Dengue virus (RNA Virus), flavivirus,
Arbovirus (arthropod borne virus)
May lead to –
Classical dengue fever
Dengue hemorrhagic fever without shock
Dengue hemorrhagic fever with shock
Dengue fever is self limiting
Prevalence of Aedes aegypti and Aedes
albopictus together with circulation of
dengue virus of more than one type in
any particular area tends to be
associated with outbreaks of DHF/DSS
It is most common among arthropod
borne viral diseases
One of the most important emerging
disease of tropical and sub tropical
regions, affecting urban and peri urban
50 million infections; 500,000 cases of
DHF; 12000 deaths.
Endemic in Bangladesh, India,
Indonesia, Maldives, Myanmar, Srilanka
Among 4 subtypes DEN-2, DEN-3
reported in Bangladesh and Maldives.
In SEA region, next to diarrhoeal disease
and ARI, leading cause of hospitalization
and deaths among children.
Category A (Indonesia, Myanmar,
Thailand- major PH problem)
Category B (India, Bangladesh,
Maldives, Srilanka- emerging disease,
Category C (Nepal, Bhutan- no reported
cases, endemicity uncertain)
Category D (DPR Korea, non endemic)
Classical Dengue Fever
‘Break bone fever’, acute viral infection
Caused by 4 serotypes (1, 2, 3, 4) of
Epidemics are explosive and often start
during rainy season, low in lower
temperature (below 26°c).
Reservoir – man and mosquito
Aedes aegypti is the main vector.
Becomes infective by feeding on a
patient from the day before onset to the
5th day (viraemia stage) of illness. After
an extrinsic incubation period of 8-10
days, the mosquito becomes infective
and able to transmit the infection for life
IP 5-6 days. Onset is sudden with chills
and high fever, intense headache,
muscle and joint pains which prevent all
Within 24 hours- retro orbital pain on eye
movement or eye pressure develops
Disease Presentation- TETANUS
Extreme weakness, anorexia,
constipation, altered taste sensation,
colicky pain and abdominal tenderness,
dragging pain in inguinal region, sore
throat, general depression.
Tempearture-102° to 104°. Fever is
typically followed by a remission of a few
hours to 2 days (biphasic curve).
Rash appears during remission or during
2nd febrile phase. Rash- diffuse, flushing,
mottling or fleeting pin point eruptions on
the face, neck or chest. Rash lasts for 2
hours to several days and may be
followed by desquamation.
Fever lasts for 5 days, rarely exceeds 7
Dengue Hemorrhagic fever
Severe form of Dengue, caused by
infection with more than one dengue
virus. Transmitted by A. aegypti.
Double infection with dengue virus; first
infection probably sensitizes the patient,
second produces immunological
IP: 4-6 days, abrupt onset with high fever
accompanied by facial flushing,
headache, anorexia, vomiting, epigastric
discomfort, tenderness at the right costal
margin and generalized abdominal pain.
Rash less common during first few days
which resembles classical dengue fever.
May appear late in illness.
Temperature 104-105°F, febrile
convulsion in infants.
Plasma leakage, abnormal hemostasis;
manifested by increased hematocrit
value and moderate to marked
Fever-acute onset, high,
continuous, lasting for 2-7 days.
Hemorrhagic manifestationspositive tourniquet test (more than
20 petechiae per 2.5 cm²
(Petechiae, purpura, echymosis,
epistaxis, gum bleeding,
haematemesis and/or malaena)
Grading of severity of DHF:
Grade I: Fever accompanied by non
specific constitutional symptoms. Only
hemorrhagic manifestation is a positive
Grade II: Spontaneous bleeding in the
form of skin and/or other hemorrhages+
manifestations of grade 1.
Grade III: Circulatory failure manifested
by rapid and weak pulse, narrowing of
pulse pressure (20 mmHg/ less) or
hypotension with the presence of cold,
clammy skin and restlessness.
Grade IV: Profound shock with
undetectable BP and pulse.
Thrombocytopenia (100,000/mm³ or
Hemoconcentration; hematocrit is
increased by 20% or more of baseline
Dengue Shock Syndrome: All above
criteria plus shock manifested by rapid
and weak pulse with narrowing of pulse
pressure or hypotension with the
presence of cold, clammy skin and
Management is symptomatic and
supportive. Bed rest in acute febrile
phase. Antipyretic and sponging. Aspirin
should be avoided particularly in areas
where DHF is endemic, since it may
cause gastritis, bleeding and acidosis.
Oral fluid and electrolyte therapy in
excessive sweating, vomiting and
Management of DHF- during febrile
phase similar to DF. Increased
hematocrit indicates significant plasma
loss and need for parenteral fluid
therapy. In grade I and II, volume
replacement can be given in 12-24
hours. Patient with signs of bleeding and
persistently increased hematocrit should
be admitted to hospital.
Volume and type of fluid similar to
diarrhoea with moderate isotonic
Hct determination at every 4-6 hours and
recording of vital signs.
Fluid used- 5% Dextrose in Ringers lactate
Management of shock
Control or eradication of the
mosquitoes carrying the virus that
To prevent mosquito bites, wear longsleeved shirts, long pants, socks and
shoes when outdoors.