and summer

Question 14

6 body parts to check for ticks

Answer 14

• In and around the hair
• Inside belly button
• Between the legs
• In and around ears
• Under the arms
• Back of the knees

Question 15

Lyme disease risk geographically in Canada (6)

Answer 15

Emerging:

• Manitoba
• Ontario
• Quebec
• New Brunswick
• Nova Scotia

Established in southern BC for years

Question 16

Geographic distribution of lyme disease in USA in 2011

Answer 16

Northeast USA

Question 17

One potential reason for dramatically increased incidence of Canadian lyme disease in 2013

Answer 17

“Warmer” winters = favorable for ticks

Question 18

2 ways to avoid direct contact with ticks

Answer 18

• Avoid wooded and bushy areas with high grass and leaf litter
• Walk in the center of trails

Question 19

Virus responsible for West Nile virus

Answer 19

Flavivirus

Question 20

Define Flavivirus

Answer 20

ssRNA virus that is a member of Japanese ecephalitis serocomplex, which includes St. Louis encephalitis

Question 21

Former geographical confinement of West Nile virus

Answer 21

• Initial description in humans in 1937 Uganda
• Confined to Africa, Middle East and Europe

Question 22

Predominant geographic distribution of WNV in Canada (2002 - 2010)

Answer 22

Predominantly western

Question 23

Year of peak of WNV cases in Canada

Answer 23

2007 (2325 cases)

NOTE: had decreased to 5 in 2010

Question 24

Pyramid of prevention for vector-borne diseases

Answer 24

Question 25

2 less effective repellents against vectors

Answer 25

• Eucalyptus oil
• 2% soybean oil

Question 26

5 ineffective repellents against vectors

Answer 26

• Citronella
• Ultrasonic devices
• Ankle/wristbands
• Geranium oil
• Baby oil

Question 27

Attractive color for mosquitoes

Answer 27

Dark colors

Question 28

Geographic distribution of falciparum malaria (4)

Answer 28

• Most of Africa; predominantly west
• India
• Southeast Asia
• Low but present in Amazonian South America

Question 29

Geographic distribution of vivax malaria (7)

Answer 29

• Central america
• Amazonian South America
• East Africa
• Madagascar
• South Asia
• North Kora
• Southeast Asia