Dengue

1. Dengue: A Global Threat
Presented by: Kiran Hanif
Lecturer Zoology
Govt Post Graduate college (W) Samanabad Lahore

2. Contents
 What is dengue?
 Causative agent
 Symptoms of dengue
 Global status of disease
 Disease transmission
 The Vector
 Life cycle of Aedes
 Prevention from disease

3. What is Dengue?
 Dengue is an arbovirus (arthropod born virus)
infection
 Also called as Bone breaking fever
 More prevalent In tropical and subtropical regions

4. Causative Agent
 The real culprit is “DEN Virus”
 It is an enveloped virus with single stranded RNA
 Genome consist of 11 kilo bases
 virus belonging to the Flaviviridae family
 Four serotypes of virus are present
 DEN-1
 DEN-2
 DEN-3
 DEN-4

5. Dengue: A Zoonotic Disease
 A zoonotic disease is a disease that can be passed
between animals and humans
 Dengue fever is a Zoonotic Disease
 The virus originally came from Monkeys

6. Symptoms of Dengue
 Fever
 Nausea
 Muscle pain
 Joint pain
 Vomit
 Headache
 Rashes

7. Global Status of Dengue
 New infections annually: 50 million
 Deaths: 24,000 annually
 More than 100 countries has dengue as epidemic
 People at risk: 2.5-3 billion
 Half of the world lives in HOT ZONE

8. We are not Alone…

9. Prevalence of Disease in Pakistan
 In Pakistan, Dengue Hemorrhagic Fever (DHF)
was first reported from Karachi in 1994
 In 2006, 5,522 cases were reported from all
over the country
 Recently, a severe dengue epidemic occurred in
2011
 > 20000 positive cases
 300 deaths in Lahore, Punjab.

10. Changing Scenario of Dengue in Pakistan

11. Cont......
 Between 2005 & 2011 the dengue affected 105 out
of 145 districts of Pakistan
 The dengue situation in Pakistan is alarming
 To control the disease, vector control is the only
option for having no vaccine and proper antiviral drug

12. Prevalence of Disease in Pakistan

13. Transmission of Disease

14. Disease Transmission
 Dengue is transmitted by the following species of
Aedes mosquito
Aedes aegypti (Indoor Mosquitoes)
Aedes albopictus (outdoor Mosquitoes)
 Both species exhibit a well-defined rising trend
in population in post monsoon seasons (September
to November).

15. Aedes aegypti
 Closely associated
with human habitation.
 Often found indoors.
 Feeds mainly on
humans and to a lesser
extent, domestic
animals.
 Usually bites more
than one person to
complete blood meal
Aedes albopictus
 Found in thickets &
wooded areas.
 An outdoor mosquito
 Feeds on humans and a
wide range of other
vertebrates
 Usually completes
blood meal from one
person

16. Aedes aegypti vs Aedes
albopictus

17. Man-Mosquito-Man Cycle
 Aedes mosquito acquires virus while feeding on the
blood of an infected person and transmit it to
another health person

18. Characteristics of Aedes
 White & black strips are present on the body
 Bites during day time
 Lays eggs in clean, stagnant water
 Only female sucks blood
 Male takes nectar as food
 Why depends on our blood?

19. Life Cycle of Aedes

20. Life Cycle of Aedes
 Life Span: 14-21 days
 Aedes lays eggs 3-4 times in her life
 Every time produces around 100 eggs
 It takes about a week for mosquito to become an
adult
 Eggs converted into Larvae in 2-3 days
 Larvae take 4-5 days to form Pupa
 Pupa converted into adult in 1-2 days

21. Pupa Eggs
Adult
Larvae

22. Diagnosis of Disease
 Diagnosis
Medical History
Physical examination
Touniquet test
 Lab testing
Cbc test
Low platelet count (<150,000)
Ab testing

23. Disease Management
What we need to
do?
 Bring fever down
Use sponge bath
and paracetamol
 Use oral fluids to
avoid dehydration
 Keep mosquitos away
What we should Avoid?
 Avoid aspirin & Brofen
other blood thinning
drugs i.e NSAIDs
 Avoid IV fluid intake

24. Prevention From Dengue

25. Disease Control
 Use mosquito repellents containing DEET to keep
them away
 Wear light colored and full sleeved clothes
 Use mosquito nets or screens in non air conditioned
rooms

27. Cont…
 The best way to fight dengue is through:
Cleanliness
&
Sanitation

28. Some Common Potential Breeding
sites

31. Cont…

33. If they Breed, U Will
Bleed
Do yourself a favor,
Keep your surrounding
Clean
A Key
Message

34. Current News about Dengue

35. Biological Control of Dengue
 Scientists has Developed some modified Mosquitoes
 They inserted a bacteria called “Wolbachia” into
Aedes
 They found that Wolbachia treated mosquitoes has
reduced life span and egg laying capacity
 Results in a population of Aedes has lesser ability to
transmit Virus
 Vector Control is the only Solution to the problem
until a proper and accessible vaccine is developed

37. Dengue Vaccine
 3 September 2014 is the day of triumph
 Sanofi Pasteur, the vaccines division of the French
pharmaceutical company Sanofi has developed a
Vaccine against Dengue
 This vaccine will be available from 2015

38. "According to the press release of Sanofi"
"For the first time ever, after 20 years of
research and industrial commitment dengue is
set to become a vaccine preventable disease."
Vaccine was supposed to be less prevalent
against DENV4 strain

39. What should
we know?
What should
we do?
Our Goal a
Dengue free
Future

40. Hope You have a Nice & Mosquito Bite Free DayHope You have a Nice &
Mosquito Bite Free Day

41. Thank You