Dengue In India: Critical Analysis

What is Dengue?

Dengue is a viral disease. It is essentially, a tropical disease occuring in hot weather and intermittent rainfall conditions.

Causes of Dengue disease?

• It is caused by Aedes Aegypti mosquito and Aedes Albopictus (minor) mosquito. It is a small, black mosquito with white stripes and is approximately 5 mm in size.
• The Aedes eggs remain dormant for > 1 year and will hatch once they come in contact with water.
• Aedes mosquitos cannot fly above 100 m and they bite during the day time. It is an asymptomatic infection.
• A person develops Dengue after 5-6 days of being bitten by an infective mosquito.

Types of Dengue

• It occurs in two forms: Dengue Fever and Dengue Haemorrhagic Fever(DHF).
• Dengue Fever is a severe, flu-like illness.
• Dengue Haemorrhagic Fever (DHF) is a more severe form of disease,  which  may cause death

Factors causing Dengue

• Urbanization, Poor town planning and improper sanitations are the factors.
• Lack of coordination between local bodies and health departments.
• There is a deficiency of manpower and hence active surveillance is not possible according to National Vector Borne Disease Control Program.

Distribution of Dengue/ DHF in India

• Disease is prevalent throughout India in most of the metropolitan cities and towns
• Outbreaks have also been reported from rural areas of Haryana, Maharashtra & Karnataka
• Deaths are more in children during DHF outbreak.

Various serotypes

• Dengue is caused by a virus of the Flaviviridae family and there are four distinct, but closely related, serotypes of the virus that cause dengue (DENV-1, DENV-2, DENV-3 and DENV-4).
• Recovery from infection is believed to provide lifelong immunity against that serotype.
• However, cross-immunity to the other serotypes after recovery is only partial and temporary.
• Subsequent infections (secondary infection) by other serotypes increase the risk of developing severe dengue.

Solutions for Dengue/ DHF

• Dengue Vaccine (Dengvaxia)

  1. A vaccine to prevent dengue (Dengvaxia®) is licensed and available in some countries for people aged 9 to 45 years.
  2. The World Health Organization recommends that the vaccine only be given to persons with confirmed previous dengue virus infection.
  3. The vaccine manufacturer, Sanofi Pasteur, announced in 2017 that people who receive the vaccine and have not been previously infected with a dengue virus may be at risk of developing severe dengue if they get dengue after being vaccinated.
• Keep the environment clean and the windows shut during day time.
• Source reduction activities like preventing water stagnation and using chemical larvicides and adulticides can be taken periodically.
• Use Singapore model which maps and analyses data on dengue using GIS.
• Fluid Management is a solution for dengue haemorrhagic fever and dengue shock syndrome.
• In the event of bleeding, WHO recommends fresh whole blood or packed cell transfusion to increase the platelet count.
• Use of alternative medicines like Nilavembu kudineer (a Siddha medicine) and papaya leaf extract and also goat milk. Also instead of distribution of Nilavembu Kudineer, the government can concentrate its energies on other public health activities.