Dengue is a febrile illness caused by a flavivirus transmitted by Aedes aegypti or Aedes albopictus mosquitoes while taking a blood meal. There are four dengue virus (DENV) types (DENV-1, DENV-2, DENV-3, and DENV-4), all of which are capable of inducing severe disease (dengue hemorrhagic fever [DHF]/dengue shock syndrome [DSS]). Dengue is endemic in more than 125 countries in tropical and subtropical regions and causes an estimated 390 million infections annually worldwide, of which 96 million are clinically apparent In dengue-endemic regions, suspected, probable, and confirmed cases of dengue infection should be reported to the relevant authorities as soon as possible, so that appropriate measures can be instituted to prevent dengue transmission

1. Duration: 40 min Electives Infectious disease St Luke
Dengue
Ivan De Paz, MD

2. Records of dengue-like illness date back more than 200 years and the viral etiology of dengue virus (DENV) was established in
the 1940s. Given estimates of 390 million infections worldwide each year and over 2.5 billion individuals at risk for infection, the
DENVs remain important arthropod-borne viruses from a medical and public health perspective.
Find out what dengue is.
Learn to recognize and manage a dengue virus infection
Dengue, Dengue Fever, Severe dengue
Learning objectives
Keywords
Lesson overview

3. DENGUE VIRUS
Member of the family FLAVIVIRIDAE
The DENV complex comprises at least four
antigenically related but distinct viruses, designated
DENV types 1 through 4
All DENVs are mosquito-borne human pathogens
that exclusively cause acute infection

4. From: Dengue: A Growing Problem With New Interventions
Pediatrics. 2022;149(6). doi:10.1542/peds.2021-055522
Map showing the risk of dengue by country as of 2020. “Frequent or Continuous” risk indicates that there are either frequent outbreaks or
ongoing transmission. “Sporadic or Uncertain” indicates that risk is either variable and unpredictable or that data from that country are not
available. For updated information, visit https://www.cdc.gov/dengue/areaswithrisk/around-the-world.html.
Figure Legend:

5. What dengue is?
Breakbone fever
Most important arthropod transmitted human viral disease (Aedes)
Dengue is a systemic and dynamic infectious disease

6. Spectrum of disease
After an incubation period of 4 to 10 days, infection by any of the
four DENV serotypes can be asymptomatic or symptomatic.
The disease can occur as dengue fever (with or without warning
signs) or severe dengue, according to the current clinical
classification

7. DENGUE SEROTYPES
DENV-1
DENV-2
DENV-3
DENV-4
Each serotype provides specific lifelong immunity

8. DENGUE INFECTION

9. DENGUE INFECTION
Primary infection is characterized by detectable levels of IgM antibodies by
days five or six after onset of fever; levels peak at about 14 to 15 days and
can remain high up to 30 to 60 days later, and then decline gradually over
time.
IgG antibodies against dengue are elevated after the eighth or ninth day of
the onset of fever and are detectable for life.
In secondary infection, very high levels of IgG antibodies against dengue are
observed from the second or third day of fever. IgM antibody levels can be
less elevated in secondary infections and are sometimes not detectable

10. DENGUE INFECTION

11. DENGUE
HEMORRHAGIC FEVER

12. PATHOPHYSIOLOGY
Capillary leak syndrome — Plasma leakage, due to an increase in capillary
permeability, is a cardinal feature of dengue hemorrhagic fever (DHF) but
is absent in dengue fever (DF)
Blood and bone marrow — Leukopenia, thrombocytopenia, and a
hemorrhagic diathesis are the typical hematologic findings in DENV
infections

13. PATHOPHYSIOLOGY
Liver — Elevations of serum aminotransferases that are usually mild are
common in DENV infections
Central nervous system — Rare cases of encephalopathy have been
attributed to DENV infections. True encephalitis has been reported, with
detection of DENV in brain tissue

14. DENGUE INFECTION
FEVER WITH RASH

15. DENGUE INFECTION
FEVER WITH JAUNDICE

16. DENGUE INFECTION
FEVER WITH UPPER RESPIRATORY TRACT
SYMPTOMS
https://www.cdc.gov/dengue/healthcare-providers/dengue-or-covid.html
Respiratory symptoms, such as cough, sore throat, and rhinorrhea, can
occur.
Difficult to differentiate from COVID-19

17. DENGUE INFECTION
FEVER WITH
RHABDOMYOLISIS
That patient that presents with muscle cramps, abnormal color of urine,
increased total CPK

18. DENGUE CASE
DEFINITION

19. DENGUE CASE
DEFINITION

20. ARBOVIRAL DISEASES

21. ARBOVIRAL DISEASES

22. FEBRILE PHASE
It lasts 2-7 days
High fever
Accompanied by facial flushing, skin erythema, generalized body ache,
myalgia, arthralgia, headache and retroorbital pain
GI symptoms are common
The liver may also be enlarged and tender
In the early febrile phase it can be difficult to clinically differentiate
dengue from other acute febrile diseases
Monitoring for warning signs and other clinical parameters is crucial to
recognizing progression to the critical phase

23. FEBRILE PHASE
When fever suddenly falls, the dengue patient may either improve
and recover from the disease or present clinical deterioration and
serious warning signs

24. CRITICAL PHASE
If the temperature drops and stays at 37.5 ºC or less during the first 3 to 7
days, some patients may experience an increase in capillary permeability,
as well as increased hematocrit levels.
This marks the beginning of the critical phase
The phase of clinical manifestations due to plasma leakage, which usually
lasts 24 to 48 hours
May be associated with epistaxis and gingivorrhagia, as well as
transvaginal bleeding in women of childbearing age (metrorrhagia or
hypermenorrhea)

25. CRITICAL PHASE
Leukopenia with neutropenia and lymphocytosis with 15 to 20% atypical
forms, followed by a rapid decrease in platelet count usually precedes
plasma leakage
At this point, patients without a large increase in capillary permeability
improve, whereas those with greater capillary permeability may worsen as
a result of loss of plasmatic volume and may present warning signs
If volemia is not promptly and properly restored, “a few hours later” these
patients tend to present signs of tissular hypoperfusion and hypovolemic
shock

26. CRITICAL PHASE
Pleural effusion and ascites may be clinically detectable depending on the degree of
plasma leakage and the volume of administrated fluids
Chest x-ray, abdominal ultrasound, are useful tools for early diagnosis of serous cavity
effusions, as well as gallbladder wall thickening from the same cause
The intensity of the progression of plasma leakage is also reflected in progressively
rising hematocrit levels, making an impact on the patient’s hemodynamics. In the first
stage, this could last hours and be expressed as a change in blood pressure due to the
narrowing of differential blood pressure or pulse pressure, accompanied by
tachycardia and other early signs of shock without a drop in blood pressure

27. CRITICAL PHASE
Shock occurs when a critical volume of plasma is lost through leakage and
is usually preceded by warning signs
The body temperature may be subnormal when shock occurs
SIRS and multiple organ damage may occur, accompanied by metabolic
acidosis and consumptive coagulopathy
Bleeding in this phase occurs mainly in the digestive system (hematemesis,
melena), but can also affect the lungs, central nervous system, or any
other organ

28. FATALITIES
A study in Puerto Rico looked at a series of deaths from confirmed cases of
dengue and found that they had presented a set of known warning signs,
including
- intense abdominal pain
- persistent vomiting
- sharp drop in fever
- altered state of consciousness

29. RECOVERY PHASE
Once patients survive the critical phase, they move on to the recovery
phase, during which there is a gradual reabsorption of the leaked fluid
from the extravascular to the intravascular compartment
This reabsorption period may last from 48 to 72 hours

30. COMPLICATIONS TO BE
AWARE OF

31. CLASSIFICATION

32. MANAGEMENT

33. MANAGEMENT
There is no specific drug for the treatment of patients infected with DENV,
CHIKV, or ZIKV. Therefore, clinical care is symptomatic, with constant
monitoring and evaluation of the patient during the symptomatic phase of
the disease and, in the case of dengue, for two more days after the fever
has subsided

34. MANAGEMENT

35. MANAGEMENT

36. DENGUE WITH WARNING
SIGNS- Group B2

37. SEVERE DENGUE

39. DIFFERENTIAL DIAGNOSIS
Covid- 19

40. DENGUE SEROTYPES