Dengue Fever

Question 1

What is the common name for dengue fever?

Answer 1

Breakbone fever

Question 2

Predisposing Factors for Dengue Fever

Answer 2

Urban environments, outdoor activities during spring & summer; mosquito bites

Question 3

Dengue fever is Transmitted Via….

Answer 3

Aedes aegypti mosquito
Mother to child
Blood transfusion/organ donation (rarely).

Question 4

Scientific name for Dengue Fever

Answer 4

Denguevirus (DENV)

Question 5

What is the subtypes of DENV?

Answer 5

DENV-1, DENV-2, DENV-3, DENV-4

Question 6

How is it possible to get infected four times with dengue?

Answer 6

Because there are four subtypes

Question 7

What percentage of Dengue Fever of infections present with symptoms?

Answer 7

25%

Question 8

What are the 3 Phases of Dengue fever?

Answer 8

(a) Febrile phase
(b) Critical phase
(c) Convalescent phase

Question 9

What phase of Dengue?
(1) Typically lasts 2–7 days and can be biphasic.
(2) Signs and symptoms may include severe headache; retroorbital pain; muscle, joint, and bone pain; & transient maculopapular rash.
(3) Minor hemorrhagic manifestations, including petechiae, ecchymosis, purpura, epistaxis, bleeding gums, hematuria, or a positive tourniquet test result.

Answer 9

Febrile phase

Question 10

What phase of Dengue?
(1) This phase of Dengue begins at defervescence and typically lasts 24–48 hours.
(2) Most patients clinically improve during this phase and move on to recovery & convalescence phase.
-(a) Thus, these patients really don’t have a critical phase, per se,
and go from febrile phase to recovery stage.
(3) However, those with substantial plasma leakage develop severe dengue as a result of a marked increase in vascular permeability.
-(a) Plasma leakage is a cardinal feature of Dengue Hemorrhagic Fever.

Answer 10

Critical phase

Question 10

What phase of Dengue?
(1) This phase of Dengue begins at defervescence and typically lasts 24–48 hours.
(2) Most patients clinically improve during this phase and move on to recovery & convalescence phase.
-(a) Thus, these patients really don’t have a critical phase, per se,
and go from febrile phase to recovery stage.
(3) However, those with substantial plasma leakage develop severe dengue as a result of a marked increase in vascular permeability.
-(a) Plasma leakage is a cardinal feature of Dengue Hemorrhagic Fever.

Answer 10

Critical phase

Question 11

Plasma leakage is a cardinal feature of what?

Answer 11

Hemorrhagic Fever.

Question 12

What Dengue issue?
Hypotension develops, systolic blood pressure rapidly declines, and irreversible shock and death may ensue despite resuscitation efforts

Answer 12

Dengue Shock Syndrome

Question 13

What phase of Dengue?
(1) As plasma leakage subsides, patient enters this phase.
(2) Patient begins to reabsorb extravasated intravenous fluids, pleural, & abdominal effusions.
(3) As a patient continues to improve, hemodynamic status stabilizes and diuresis ensues.
(4) The patient’s hematocrit stabilizes or may fall because of the dilutional effect of the reabsorbed fluid, and the white cell count usually starts to rise, followed by a recovery of platelet count.
(5) this phase; rash may desquamate and be pruritic.

Answer 13

Convalescent phase (Recovery stage)

Question 14

Two hallmarks of Severe Dengue are….

Answer 14

infection-induced capillary permeability (leaky capillaries) and disordered/diminished blood clotting

Question 15

What are the 3 main reasons for the two hallmarks of Dengue fever

Answer 15

(a) Leaky capillaries (in the critical phase) occurring secondary to an immune system response to the virus.
(b) Dengue-infected cells become necrotic, and then affect both coagulation (blood clotting) and fibrinolysis (breakdown of clots).
(c) Low platelet count degrades the normal clotting response.

Question 16

What is a relatively accurate way to get a general determination of a patients’ capillary fragility or hemorrhagic tendency?

Answer 16

Tourniquet Test (or capillary fragility test)

Question 17

How is a Tourniquet test done?

Answer 17

1. Obtain baseline BP, rest for 90-120 sec
2. Inflate to in-between SBP/DBP
3. Leave inflated for 5 min then wait for 2 min
4. count petechiae below AC fossa
5. A positive test is 10 or more petechiae per 1 square inch

Question 18

What is a Positive tourniquet test?

Answer 18

10 or more petechiae per 1 square inch

Question 19

Should consider dengue in a patient who was in an endemic area within how many weeks of symptom onset?

Answer 19

two

Question 20

Laboratory confirmation can be made when and from what?

Answer 20

Within 7 days of onset, acute phase serum specimen

Question 21

Later in the illness (≥4 days after fever onset), IgM against dengue virus can be detected with ______

Answer 21

ELISA

Question 22

True/False
Specific antivirals are available for dengue

Answer 22

False

Question 23

Dengue Fever – Treatment

Answer 23

-Ensure patient stays well hydrated
-Fever should be controlled with acetaminophen
-Febrile patients should avoid mosquito bites to reduce risk of further transmission.

Question 24

Dengue Fever Contraindications

Answer 24

-avoid aspirin, aspirin containing drugs, and NSAIDS because of their anticoagulant properties.
-Invasive medical procedures such as NG intubation, intramuscular injections and arterial punctures are avoided due to bleeding risk

Question 25

Severe Dengue Management

Answer 25

(a) Typically requires ICU-level monitoring & blood products
(b) Maintenance of the patient’s body fluid volume is critical for
severe dengue care

Question 26

What is the Prophylaxis available to prevent dengue?

Answer 26

No prophylaxis is available to prevent dengue

Question 27

Dengue Fever – Disposition

Answer 27

MEDEVAC – Med advice on further management while awaiting
MEDEVAC
-Patients presenting with signs/symptoms of even mild dengue should be evacuated to definitive medical care facility as soon as possible.