Microbio Week 12 - Arboviruses (Exam 3)

Question 1

What is the major spreading cycle of arboviruses in the US?

Answer 1

Mosquitos -> birds -> mosquitos -> birds

Question 2

What is arboviral cycle spread to humans considered?

Answer 2

Incidental

Question 3

Why is arboviral cycle spread to humans considered incidental?

Answer 3

Humans are dead end hosts

Question 4

Can humans spread arboviruses back to a mosquito or to other people?

Answer 4

NO!

(this is NOT an urban cycle)

Question 5

What is the urban cycle spread of arboviruses?

Answer 5

Human -> mosquito -> human -> mosquito

Question 6

What 4 things are needed for urban cycle spread of arboviruses?

Answer 6

1. Virus has to infect urban mosquitos
2. High enough virus levels in infected person’s blood to infect mosquito
3. High enough levels of mosquitos to sustain spread of disease
4. High enough density of people susceptible to infection

Question 7

Which arbovirus has the most cases in the US?

Answer 7

West Nile

Question 8

80% of West Nile virus infections are (symptomatic/asymptomatic)

Answer 8

Asymptomatic

Question 9

How many cases of reported symptomatic West Nile virus infections are there every year?

Answer 9

1,000 - 5,000

Question 10

Is West Nile transmitted through urban spread?

Answer 10

NO

Question 11

What is the vector for West Nile virus? When do bites occur?

Answer 11

Mosquito that feeds on birds
Bites occur from dusk-dawn

Question 12

_____% of people infected will get West Nile Fever, which can occur at any age. Many can have lingering problems with ___________

Answer 12

20%; fatigue

Question 13

The older you are, the more likely you will get the ___________ form of West Nile virus

Answer 13

neuroinvasive

Question 14

Of the infected with neuroinvasive West Nile virus, about ______% have meningitis and recover completely

Answer 14

50%

Question 15

The remaining 50% of those infected with neuroinvasive West Nile virus have more severe complications like _____________ and/or __________ __________ _____________.

This is where the deaths more than likely occur. Survivors can have long-term complications like memory loss, muscle weakness, fatigue, and difficulty doing daily activities

Answer 15

encephalitis; acute flaccid paralysis

Question 16

What is the first arbovirus known to have an urban cycle?

Answer 16

Yellow fever

Question 17

Several countries in _________ and __________ ___________ are endemic for Yellow fever

Answer 17

Africa; South America

Question 18

What is a common complication of severe disease in yellow fever?

Answer 18

Jaundice

Question 19

The same mosquito vector spreads which 4 viruses?

Answer 19

Yellow fever
Zika
Dengue
Chikungunya

Question 20

What is the #1 arbovirus worldwide?

Answer 20

Dengue

Question 21

How many serotypes does Dengue have?

Answer 21

4

Question 22

T/F: The first time you are infected with dengue, you usually get the severe form of dengue disease.

Answer 22

FALSE, you DON’T get the severe form unless infected again

Question 23

If you are infected again with a different serotype of Dengue now, you are at risk of which severe diseases?

Answer 23

Dengue hemorrhagic fever
Dengue shock