Dengue fever is a viral disease transmitted by the Aedes aegypti mosquito that is endemic in over 100 tropical and subtropical countries. It has seen a global spread since a pandemic began in Southeast Asia after World War II, with several major epidemics occurring since the 1980s. The disease causes a range of clinical symptoms from a self-limiting undifferentiated fever to the potentially lethal dengue hemorrhagic fever/dengue shock syndrome. While supportive care is the primary treatment, prevention efforts focus on reducing mosquito breeding sites and insecticide spraying. Currently no vaccine exists against the four dengue virus serotypes.

1. Dengue FeverDengue Fever
Presented by:
Lt. Anurag Danda
Lt. Ankush Dhiman
Moderated by:
Col.K.K.Astha,Sr.Adv. & HoD Medicine,MH Kirkee

2. Distribution
 Endemic in more thanEndemic in more than
100 tropical and100 tropical and
subtropical countriessubtropical countries
 Pandemic began in SouthPandemic began in South
East Asia after WW IIEast Asia after WW II
with subsequent globalwith subsequent global
spreadspread
 Several epidemics sinceSeveral epidemics since
1980s1980s
 Distribution is comparableDistribution is comparable
to malariato malaria

3. EpidemiologyEpidemiology
A double peak
hemorrhagic fever
epidemic occurred
in India for the first
time in Calcutta
between July 1963
& March 1964
In New Delhi,
outbreaks of
dengue fever
reported in
1967,1970,1982,
1996,2012

4. Burden of disease in S.E. AsiaBurden of disease in S.E. Asia
CATEGORY-A
(INDONESIA,MYANMAR & THAILAND)
CATEGORY-B
(INDIA,BANGALADESH,MALDIVES & SRILANKA)
CATEGORY-C
(BHUTAN, NEPAL)
CATEGORY-D
(DPR KOREA)

5. Dengue Endemic Areas
(1996 to 2015 = 30 States/UTs)
Risk factors:
•Construction
activities
• Water storage
practice
•Population
movement
•Heavy rainfall
•Vector abundance

7. WHAT IS DENGUE ?
•Flaviviral disease
•small 50nm ss RNA viruses
•4 serotypes,DEN-1, DEN-2, DEN-3 and DEN-4,cross reactivity possible
• DEN1 and DEN2 serotypes widespread in India
•Transmitted by female Aedes aegypti mosquito

8. VECTOR OF DENGUE
Transmitted by the bite of female Aedes mosquito
•In India Ae. aegypti - main vector in most urban areas;
• Ae albopictus is- few areas of southern India.
Intrinsic incubation period – 8-10 days
Extrinsic incubation period – 5-6 days
(3-10 days)

9. TRANSMISSION CYCLE OF DENGUE
##There is evidence that vertical transmission of dengue virus from infected
female mosquitoes to the next generation occurs through transovarian

10. Epidemiological triadEpidemiological triad

11. Few common and favoured
breeding places/sites of
Ae. aegypti

12. 1.The virus is inoculated into humans with the
mosquito saliva.
2.The virus localizes and replicates in various target
organs, for example, local lymph nodes and the
liver.
3.The virus is then released from these tissues and
spreads through the blood to infect white blood
cells and other lymphatic tissues.
4.The virus is then released from these tissues and
circulates in the blood.
5.The mosquito ingests blood containing the virus.
6.The virus replicates in the mosquito midgut, the
ovaries, nerve tissue and fat body. It then escapes
into the body cavity, and later infects the salivary
glands.
7.The virus replicates in the salivary glands and
when the mosquito bites another human, the cycle
continues.
TRANSMISSION CYCLE OF DENGUE

13. PathogenesisPathogenesis

15. 1.Undifferentiated fever;
2.Classic dengue fever;
3.Dengue hemorrhagic fever, or DHF; and
4.Dengue shock syndrome, or DSS.
.
Dengue clinical syndrome

17. CLASSICAL DENGUE
 Acute febrile illness with headache, retro-orbital pain,Acute febrile illness with headache, retro-orbital pain,
myalgia, arthralgiamyalgia, arthralgia
 ““Break-bone fever” -High fever 5-7 daysBreak-bone fever” -High fever 5-7 days
 Followed by marked fatigue days to weeksFollowed by marked fatigue days to weeks
 Classic dengue 15-60% of infectionsClassic dengue 15-60% of infections
 Nausea, vomiting, diarrhea (30%)Nausea, vomiting, diarrhea (30%)
 Macular or maculopapular rash (50%)Macular or maculopapular rash (50%)
 Respiratory symptoms: cough, sore throat (30%Respiratory symptoms: cough, sore throat (30%))
 ““Dengue triad" of fever, rash and headacheDengue triad" of fever, rash and headache

18. Dengue Hemorrhagic Fever
WHO classification of DHF
 Thrombocytopenia (platelet count
<100,000)
 Fever 2-7 days
 Hemorrhagic manifestations with a
positive tourniquet test
 Hemoconcentration or evidence of
plasma leakage
Usually occurs in secondary
infections after actively or passively
(maternal) acquired immunity to a
different viral serotype
Only 2-4% of secondary infections
result in severe disease
Mortality is 10-20% if untreated,
but decreases to <1% if adequately
treated
Plasma leakage may progress to
dengue shock syndrome

19. SIGNS & SYMPTOMS OF
DENGUE SHOCK SYNDROME
•Severe continuous stomach pains
•Skin becomes pale, cold or clammy
•Bleeding from nose, mouth & gums and skin rashes
•Frequent vomiting with or without blood
•Sleepiness and restlessness
•Patient feels thirsty and mouth becomes dry
•Rapid,weak pulse
•Difficulty in breathing

31. Management of Dengue Fever (DF)
• No specific therapy, symptomatic and supportive
i. Bed rest .
ii. Use cold sponging to keep temperature below 39o C.
iii. Antipyretics may be used to lower the body temperature. Aspirin/NSAID like
Ibuprofen etc should be avoided since it may cause gastritis, vomiting, acidosis
and platelet disfunction.
Paracetamol is preferable in the doses as follows:
1-2 years: 60 -120 mg/doses 3-6 years: 120 mg/dose 7-12 years: 240 mg/dose
Adult : 500mg/dose
In children the dose is calculated as per 10mg/KG Body Weight per dose
which can be repeated at the interval of 6hrs
iv. Oral fluid and electrolyte therapy are recommended for patients with
excessive sweating or vomiting.
v. Patients should be monitored in DHF endemic area until they become
afebrile for one day without the use of antipyretics and after platelet and
haematocrit determinations are stable, platelet count is >50,000/ cumm.

38. PreventionPrevention
Personal:
 clothing to reduce exposed skin
 insect repellent especially in early morning, late
afternoon. Bed netting important
 mosquito repellants(pyrethroid based)
 coils, sanitation measures
Environmental:
 reduced vector breeding sites
 solid waste management
 public education
 empty water containers and cut weed/tall grass

39. Biological:
 Target larval stage of Aedes in large water storage
containers
 Larvivorous fish (Gambusia), endotoxin producing bacteria
(Bacillus), copepod crustaceans (mesocyclops)
Chemical:
Thermal fogging-malathion,pyrethrum
 Insecticide treatment of water containers
 Space spraying (thermal fogs)
 Indoor space spraying(2% pyrethrum), organophosphorus
compounds

42. Public Health
 Major and escalating global public health problem
 Global demographic changes: urbanization and population
growth with substandard housing, water, and waster
management systems
 Water collections around new constructions
 Dry Days
 Effective mosquito control

43. Vaccine
 No current dengue vaccine
 Estimated availability in 5-10 years
 Vaccine development is problematic as the vaccine
must provide immunity to all 4 serotypes
 Lack of dengue animal model
 Live attenuated tetravalent vaccines under phase 2
trials
 New approaches include infectious clone DNA and
naked DNA vaccines

44. THANK YOUTHANK YOU