Flaviviridae

Question 1

What is the structure of flaviviridae?

Answer 1

positive sense strand DNA

enveloped

Question 2

is there a vaccine for dengue virus?

Answer 2

yes

Question 3

What is dengue hemorrhagic fever also known as?

Answer 3

Break bone fever

Question 4

Where is dengue fever mostly?

Answer 4

from tropical areas

rural and urban tropical areas 400-500 million infected per year

Question 5

What vector transmit dengue fever?

Answer 5

Aedes aegypti

Aedes albopictus.

Question 6

What is the pathogenesis of dengue fever?

Answer 6

Inoculation by mosquito

Infection of cells:
DC’s of skin and fibroblasts

Dissemination to regional lymph nodes
Monocytes, WBC’s

Dissemination through peripheral blood throughout the body
Monocytes, WBC’s and other cells

Question 7

What is the disease progression of dengue fever?

Answer 7

Asymptomatic
Dengue Fever (febrile illness)  (lasts 2-7 days)
sever dengue (dengue hemorhrhagic fever, dengue shock syndrome)

Question 8

What are the symptoms of dengue fever?

Answer 8

Fever (can be biphasic)
Myalgia and deep bone pain (break bone fever)
Rash (usually appears on day 3-4 and lasts 1-5 days)
Severe headache and “Pain behind the eyes”
Enlarged lymph nodes
Vomiting, and diarrhea

Question 9

What are symptoms of severe dengue?

Answer 9

Complication due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding 
90% younger than 15 years
Hemorrhagic symptoms
Bleeding, GI, skin, mucous membranes
Dengue shock syndrome

Question 10

When is immunity to dengue achieved?

Answer 10

when infected with the same strain will be immune to that strain

Question 11

What can make severe dengue worse?

Answer 11

Some evidence that infection with another strain can drive severe dengue manifestation

Question 12

How is dengue diagnosed?

Answer 12

Isolation of virus
Serological tests
Nucleic acid tests (RT-PCR) (serum, plasma, CSF)