Dengue (DEEngee)
Break-bone FeverWho is Responsible• Usually Four types of Dengue Virus,
Fifth type has been identified in 2013
• DENV-1• DENV-2• DENV-3• DENV-4• DENV-5 (Sylvatic- Occurring in WildAnimals

3 D Structure of VirusHard Facts• It is estimated that there are over 100 million cases ofdengue worldwide each year.
• About 2.5 billion people, or 40% of the world’s
population, live in areas where there is a risk ofdengue transmission.
• Dengue is endemic in at least 100 countries in Asia,
the Pacific, the Americas, Africa, and the Caribbean.
• Infection with one serotype does not protect against
the others.
• Many suffering from Mild Dengue recover
uneventfully.
• Dengue hemorraghic fever (DHF) and Dengue shock
syndrome (DSS) are Severe forms of Dengue.

Dengue Virus

The Villain (Vector)
Aedes aegyptis, Aedes albopictus, Aedes
polynesiensis

Who are at Risk!

Vector & Host

Life Cycle

Life Cycle

Life Cycle

Overview (Habit )Typically:• These mosquitoes do not fly far, themajority remaining within 100
metres of where they emerged.
Max. flying distance is 400 mtrs.
• They feed almost entirely onhumans, mainly during daylight
hours, and both indoors andoutdoors

Overview (Human–Vector contact )• Household and immediate vicinity• Schools, Hospitals and Workplaces• Many purposely-filled household containers
such as those used for domestic water
storage and for decorative plants• Rain-filled habitats – including used tyres,discarded food and beverage containers,
blocked gutters and buildings underconstruction.

How it Starts & Ends
• Symptoms usually begin 4 - 7 days after the mosquito
bite and typically last 3 - 10 days.
• For transmission to occur the mosquito must feed on a
person during a 5- day period when large amounts ofvirus are in the blood; this period usually begins alittle before the person become symptomatic.
• Some people without significant symptoms can still
infect mosquitoes.
• After entering the mosquito in the blood meal, therequires an additional 8-12 days incubation before it
can then be transmitted to another human.
• The mosquito remains infected for the remainder of its
life, which might be days or a few weeks.

What Happens

Classification

Clinical CourseConfusion (DD)Problems & Solutions
Inside House• Use mosquito repellants, coils, door &window screens, Mosquito nets, airconditioningHabitat of Lady Aedes
Flower Vases filled with water• Empty, Clean and Scrub weekly

Habitat of Lady Aedes
Plants as breeding place

Habitat of Lady Aedes
Used Bottles & thrown out Utensils• Collect and dispose of

Habitat of Lady Aedes
Coconut Shells

Habitat of Lady Aedes
Discarded Tyres• Should be collected, recycled & disposedof by proper incineration in wastetransformation facilities

Habitat of Lady Aedes
Gutters• Fill with sand, soil or concrete; Clear clogging

Habitat of Lady Aedes
Roof Top Gutters• Modify design, repair and/or clean

Building structures• Under revised legislation in Singapore,roof gutters are not permitted onbuildings in new developments because
they are difficult to access andmaintain.
• Moreover, property owners arerequired to remove existing gutters on
their premises if they are unable tomaintain them satisfactorily

Habitat of Lady AedesTree Holes• Fill with sand, soil or concreteHabitat of Lady Aedes
Water-storage-tank or cistern• Containers can be fitted with tight lids or,
if rain-filled, tightly-fitted mesh screenscan allow for rainwater to be harvested
from roofs while keeping mosquitoes out.

Habitat of Lady Aedes
Drums (150–200 litres)• Empty, Clear and scrub weekly• Mosquito-proof coverHabitat of Lady Aedes
Potted plants with saucers• Empty, Clear and scrub weekly

Habitat of Lady Aedes
Animal water container• Empty, Clean & Scrub weekly

Habitat of Lady Aedes
Discarded food and drink containers• Collect, Recycle and Dispose of

Habitat of Lady Aedes
Hollow fence posts• Modify design,• Fill with sand, soil or concreteHabitat of Lady Aedes
Discarded large appliances• Collect, Recycle & Dispose of

Habitat of Lady Aedes
Discarded buckets• Collect, Recycle & Dispose of

Habitat of Lady Aedes
Rock Holes• Fill with sand, soil or concreteHabitat of Lady Aedes
Defrosted Water in Fridge drain pan• Empty, Clean and Scrub the containerweeklyHabitat of Lady Aedes
Water in water Coolers• Empty and Clean

Solid Waste Management• Solid Waste:-Mainly refers to non-bio
degradable items of household,community and industrial waste.
• The basic rule of “reduce, reuse, recycle”
is highly applicableHabitat of Lady Aedes
Construction Sites
Fill, drain water

Street cleansing• A reliable and regular street
cleansing system that removes
discarded water-bearing containers
and cleans drains to ensure they do
not become stagnant and breed
mosquitoes will both help toreduce larval habitats of Ae. aegypti
and remove the origin of other urbanpests.

Individual and household protection• Wear long sleeves and pants for additional
protection that minimizes skin exposure during
daylight hours when mosquitoes are mostactive• Repellents may be applied to exposed skin or toclothing.
• The use of repellents must be in strict
accordance with label instructions.
• Insecticide-treated mosquito nets afford good
protection for those who sleep during the day(e.g. infants, the bedridden and night-shiftworkers).

Individual and household protection• Where indoor biting occurs, household
insecticide aerosol products, mosquito
coils or other insecticide vaporizers may
also reduce biting activity.
• Make sure that the household fixtures
such as window and door screens are
secure and without holes.
and• If available, use air-conditioning.

Protect Yourself• If someone in your house is ill with dengue,
take extra precautions to prevent mosquitoes
from biting the patient and going on to biteothers in the household.
• Sleep under a mosquito bed net, eliminate
mosquitoes you find indoors and wearrepellent!
• Repellents containing DEET, picaridin, oil oflemon eucalyptus or IR3535 as the active
ingredient are recommended.
• Clothing impregnated with permethrin is anoption (pre-treated or you can treat yourself)

Salient Feature on Diagnosis• Typical symptoms as called break bone fever• Physical examination• Tourniquet Test

Salient Feature on Diagnosis• Changes in Haematocrit• Depressed White Blood Cell count• Decreased Platelet count (<1,00,000)• Non-Structural Antigen (NS1) positive on 1st or
2nd day (suspect), confirm with Elisa.
• IgG and IgM (Rapid Test) usually becomes
positive on day 4-5 of fever; confirm with Elisa• Elisa Test positive• Virus isolation

Salient Features on Treatment
Say No to;• Pain killers that can cause stomach ulcers• Injectables (both IM & IV)• Antibiotics• Blood Transfusion, unless specificallyindicated
Say Yes to• Paracetamol for fever (Max. 3 times/24 hours)• Platelet Concentrate (If, Platelet < 10,000)• Platelet <50, 000 with bleeding

Take Home Message• Dengue may go un-noticed with mildsymptoms• Can be dangerous with DHF and DSS• No vaccine is available at present• No specific treatment is available• It can be prevented• Don’t give your blood to Aedes mosquito forsuccessful ovulation and don’t provide shelter• Kill the enemy from the beginning• Report break bone fever immediately to doctor• Don’t get panicOne Sentence Message• Be a part of Swachh Bharat Mission of
the Honorable Prime Minister of India
to beat the Dengue’s ugly face.

Thank YouAcknowledgement:WHOCDC