Dengue Fever

Question 1

What is a single-stranded RNA virus of the genus Flavivirus and has 4 subtypes, making it possibleo be infected four times.

Answer 1

Dengue Fever

Question 2

What is the common name for Dengue Fever

Answer 2

Breakbone fever

Question 3

How is dengue fever transmitted?

Answer 3

Aedes aegypti mosquito; mother to child; blood transfusion/organ donation

Question 4

incubation period for dengue fever

Answer 4

3-14 days; period of illness is 3-7 days.

Question 5

Who qualifies for dengue fever vaccine?

Answer 5

only given to previously infected sero-confirmed individuals.

Question 6

what percentage of dengue fever infections present asymptomatically and the person doesnt realize they are infected

Answer 6

75%

Question 7

what percentage of dengue fever infected patients progress to threatening severe dengue

Answer 7

5%

Question 8

what are the three phases of dengue fever

Answer 8

febrile
critical
convalescent

Question 9

how long does the febrile phase of dengue fever last

Answer 9

2-7 days and can be biphasic

Question 10

signs and sx of dengue fever (febrile phase)

Answer 10

retroorbital pain
muscle, joint, and bone pain
macular/maculopapular rash

(hemo sx- ecchymosis, epistaxis, bleeding gums, hematuria, + TQ test)

Question 11

how long does critical phase last of dengue fever?

Answer 11

begins at cessation of fever, typically lasts 24-48 hrs.

Question 12

Why is the “critical phase” of dengue fever go by that name.

Answer 12

most patients clinically improve and move on to recovery/convalescence phase

however, those with substantial plasma leakage develop severe dengue.

Question 13

signs of severe plasma leakage with dengue fever

Answer 13

pleural effusions or ascites, hypoproteinemia, and hemoconcentration (may appear well despite early shock)

Question 14

What is “dengue shock syndrome”

Answer 14

once hypotension develops, SBP declines rapidly, and irreversible shock occurs.

(may develop hematemesis, bloody stool, melena)

Question 15

What happens during convalescent/recovery phase of dengue fever

Answer 15

rash may desquamate and be pruritic

patient begins to absorb extravasated intravenous fluids, pleural, and abdominal effusions.

Question 16

what are the two hallmarks of severe dengue

Answer 16

infection-induved capillary permeability and disordered/diminished blood clotting.

Question 17

What are the three main reasons Dengue fever can cause leaky capillaries?

Answer 17

secondary to an immune response to the virus
cells become necrotic, and affect both agulation and fibrinolysis
low platelete count degrates the normal clotting response

Question 18

What is a positive dengue TQ test

Answer 18

10 or more petechia below AC fossa after an inflated cuff left on arm for 5 min and rested for 2.

*cuff will be inflated between SBP and DBP.

Question 19

How is dengue diagnosed with lab?

Answer 19

serum obtained early <7 days.
or later in the illnes (greater than 4 days after fever) with ELISA.

Question 20

Treatment for Dengue

Answer 20

hydration. avoid aspirin and NSAIDS. avoid procedures due to bleeding risk.
acetaminophen for fever.

(maintenance of body fluid volume is critical for severe dengue)