• Fever Dengue (pronounced DEN-gee) is caused by
viruses that are transmitted by mosquito bites.
• Aedes aegypti is the mosquito that most commonly
spreads this disease through its bite.
• It is a severe illness with symptoms as fever,
headache, intense muscle and joint pains,
exhaustion, lymphadenopathy (swollen glands) and
• There are other name for dengue is
• Because dengue fever is caused by a virus,
there is no specific medicine or antibiotic to
• For typical dengue fever, the treatment is
directed toward relief of the symptoms
• The acute phase of the illness with fever lasts
about one to two weeks.
• Dengue can affect anyone but tends to be more
severe in people with compromised immune
• Because it is caused by one of five serotypes of
virus, it is possible to get dengue fever multiple
• However, an attack of dengue produces
immunity for a lifetime to that particular viral
serotype to which the patient was exposed.
Epidemiology of dengue fever
• Dengue is prevalent throughout the tropics and
• Dengue is also known as “breakbone fever”
because of the intense joint and bone pain
caused by the infection.
• About 40 percent of the world is currently at
risk for dengue.
• Only forty years ago, according to the WHO,
there were only nine countries worldwide that
experienced severe dengue epidemics.
• Today, the WHO estimates between 50 and 100
million dengue infections every year, and
dengue is endemic in over 100 countries
Causes of dengue fever
• It is caused by the following four serotypes:
– DENV-3, and
– DENV-4 (the numbers reflect the order of discovery
and have no relation to disease severity)
• These four serotypes originated in monkeys and jumped
to humans in tropic and sub tropic regions over a
• However a fifth type has been discovered by Nikos
Vasilakis, PhD of the University of Texas Medical
Branch in Galveston:
How dengue spreads?
• The virus is contracted from the bite of a
striped Aedes aegypti mosquito that has
previously bitten an infected person.
• The mosquito flourishes during rainy seasons but
can breed in water-filled flower pots,
plastic bags, and cans year-round. One mosquito
bite can cause the disease.
• The virus is not contagious and cannot be spread
directly from person to person. There must be a
What are dengue fever signs and symptoms?
• After being bitten by a mosquito carrying the
virus, the incubation period ranges from three
to 15 (usually five to eight) days before the
signs and symptoms of dengue appear in
The signs and symptoms are as follows:
• Sudden onset of fever for 2 to 7 days
• Severe headache with retro-orbital (behind
the eye) pain
• Joint and muscle pain
• Skin rashes
• Nausea and vomiting
• Bleeding from the nose or gums or easy
bruising in the skin
• There are currently no licensed dengue vaccines
available. Several vaccine candidates are in clinical
or pre-clinical development.
• The most advanced candidate, a chimeric tetravalent
vaccine based on the yellow fever 17d backbone, is
currently under evaluation in Phase III clinical trials.
• Prevention is currently the best method of dengue
• For typical dengue, the treatment is concerned with
relief of the symptoms.
• Bed rest and mild analgesic-antipyretic therapy are
often helpful in relieving lethargy, malaise, and fever
associated with the disease.
• Aspirin and non steroidal anti-inflammatory drugs
should only be taken under a doctor's supervision
because of the possibility of worsening bleeding
• Acetaminophen (paracetamol) and codeine may be
given for severe headache and for joint and muscle
• Oral rehydration therapy is recommended for
patients with moderate dehydration caused by
high fever and vomiting.
• Patients with known or suspected dengue fever
should have their platelet count and hematocrit
measured daily from the third day of illness
until 1-2 days after defervescence.
• Patients with clinical signs of dehydration and
patients with a rising hematocrit level or falling
platelet count should have intravascular volume
deficits replaced under close observation.
• Those who improve can continue to be
monitored in an outpatient setting, and those
who do not improve should be admitted to the
hospital for continued hydration.
When to admit the patient?
• BP < 90/60 mm Hg
• HCt > 50 %
• Platelets < 50,000/cu.mm
• Bleeding other than petechiae
• When danger signs develop
Factors that affect disease severity include
• Patient age
• Nutritional status
• Sequence of infection with different dengue
• Hepatic failure
• Virus genotype
• Quality and extent of available medical care
• Stay in air-conditioned or well-screened
housing. It's particularly important to keep
mosquitoes out at night.
• Reschedule outdoor activities. Avoid being
outdoors at dawn, dusk and early evening, when
more mosquitoes are out.
• Wear protective clothing. When you go into
mosquito-infested areas, wear a long-sleeved
shirt, long pants, socks and shoes.
• Use mosquito repellent. Permethrin can be applied
to your clothing, shoes, camping gear and bed
netting. You can also buy clothing made with
permethrin already in it. For your skin, use a
repellent containing at least a 10 percent
concentration of DEET.
• Reduce mosquito habitat. The mosquitoes that
carry the dengue virus typically live in and around
houses, breeding in standing water that can collect in
such things as used automobile tyres. Reduce the
breeding habitat to lower mosquito populations.
• Dengue is an infectious disease caused by a virus.
• You can get it if an infected mosquito bites you.
• It is common in warm, wet areas of the world.
• Outbreaks happen in the rainy season.
• Most people with dengue recover within 2 weeks.
• However, some dengue infections are severe and
cause bleeding from your nose, gums or under
• Early diagnosis and treatment of dengue is critical
as epidemics of the disease become larger and
• An estimated 50 to 100 million people are infected
with dengue each year in over 100 countries.
• In severe cases, people infected with dengue may
experience severe bleeding, shock and death.
• Severe dengue is often treated with
aggressive emergency treatment, which includes
fluid and electrolyte replacement.
• Prompt treatment can be life saving. Dengue can be
prevented by limiting exposure to
the mosquitoes that carry the virus.
• Abdullah, 2013, Dengue, Arabic health
encyclopedia. Available at:
• Mayo clinic staff, 2013, Dengue fever, Disease
and conditions. Available at:
• John, 2013, Dengue fever Diagnosis,
MedicineNet.com, Available at:
• Adam, 2009, Dengue fever explained, Ezine
articles. Available at:
• Suzanne et al, 2014, Dengue treatment and
management, Medscape. Available at:
• WHO, 2014, Dengue, Vaccines and disease.