Dengue fever, also known as breakbone fever, is a mosquito-borne tropical disease caused by the dengue virus. It causes flu-like symptoms including fever, headache, muscle and joint pains, and skin rash. In some cases it can develop into life-threatening dengue hemorrhagic fever resulting in bleeding and blood plasma leakage. It is transmitted by several species of mosquito and prevention focuses on reducing mosquito habitats and exposure to bites. There is no vaccine currently available. Research is ongoing into vector control methods, vaccine development, and antiviral drugs to treat dengue.

1. Dengue Fever
Group presentation on
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2. Introducing Us
Alvi Ehsan
Maimuna Mahmud
Taslima Khanam Lima
Gaulib Haidar
Sudipto Bala(L)
Sunzida Haque
151-2614-630
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132-0225-020
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3. Contents
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4. Dengue
-What it is and how it occurs
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5. Dengue
Dengue fever known as break-bone fever is a mosquito-borne tropical disease
caused by the dengue virus. However Symptoms of dengue fever include fever,
headache, muscle & joint pains, and a characteristic skin rash that is similar to
measles.
In a small proportion of cases the disease develops into the life-threatening
dengue hemorrhagic fever, resulting in bleeding, low levels of blood platelets
and blood plasma leakage.
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6. Dengue
Dengue is not transmitted directly from person-to-person.
Dengue is transmitted by several species of mosquito.
As there is no commercially available vaccine, prevention is
sought by reducing the habitat and the number of
mosquitoes and limiting exposure to bites.
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7. History & origin
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8. Transmission
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9. Signs and symptoms
Many people, especially children and teens, may experience NO signs or
symptoms during a mild case of dengue fever. When symptoms do occur, they
usually begin four to 10 days after one is bitten by an infected mosquito.
Signs and symptoms of dengue fever most commonly include:
 Fever, as high as 106 F (41 C˚)
 Headaches
 Muscle, bone and joint pain
 Pain behind eyes 9

10. Signs and symptoms
One may also experience:
 Widespread rash
 Nausea and vomiting
 Rarely, minor bleeding from gums or nose
 Red spots or patches on the skin
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11. Signs and symptoms
One may also experience:
o Widespread rash
o Nausea and vomiting
o Rarely, minor bleeding from gums or nose
o Red spots or patches on the skin
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12. Signs and symptoms
Most people recover within a week or so. In some cases, symptoms worsen and can
become life-threatening. Blood vessels often become damaged and leaky. And
the number of clot forming cells (platelets) in one’s bloodstream drops. This can
cause:
 Bleeding from nose and mouth
 Severe abdominal pain
 Persistent vomiting
 Bleeding under the skin, which may look like bruising
 Problems with lungs, liver and heart 12

13. Signs and symptoms
Typically, people infected with dengue virus are asymptomatic (80%)
or only have mild symptoms such as an uncomplicated fever, others
have more severe illness (5%), and in a small proportion it is life-
threatening.
The incubation period (time between exposure and onset of
symptoms) ranges from 3 to 14 days, but most often it is 4 to 7 days.
Children often experience symptoms similar to those of the common
cold and gastroenteritis (vomiting and diarrhea) and have a greater
risk of severe complications, though initial symptoms are generally
mild but include high fever. 13

14. Signs and symptoms –
clinical phase of infection
The course of infection is divided
into three phases
Febrile Critical Recovery
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15. Signs and symptoms –
clinical phase of infection
The course of infection is divided
into three phases
Febrile Critical Recovery
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16. Signs and symptoms – Febrile phase
 High fever, potentially over 40°C (104°F) associated with generalized pain and a
headache; this usually lasts 2 to 7 days. The fever usually is breaking and then
returning for one or two days.
 Nausea and vomiting.
 Measles-like rash, flushed skin may occur anytime from the first day of symptoms
to the first week. A rash described as "islands of white in a sea of red" has also
been described.
 Some petechiae (small red spots that do not disappear when the skin is pressed,
which are caused by broken capillaries) can appear.
 Some mild bleeding from the mucous membranes of the mouth and nose may
occur. 16

17. Signs and symptoms – Critical phase
In some people, the disease proceeds to a critical phase as fever resolves. The symptoms of
this phase are:
 Leakage of plasma from the blood vessels typically lasting one to two days.
 Decreased blood supply to vital organs.
 Organ dysfunction and severe bleeding may occur, typically from the gastrointestinal
tract.
 Shock or dengue shock syndrome and hemorrhage (dengue hemorrhagic fever) may
occur (less than 5% of all cases of dengue).
Those who have previously been infected with other serotypes of dengue virus ("secondary
infection") are at an increased risk. This critical phase, while rare, occurs relatively more
commonly in children and young adults.
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18. Signs and symptoms – Recovery phase
Recovery occurs next, with:
 Resorption of the leaked fluid into the bloodstream, usually lasting two to three days.
 The improvement is often striking, and can be accompanied with severe itching and a
slow heart rate.
 Another rash may, which is followed by peeling of the skin.
 A fluid overload state may occur.
 If it affects the brain, it may cause a reduced level of consciousness or seizures.
 A feeling of fatigue may last for weeks in adults.
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19. Associated problems
 Dengue can occasionally affect several other body systems, either in isolation or along
with the classic dengue symptoms. A decreased level of consciousness occurs in 0.5–6% of
severe cases, which is attributable either to inflammation of the brain by the virus or
indirectly as a result of impairment of vital organs, for example, the liver.
 Other neurological disorders have been reported in the context of dengue, such as
transverse myelitis and Guillain-Barré syndrome.
 Infection of the heart and acute liver failure are among the rarer complications.
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20. Prevention
There are no approved vaccines for the dengue virus. Prevention thus depends on control of
and protection from the bites of the mosquito that transmits it. The World Health Organization
recommends an Integrated “Vector Control program” consisting of five elements:
1. Advocacy, social mobilization and legislation to ensure that public health bodies and
communities are strengthened
2. Collaboration between the health and other sectors (public and private)
3. An integrated approach to disease control to maximize use of resources
4. Evidence-based decision making to ensure any intervention is targeted appropriately
5. Capacity-building to ensure an adequate response to the local situation
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21. Control
 The primary method of controlling Aedes aegypti is by eliminating its habitats. This is done
by:
1. Adding insecticides or biological control agents to affected area.
2. Generalized spraying with organophosphate or pyrethroid insecticides
3. Reducing open collections of water through environmental modification
 Some other methods of controlling dengue are:
 Prevent mosquito bites by wearing clothing that fully covers the skin
 Using mosquito netting while resting
 Applying insect repellent (DEET being the most effective).
 DEET, is a slightly yellow oil. It is the most common active ingredient in insect repellents. It is
intended to be applied to the skin or to clothing, and provides protection against
mosquitos, ticks, fleas, chiggers, leeches, and many other biting insects.
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22. Treatment
There is no specific medicine to treat dengue infection. If one thinks one may have dengue
fever, one should:
 Use pain relievers with acetaminophen
 Avoid medicines with aspirin, which could worsen bleeding.
 Rest
 Drink plenty of fluids
 Must see a doctor.
 If one starts to feel worse in the first 24 hours after fever goes down, one must get to a
hospital immediately to be checked for complications.
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23. Treatment
More severe variations of dengue fever (hemorrhagic and shock syndrome) usually require
additional supportive treatments. These patients often require hospitalization with the
following medical services:
 IV hydration
 Blood transfusions
 Platelet transfusions
 Blood pressure support
 Other intensive-care measures
Consultation with infectious-disease and critical-care specialists is often advised to optimize
patient care.
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24. Treatment - Self-Care at Home
 Home care for dengue fever is simply supportive care.
 Good oral hydration, pain control with Tylenol (or other non-NSAIDs) is usually adequate
treatment for most people.
 However, there is no role for home care in patients with dengue hemorrhagic fever or for
dengue shock syndrome; depending on the patient's condition, many clinicians consider
these conditions to be medical emergencies.
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25. Dengue throughout the globe
o Dengue is common in
More than 110 countries:
1. Malaysia
2. Bangladesh
3. India
4. Pakistan
5. Brazil
6. USA
o It infects 50 to 528 million people worldwide a year, leading to
half a million hospitalizations, and approximately 25,000 deaths.
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26. Dengue throughout the globe–
Southeast Asia
 For the decade of the 2000s, countries of
Southeast Asia were estimated to have
about 3 million infections and 6,000
deaths annually.
Malaysia
Thailand
Burma
Cambodia
East Timor
Indonesia
Laos
Brunei
Philippines
Singapore
Vietnam
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27. Dengue throughout the globe
Worldwide dengue distribution, 2006.
Red: Epidemic dengue
Blue: Aedes aegypti
o The geographical distribution
is around the equator. Of the
2.5 billion people living in
areas where it is common,
70% are from Asia and the
Pacific.
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28. Dengue throughout the globe – Africa
 34 African countries have reported dengue
including:
 Egypt
 South Africa
 Aedes aegypti mosquitoes are present in at
least 9 African countries including:
 Niger
 Chad
 Data are not available for 5 African
countries:
 Western Sahara
 Morocco
 Algeria
 Tunisia
 Libya
Dark Red = Countries in which
dengue has been reported
Light Red = Countries in which
dengue has not been reported but
where Aedes aegypti mosquitoes
are present
White = Countries for which data
are not available 28

29. Dengue throughout the globe
 Dengue fever, which was once confined
to Southeast Asia, has now spread to:
 Southern China
 Countries in the Pacific Ocean
 America, and
 Possess a threat to Europe.
 Rates of dengue increased 30 fold
between 1960 and 2010.
This increase is believed to be due to a
combination of:
 Urbanization
 Population growth
 Increased international travel, and
 Global warming.
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30. Why is dengue alarming?
Country Number of Cases Deaths
Brazil 56,882 39
Paraguay 27,000 31
Thailand 52,008 50
Philippines 18,885 115
Country Number of Cases Deaths
Brazil 205,000 78
Paraguay 70,000 35
Thailand 150,000 50
Philippines 42,500 200
Data of 2011 Data of 2013
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31. Research and development
Research efforts to prevent and treat dengue include:
1. Vector control
2. Vaccine development, and
3. Antiviral drugs
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32. Research and development –
Vector control
 A number of novel methods have been used to reduce
mosquito numbers with some success including the
placement of the guppy (millionfish or rainbow fish) or
copepods in standing water to eat the mosquito larvae.
 Attempts are ongoing to infect the mosquito population with
bacteria of the Wolbachia genus, which makes the
mosquitoes partially resistant to dengue virus.
 There are also trials with genetically modified male A. aegypti
that after release into the wild mate with females, and render
their offspring unable to fly.
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33. Research and development –
Vaccine development
 There are ongoing programs working on a dengue vaccine to cover all four serotypes.
Now that there is a fifth serotype this will need to be factored in.
 As of 2012, a number of vaccines were undergoing testing. The most developed is based
on a weakened combination of the yellow fever virus and each of the four dengue
serotypes.
 Two studies of a vaccine found it was 60% effective and prevented more than 80 to 90%
of severe cases. It is hoped that the first products will be commercially available by 2015.
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34. Research and development –
Antiviral Drugs
 Apart from attempts to control the spread of the Aedes mosquito and work to develop a
vaccine against dengue, there are ongoing efforts to develop antiviral drugs that would
be used to treat attacks of dengue fever and prevent severe complications.
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