2. M.Phil Zoology (1st Semester)
Incidence of dengue in 2013: Dengue outbreak in District Swat KPK, Pakistan
Presenting By
Asar Khan
M.Phil Zoology (1st Semester)
Good morning/afternoon everyone, I’m sure you all know that dengue is a serious problem now, but how much about dengue do you really know?

3. The dengue virus a member of the Family Flaviviridae and Genus flavivirus contains four antigenically related but distinct serotypes; DEN-1, DEN-2, DEN-3 and DEN-4.
So what is dengue fever?
Dengue fever is an illness caused by the dengue virus which is spread by the Aedes mosquito.

4. Worldwide occurrence

5. A dengue epidemic requires the presence of the following three main factors.
• The vector mosquito
• The dengue virus.
• A large number of
susceptible human hosts.

6. Close-up of an Aedes mosquito
Vector Mosquitoes
Aedes mosquitoes are the principle vector in the transmission of disease.
Two Species involved…
Aedes aegypti and
Aedes albopictus
Close-up of an Aedes mosquito
Now I’ll tell you about the Aedes mosquito which spreads dengue.
1) You can identify an Aedes mosquitoe from other mosquitoes by the black & white stripes on its body and legs. Because of this, it is also known as the ‘tiger mosquito.
2) It usually bites during the day.
3) The Aedes mosquito lays its eggs in clean, stagnant water. A pool of water as small as a twenty cent coin is all that is needed for it to breed. 

7. Characteristics of the Aedes Mosquito
One distinct physical feature – black and white stripes on its body and legs.
Bites during the day
(Dawn & Dust).
Lays its eggs in clean, stagnant water.
Now I’ll tell you about the Aedes mosquito which spreads dengue.
1) You can identify an Aedes mosquitoe from other mosquitoes by the black & white stripes on its body and legs. Because of this, it is also known as the ‘tiger mosquito.
2) It usually bites during the day.
3) The Aedes mosquito lays its eggs in clean, stagnant water. A pool of water as small as a twenty cent coin is all that is needed for it to breed. 

8. Life cycle of the Aedes Mosquito
Stagnant water
1-2 days
Pupae
Larvae
Eggs
4-5 days
2-3 days
As seen in this diagram of the Aedes mosquito’s life cycle, it only takes about a week for the mosquito complete the 4 stages consisting of the egg, larva and pupa stage before it becomes an adult mosquito. As one female mosquito lays up to 300 eggs each time, just imagine how many mosquitoes can be hatched!

9. Do you know…? Only the female Aedes mosquito feeds on blood.
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.
Only the female mosquitoes feed on blood, as they need the blood protein to lay their eggs.
Despite a short life span of two to three weeks, each female Aedes mosquito is able to lay up to 300 eggs.

10. Dengue Fever Sings & Symptoms
Symptoms, usually begin 4-6 days after infection and last for up to 10 days, may include. . .
Sudden high fever,
Severe headache,
Pain behind the eyes,
Severe joint and muscle pain ,
Nausea, Vomiting ,
Skin rash which appears three to four days
after the onset of fever.

11. What is DHF & DSS... ?
However, serious problems can develop. These include dengue hemorrhagic fever (DHF), a rare complication characterized by
high fever, damage to lymph and blood vessels, bleeding from the nose and gums,
enlargement of the liver, and failure of the circulatory system.
The symptoms may progress to massive bleeding, shock, and death. This is called dengue shock syndrome (DSS).

14. Methods & Materials Study area
Nine regions of district Swat were brought under considerations which were adversely effected by dengue virus including . . .
Mingora, Saidu Sharif,
Watkay, Barikot, Matta,
Matiltan, Charbagh,
Manglawar & Salampur.

15. The research was carried out in collaboration with Saidu Teaching Hospital (STH) and Shifa Medical Center Saidu Shariff Swat in five months period (July-November 2013).
During this visit to different hospitals five (5) ml blood was collected from each patient along with a proforma containing the whole information of respective patients.

16. Collection of Clinical Data
The data regarding signs, symptoms and laboratory analysis was collected from the admitted patients who presented dengue infection symptoms and fulfilling the diagnostic criteria of dengue fever and DHF having positive IgG, IgM, NS1 anti-dengue antibodies.

18. Epidemiological findings
We investigated 6000 cases of Dengue fever & DHF patients out of which 4121 (68.73%) were male and 1879 (31.31%) females.
Most of the effected patients were in age of years.
Figure 1.0 shows the age and sex wise distribution ratio of dengue infected patients.

19. Dengue infection among population (n=6000)

20. Clinical findings
The most common symptoms among the infected patients was fever (100%), vomiting (70.18%) , abdominal pain (50.16%) , while in some patients skin rashes (Petechiae) (18.66%), gum bleeding (2.65%), & Splenomegaly (34.16%) was also observed.

21. During the 5 months study patients identified with dengue fever and DHF in which the condition of fever in . . .
1346 (22.43%) patients were found continuous up to many days, 3880 (63.33%) was presenting intermittent and 854 (14.23%) patients were remittent.

22. anti dengue antibodies among all the patients in which 4121 were male showing NS1 (3359) and IgG, IgM (762) and of females NS1 (1171) and IgG, IgM (708) was investigated respectively.

23. The rate of infection was low in July and gradually increased in rainy months and the rate became much high in September and October it might be due to the well-established breeding sites of Aedes (vectors) in raining months.

24. Serotypes confirmation
All the blood samples were confirmed through IgG, IgM & NS1 strips.
The positive samples were run further for serotyping at NIFA (Nuclear Institute for Food & Agriculture) Peshawar.
For the confirmation samples of infected patients were sent to NIFA as a result dengue virus type 2 and 3 were detected.

26. In November 2010 outbreak, it was reported by a private news channel that out of the 5,050 patients, 2,350 patients were from Sindh, 1,885 from Punjab and at 158 patients from Khyber Pakhtunkhwa. The samples had an infection with DEN-2 and DEN-1 (Mahmood et al., 2010).

27. Samples had concurrent infection with serotypes DEN-2 and DEN-3
Samples had concurrent infection with serotypes DEN-2 and DEN-3. Studies showed that serotype DEN-2 was dominant in samples of dengue virus infection collected during the period of three years from 2007 to 2009 (Fatima et al., 2011).
In 2008, a dengue outbreak was reported in Lahore infecting large number of citizens of Lahore. Samples were found to have DEN-4, DEN-2 and DEN-3 infection (Humayoun et al., 2010).

28. Of the 414 patients’ serum samples collected for this study, 88
Of the 414 patients’ serum samples collected for this study, 88.40% (366/414) were found to be anti-DENV IgG and/or IgM positive A total of 28.68% (105/366) patients were found to have active DENV infections using the reverse transcriptase chain-reaction (RT-PCR).
Of these 105 RT-PCR positive samples, the majority (65.71%: 69/105) contained DENV-3 followed by DENV-2 (33.33%: 35/105). One sample contained both DENV-2 and DENV-3, while DENV-1 or DENV-4 was not identified in any of these samples (Ajmad et al., 2013).

29. Table showing detection of dengue serotypes in different outbreaks in Pakistan from 1994 to 2013
Outbreak Area
DENV-I
DENV-II
DENV-III
DENV-IV
Year
Karachi x √
1994
1995
Balochistan
1998
2005
2006
Lahore
2008
2009
Sindh
2010
2011
2012
Swat
2013

31. For the prevention of such types of outbreaks
public awareness campaigns are needed through which we can aware the people to use mosquito repellent nets, mosquito quills, mosquito repellents in order to reduce the chance of infection by eliminating the vectors.
Family support for the infected patients is also needed; fluids should be given orally if they do not tolerate the fluids orally intravenous fluids are to be given.

33. To use insecticides at Aedes breeding sites

34. Change water in vases on alternate days.

35. Remove water from flowerpot plates on alternate days.

36. Turn over all pails and water storage containers.

37. Cover bamboo pole holders when not in use.
Tell your parents or any adults in your house to cover bamboo pole holders when they are not in use.
Cover bamboo pole holders when not in use.

38. Clear blockages and put insecticide in roof gutters monthly.
And tell your parents or any adults in your house to clear blockages and put BTI insecticide in roof gutters monthly.
Clear blockages and put insecticide in roof gutters monthly.

39. Do not litter. Rubbish such as cups ad bottles can collect rain water and breed mosquitoes.
Do not litter. Rubbish such as cups and bottles can collect rain water and breed mosquitoes.