DENGUE

Key point: Early recognition and

timely intervention

Airamsherlyn P. Natinga, M.D.

DISCUSSION

Epidemiology

estimated 50 million dengue infections occur annually

approximately 2.5 billion people live in dengue endemic countries

Epidemiology From 1993 to 2007, a total of 307,850

cases of dengue with 3,406 deaths were reported in the Philippines.

Most of the cases occur in children between 1 to 10 years old with a case fatality rate of 1.7%.

“Dengue is one disease entity with different clinical presentations and

often with unpredictable clinical evolution and outcome.”

Expert consensus groups

Case Classification

Expert group (Geneva, Switzerland, 2008)

Criteria for Dengue ± Warning Signs

Herman’s Rash

Dengue with warning signs

Severe dengue

Transmission

Dengue virus (DEN)

small single-stranded RNA virus comprising four distinct serotypes (DEN-1 to -4)

genus Flavivirus, family Flaviviridae Asian genotypes of DEN-2 and DEN-3 are

frequently associated with severe disease accompanying secondary dengue infections

Dengue virus (DEN)

Vector: Aedes aegypti

immature stages are found in water-filled habitats, mostly in artificial containers closely associated with human dwellings and often indoors.

Host

After an incubation period of 4-10 days, infection by any of the four virus serotypes can produce a wide spectrum of illness, although most infections are asymptomatic or subclinical

Individual Risk factors

Age Ethnicity Chronic illnesses

Blood meal

viremia

Immune response

Genetic

Virus

Severe dengue

Plasma leakage

Transient and reversible imbalance of inflammatory mediators, cytokines and

chemokines

Endothelial cell dysfunction

Derangement of hemocoagulation system

Shock Bleeding

Course of dengue illness

Clinical problems

Management

Group A able to tolerate adequate volumes of oral

fluids and pass urine at least once every six hours, and do not have any of the warning signs, particularly when fever subsides.

Sent home

Group B Referred for in-hospital management

Group C Emergency treatment and urgent referral

Prevention

Vector control

- controlling larval habitats and combatting adult mosquitos by screening widows and doors and using household insecticide space sprays.

Provision of reliable potable water. Sanitation Solid waste management Health education COMMUNITY PARTICIPATION

New Avenues

Tetravalent dengue vaccines are under development.