1. Dengue: Infection and Treatment
by Mahmoud Lubbad

2. Alternative Names Onyong- Nyang Fever West Nile Fever Break Bone Fever
Dengue like Disease

3. Dengue
The word dengue is derived from African word denga: meaning fever with hemorrhage .
Is caused by virus transmitted of bites of mosquito Aedes.

4. History
The first outbreak that resembles a disease now recognized as dengue fever was that described by Benjamn Rush in Philadelphia, Pennsylvania in 1780.

5. Problem statement
Dengue fever is the most common arthropod borne viral disease.
Dengue fever is one of the most important emerging disease of the tropical and sub tropical regions, affecting urban and pre urban areas.

6. Virus 2

7. Group A
Togaviruses
e.g. encephalitis
Group B
Togaviruses
Sandfly fever
Rift valley fever
Cramean –Congo fever
By Mosquito
Yellow fever, Denque
fever
By Ticks
Russian fever
E. Spring Summer fever

8. The Dengue Virus Four types :Has 4 serotypes (DEN-1, 2, 3, 4)
Causes dengue and dengue hemorrhagic fever
Is an arbovirus
Transmitted by mosquitoes
Composed of single-stranded RNA

9. Dengue Viruses
Each serotype provides specific lifetime immunity, and short-term cross-immunity
All serotypes can cause severe and fatal disease
Genetic variation within serotypes
Some genetic variants within each serotype appear to be more virulent or have greater epidemic potential 4

10. Dengue Symptoms Undifferentiated fever Classic dengue fever
Dengue hemorrhagic fever
Dengue shock syndrome 17

11. Undifferentiated Fever
May be the most common manifestation of dengue
Prospective study found that 87% of students infected were either asymptomatic or only mildly symptomatic
Other prospective studies including all age- groups also demonstrate silent transmission
DS Burke, et al. A prospective study of dengue infections
in Bangkok. Am J Trop Med Hyg 1988; 38:

12. Clinical Characteristics of Dengue Fever
Headache
Muscle and joint pain
Nausea/vomiting
Rash
Hemorrhagic manifestations 18

13. Hemorrhagic Manifestations of Dengue
Skin hemorrhages: نزيف الجلد petechiae, purpura, ecchymoses
Gingival bleeding نزيف للثة
Nasal bleeding نزيف للأنف
Gastro-intestinal bleeding: نزيف للأمعاء hematemesis, melena,
Hematuria
Increased menstrual flow زيادة تدفق الطمث 20

14. Skin bleeds

15. Bleeding into the eye

16. Large bleed into skin

17. Clinical Case Definition for Dengue Shock Syndrome
Evidence of circulatory failure manifested indirectly by all of the following:
Rapid and weak pulse
Narrow pulse pressure ( 20 mm Hg) OR hypotension for age
Cold, clammy skin and altered mental status
Frank shock is direct evidence of circulatory failure 22

18. Aedes Aegypti Mosquito8

19. 3-14 days (commonly 4-7 days)
Incubation period
3-14 days (commonly 4-7 days)

20. Aedes Aegypti Dengue transmitted by infected female mosquito
Highly domesticated tropical mosquito.
Prefer to lay eggs in artificial containers e.g. flower vases, automobile tires…etc.
Prefer to rest indoors.
Prefer to feed on humans during daytime hours. 9

21. Vector
Aedes mosquitoes (Tiger mosquito): distinguished by white stripes on black body.
Important members Aedes family: Aedes . Aegypty, Aedes.vittatus and Aedes. albopictus.
They are most abundant during rainy season.

23. Vector Lays egg singly, and eggs are cigar shaped.
Female mosquito acts as vector.
They do not fly over long distance- <100mts(110yards), this factor facilitates its eradication.

24. World Distribution of Dengue 1999
Areas infested with Aedes aegypti
Areas with Aedes aegypti and recent epidemic dengue

25. Dengue fever in KSA Year N. of suspected cases N. of confirmed cases
1994
1995
1996
1997
1998
1999
2000
2001
2002
673
136 57 62 31 26 17 07 11
289 6 2 15 00 3 4
Total
1020
319

27. Rift Valley Fever cases
Dengue Fever cases
Year-wise
289
1994 6
1995 2
1996 15
1997
1998 3
1999
1328
2000
2001 4
2002
2003
2004
406
2005
1544
2006
490
2007
913
2008
3350
2009
3526
2010
2011

28. Vector and Transmission

29. Replication and Transmission of Dengue Virus (Part 1)
1. Virus transmitted
to human in mosquito
saliva 2
2. Virus replicates
in target organs 4 3
3. Virus infects white
blood cells and
lymphatic tissues
4. Virus released and
circulates in blood 6

30. Replication and Transmission of Dengue Virus (Part 2)6
5. Second mosquito
ingests virus with blood
6. Virus replicates
in mosquito midgut
and other organs,
infects salivary
glands 7 5
7. Virus replicates
in salivary glands 7

31. Pathogenesis
In experimental studies of dengue virus infection in rhesus monkeys, after subcutaneous inoculation, virus was disseminated rapidly to regional lymph nodes and then to lymphatic tissue through out the body.

32. What are the tests needed?
Routine blood test
Tests to check the clotting process
Special tests to identify the Dengue or its foot marks in our blood
Urine to check protein leak

33. Special Test (ELISA)
ELISA Plate
IgM-capture ELISA

34. Treatment of Dengue Supportive measures – Mosquito screen
Avoid Aspirin .
Plenty of water and salt are required
Children below 12 require careful watch
for dangerous form
No antibiotics are of proven value

35. Prevention

36. Mosquito Control How to prevent mosquito spread?
Frequently (once in 2-3 days) empty all water storage containers
Cover your over tanks to prevent mosquitoes breeding in fresh water
Do not allow empty vessels, coconut shells, plastic containers, flower pots, tires etc to collect rain water in them

37. How to prevent mosquito bites?
Screen your homes with mosquito screens like Netlon .
Wear full clothing – long sleeves.
Apply mosquito repellents like Odomos.
Keep Dengue fever patient under mosquito net.
True community participation is key.
          

38. Thank you