CS2 - Dengue Part 2

Question 2

How should dengue without warning signs (Group A) be treated in an outpatient setting?

Answer 2

Treatment focuses on supportive care and preventing complications such as dehydration:

Prevent dehydration:

Administer oral rehydration solution to maintain hydration.
Ensure fluids are maintained.
Fever control:

Paracetamol (acetaminophen) should be given every 6 hours to control fever and pain.
Avoid NSAIDs (Nonsteroidal Anti-Inflammatory Drugs), as they can increase the risk of bleeding.
Use a tepid sponge to help reduce fever.

Question 3

What observations should be made for patients with dengue without warning signs?

Answer 3

Close monitoring is essential to identify any worsening condition. Look out for:

Warning signs such as signs of dehydration, bleeding, or organ dysfunction.
No improvement in symptoms after treatment.
Deterioration during defervescence (cooling down of the fever).
No urination for more than 4-6 hours, which could indicate dehydration or renal issues.

Question 4

When should dengue without warning signs (Group A) be hospitalized?

Answer 4

Hospitalization is required if the patient shows any signs of:

Warning signs or worsening condition.
No improvement or deterioration in symptoms.
Failure to urinate for 4-6 hours, suggesting severe dehydration.

Question 5

What is the general approach for dengue recovery in Group A patients?

Answer 5

Recovery involves:

Supportive care with hydration and fever control.
Observation for warning signs and any signs of deterioration.
Ensuring the patient remains well-hydrated and monitoring vital signs regularly.

Question 6

How do NSAIDs work at the biochemical level?

Answer 6

NSAIDs primarily inhibit the enzymes cyclooxygenase (COX), leading to the disruption of the arachidonic acid pathway. This results in the decreased production of prostaglandins (PGs) and leukotrienes (LTs).

Cyclooxygenase (COX): COX is responsible for converting arachidonic acid to prostaglandins (PGs) like PGI2 (prostacyclin), TXA2 (thromboxane A2), and PGE2, which play crucial roles in vasodilation, platelet aggregation, and inflammation.
Lipoxygenase: Also acts on arachidonic acid to produce leukotrienes (LTs) such as LTB4, LTC4, LTD4, and LTE4, which mediate chemotaxis, bronchospasm, and vascular permeability.

Question 7

What are the effects of prostaglandins (PGs) in the body?

Answer 7

Prostaglandins have multiple roles depending on the type:

PGI2 (prostacyclin): Causes vasodilation and decreases platelet aggregation.
TXA2 (thromboxane A2): Induces vasoconstriction and increases platelet aggregation.
PGE2: Involved in vascular permeability and fever.

Question 8

How do leukotrienes (LTs) affect the body?

Answer 8

Leukotrienes are involved in inflammation and immune response:

LTB4: Plays a role in chemotaxis, attracting immune cells to sites of infection or injury.
LTC4, LTD4, LTE4: Cause bronchospasm and increase vascular permeability, leading to inflammation and tissue swelling.

Question 9

What is the role of NSAIDs in inflammation and pain?

Answer 9

NSAIDs reduce inflammation and pain by inhibiting the cyclooxygenase (COX) enzymes, thereby:

Decreasing prostaglandin (PG) production.
Reducing vasodilation, vascular permeability, and platelet aggregation.
Limiting chemotaxis and bronchospasm in response to inflammatory stimuli.

Question 10

Why are NSAIDs avoided in some conditions like dengue fever?

Answer 10

NSAIDs are avoided in certain viral infections like dengue fever due to their potential to:

Increase the risk of bleeding by inhibiting platelet aggregation.
Cause gastric irritation or damage, leading to bleeding.
Aggravate renal issues in some cases.

Question 11

What are the main types of cyclooxygenase (COX) enzymes?

Answer 11

There are two main types of COX enzymes:

COX-1: Constitutive enzyme involved in normal physiological processes like gastric protection, vascular homeostasis, platelet aggregation, renal function, and reproductive functions.
COX-2: Inducible enzyme primarily expressed at the site of inflammation, contributing to pain, fever, and swelling during inflammatory responses.

Question 12

What are the functions of COX-1?

Answer 12

COX-1 is involved in:

Gastric protection: Helps maintain the integrity of the stomach lining.
Vascular homeostasis: Regulates blood vessel tone.
Platelet aggregation: Plays a role in blood clotting.
Renal function: Helps in kidney function and fluid balance.
Reproductive functions: Involved in processes like labor and pregnancy.

Question 13

Where is COX-2 primarily expressed, and what is its role?

Answer 13

COX-2 is primarily expressed at the site of inflammation and is involved in:

Pain and swelling during inflammatory responses.
Fever production during immune activation.
Induction of prostaglandins that mediate inflammation and tissue damage.

Question 14

How do NSAIDs affect COX-1 and COX-2?

Answer 14

NSAIDs inhibit both COX-1 and COX-2 enzymes, though some NSAIDs are selective for COX-2 inhibition:

Non-selective NSAIDs inhibit both COX-1 and COX-2, reducing inflammation, pain, and fever but also potentially causing gastric irritation, ulceration, and bleeding due to the inhibition of COX-1.
COX-2-selective NSAIDs mainly inhibit COX-2, reducing inflammation and pain with less effect on COX-1, thus sparing some of the protective functions like gastric protection.

Question 15

Why is COX-1 inhibition a concern in certain treatments?

Answer 15

nhibiting COX-1 can lead to several adverse effects, such as:

Gastric irritation or ulceration because COX-1 is involved in maintaining the stomach lining.
Bleeding risks, as COX-1 plays a role in platelet aggregation.
Potential renal dysfunction as COX-1 helps in regulating kidney function.

Question 16

What role does COX-1 play in vascular homeostasis?

Answer 16

COX-1 helps in the regulation of vascular homeostasis, meaning it contributes to the balance of blood vessel tone, supporting appropriate blood flow and blood pressure regulation.

Question 17

What is the treatment approach for Dengue with warning signs (Group B)?

Answer 17

The treatment approach for Dengue with warning signs (Group B) involves inpatient care with:

Fluid monitoring: Track intake and output of fluids.
Laboratory tests: Regular Full blood count (FBC) to monitor blood cell levels.
Vital signs monitoring: Measure vital signs every 4 hours.
Adequate fluid intake: Ensure the patient maintains proper fluid intake.
IV isotonic crystalloid solution: Administer if fluid intake is inadequate.

Question 18

What is the role of fluid monitoring in the treatment of Dengue with warning signs?

Answer 18

Fluid monitoring is crucial for managing fluid balance, ensuring the patient remains adequately hydrated while avoiding fluid overload. Regular monitoring of intake/output helps assess whether more fluids are needed or if adjustments should be made.

Question 19

How are IV fluids used in treating Dengue with warning signs?

Answer 19

If fluid intake is inadequate, IV isotonic crystalloid solutions are administered. Fluid reassessment occurs every 2-4 hours, adjusting the fluid intake based on:

Improvement: Continue IV fluids for another 2-4 hours.
No improvement: Increase IV fluids for 1-2 hours.

Question 20

What action should be taken if the patient’s condition does not improve after fluid reassessment?

Answer 20

If the patient shows no improvement after fluid reassessment, the IV fluids should be increased for 1-2 hours. Regular monitoring should continue to adjust the treatment as needed.

Question 21

What should be done if compensated or hypotensive shock develops in Dengue with warning signs?

Answer 21

f the patient develops compensated or hypotensive shock, they should be treated according to Group C guidelines, which involve more intensive management, including higher priority fluid resuscitation and other supportive measures.

Question 22

What is the proportion of extracellular fluid in the body?

Answer 22

Extracellular fluid makes up about 1/3 of the body’s total fluid volume.

Question 23

What are the components of extracellular fluid?

Answer 23

Extracellular fluid consists of:

25% plasma (the fluid component of blood)
75% interstitial fluid (ISF) (fluid surrounding cells)

Question 24

What is plasma in the context of extracellular fluid?

Answer 24

Plasma is the fluid portion of blood and accounts for 25% of extracellular fluid. It transports cells, nutrients, waste products, and proteins throughout the body.

Question 25

What is interstitial fluid (ISF) in the context of extracellular fluid?

Answer 25

interstitial fluid (ISF) is the fluid that surrounds the cells, making up 75% of the extracellular fluid. It acts as the medium for nutrient and waste exchange between blood and cells

Question 26

How is extracellular fluid controlled within the body?

Answer 26

The control of extracellular fluid involves maintaining balance through fluid movement between plasma (inside blood vessels) and interstitial fluid (in the space between cells). This balance is regulated by factors such as capillary pressure, osmotic gradients, and cell membrane permeability.

Question 27

What is the relationship between hydrostatic and osmotic pressures at the arterial end of a capillary?

Answer 27

At the arterial end of a capillary, hydrostatic pressure is greater than osmotic pressure, leading to a net flow of fluid out of the capillary into the interstitial space.

Question 28

What is the relationship between hydrostatic and osmotic pressures at the venous end of a capillary?

Answer 28

At the venous end of a capillary, hydrostatic pressure is less than osmotic pressure, leading to a net flow of fluid into the capillary from the interstitial space.

Question 29

What is the direction of fluid flow at the arterial end of a capillary?

Answer 29

At the arterial end, the net flow is out, meaning fluid is pushed from the capillary into the surrounding tissue due to high hydrostatic pressure.

Question 30

What is the direction of fluid flow at the venous end of a capillary?

Answer 30

At the venous end, the net flow is in, meaning fluid is drawn back into the capillary from the interstitial space due to higher osmotic pressure.

Question 31

What causes the net flow out of fluid at the arterial end of the capillary?

Answer 31

The net flow out at the arterial end is caused by high hydrostatic pressure in the capillary, which forces fluid into the surrounding tissues, despite the osmotic pressure trying to pull fluid back.

Question 32

: What causes the net flow in of fluid at the venous end of the capillary?

Answer 32

The net flow in at the venous end occurs because osmotic pressure in the capillary exceeds the hydrostatic pressure, drawing fluid back into the capillary.

Question 33

How does extracellular fluid play a role in fluid balance during dengue?

Answer 33

In dengue, increased capillary permeability leads to fluid leakage from the plasma into the interstitial space, causing fluid loss and contributing to shock if not managed properly.

Question 34

hat happens to extracellular fluid distribution in severe dengue?

Answer 34

In severe dengue, plasma leakage into the interstitial space causes a reduction in circulating plasma volume, leading to hypovolemic shock and the need for careful fluid management.

Question 35

Why is fluid management critical in dengue treatment?

Answer 35

Fluid management is essential in dengue because plasma leakage can lead to dehydration, shock, and organ dysfunction, requiring precise fluid resuscitation and monitoring to restore balance.

Question 36

What occurs at the arterial end of the capillaries in dengue?

Answer 36

At the arterial end of the capillaries in dengue, hydrostatic pressure is higher than osmotic pressure, leading to net fluid outflow into the interstitial space.

Question 37

What happens at the venous end of the capillaries in dengue?

Answer 37

At the venous end of the capillaries in dengue, osmotic pressure exceeds hydrostatic pressure, leading to a reduced fluid return into the capillaries (less fluid is reabsorbed).

Question 38

How does capillary exchange change in dengue compared to normal conditions?

Answer 38

n dengue, increased capillary permeability causes fluid leakage into the interstitial space, reducing the return of fluid at the venous end and exacerbating fluid imbalance and hypovolemic shock.

Question 39

How does hydrostatic pressure affect capillary exchange in dengue?

Answer 39

In dengue, increased hydrostatic pressure at the arterial end pushes more fluid out of the capillaries, contributing to plasma leakage into the interstitial space, worsening fluid loss.

Question 40

What is the result of impaired fluid reabsorption at the venous end in dengue?

Answer 40

The impaired fluid reabsorption at the venous end due to reduced hydrostatic pressure and increased permeability worsens plasma leakage, leading to hypovolemia and shock.

Question 41

How is the fluid flow affected in severe dengue?

Answer 41

In severe dengue, the net fluid flow is increased out of capillaries at the arterial end, and the fluid return at the venous end is greatly reduced, causing plasma leakage and contributing to circulatory failure.

Question 42

What is the primary composition of a crystalloid solution?

Answer 42

A crystalloid solution primarily contains electrolytes dissolved in water, such as saline or Ringer's solution.

Question 43

What is the key difference between crystalloids and colloids?

Answer 43

Crystalloids contain electrolytes in water, while colloids contain proteins or polysaccharides (large molecules) that help maintain osmotic pressure.

Question 44

How do crystalloids affect fluid balance in dengue treatment?

Answer 44

Crystalloids are used to replace lost fluids and maintain hydration, and they can pass through capillary membranes into the interstitial space to balance the fluid loss in dengue.

Question 45

What is the role of colloid solutions in managing fluid loss in dengue?

Answer 45

Colloid solutions, which contain proteins like albumin, help expand plasma volume by retaining water in the blood vessels and are used to restore plasma during severe dengue or hypovolemic shock.

Question 46

How do crystalloids differ from colloids in terms of fluid retention?

Answer 46

Crystalloids tend to diffuse easily across capillary membranes, leading to less retention in the vascular space, while colloids contain larger molecules that stay in the vascular compartment, promoting greater fluid retention within the blood vessels.

Question 47

Why are crystalloids preferred for initial fluid management in dengue?

Answer 47

Crystalloids are preferred for initial fluid replacement because they are easily available, inexpensive, and effective in maintaining hydration in the early stages of dengue.

Question 48

What is a key characteristic of compensated shock regarding blood pressure (BP)?

Answer 48

n compensated shock, the blood pressure remains normal despite the body's compensatory mechanisms.

Question 49

What is commonly observed in terms of heart rate during compensated shock?

Answer 49

Tachycardia (increased heart rate) is a common sign, as the body attempts to maintain perfusion to vital organs.

Question 50

How does the respiratory rate change during compensated shock?

Answer 50

The respiratory rate increases as the body tries to compensate for oxygen delivery and maintain acid-base balance.

Question 51

What causes cold, clammy skin in compensated shock?

Answer 51

Peripheral vasoconstriction occurs to preserve blood flow to vital organs, causing the skin to become cold and clammy.

Question 52

What does a weak peripheral pulse indicate in compensated shock?

Answer 52

A weak peripheral pulse suggests reduced blood flow to the extremities due to compensatory vasoconstriction.

Question 53

What is the significance of delayed capillary refill in compensated shock?

Answer 53

Delayed capillary refill indicates poor peripheral circulation and inadequate perfusion, often a sign of compensatory shock.

Question 54

How is urine output affected in compensated shock?

Answer 54

Reduced urine output occurs as the kidneys receive less blood flow due to compensatory mechanisms aiming to preserve vital organ perfusion.

Question 55

What is the key focus of treatment for dengue with compensated shock (Group C)?

Answer 55

The focus is on fluid monitoring and vital signs monitoring to manage shock and maintain hemodynamic stability.

Question 56

How frequently should vital signs be monitored in dengue with compensated shock (Group C)?

Answer 56

Vital signs should be monitored every 1-2 hours to assess and manage shock progression.

Question 57

What is the initial fluid management approach for improved clinical status in dengue with compensated shock?

Answer 57

Fluid reduction to 5-7 ml/kg/hour over 2-4 hours is recommended for further improvement.

Question 58

What is the next step in fluid management for dengue with compensated shock after further improvement?

Answer 58

Fluid intake should be further reduced to 3-5 ml/kg/hour over 2-4 hours, with adequate intake/output.

Question 59

What happens when the clinical status shows poor hemodynamic status in dengue with compensated shock?

Answer 59

Reassess hematocrit (HCT), and if HCT is increasing, administer isotonic crystalloids at 10-20 ml/kg/hour for 1 hour, then reassess.

Question 60

What should be done if the hematocrit (HCT) shows improvement in dengue with compensated shock?

Answer 60

If HCT improves, continue fluids at a rate of 7-10 ml/kg/hour for 2 hours. Q

Question 61

What is the recommended action if the hematocrit (HCT) shows decreasing levels in dengue with compensated shock?

Answer 61

Blood transfusion should be considered if HCT decreases, indicating significant blood loss.

Question 62

What is the cause of hypotensive (hypovolemic) shock?

Answer 62

The cause is loss of intravascular volume, often due to dehydration, blood loss, or fluid shifts.

Question 63

What are the effects of hypotensive (hypovolemic) shock?

Answer 63

The effects include reduced cardiac output, hypotension, reduced organ perfusion, organ dysfunction, and potentially multiorgan failure.

Question 64

What is the result of reduced cardiac output in hypotensive (hypovolemic) shock?

Answer 64

Reduced cardiac output leads to insufficient blood flow to organs and tissues, resulting in hypotension and impaired organ perfusion.

Question 65

How does hypotensive (hypovolemic) shock affect organ function?

Answer 65

Inadequate blood flow leads to organ dysfunction, as vital organs do not receive enough oxygen and nutrients.

Question 66

What severe consequence can occur in hypotensive (hypovolemic) shock if left untreated?

Answer 66

Multiorgan failure can occur due to prolonged reduced organ perfusion, leading to irreversible damage to organs.

Question 67

What is the first step in treating dengue with hypotensive shock (Group C)?

Answer 67

The first step is to administer an isotonic crystalloid or colloid bolus of 20 ml/kg over 15 minutes.

Question 68

What should be monitored in patients with dengue and hypotensive shock (Group C)?

Answer 68

Fluid intake/output, lab tests (including organ function tests and hematocrit (HCT)), and vital signs should be monitored, with vital signs checked hourly.

Question 69

After the initial bolus of fluid in hypotensive shock, what is the next step if the patient's condition improves?

Answer 69

If the patient's condition improves, continue with isotonic crystalloids/colloid infusion at a rate of 10 ml/kg/hour for 1 hour.

Question 70

What should be done if the patient's haemodynamic status remains poor in hypotensive shock?

Answer 70

If the status remains poor, reassess hematocrit (HCT) and administer isotonic crystalloids at 10-20 ml/kg/hour for 1 hour.

Question 71

How should fluid administration be adjusted in hypotensive shock based on clinical improvement?

Answer 71

If improvement occurs, reduce fluid administration: 5-7 ml/kg/hour for 1-2 hours. 3-5 ml/kg/hour for 2-4 hours. 2-3 ml/kg/hour for 2-4 hours. Finally, fluids can be discontinued after reassessment.

Question 72

What is the next step if the hematocrit (HCT) is decreasing during treatment of hypotensive shock in dengue?

Answer 72

If HCT is decreasing, a blood transfusion is indicated.

Question 73

What should be monitored in patients with dengue and warning signs (Group B)?

Answer 73

Fluid intake/output, full blood count (FBC), and vital signs (checked every 4 hours) should be monitored.

Question 74

How should fluid intake be managed for patients with dengue and warning signs?

Answer 74

Ensure adequate fluid intake and monitor for vital signs of shock and further warning signs. If fluid intake is inadequate, hematocrit (HCT) should be monitored and IV isotonic crystalloid solution should be administered.

Question 75

What is the initial rate for IV fluid administration for dengue with warning signs?

Answer 75

The initial IV fluid rate is 5-7 mL/kg/hour for the first 1-2 hours.

Question 76

How should fluid administration be adjusted after the first 1-2 hours in dengue with warning signs?

Answer 76

fter 1-2 hours, if needed, reduce the rate to 3-5 mL/kg/hour for 2-4 hours.

Question 76

What should be done if the patient's clinical status does not improve after initial treatment?

Answer 76

If the patient's clinical status does not improve, increase IV fluid rate to 5-10 mL/kg/hour for 1-2 hours and continue to monitor clinical status and HCT.

Question 77

When should IV fluids be continued for dengue with warning signs (Group B)?

Answer 77

If the patient's condition improves, continue IV fluids at 3-5 mL/kg/hour for another 2-4 hours while continuing to monitor clinical status and HCT.

Question 78

What should be monitored for patients with dengue and compensated shock (Group C)?

Answer 78

Fluid intake/output, organ function tests, hematocrit (HCT), and vital signs (monitored every 1-2 hours).

Question 79

How should fluids be managed for patients with dengue and compensated shock?

Answer 79

Start with fluid monitoring and assess clinical status. If the patient's condition improves, reduce the fluid rate to 5-7 mL/kg/hour for 2-4 hours.

Question 80

What should be done if the patient shows further improvement in compensated shock (Group C)?

Answer 80

If further improvement occurs, reduce fluids to 3-5 mL/kg/hour for 2-4 hours and continue monitoring for adequate intake/output. If intake is adequate, fluids should be discontinued.

Question 81

What should be done for poor hemodynamic status in dengue with compensated shock?

Answer 81

For poor hemodynamic status, reassess HCT and consider administering isotonic crystalloids at 10-20 mL/kg/hour for 1 hour. Reassess after 1 hour and adjust as necessary.

Question 82

How should fluid administration be adjusted if HCT is increasing during compensated shock treatment?

Answer 82

If HCT is increasing, continue isotonic crystalloids at 7-10 mL/kg/hour for the next 2 hours.

Question 83

What is the next step if HCT is decreasing during treatment of dengue with compensated shock?

Answer 83

If HCT is decreasing, consider administering a blood transfusion.

Question 84

What type of RNA does the Flaviviridae family have?

Answer 84

The Flaviviridae family has +ssRNA (~11kb in size).

Question 85

What are the structural proteins of the Flaviviridae family?

Answer 85

The structural proteins include Capsid (C), Membrane (M), and Envelope (E).

Question 86

What are the non-structural proteins of the Flaviviridae family?

Answer 86

The non-structural proteins are NS1, NS2A-B, NS3, NS4A-B, and NS5.

Question 87

What is the genome homology percentage within the Flaviviridae family?

Answer 87

The genome homology within the Flaviviridae family is about 65%.

Question 88

What type of virus is Dengvaxia®?

Answer 88

Dengvaxia® is an attenuated virus vaccine for dengue.

Question 89

What is the vaccination schedule for Dengvaxia®?

Answer 89

The Dengvaxia® vaccination schedule involves 3 doses, given 6 months apart.

Question 90

How long does Dengvaxia® provide longevity of protection?

Answer 90

Dengvaxia® provides protection for around 6 years post the final vaccination.

Question 91

What are the FDA conditions for use of Dengvaxia®?

Answer 91

The FDA conditions for use are: Age 9-16 Reside in endemic area Confirmed seropositive

Question 92

What is the issue with Dengvaxia® in seronegative individuals?

Answer 92

There is a risk of severe dengue in seronegative individuals.

Question 93

Is Dengvaxia® available for travelers?

Answer 93

Dengvaxia® is not available to travelers.

Question 94

What type of virus is Qdenga®?

Answer 94

Qdenga® is an attenuated virus vaccine for dengue.

Question 95

What is the vaccination schedule for Qdenga®?

Answer 95

The Qdenga® vaccination schedule involves 2 doses, given 3 months apart.

Question 96

How long does Qdenga® provide longevity of protection?

Answer 96

Qdenga® provides protection for approximately 4.5 years post the final vaccination.

Question 97

What are the MHRA conditions for use of Qdenga® in 2023?

Answer 97

The MHRA conditions for use are: Age 4+ Confirmed seropositive Planning to travel to a dengue hotspot

Question 98

What is the issue with Qdenga® in seronegative individuals?

Answer 98

There is a risk of severe dengue in seronegative individuals.

Question 99

Why was Qdenga® withdrawn by the FDA?

Answer 99

The FDA withdrew Qdenga® due to safety concerns.

Question 100

What is the sequence homology of the E protein in the context of dengue vaccines?

Answer 100

The E protein in dengue vaccines has 50% sequence homology across the different serotypes.

Question 101

What is Antibody Dependent Enhancement (ADE) in dengue?

Answer 101

Antibody Dependent Enhancement (ADE) occurs when previous infection or a poor vaccination response leads to enhanced infection. It is a main driver of severe dengue progression.

Question 102

: How does ADE contribute to severe dengue progression?

Answer 102

ADE leads to more severe disease progression by facilitating the entry of the virus into immune cells, exacerbating the immune response.

Question 103

What is D1ME100 in the context of dengue vaccines?

Answer 103

D1ME100 is a DNA vaccine specifically designed to target DENV-1 (Dengue virus serotype 1).

Question 104

What type of vaccine is D1ME100 for dengue?

Answer 104

D1ME100 is a DNA vaccine, which contains genetic material to stimulate an immune response against DENV-1.

Question 105

What is the target of D1ME100 in terms of dengue virus?

Answer 105

The target of D1ME100 is Dengue virus serotype 1 (DENV-1).

Question 106

What type of vaccine is V180 (DEN-80E)?

Answer 106

V180 (DEN-80E) is a subunit vaccine designed for dengue.

Question 107

xWhat component of the dengue virus does V180 target?

Answer 107

V180 targets a truncated form of the E protein of the dengue virus, which is 80% of the full-length E protein.

Question 108

What is unique about the E protein in V180 (DEN-80E)?

Answer 108

The E protein in V180 is truncated, lacking the membrane anchor, making it purifiable for vaccine production.

Question 109

Can V180 be used for all serotypes of the dengue virus?

Answer 109

Yes, V180 can be made for each dengue serotype and has the potential to be tetravalent.

Question 110

What were the findings from the early Phase 1 clinical trials of V180?

Answer 110

In the early Phase 1 clinical trials, V180 (DEN-80E) was administered in 3 injections over 6 months, with 10 μg and 50 μg doses being well tolerated.

Question 111

What type of vaccine is TDEV-PIV?

Answer 111

TDEV-PIV is an inactivated dengue vaccine.

Question 112

How many serotypes of dengue does TDEV-PIV protect against?

Answer 112

TDEV-PIV is tetravalent, meaning it provides protection against all four dengue serotypes.

Question 113

Which dengue virus proteins does TDEV-PIV target?

Answer 113

TDEV-PIV generates antibodies against the E (envelope), M (membrane), C (capsid), and NS1 proteins of the dengue virus.

Question 114

What were the results of the Phase 1 trials of TDEV-PIV?

Answer 114

TDEV-PIV showed good immunogenicity and was well tolerated in Phase 1 trials.

Question 115

What is the main treatment approach for dengue?

Answer 115

The treatment of dengue largely depends on fluid management.

Question 116

Why are NSAIDs contraindicated in dengue treatment?

Answer 116

NSAIDs are contraindicated due to their bleeding risk, which is heightened in dengue.

Question 117

Why must dengue vaccines protect against all 4 serotypes?

Answer 117

Dengue vaccines must protect against all 4 serotypes because protection against only a single serotype increases the risk of severe dengue.

Question 118

How can Tfh cell activation influence dengue vaccine efficacy?

Answer 118

Tfh cell activation may increase vaccine efficacy, potentially enhancing immune response to the dengue virus.

Question 119

What are the conditions for the approval of Dengvaxia®?

Answer 119

Dengvaxia® is currently approved for ages 9-16 in endemic areas.

Question 120

What types of dengue vaccines are currently in Phase 1 trials?

Answer 120

DNA, inactivated virus, and subunit vaccines are currently in Phase 1 trials for dengue.

Question 121

How is dengue fever managed? What are the pharmacological contraindications?

Answer 121

Dengue fever is primarily managed with fluid replacement (oral or intravenous) to prevent dehydration. Paracetamol is used for fever control, while NSAIDs are contraindicated due to their risk of bleeding. Steroids and antibiotics are not routinely used unless there is a secondary infection.

Question 122

What is compensated shock and how is it treated in dengue?

Answer 122

Compensated shock in dengue occurs when there is reduced circulatory volume but the body compensates to maintain normal blood pressure. Signs include tachycardia, peripheral vasoconstriction, and reduced urine output. Treatment: Fluid monitoring and IV isotonic crystalloids (5-7 mL/kg/hour for 2-4 hours). Adjust fluids based on clinical status and hematocrit (HCT).

Question 123

What is hypovolemic shock and how is it treated in dengue?

Answer 123

Hypovolemic shock is caused by severe fluid loss, leading to reduced cardiac output, hypotension, and organ dysfunction. Treatment: IV isotonic crystalloids or colloids bolus (20 mL/kg in 15 minutes). Monitor HCT, clinical status, and vital signs. If HCT increases, continue isotonic fluids (10-20 mL/kg/hour); if HCT decreases, consider blood transfusion.

Question 124

What are the key strategies in the development of dengue vaccines?

Answer 124

Key dengue vaccine strategies include: Attenuated virus vaccines (e.g., Dengvaxia®) targeting all four serotypes. DNA vaccines that induce immune responses to the virus. Inactivated virus vaccines, which stimulate immunity without causing disease. Subunit vaccines targeting specific viral proteins, such as the E protein. Each vaccine has advantages and challenges, such as ensuring efficacy against all four serotypes and minimizing the risk of antibody-dependent enhancement (ADE), where a prior infection or vaccination with a single serotype may worsen future disease.

Question 125

What are the challenges in developing a dengue vaccine?

Answer 125

Ensuring protection against all four serotypes of the virus. Preventing antibody-dependent enhancement (ADE), where a vaccine or previous infection can make future infections more severe. Balancing efficacy and safety, especially considering variations in the population's prior exposure to the virus

Question 126

Why should vaccines be used to prevent dengue?

Answer 126

Dengue causes significant morbidity and mortality, especially in tropical and subtropical regions. Vaccination can drastically reduce infection rates and severity of the disease, alleviating the public health burden. Vaccines can also reduce the economic impact of dengue outbreaks and lower healthcare costs by preventing severe cases and hospitalizations.