2. DENGUE
Muhammad SOHAIL
SARWAR
UNIVERSITY OF LHR

3. Introduction to Dengue
Dengue is a mosquito-borne infection that in recent
decades has become a major international public
health concern. Dengue is found in tropical and sub-
tropical regions around the world, predominantly in
urban and semi-urban areas.
It is caused by a virus which is transmitted to the
humans by mosquito known as ”Aedes aegypti &
Aedes albopictus”

4.  According to the World
Health Organization
(WHO), Dengue is a
mosquito-borne infection
that causes a severe flu-like
illness, and sometimes a
potentially lethal
complication called dengue
hemorrhagic fever.
 The incidence of dengue has grown dramatically
around the world in recent decades. Some 2.5 billion
people – two fifths of the world's population – are now at
risk from dengue. WHO currently estimates there may be
50 million dengue infections worldwide every year.

5. Dengue Virus
5

6. Introduction to Dengue Virus
 Dengue virus is know as DENV.
DENV is an single stranded RNA
positive-strand virus of the family
Flaviviridae, genus Flavivirus.
DENV causes a wide range of diseases
in humans, from a self limited Dengue
Fever (DF) to a life-threatening
syndrome called Dengue Hemorrhagic
Fever (DHF) or Dengue Shock
Syndrome (DSS)
There are four antigenically
different serotypes of the virus:
a.DENV-1 b.DENV-2
c.DENV-3 d.DENV-4

7. Aedes aegypti and Aedes albopictus
7

8. 3,500
mosquito
species
Culex Anopheles Aedes
Yellow
West Nile Malaria Fever,
Virus Dengue

9. What does “aedes” mean?
“Unpleasant” (Greek) by Meigen in 1818

10. AEDES AEGYPTI AEDES ALBOPICTUS

11. AEDES AEGYPTI AEDES ALBOPICTUS
 Egyptian tiger mosquito  Asian Tiger mosquito
 Origin: Africa  Origin: Africa/S.E. Asia
 Primary vector for:  Vector for:
 Yellow fever  Same as aegypti
 Dengue fever  Prefers to breed in trash
 Prefers to breed in water (out)
storage containers (in  Outdoor day biter 
and out) humans, livestock,
 Day biter  humans amphibians, reptiles,
and birds

12.  All in all, it takes 8-10
days.
 Two phases:
terrestrial and aquatic
 Eggs are resistant to
environmental stress.
 Eggs  larva (feeder)
in presence of water
 Larva  pupa (non-
feeder)
 Pupa  young adult
(still water)

13. Characteristics of the
Aedes Mosquito
One distinct physical feature – black and white
stripes on its body and legs.
Bites during the day.
Lays its eggs in clean, stagnant water
Only the female Aedes mosquito feeds on blood.
This is because they need the protein found in blood
to produce eggs. Male mosquitoes feed only on plant
nectar.
On average, a female Aedes mosquito can lay about
300 eggs during her life span of 14 to 21 days.

14. How Do Aedes Mosquitoes Transmit
Diseases...
Mosquito bites and sucks And passes the virus
blood containing the virus to healthy people
from an infected person. when it bites them.
Virus is carried in its
body.

15.  Mosquitoes sense the  Body temperature
presence of:  Dark-colored materials
 Genetics – 85%  clothing's, garbage cans
 Chemicals (respiratory,  Movement
skin)  Floral/fruity fragrances
 Carbon dioxide (activity,  Moisture
using candle)
 Lactic acid (exercise, after
eating salty foods, high-
potassium)
 Steroids
 Uric acid
 Cholesterol

16. Mosquitoes will practically breed anywhere
where there is a collection of water that stands
longer than five to seven days. Some prefer
lighted areas and some shady areas. Some
prefer fresh water and some stagnant water.

17. Ponds
Streams Swamps
Common natural breeding grounds
Rock holes
Ditches
Tree holes
17

18. Rain barrel
Cans
Wells
Common man-made breeding grounds
Vases
Roof gutter
Old tires Road gutter

19. Dengue Fever, Dengue Hemorrhagic Fever

20. Where did the word “dengue” come
from?
Spanish, “dengue” for “fever”
Swahili, “Ka-dinga pepo” for “sudden
cramp-like illness caused by an evil
spirit.”

21.  Chronology
 265-420 AD in China; called
“water poison”
 Slaves in Caribbean, “Dandy
fever”
 1780 in Madras, India
 1780, Benjamin Rush coined
the term “breakbone fever”
 1799 in Cairo and
Alexandria, Egypt;
Jakarta, Indonesia1943:
Japanese scientists first
identified the virus
 1953: First report of Dengue
Hemorrhagic Fever in Manila
 1956: Four types of dengue
 1994, Karachi , Pakistan
Number of cases vs. number of countries
1955-2007

22. Dengue virus
infection
No With
symptoms symptoms
No different Dengue Fever (DF) Dengue Hemorrhage
from other Syndrome Fever (DHF) (plasma
fever leakage)
Symptoms: Sudden rise
Without With unusual in temperature, facial
hemorrhage hemorrhage flush, DF symptoms like
Symptoms: high fever; vomiting, headache, etc.,
severe headache; pain sore throat, gum
behind the eyes; muscle, bleeding, breathlessness,
bone and joint pains; elevated blood
nausea, vomiting, and hematocrit
rash. Skin hemorrhage
(tiny purplish-red spots No Dengue Shock
on skin) sometimes seen
shock Syndrome
Symptoms: Occurs at the
end of fever on 3rd to 7th
day, skin becomes cool
and blotchy, pulse weak
and rapid, lethargy,
restlessness, acute
abdominal pain
frequently felt just before
onset of shock
Dengue Dengue Hemorrhage
Fever Fever
22

23. Signs and Symptoms of Dengue
Fever
Recognition of Dengue fever
- Sudden onset of high fever
- Severe headache (mostly in the
forehead)
- Pain behind the eyes which worsens
with eye movement
- Body aches and joint pains
- Nausea or vomiting

24.  Diagnosis:
 Medical history
 Physical examination
 Tourniquet test
 Lab:
 Low platelet count
(<150,000)
 Complete blood
count/hematocrit
 Blood test for
antibodies

25. WHAT TO DO WHAT NOT TO DO
 Bring the fever down.  Avoid certain drugs like
Sponge bath and aspirin, NSAIDs
paracetamol. (ibuprofen, mefenamic
 Maintain hydration acid)
using oral fluids.  Avoid IV fluids. Use oral
 Keep mosquitoes away. fluids if child is able to
Use mosquito nets. drink.
 Fluids in the lungs
 Water retention

26. Critical Period: Risk for DHF is high 5-7 days after fever subsides.
 Refuse fluids or Mottled skin
vomiting.
 Sleepy or restless child.
 Gastrointestinal
dehydration
bleeding
 Abdominal pain
 Skin mottling, cold
sweaty skin, cold hands
and feet
 No urine for the past 6
hours.
GI bleeding
Abdominal pain

27.  Odds of getting DHF?  Causes of death
 DHF is a second  Shock due to
infection. dehydration
 90% of DHF patients has  Severe hemorrhage
previous infection.
 Encephalitis
 Getting a second infection
does not mean you’re  Liver failure
going to get DHF
 Risk of dying from DHF
with inadequate
treatment is 10%-15%
 Risk of dying from DHF
with adequate treatment
is < 1%

28. Barriers Against Mosquito Bites and Infection
28

29.  DEET  Natural
 Apply insect repellent  Need frequent
 DEET (20-30%) application
 If repellent is aerosol,  Citronella, lemon
open air eucalyptus, castor oil,
 If child, don’t apply to peppermint oil.
hands
 Multiple repellents tend
 Apply on clothing. to be more effective due
 Mosquito net if room is to mosquito differences.
non-air-conditioned or
screened

30. Change the water in vases
and for aquatic plants at
least once a week and Cover up tires before
leave no water in the disposal to prevent water
saucers underneath the from collecting.
Keep drains free from plants
blockage
Cover water
containers, wells, and
water tanks tightly Check whether there is
water collecting on the
tray under an air-
Dispose of unwanted
conditioner and in the
containers where water may
drainage system, and
collect such as lunch boxes
Repair uneven surfaces of remove stagnant water
and soft drink cans into
covered bins the ground to prevent
water from collecting
Let’s Act to Prevent Dengue

31. Use mosquito nets or screens
when the room is not air-
conditioned
Wear light-coloured and
long-sleeved clothing and
pants
Apply mosquito repellents
containing DEET to exposed
parts of the body
Install screens on
windows and doors, or
place mosquito coils
/electric mosquito mats
/anti-mosquito liquid
near the windows
Avoid visiting
scrubby areas

32.  At present, there are no
approved vaccines.
 At the US National Institute of
Health, 11 vaccines are
undergoing testing.
 Difficulties with vaccine
development:
 Four serotypes with no cross-
immunity.
 No good animal model for
testing.
 Vaccines should be tetravalent
 against the DENV-1 to 4

33. References
Books
 Mandell’s Book of Infectious Disease, Seventh Edition
 Davidson’s Book Medicine
websites
 www.medicinenet.com
 www.denguevirusnet.com
 www.drugbank.ca
 www.who.org

34. THANK YOU!
Muhammad Asif Mahmood
(Pharmacist)
For Feedback
www.facebook.com/Best.Pharmacist
Asif.Mahmood247@Gmail.com