This document provides information on dengue fever, including: - It is caused by four dengue virus serotypes transmitted by Aedes aegypti mosquitoes. - There are two clinical forms: classical dengue fever and more severe dengue hemorrhagic fever. - Dengue is most common in urban and semi-urban areas in tropical regions during rainy seasons, and most often affects children under 15 in Asia. - Symptoms include fever, headache, rash and joint pain. Treatment is symptomatic and supportive, with prevention focusing on mosquito control and personal protection measures. While a vaccine exists, further research is still needed.

1. Community
Medicine
RIT 3rd
Dengue
#MEHRAN RIT student Affro asian institute .pak1

2. Introduction
• Dengue fever is caused by the bites of infective female Aedes
aegypti mosquito.
• This mosquito transmits dengue virus into the blood of a healthy
person.
• Dengue infections are caused by four closely related viruses
named:
• DEN-1
• DEN-2
• DEN-3
• DEN-4
• These four viruses are called serotypes because each has different
interactions with antibodies in human blood serum.
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3. Modes of Transmission
 This is a vector borne communicable disease.
 This is the commonest arthropod borne viral infection in
humans as the vector is a mosquito in the transmission
of this infection.
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4. Clinical forms of dengue
• There are two clinical forms of dengue:
Classical dengue fever/breakbone fever
This fever is characterized by abrupt onset of fever ,
malaise , headache, facial flushing , retro bulbar pain and
rashes on skin.
Dengue hemorrhagic fever
This is a severe form of dengue fever and is as a result of
two or more sequential infections with different dengue
serotypes.
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5. Epidemiology
“This is the branch of medicine which
deals with the incidence , distribution
and possible control of disease and
factors relating to health.”
 Distribution by:
a) Time: The peak of dengue epidemic period is
around June to August during the rainy
season.They bite mostly during daytime.
b) Place:
They breed in standing water and are
often found in urban and semi-urban
areas.
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c) Person:
In Asia dengue fever affect mainly children under 15
years of age.
In America the age distribution is different
where this infection occur in all age groups
but majority of fatalities during epidemics
occur in children
AGE
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• Dengue seropositivity was found significantly associated
with Female gender.
• South America report that both sexes are equally
affected although a male to female ratio of 0.65:1.
Gender
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Possible control of dengue
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• Possible factors
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11. Symptoms
• Basic symptoms:
headache
Gums, nose and eyes bleeding
fever
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• Vascular symptoms:
leukopenia
thrombocytopenia
Late Eosinophilia
Neutropenia
Reduced coagulation
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• Skin symptoms:
rashes
bruising
petechiae
purpura
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14. • Other symptoms:
• Joint pain.
• Vomiting.
• Intestinal bleeding.
• Hepatic injury.
• Internal haemorrhaging.
• Altered haematopoiesis.
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16. Incubation period
• Incubation period:
The incubation period is 3 to
10 days following the mosquito bite.
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17. Treatment
• Treatment is smptomatic and supportive.
• Antipyretic and body sponging is required to keep the
temprature below 40c.
• Aspirin should be avoided.
• In case of shock vigorous replacement of volume is
required.
• Immediate replacement of plasma volume with 5%
dextrose in normal saline solution is given.
• Blood transfusion is recommended in case of persistent
shock.
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18. Prevention
• Travelers should be advised to sleep under impregnated
nets and to use topical repellents.
• Adult mosquitoes should be destroyed by sprays and
breeding sites should be eradicated.
• Keep flower pots dry.
• Cover body and arms especially at sunrise and sunset.
• Apply mosquito repellent lotion on uncovered body parts.
• Wash water containers daily and keep them properly
covered.
• So far no effective vaccine has been made.
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• Integrated vector control:
Combining two or more
vector control methods to avoid excessive use of one
method. This strategy is used to counteract technical ,
financial , enviornmental and operational problems.
IVC
Biological
Chemical
Personal
protection
Health
education
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• There are some preventive tips
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21. Vaccination
• As of 2019 one version is commercially available , known as
CYD-TDV under brand name Dengvaxia.
• Dengvaxia is a weakened but live vaccine and works by
triggering an immune response against four types of dengue
virus.
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• Age for vaccination:
The vaccine should be used within
the indicated age range , typically 9 to 45 years of age.
The optimal age group is the age at
which incidence of severe dengue is highest and this can
be ascertained from national and subnational routine
hospital data.
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23. Any Question????????
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