Transcript Measures to Prevent Dengue Fever

The content and pictures are adapted from the
Food and Environmental Hygiene Department’s website.
What is dengue fever?

Dengue fever is prevalent in
tropical and subtropical
regions。
mosquito bites

Transmitted by
viral disease.
, it is an acute

Prevalent in over 60 countries and regions, and
about 2 billion world population are under threat of
its infection.
What are the symptoms of
dengue fever …
High fever for 3 to 5 days
 Severe headache
 Muscle and joint pain
 Pain behind the eyes
 loss of appetite, nausea
 Rash
 Severe cases may have bleeding, shock
and even death

How does it spread?

Transmitted by mosquitoes, cannot be directly transmitted from
person to person.。

The vectors that spread the disease include:


Aedes aegypti
Aedes albopictus Found in Hong Kong
How can you prevent it?

At present, there is
dengue.
no effective vaccine for
So？
We should first understand
the vector of dengue fever－
Aedes albopictus
Profile of Aedes albopictus



Name
Class
Origin of birth

Food
Active time

Characteristics

Aedes albopictus
Insect
South of Liaoning, east of
Shaanxi, more common in
the south of the Yangtze
River
Blood（female）
Daytime, especially 2
hours after sunrise and
several hours before
sunset
Spread dengue virus
Life cycle of Aedes albopictus
 eggs：
Usually laying
eggs in stagnant water, a
female mosquito can produce a
time of about one hundred eggs.
Life cycle of mosquitoes
 Larva：
Like a caterpillar,
it floats with a respirator connecting
it to the water surface.
Life cycle of mosquitoes
Pupa: Like a circular ball, the pupa
comes to the water surface to
breathe with a respirator.
Life cycle of mosquitoes

Adult：breaks out of the pupa
and leaves the water.
Precautionary measures to prevent
mosquitoes breeding：No. 1
Precautionary measures to prevent
mosquitoes breeding：No. 2
Precautionary measures to prevent
mosquitoes breeding：No. 3
Precautionary measures to prevent
mosquitoes breeding：No. 4
Precautionary measures to prevent
mosquitoes breeding：No. 5
Precautionary measures to avoid
mosquitoes bites



Wear long-sleeved clothes and
long trousers
Use insect repellent over exposed
parts of the body when outdoors
Use mosquito screens or nets
when a room is not airconditioned
Please say how they remove stagnant water
and eliminate mosquito breeding
Answers:
Leave no water in the
saucers under flower
pots
Dispose of rubbish
properly
Pierce the tyres
Cover tightly all
water containers