Download dengue and its precautions - Kendriya Vidyalaya No.3 Agra

OVERVIEW OF DENGUE SYNDROME AND ITS PREVENTION
Introduction:
Dengue fever (DF) and dengue hemorrhagic fever (DHF) are acute febrile
diseases, caused by a family of viruses that are transmitted by mosquitoes.
It is transmitted by the bite of an Aedes aegypti (rarely Aedes albopictus)
mosquito that has been infected with any one of the four dengue viruses.
Dengue is also known as "breakbone" or "dandy fever." The name
breakbone fever was given because of the contortions caused due to the
intense joint and muscle pain. The name dandy fever was given because of
the postures and gait of West Indian slaves who contracted dengue.
Dengue hemorrhagic fever is a more severe form of the viral illness and can
be life-threatening or even fatal.
Geographical Spread:
This disease is predominant in the tropical and subtropical areas of the
world. In India it has been noted since 1812. In Calcutta there has been
epidemics several times in 1960,1963,1964 and 1970.There has been
explosive outbreak in Delhi 1982 and 1996. When 72247 cases were
reported out of which 297 died .
It is due to growing urban population , poor housing condition, overcrowding
and inadequate sanitation.
Causes of Dengue
As said before dengue fever (DF) and dengue hemorrhagic fever (DHF) is
caused by dengue virus which belongs to genus Flavivirus family
Flaviviridae. This virus is transmitted by Aedes aegypti mosquito that has
previously bitten an infected person.
Aedies mosquito is also known as Tiger Mosquito as it has got black and
white stripes on his back.It is a day time biting mosquito and breeds in clean
stagnated water.
This species of mosquito flourishes during rainy seasons. However, they can
breed all round the year in water-filled flower pots, plastic bags, and cans.
One mosquito bite is strong enough to inflict the disease.
However, the virus is not contagious and does not spread from person to
person. It requires the mosquito as a medium and a person-to-mosquito-toanother-person pathway.
Symptoms of Dengue :
The incubation period of dengue fever is usually 5 – 6 days. However, this
period at times may vary between 3 to 10 days. Dengue fever affects one
and all, starting from infants to young children and adults. But it is seldom
fatal in nature.
The symptoms manifested by dengue vary according to the age of the
patient. Infants and young children usually have a non-specific febrile illness
which is characterised by the appearance of rash.
On the other hand, the symptoms manifested by older children and adults
are:

Abrupt onset of high fever (up to 105 degrees Fahrenheit)

Severe headache

Severe muscle and joint pain (break bone fever)

Rash and other haemorrhagic manifestation
Leucopenia
However, dengue hemorrhagic fever (DHF) is a potentially deadly
complication and the symptoms manifested are:


High fever

Headache

Anorexia

Vomiting and abdominal pain

Haemorrhagic diathesis, commonly demonstrated by scattered fine
petechiae on the extremities, face, trunk, and in the axillae

Bleeding nose, gums, and gastrointestinal tract

Hematuria (though a rare symptom)

Enlargement of the liver
The alarming signs in Dengue are

Bleeding nose and gums, hemetemesis

Refusal to food or drink

Difficulty in breathing

Reduced urination

Minute spots on the skin signifying bleeding within the skin

Abnormal behaviour

Drowsiness
Diagnosis of Dengue





Isolation of virus in serum
Serological diagnosis: IgM antibodies and IgG antibodies
Chemistry panel
Guaiac test
Complete blood count




Liver
Hemoconcentration (hematocrit increased by 20%)
Thrombocytopenia (platelet count <100 x 109/L)
Leukopenia
function tests
Imaging Studies


Chest radiography
Head CT scan without contrast
Treatment for dengue
Dengue is caused by a virus. There is no specific treatment or antibiotic for it. The
treatment provided to a patient during dengue infection is mainly supportive in nature which
is purely concerned with the relief of the symptoms (symptomatic).
The patient is advised to take complete rest and increase the intake of fluids in order to
prevent dehydration and significant hemo-concentration. However, if the patient is unable
to maintain oral intake, supplementation with intravenous fluids may be necessary.
In case if the platelet level drops significantly, a platelet transfusion becomes necessary.
Mortality/Morbidity

Treated DHF/DSS is associated with a 3% mortality rate.

Untreated DHF/DSS is associated with a 50% mortality rate.
Prevention
The best precaution for Dengue is the prevention of mosquito bites.
Some important tips:

Use insect repellent containing DEET, Picaridin, oil of lemon eucalyptus, or IR3535 on
exposed skin.

Wear long sleeves and pants.

Treat the clothes with permethrin or other repellents.

Use secure screens on windows and doors to keep mosquitoes out.

Get rid of mosquito sources in and around the house by emptying standing water
from flower pots, buckets and barrels. Also, change the water in pet dishes and
replace the water in bird baths once every week. In order to drain out water, drill
holes in tire swings. Moreover, keep children's wading pools empty while not at use

Since the infection of dengue essentially requires a mosquito, the transmission of the
virus to mosquitoes must be interrupted in order to prevent the illness. To achieve
this, infected patients should limit his exposure to mosquito bites and remain
confined under mosquito netting until the second bout of fever is over. Thereafter,
the infection is no longer contagious.
Vaccination
Currently, no vaccine is available for the prevention of dengue infection. However,
immunogenic, safe tetravalent vaccines have been developed and are undergoing
clinical trials.
By Dr. Bhavna Singh