Dengue fever is caused by four related viruses transmitted by Aedes mosquitoes, most commonly Aedes aegypti. It presents with fever, pain, rash and bleeding and is diagnosed based on symptoms, platelet count and hematocrit levels. While most cases resolve after a few days of rest, severe dengue can progress to dengue shock syndrome which requires careful monitoring of vital signs and fluid balance in a hospital intensive care setting.

1. Dengue Fever
A World Wide Problem

2. Introduction
Dengue is an arthropod-borne disease caused by
any one of four closely related viruses. Infection
with one serotype of dengue virus provides
immunity to that serotype for life. A person can be
infected as many as four times, once with each
serotype. Dengue viruses are transmitted from
person to person by Aedes mosquitoes (most
often Aedes aegypti) in the domestic environment.
Endemic in Asia for many years, In the past 20
years, dengue transmission and the frequency of
dengue epidemics has increased greatly in most
tropical countries of the American region

3. The Culprit !
 Aedes aegypti,

4. Distribution

5. Symptoms and Signs
 Fever
 Pain
 Anorexia
 Abdominal Pain
 Nausea and Vomiting
 Petechial Rash

6. Exam
 Appearance
 Fever range 102 to 105
 Tourniquet Test
 Liver/Epigastric Tenderness
 Lab Findings: CBC, UA special tests
 XRAY: Pleural Effusions,

7. Clinical Case Definition for
Dengue Hemorrhagic Fever
4 Necessary Criteria:
 Fever, or recent history of acute fever
 Hemorrhagic manifestations
 Low platelet count (100,000/mm3 or less)
 Objective evidence of “leaky capillaries:”
– elevated hematocrit (20% or more over
baseline)
– low albumin
– pleural or other effusions

8. Laboratory Tests
in Dengue Fever
 Clinical laboratory tests
– CBC--WBC, platelets, hematocrit
– Albumin
– Liver function tests
– Urine--check for microscopic hematuria
 Dengue-specific tests
– Virus isolation
– Serology

9. Pleural Effusion
PEI = A/B x 100
B
A
Vaughn DW, Green S, Kalayanarooj S, et al. Dengue in the early febrile CENTERS FOR DISEASE CONTROL
phase: viremia and antibody responses. J Infect Dis 1997; 176:322-30. AND PREVENTION

10. Positive Tourniquet Test

11. Clinical Course
 4 to 7 Days
 Bimodal Course (? Multiple strains)
 Recovery
 When to worry

12. Warning Signs for Dengue
Shock
Alarm Signals:
Alarm Signals:
•• Severe abdominal pain
Severe abdominal pain
•• Prolonged vomiting
Prolonged vomiting
Four Criteria for DHF:
Four Criteria for DHF: •• Abrupt change from fever
Abrupt change from fever
•• Fever
Fever
•• Hemorrhagic manifestations
Hemorrhagic manifestations
•• Excessive capillary permeability
Excessive capillary permeability
••≤ 100,000/mm33platelets
≤ 100,000/mm platelets
to
to
hypothermia
hypothermia
Initial Warning Signals:
Initial Warning Signals:
•• Disappearance of fever ••WhenPatients Develop
Change in levelof
Patients of
Change in levelDevelop
When
Disappearance of fever consciousness (irritability
consciousness (irritability
•• Drop in platelets DSS:
DSS:
Drop in platelets
•• Increase in hematocrit
Increase in hematocrit •• 3 to 6 days after onset of
3 to 6 days after onset of
or
or
somnolence)

13. Treatment
 Careful watch of Vital Signs
 IV Hydration
 Monitoring of CBC (Esp HCT and Platelet
Cnt)
 “Judicious use of platelets”
 “ICU” care

14. Post Dengue Syndrome
 Depression
 Chronic Fatigue
 Neuropathy
 Arthritis/Arthalgia