Dengue

Question 1

DENV Transmission (CDC): 5

Answer 1

1. Bite of infected female Aedes mosquitoes
2. Bloodborne transmission (approx. 7 day viremia in humans)
3. Perinatal
   (no cases of congenital transmission)
4. Body fluids (breast milk, vaginal secretions and semen
5. Sexual (rare)

Question 2

How many serotypes does dengue have?

Answer 2

4 (Each serotype provides specific lifetime immunity, and shortterm cross-immunity)

Question 3

Live in/travel to endemic area.
Fever and 2 of the following criteria

Nausea/vomiting
Rash
Aches and pains
Tourniquet test positive
Leukopenia
Any warning sign
Laboratory-confirmed dengue

Molecular techniques/ IgM or IgG seroconversion

Answer 3

Probable Dengue

Question 4

Abdominal pain or tenderness
Persistent vomiting
Clinical fluid accumulation (ascites, pleural effusion)
Mucosal bleeding
Lethargy, restlessness
Postural hypotension
Liver enlargement >2 cm
Progressive increase in hematocrit

Answer 4

Dengue with Warning Signs

Question 5

Shock or respiratory distress due to severe plasma leakage
Severe bleeding (based on evaluation by attending physician)
Severe organ involvement (such as liver or heart)

Answer 5

Severe Dengue

Question 6

3 Phase Clinical Course of Dengue

Answer 6

1. Febrile
2. Critical
3. Convalescent

Question 7

Incubation Period

Answer 7

5-7 days (3-10 days)

Question 8

Signs and symptoms of Dengue Fever (FEBRILE PHASE)

Answer 8

severe headache
retro-orbital pain
bone, joint, and muscle pain
macular or maculopapular rash
minor hemorrhagic manifestations
positive tourniquet test result

Question 9

Warning signs of progression to severe dengue occur in what phase?

Answer 9

Late febrile phase around the time of defervescence

Question 10

Critical Phase or?

Answer 10

Defervescence (typically lasts for 24-48 hours)

Question 11

What phase does substantial plasma leak can develop ascites or pleural effusions, hemoconcentration, and hypoproteinemia occur?

Answer 11

Critical Phase

Question 12

What phase is being described below?
Extravasated intravenous fluids and abdominal and pleural effusions are reabsorbed, hemodynamic status stabilizes (although bradycardia could manifest), and diuresis ensues

Answer 12

Convalescent Phase

Question 13

Considered as laboratory confirmation in dengue patients?

Answer 13

1. Presence of the virus by RT-PCR
2. NS1 (nonstructural protein 1) in a px with compatible clinical and travel history

Question 14

T/F: ELISA IgG is useful for routine diagnostic testing

Answer 14

FALSE. IgG remains detectable for life after an infection
- might produce cross-reactivity with other flaviviruses

Question 15

What is the mainstay of treatment when plasma leakage is recognized?

Answer 15

Intravenous Fluid Therapy

Question 16

T/F: Prophylactic platelet transfusions in dengue patients are beneficial.

Answer 16

False. It can contribute to fluid overload. (administration of corticosteroids has no demonstrated benefit and may be harmful except in cases of autoimmune-related complications.

Question 17

Who is eligible for dengvaxia?

Answer 17

People who test positive for previous DENV infection or who have other lab confirmed evidence of a previous DENV infection

Question 18

Flavivirus virion:

Answer 18

Enveloped, icosahedral, non-segmented, (+)ssRNA

Question 19

Influenza-like syndrome characterized by biphasic fever,myalgia, arthralgia, rash, leukopenia and lymphadenopathy

Answer 19

DENGUE FEVER (BREAKBONE FEVER)

Question 20

Severe, often fatal, febrile disease characterized by capillary permeability, abnormalities of hemostasis and a protein-losing shock syndrome

Answer 20

Dengue Hemorrhagic Fever

Question 21

What are viruses under flaviviridae?

Answer 21

West Nile, Hepatitis C and G, Yellow Fever virus, Japanese Encephalitis, Dengue, and Zila

Question 22

Structural proteins (3)

Answer 22

1. Capsid
2. Envelope
3. Membrane

Question 23

Non-Structural Proteins (7)

Answer 23

NS1, NS2A, NS2B, NS3, NS4A, NS4B, NS5

Question 24

What proteins control the entry of the virus?

Answer 24

E and M proteins

Question 25

Other names of Dengue Fever:

Answer 25

Breakbone fever, Dandy Fever, Seven-Day Fever

Question 26

What are the vectors?

Answer 26

Aedes aegypti and Aedes albopictus

Question 27

Differentiate aegypti from albopictus

Answer 27

Aegypti:
Tropical and subtropical SE, 50-120 eggs, DISCORDANT (takes more than one meal), highly anthropophilic, NERVOUS FEEDER
Albopictus:
Tropical and temperate, 100 eggs, zoophagic, CONCORDANT, AGGRESSIVE FEEDER

Question 28

Rash appearance

Answer 28

3rd and 4th day after onset of fever
Lasts for 1-5 days

Question 29

Rash appearance

Answer 29

3rd or 4th day after onset of fever
Lasts for 1-5 days

Question 30

More info about rash appearance

Answer 30

Appearance: The rash can be blotchy, red, and patchy, often described as “island-like” with patches of normal skin between the redness.

Location: Begins on the chest and spreads to the limbs and face.

Other Features: It may be accompanied by petechiae (small red or purple spots caused by bleeding under the skin). It is often itchy.

Associated Symptoms: High fever, severe headache, retro-orbital pain (pain behind the eyes), muscle and joint pain (“breakbone fever”), and bleeding tendencies.