Need for health education to control dengue

Context: Dengue is the fastest transmitted mosquito-borne
viral disease. It is commonly known as breakbone or 7-day fever, characterized
by intense muscle spasms, joint pain, high fever, headache, body aches, nausea,
vomiting, swollen glands, rash, pain behind the eyes, etc. The virus, which has
four serotypes –DEN-1, DEN-2, DEN-3, and DEN-4 of the Flavivirus genus, is
transmitted to humans by the day-biting mosquito vector species Aedes aegypti
and Aedes albopictus. In India, all four serotypes of dengue are found. Globally,
dengue is a common disease in more than 100 countries, and almost half of the
world’s population, about 4 billion people, lives in areas at risk of dengue.
In India, dengue is prevalent in almost all States and is the leading cause of
hospitalization.

Key points

·      
Overview: Dengue transmission is closely associated with three
key factors — rainfall, humidity and temperature — which dictate the
geographies in which dengue spreads and the transmission rate.

·      
Dengue: Dengue is a mosquito-borne tropical disease caused by
the dengue virus (Genus Flavivirus), transmitted by several species of female
mosquito within the genus Aedes, principally Aedes aegypti.

Symptoms- Sudden
high fever, severe headaches, pain behind the eyes, severe bone, joint, and
muscle pain, etc.

Diagnosis and Treatment- Diagnosis of dengue infection is done with a blood test. There is no
specific medicine to treat dengue infection.

·      
Spreading
and carries: Dengue spreads through the
bite of two mosquitoes — Aedes aegypti and Aedes albopictus.

Ø  Aedes aegypti is prevalent in the southern peninsula, eastern coastline,
north-eastern states and the northern plains.

Ø  Aedes albopictus dominates the eastern and western coastlines, north-eastern states and
the lower Himalayas.

·      
Status of
Dengue: Incidence of dengue has grown
dramatically around the world in recent decades, with a vast majority of cases
under-reported, according to the World Health Organization (WHO). WHO estimates
39 crore dengue virus infections per year, of which 9.6 crore show symptoms. According
to data shared by the National Centre for Vector Borne Diseases Control, India
recorded 63,280 dengue cases as of September 2022.

·      
Controlling
Dengue Using Bacteria: Recently
researchers from the World Mosquito Program have used mosquitoes infected with
Wolbachia bacteria to successfully control dengue in Indonesia.

Ø  Method- The
scientists infected some mosquitoes with Wolbachia and then released them in
the city where they bred with local mosquitoes, until nearly all mosquitoes in
the area were carrying Wolbachia bacteria. This is called the Population
Replacement Strategy. At the end of 27 months, the researchers found that the
incidence of dengue was 77% lower in areas where Wolbachia-infected mosquitoes
had been released, as compared to areas without such deployments.

·      
Dengue
Vaccine: The dengue vaccine CYD-TDV
or Dengvaxia was approved by the US Food & Drug Administration in 2019,
the first dengue vaccine to get the regulatory nod in the US. Vaccine
manufacturer Indian Immunologicals Limited (IIL) is developing India's
first Dengue vaccine and has received permission for a Phase-1 trial.

·      
Prevention: If we have some knowledge about the behaviour of
vector mosquitoes and pay attention to a few points, dengue transmission can be
prevented quite simply, as follows:

(i) Person-to-person transmission of the dengue virus
takes place through bites from infected Aedes mosquitoes. So, if one person in
a house is infected with dengue, there is a possibility of infecting others in the
household, as a single Aedes female mosquito can take blood meals from multiple
people.

(ii) Dengue vectors Aedes aegypti and Aedes albopictus
do not breed in drains or other large water accumulations, which are breeding
grounds for Anopheles, Culex, and Mansonia mosquitoes.

(iii) Dengue-carrying mosquitoes breed in small,
unused containers such as broken utensils, bottles, plastic cups, unused tires,
electric pin holders, coconut shells, battery boxes, water coolers, bamboo stumps,
flowerpots, overhead tanks, or any small objects that can store water.

(iv) In hilly regions, people tend to store drinking
water in containers, sometimes without covers or lids, or collect rainwater outside,
facilitating Aedes mosquito breeding. It is recommended to regularly monitor
and cover these containers if possible.

(v) Adult Aedes mosquitoes tend to bite during the
daytime, so efforts should be made to avoid mosquito bites by wearing loose-fitting,
long-sleeve shirts and trousers, as well as using mosquito repellent gel or oil
during the day.