Dengue
Upcoming SlideShare
Loading in...5
×
 

Like this? Share it with your network

Share

Dengue

on

  • 14,016 views

 

Statistics

Views

Total Views
14,016
Views on SlideShare
13,986
Embed Views
30

Actions

Likes
7
Downloads
1,127
Comments
3

1 Embed 30

http://www.slideshare.net 30

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
  • like
    Are you sure you want to
    Your message goes here
    Processing…
  • thanks...
    Are you sure you want to
    Your message goes here
    Processing…
  • thanks
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment
  • 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?
  • Today I’ll be sharing with you more information about dengue, meant for all schools, from The National Environment Agency. I will explain how dengue is spread and what we can do to stop it. Please listen carefully as dengue can strike anyone…you and me.  
  • So what is dengue fever? Dengue fever is an illness caused by the dengue virus which is spread by the Aedes mosquito.  
  • How do you know if you have dengue fever? You have dengue fever if you have a fever that does not go away even after a few days; You may also experience headaches, muscle and joint pains, skin rash, and vomiting.
  • Dengue fever and dengue haemorrhagic fever are the most common diseases spread by the Aedes mosquitoes. The mosquitoes can carry 4 different types of dengue viruses hence you can be infected with dengue fever more than once. If you had dengue fever before and are infected again, you are more likely to develop the more deadly and serious dengue haemorrhagic fever.
  • 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. 
  • 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.
  • 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!
  • We all know by now that the Aedes mosquito spreads the dengue virus, but how exactly do they do it? Mosquitoes cannot transmit the dengue virus amongst themselves, they need to first bite a person who is already infected with the dengue virus. The infected mosquito will then carry the dengue virus and pass it onto a healthy person when it bites him/her and causing them to fall sick. The cycle then continues with the new victim.
  • So now that you know more about the dengue, what can you do to stop it?
  • The most important thing you need to do is to stop the Aedes mosquito from breeding. Remove all stagnant water. Don’t let it lay its eggs.
  • Here are the 10-minute mozzie wipe out exercise that you could work on to help get rid of stagnant water in and around your house.
  • Change water in vases on alternate days.
  • Remove water from flower-pot plates on alternate day.
  • Turn over all pails and water storage containers.
  • Tell your parents or any adults in your house to cover bamboo pole holders when they are not in use.
  • And tell your parents or any adults in your house to clear blockages and put BTI insecticide in roof gutters monthly.
  • Do not litter. Rubbish such as cups ad bottles can collect rain water and breed mosquitoes.
  • If you are going on holiday and there is no one in your house, there are a few things you should do before you leave to stop mosquitoes from breeding.
  • Cover all toilet bowls in your home. Seal off the overflow pipe of the flushing cistern. Cover all gully/floor traps. This prevents mosquitoes from getting to the water inside these places and breeding when you are away. Add sand granular insecticide to places that mosquitoes could potentially breed, such as flower vases and places where stagnant water could not be removed.
  • Clear blockages and add Bti insecticide in roof gutters. Ask a relative or close friend to check your home regularly for stagnant water if you are going away for a long period of time. Leave your contact with your neighbours or the neighbourhood police post / centre you can be reached easily.
  •   You can also help prevent dengue by telling people what you have learned today. Tell your family, friends and neighbours why mosquito breeding is bad and how they can help stop it.  
  • 2
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 17
  • 18
  • 21
  • 22
  • 13
  • We will now have a quiz to test how much you have learnt about dengue and Aedes mosquito. We are giving away some tokens for those who answer correctly.

Dengue Presentation Transcript

  • 1. Junhel Dalanon, DDM, MAT
  • 2. Contents
    • What is dengue fever
    • Symptoms of dengue fever
    • Characteristics of the A edes mosquito
    • Life cycle of the Aedes mosquito
    • How the Aedes mosquito transmit diseases
    • How to prevent the spread of dengue fever
    • The 10-Mininute Mozzie Wipe-out Exercise
    • Quiz
  • 3. What is dengue fever? Dengue Fever is an illness caused by infection with a virus transmitted by the Aedes mosquito .
  • 4. Symptoms of Dengue Fever Example of a skin rash due to dengue fever
  • 5. Do you know…
    • Dengue Fever (DF) and Dengue Haemorrhagic Fever (DHF) are the most common mosquito-borne viral disease in the world.
    • It can be fatal.
  • 6. 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.
    Close-up of an Aedes mosquito
  • 7.
    • 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.
    Do you know…
  • 8. Life cycle of the Aedes Mosquito 1-2 days Stagnant water Pupae 4-5 days Larvae Eggs 2-3 days
  • 9. How Do Aedes Mosquitoes Transmit Diseases... Mosquito bites and sucks blood containing the virus from an infected person. Virus is carried in its body. And passes the virus to healthy people when it bites them.
  • 10. This is what you can do to help…
  • 11. Prevent Aedes from Breeding! Remove ALL sources of stagnant water. Deny the Aedes mosquito of any chance to breed.
  • 12. 10-Minute Mozzie Wipe-Out Exercise
  • 13. Do the 10-Minute Mozzie Wipe-out everyday. Change water in vases on alternate days.
  • 14. Do the 10-Minute Mozzie Wipe-out everyday. Remove water from flowerpot plates on alternate days.
  • 15. Do the 10-Minute Mozzie Wipe-out everyday. Turn over all pails and water storage containers.
  • 16. Do the 10-Minute Mozzie Wipe-out everyday. Cover bamboo pole holders when not in use.
  • 17. Do the 10-Minute Mozzie Wipe-out everyday. Clear blockages and put Bti insecticide in roof gutters monthly.
  • 18. Unwanted items Do not litter. Rubbish such as cups and bottles can collect rain water and breed mosquitoes.
  • 19. Before you leave for holidays…
  • 20.
    • Cover all toilet bowls in your home.
    • Seal off the overflow pipe of the flushing cistern.
    • Cover all gully/floor traps.
    • Add sand granular insecticide to places that mosquitoes could potentially breed, such as flower vases and places where stagnant water could not be removed.
    Before you leave for holidays…
  • 21.
    • Clear blockages and add Bti insecticide in roof gutters.
    • • Turn over all water storage containers.
    • Ask a relative or close friend to check your home regularly for stagnant water if you are going away for a long period of time.
    • Leave your contact with your neighbours or the neighbourhood police post/ centre so that you can be reached easily.
    Before you leave for holidays…(Cont’d)
  • 22. Spread the dengue prevention message to others… Let your family , friends and neighbours know about the dangers of breeding Mozzies!!
  • 23.
    • Dengue is an arthropod-borne disease caused by any one of four closely related viruses, ( Arbovirus ).
    • Characterized by fever, severe headache, backache joint pains nausea and vomiting, eye pain and rash
    • Occasionally produces shock and hemorrhage, leading to death.
    • Also called breakbone fever , dandy fever or dengue fever.
    Dengue fever
  • 24. Epidemiology
    • Globally, there are an estimated 50 to 100 million cases of dengue fever (DF) and several hundred thousand cases of dengue hemorrhagic fever (DHF) per year.
    • 2.5 billion people are at risk world-wide
    • In the last 20 years, dengue transmission and the frequency of dengue epidemics has increased greatly in most tropical countries
    • It is a resurgent (re-emergent) disease worldwide in the tropics
  • 25.
    • Major global demographic changes (urbanization and population growth)
    • These demographic changes have resulted in sub-standard environmental sanitation that facilitates transmission of Ae. aegypti -borne disease; (Overcrowding in cities with poor sanitation)
    Factors contribute to the emergence and re-emergence of arthropod-borne diseases
  • 26.
    • Increased travel by airplane resulting in a frequent exchange of dengue viruses and other pathogens.
    • Inadequate mosquito control services; the use of insecticide space sprays for adult mosquito proved ineffective approach for controlling Ae. aegypti . (Domestic habitat)
    • The emergence of resistance to insecticides linked to their increased misuse.
  • 27.  
  • 28. Mean Annual Number of DHF Cases Thailand, Indonesia and Vietnam, by Decade * Provisional data through 1998
  • 29. Reported Cases of DHF in the Americas, 1970 - 1999 * Provisional data through 1999
  • 30.  
  • 31.  
  • 32. Distribution of suspected and confirmed 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 0 0 4 Total 1020 319
  • 33. Virus, Vector and Transmission
  • 34. Dengue Viruses
    • Four closely related single-stranded RNA Dengue viruses (DEN-1, DEN-2, DEN-3 and DEN-4)
    • Each serotype provides specific lifetime immunity, and short-term cross-immunity (A person can be infected as many as four times, once with each serotype)
    • All serotypes can cause severe and fatal disease
  • 35. Transmission of Dengue Virus by Aedes aegypti Viremia Viremia Extrinsic incubation period DAYS 0 5 8 12 16 20 24 28 Human #1 Human #2 Illness Mosquito feeds / acquires virus Mosquito refeeds / transmits virus Intrinsic incubation period Illness
  • 36. Replication and Transmission of Dengue Virus (Part 1) 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
  • 37. Replication and Transmission of Dengue Virus (Part 2) 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
  • 38. Aedes aegypti Mosquito
  • 39. Aedes aegypti
    • Dengue transmitted by infected female Aedes aegypti mosquito
    • Primarily, it is a daytime feeder
    • Highly domesticated tropical mosquito, lives around human habitation
    • Lays eggs and produces larvae preferentially in artificial water containers inside and around the houses for example; plastic containers, flower vases, buckets, used automobile tires,..
  • 40. Dengue Clinical Syndromes
    • Undifferentiated fever (87% of Patients are asymptomatic or mild fever)
    • Classic dengue fever (DF)
    • Dengue hemorrhagic fever (DHF)
    • Dengue shock syndrome (DSS)
  • 41. Clinical Characteristics of Dengue Classic Fever
    • Incubation period 3-14 days (commonly 4-7 days)
    • Fever
    • Headache
    • Muscle and joint pain
    • Nausea/vomiting
    • Rash
    • Hemorrhagic manifestations
  • 42. Dengue Hemorrhagic Fever (DHF)
    • Fever, or recent history of acute fever
    • Hemorrhagic manifestations
    • Low platelet count (100,000/mm 3 or less)
    • Objective evidence of “leaky capillaries:”
      • elevated hematocrit (20% or more over baseline)
      • low albumin
      • pleural or other effusions
    4 Necessary Criteria:
  • 43. Dengue Shock Syndrome (DSS)
    • 4 criteria for DHF
    • Evidence of circulatory failure.
  • 44. Risk Factors Reported for DHF
    • Virus serotype
      • DHF risk is greatest for DEN-2 , followed by DEN-3, DEN-4 and DEN-1
    • Pre-existing anti-dengue antibody
      • previous infection
      • maternal antibodies in infants
    • Host genetics
    • Age (fatal cases are among children and young adult).
    • Higher risk in secondary infections
    • Higher risk in locations with two or more serotypes circulating simultaneously at high levels (hyper-endemic transmission)
  • 45. Increased Probability of DHF Hyperendemicity Increased circulation of viruses Increased probability of secondary infection Increased probability of occurrence of virulent strains Increased probability of immune enhancement Increased probability of DHF Gubler & Trent, 1994
  • 46. Common Misconceptions about Dengue Hemorrhagic Fever
    • Dengue + bleeding = DHF
      • Need 4 WHO criteria & capillary permeability
    • DHF kills only by hemorrhage
      • Patient dies as a result of shock
    • Poor management turns dengue into DHF
      • Poorly managed dengue can be more severe, but DHF is a distinct condition, which even well-treated patients may develop
    • DHF is a pediatric disease
      • All age groups are involved
    • DHF is a problem of low income families
      • All socioeconomic groups are affected
  • 47. Treatment of Dengue Fever
    • Antipyretics (Acetaminophen) preparations to manage the pain and fever.
    • Avoid Aspirin and non-steroidal anti-inflammatory.
    • Rest and drink plenty of fluids
    • Monitor blood pressure, hematocrit, platelet count,...
    • Keep patient in screened sickroom or under a mosquito net
    • Mosquito barriers are only needed until fever subsides, to prevent Aedes aegypti mosquitoes from biting patients and acquiring virus.
  • 48. Prognosis
    • Dramatic clinical response to aggressive fluids and electrolytes.
    • Convalescence may be prolonged, with weakness and mental depression
    • Survival is related directly to early hospitalization and aggressive supportive care
    • Treated DHF is associated with a 3% mortality rate
    • Un-treated DHF is associated with a 50% mortality rate.
  • 49. Prevention
    • Personal protection against mosquito biting by:
      • Screening doors and windows
      • Protective clothing
      • Application of mosquito repellents on exposed skin
    • However, the best preventive measure is vector control.
  • 50. Vector Control Methods:
    • Biological control
      • Largely experimental
      • Option: place fish in containers to eat larvae
    • Environmental control
      • Elimination of larval habitats; Cover water holding containers, Discard artificial containers,…
      • It is the most likely method to be effective in the long term.
  • 51. Vector Control Methods:
    • Chemical Control
    • Larvicides may be used to kill immature aquatic stages
    • Ultra-low volume fumigation is ineffective against adult mosquitoes as Aedes aegypti is fully domesticated
    • Mosquitoes may have resistance to commercial aerosol sprays.
  • 52. Dengue Vaccine?
    • No licensed vaccine at present
    • Effective vaccine must be tetravalent
    • Field testing of an attenuated tetravalent vaccine currently underway
    • Effective, safe and affordable vaccine will not be available in the immediate future.
  • 53. Community Participation
    • Active community involvement and participation to reduce larval breeding sources is the key for prevention and control.
    • Educate the public in the basics of dengue, such as:
      • Where the mosquito lays her eggs
      • The link between larvae and adult mosquitoes
      • General information about dengue transmission, symptoms and treatment
  • 54. Public Education
    • Dengue fever is NOT contagious through person-to-person contact
    • Early hospitalization is important.
    • Reduce A aegypti vector populations
    • Reduce exposure to A aegypti .
      • Use insect repellent.
      • Sleep under a mosquito net in affected areas.
      • Wear protective clothing.
    • Vaccine is NOT available.
  • 55. Quiz
  • 56. Why is the Aedes mosquito dangerous to us?
  • 57. ANSWER: It can carry the dengue virus and infect a healthy person with dengue fever.
  • 58. Name the 5 steps in the 10-Minute Mozzie Wipe-out Exercise
  • 59. ANSWER:
    • Change water in vases on alternate.
    • Remove water from flowerpot plates on alternate days.
    • Turn over all pails and water storage containers.
    • Cover bamboo pole holders when not in use.
    • Clear blockages and put in Bti insecticide in roof gutters monthly.
  • 60. What are the things that you should do before going for a holiday?
  • 61. ANSWER:
    • Cover all toilet bowls in your home.
    • Seal off the overflow pipe of the flushing cistern.
    • Cover all gully/floor traps.
    • Add sand granular insecticide to places that mosquitoes could potentially breed, such as flower vases and places where stagnant water could not be removed.
    • Clear blockages and add Bti insecticide in roof gutters.
    • • Turn over all pails and water storage containers.
    • Ask a relative or close friend to check your home regularly for stagnant water if you are going away for a long period of time.
    • Leave your contact with your neighbours or the neighbourhood police post/ centre so that you can be reached easily.