Dengue Overview : Nepal

1. 1

2. Introduction
Dengue
- Breakborne fever
- Acute mosquito-borne viral infection
- Infectious tropical disease
- Transmitted by female mosquitoes (Aedes aegypti)
- RNA (50mm) virus of the family flaviviridae
genus flavivirus
- Endemic in more than 110 countries
- Emerged in Nepal since 2005.
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3. 3

4. Phases of Dengue
Phases Common Clinical Problems
Febrile Phase
(2-7 days)
⁃ High fever
⁃ Aches and pain
- headache
- retro-orbital pain
- myalgia
- arthralgia
⁃ Poor appetite
⁃ Nausea
⁃ Vomiting
⁃ Abdominal pain
⁃ Dehydration
⁃ Electrolyte imbalance-hyponatremia
⁃ Hypoglycemia
⁃ Febrile seizures in young children
4

5. Phases Common Clinical Problems
Critical Phase
(24-48 hrs.)
⁃ Plasma leakage that may lead to shock
⁃ Severe hemorrhage
⁃ Organ impairment if not properly
managed
⁃ Common complications: acidosis,
hypocalcemia, hypoglycemia
5
Phases III- Recovery
Phase (3-5 days)
Common Clinical Problems
 Hypokalemia-due to diuresis
 Hypervolemia- only if intravenous fluid
therapy has been excessive
 and/or has extended into this period)

6. 6

7. High fever typically
of 2 to 7 days duration, and
presents 2 or more of the
following:
ꚛ Nausea, vomiting
ꚛ Exanthema/rash
ꚛ Myalgia/arthralgia
ꚛ Headache, retro-orbital
ꚛ pain
ꚛ Petechiae or tourniquet
ꚛ test positive
ꚛ Leukopenia
Dengue with any of the
following:
ꚛ Abdominal pain or
ꚛ tenderness
ꚛ Persistent vomiting
ꚛ Clinical fluid
accumulation
ꚛ Mucosal bleeding
ꚛ Lethargy, restlessness
ꚛ Liver enlargement > 2 cm
ꚛ Laboratory: increase in
ꚛ hematocrit, concurrent
ꚛ with rapid decrease in
ꚛ platelet count.
Dengue with at least 1 of the
following
ꚛ Severe plasma leakage
leading to shock
ꚛ Severe bleeding (as
evaluated by a clinician)
ꚛ Severe organ involvement
(i.e., AST or ALT 1000 or
greater, impaired
consciousness, organ
failure).
7
Without
With warning
sings
1. Severe plasma leakage
2. Severe hemorrhage
3. Severe organ
impairment

8. Replication and Transmission
of Dengue Virus
8
1. Virus transmitted
to human in mosquito
saliva
2. Virus replicates
in target organs
3. Virus infects white
blood cells and
lymphatic tissues
4. Virus released and
circulates in blood
3
4
1
2

9. Contd..
9
5. Second mosquito
ingests virus with blood
6. Virus replicates
in mosquito midgut
and other organs,
infects salivary
glands
7. Virus replicates
in salivary glands
6
7
5

10. Transmission
Mosquito-to-human transmission
• The virus is transmitted to humans through the bites of
infected female mosquitoes, primarily the Aedes aegypti
mosquito.
Human-to-mosquito transmission
• Mosquitoes can become infected from people who are viremic
with DENV.
Other modes of transmission
• Vertical transmission
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11. 11

12. Dengue Clinical Syndromes
• Four type
• Undifferentiated fever;
• Classic dengue fever;
• Dengue hemorrhagic fever, or DHF; and
• Dengue shock syndrome, or DSS
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13. Clinical Case Definition
• Classical Dengue fever
- An acute febrile viral disease frequently presenting
with
⁖ headaches,
⁖ bone or joint pain,
⁖ muscular pains,
⁖ rash, and
⁖ leucopenia
13

14. • Dengue Hemorrhagic Fever
⁘Fever, or recent history of acute fever
⁘Hemorrhagic manifestations
⁘Low platelet count (100,000/mm3 or less)
⁘Objective evidence of “leaky capillaries:”
⁖ elevated hematocrit (20% or more over baseline)
⁖ low albumin
⁖ pleural or other effusions
14

15. • 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
15

16. Four Grades of DHF (WHO Classification)
Grade 1
Fever and nonspecific constitutional symptoms
Positive tourniquet test is only hemorrhagic manifestation
Grade 2
Grade 1 manifestations + spontaneous bleeding
Grade 3
Signs of circulatory failure (rapid/weak pulse, narrow pulse
pressure, hypotension, cold/clammy skin)
Grade 4
Profound shock (undetectable pulse and BP)
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17. Danger Signs in Dengue Hemorrhagic Fever
• Abdominal pain - intense and sustained
• Persistent vomiting
• Abrupt change from fever to hypothermia, with
sweating and prostration
• Restlessness or somnolence
17

18. Diagnostic Tool
Test methods
Primary
health care
centers
District/
provincial
hospital
Referral or
specialized
hospitals
National
Reference
Laboratory
Virus isolation Yes
Nucleic acid detection Yes Yes
NS1 Ag
detection
RDT Yes* Yes Yes Yes
ELISA Yes Yes
IgM
detection
RDT Yes* Yes Yes Yes
ELISA Yes Yes
IgG
detection
RDT Yes* Yes Yes Yes
ELISA Yes Yes
Neutralization
assay
Yes
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* may be used in early case detection for the rapid prevention and control in the
beginning of dengue outbreak

19. Epidemiological
triad
19
Host
EnvironmentAgent
Vector
Climate
Rainfall
Humidity
Temperature
Serotype
Virulence
DENV-2
DENV-3
DENV-4
DENV-1
Sanitation
Urbanization
Pop Density
Human Host
Prior
Infection
Age
Race
Gender
Increased
risk for
DHF

20. Current state of Dengue (Global)
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21. 21

22. SAARC
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23. 23

24. Dengue Status
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25. 25
CurrentstateofDengueNepal

26. Dengue Outbreak in Nepal -2016
26Source: Profile of the 2016 dengue outbreak in Nepal

27. Dengue Outbreak in Nepal -2019
1246
268
7151
3807
1977
73 1400
1000
2000
3000
4000
5000
6000
7000
8000
Provience 1 Provience 2 Provience 3 Provience 4 Provience 5 Provience 6 Provience 7
Dengue case
Number
27Source:EDCD २०७६/७/७

28. Global Strategy for Dengue
Prevention & Control 2012-2020
Goal
To reduce the global burden of disease
Objectives
• To reduce dengue mortality by at least 50% by 2020
• To reduce dengue morbidity by at least 25% by 2020
• To estimate the true burden of the disease by 2015
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29. Strategies
• Technical element 1: Diagnosis and case
management
• Technical element 2: Integrated surveillance and
outbreak preparedness
• Technical element 3: Sustainable vector control
• Technical element 4: Future vaccine implementation
• Technical element 5: Basic operational and
implementation research
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30. Enabling Factors for Effective
Implementation
• Advocacy and resource mobilization
• Partnership, co-ordination and collaboration
• Communication to achieve behavior outcome
• Capacity building
• Monitoring and evaluation
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31. Nepal’s Dengue Control Programme
Goal — To reduce the morbidity and mortality due to dengue fever,
dengue haemorrhagic fever (DHF) and dengue shock syndrome
(DSS).
Objectives:
• To develop an integrated vector management (IVM) approach for
prevention and control.
• To develop capacity on diagnosis and case management of dengue
fever, DHF and DSS.
• To intensify health education and IEC activities.
• To strengthen the surveillance system for prediction, early
detection, preparedness and early response to dengue outbreaks.
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32. Strategies:
• Early case detection, diagnosis, management and
reporting of dengue fever, DHF and DSS.
• Regular monitoring of dengue fever, DHF and DSS
cases and surveillance through the EWARS.
• Mosquito vector surveillance in municipalities.
• The integrated vector control approach where a
combination of several approaches are directed
towards containment and source reduction
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33. Denguecasemanagement
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34. Treatment
No specific treatment for dengue fever.
Patients with dengue should seek medical advice upon the
appearance of warning signs.
• For muscle aches and pains, and fever, Fever reducers and pain
killers can be taken (acetaminophen or paracetamol.)
• Avoid NSAIDs (non-steroidal anti-inflammatory drugs), Like
Ibuprofen and aspirin.
(Cause it thinning the blood, and in a disease with risk of
hemorrhage, blood thinners may exacerbate the prognosis.)
• For severe dengue, medical care by physicians and nurses can
decreasing mortality rates from more than 20% to less than 1%.34

35. Prevention and Control
35
• Environment
al
• Chemical
• Biological
• Insect growth
Regulators
• Chemical
- Space spray
• Genetic
• Mosquito net
• Screening
• Repellants
• Protective
• Clothing
Public law
Anti Larval Anti Adult
Personal
Protection
Legislative
Control

36. Stages of Mosquito
36

37. Environmental Prevention
Environmental modification- Long lasting physical
transformation to reduce vector larval habitats such as
good piped water supply.
Environmental manipulation- Temporary changes to
vector habitats such as frequent emptying and cleaning of
water storage containers, cleaning gutters, proper disposal
of discarded containers and tyres.
Change in human habitation or behavior- Mosquito
screening nets in windows, doors; bed nets for sleeping
during day time, etc.
37

38. Example:
• Improvement of water supply and
water-storage systems
• Mosquito-proofing of water-storage
containers
• Solid waste management
• Street cleansing which removes
discarded water bearing containers
such as plastic cups, bottles, bottle
caps, plastic package covers, etc and
clean drains regularly
• Legislation for building structures to
reduce potential larval habitats
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39. Aedes aegypti Breeding Sites
39

40. Chemical Control
• Complementary to environmental management
• Except in emergencies
Biological
Only certain species of larvivorous fish
-Gambusia affinis, Poecilia reticulata and predatory
Insect growth regulators (IGR)
• Highly toxic to insect larvae or pupae interfering with
development into adults.
• Costly and limited availability.
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41. Anti-Adult Measures
Fogging (Chemical Method)
Only in emergency situations
• Can be done on day 0,2,7
• Chemicals
• Organophosphate
• Pyrethroid
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42. Personal Protection Measures
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43. Legislative Control
• Suitable laws and regulations should be enacted and
implemented for regulating storage/ utilization of
water by communities, various agencies and
avoidance of mosquito genic conditions at
construction sites, factories.
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44. Vaccination against dengue
• First dengue vaccine, Dengvaxia® (CYD-TDV)
• Developed by Sanofi Pasteur
• Licensed in December 2015
• Approved by regulatory authorities in ~20 countries.
• The vaccine is targeted for persons living in endemic areas,
ranging from 9-45 years of age
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45. Community Engagement:
• Educating the community on the risks of mosquito-
borne diseases;
• Engaging with the community to improve participation
and mobilization for sustained vector control
Active Mosquito and Virus surveillance:
• Active monitoring and surveillance of vector abundance
and species composition should be carried out to
determine effectiveness of control interventions;
• Prospectively monitor prevalence of virus in the
mosquito population, with active screening of sentinel
mosquito collections
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46. Policy Related to Dengue
National Urban Policy – 2007
The second main objective of the policy
- To improve the quality of life of urban inhabitants through
creation of clean, safe and prosperous urban environment.
Strategies to achieve the above mentioned objective for addressing
the issues of eliminating water-born vector-based virus-caused fever
like Dengue.
These are:
⁃ To encourage and guide local authority to carry out urban
development activities according to approved plan,
⁃ To encourage environment friendly public transportation
system,
⁃ To develop balanced town and suburb through conservation
and sustainable use of natural resources and traditional
physical structures, 46

47. • To develop dense urban settlements with physical facilities by
discouraging scattered settlements,
• To identify and utilize possible resource for urban infrastructure
development.
• To develop healthy cities by giving priority to environment
conservation while executing town development activities and
mobilizing natural resources.
• To encourage well facilitated large town and settlements in order to
reduce degrading state of natural resources and investment in
infrastructure facilities by discouraging development of scattered
settlements.
• To establish a system of development and implementation of
disaster management plan by local institution to reduce loss of lie
and property from likely natural disaster 47

48. National Shelter policy 1996
(Revision 2007)
Main Objective
-To develop the concept of shelter for all through increased
production of environment friendly shelters.
Strategy to achieve above objective are
To increase in housing production along with upgrading
of existing housing stock,
To increase and develop required physical infrastructure
and service facilities,
To improve construction technology and building
materials in construction.
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49. 49
Type of Articles
Journal name &
Published year
Title
Author name
and Address

50. Key Finding
ꚛ Dengue is an emerging disease in Nepal.
ꚛ It is rapidly spreading into new areas across the country.
ꚛ All four DENV serotypes are circulating in Nepal.
ꚛ A subsequent DENV infection with a different serotype
can lead to severe form of DHF/DDS.
ꚛ No specie antiviral treatment is available.
ꚛ Treatment is symptomatic and supportive.
ꚛ A nationwide integrated epidemiological entomological
surveillance needs to be put high on the priority by health
policy-makers.
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52. Bibliography
• Pun, S.B., 2011. Dengue: an emerging disease in Nepal. Journal of the Nepal Medical
Association, 51(184).
• WHO TDR Neglected Tropical Disease Research [webpage on the Internet]. Geneva:
World Health Organization (WHO); 2013 [cited Dec 23, 2019]. Available from:
http://www.who.int/tdr/research/ntd/en/.
• Dengue Control – Control Strategies [webpage on the Internet]. Geneva: World Health
Organization (WHO); 2013 [cited Dec 23, 2019]. Available from:
http://www.who.int/denguecontrol/control_strategies/en/.
• National Guidelines on Prevention, Management and Control of Dengue in Nepal 2019:
web : https://www.who.int/docs/default-source/nepal-documents/national-guidelines-on-
prevention-management-and-control-of-dengue-in-nepal.pdf?sfvrsn=e02216fd_2
• Annual Report, Department of Health Services 2074/75 (2017/18) web :
https://dohs.gov.np/category/annual-report/
• Epidemiology and Disease Control Division web; http://www.edcd.gov.np/section/dengue-
control-program 52

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