Dengue fever is a mosquito-borne disease spread by infected female Aedes Aegypti mosquitos. The majority of cases occur in tropical regions of the world, such as the Indian subcontinent, Southeast Asia, Southern China, Taiwan, the Pacific Islands, the Caribbean, Mexico, Africa, Central and South America, and the Caribbean Islands.
The World Health Organization estimates that 39 million people contract dengue fever each year, with 9.6 million showing symptoms. According to the National Vector-Borne Disease Control Programme, India had over 1 lakh dengue cases in 2018 and over 1.5 lakh cases in 2019.
WHAT CAUSES DENGUE?
Dengue fever is spread by female mosquitos of the Aedes genus, specifically the Aedes aegypti species. The ideal conditions for this mosquito species are usually found between 35° North and 35° South, at a height of 1000 metres (3300 ft). They are most likely to bite in the early morning and late evening.
In a mild case of dengue fever, children and teenagers show few signs or symptoms. If symptoms appear after being bitten by an infected mosquito, they will last for four to seven days.
- Muscle or joint pain
- Loss of appetite
- Inflamed glands
- Aches and pains behind the eyes
Dengue fever is largely dependent on mosquito control and protection from bites from the mosquito that transmits the disease.
The primary method of controlling Aedes aegypti breeding is to destroy its habitats and breeding grounds. Eliminating Aedes aegypti's habitat is the primary method of control. This entails removing all open water sources. This is accomplished by eliminating open water sources or treating these areas with insecticides or biological control agents.
The elimination of open water collection is a far more effective and optimal method of control, as insecticides may have negative health consequences for the local population due to the risk of contaminating local food sources.
Mosquito bites can be avoided by wearing clothing that completely covers the skin, sleeping with mosquito netting, and/or applying insect repellent (DEET being the most effective). While these measures can help reduce an individual's risk of infection, they don't do much to reduce the frequency of outbreaks, which appear to be on the rise in some areas, owing to urbanisation expanding the Aedes aegypti's habitat.
NATIONAL DENGUE DAY
The Ministry of Health and Family Welfare of the Government of India has declared May 16th as National Dengue Day.
RECENT DEVELOPMENTS TO PREVENT DENGUE
• In Yogyakarta, Indonesia, researchers from the World Mosquito Program used mosquitoes infected with Wolbachia bacteria to successfully control dengue fever. When Aedes aegypti mosquitoes carry natural bacteria called Wolbachia, they reduce the mosquitoes' ability to transmit viruses like dengue, Zika and chikungunya.
• The World Mosquito Program is a non-profit organisation based in Australia dedicated to protecting the global community from mosquito-borne diseases.
• Wolbachia are natural bacteria that can be found in up to 60% of insect species, including some mosquitos.
• Wolbachia, on the other hand, is rarely found in the Aedes aegypti mosquito, which is the primary vector of human viruses like Zika, dengue, chikungunya, and yellow fever.
• Humans, animals, and the environment are all safe from Wolbachia.
• The Indian Council of Medical Research (ICMR) has also been working on a similar project to develop a Wolbachia-containing Aedes aegypti strain known as the Puducherry Strain.
• The strain was created in collaboration with Monash University in Australia at the Vector Control Research Centre (VCRC) in Puducherry.
• In India, the National Vector Borne Disease Control Programme (NVBDCP) is the central nodal agency for the prevention and control of six vector-borne diseases: Malaria, Dengue, Lymphatic Filariasis, Kala-azar, Japanese Encephalitis, and Chikungunya. The Ministry of Health and Family Welfare oversees it.
• The CYD-TDV or Dengvaxia dengue vaccine was approved by the US Food and Drug Administration in 2019, making it the first dengue vaccine to receive regulatory approval in the US.
• Dengvaxia is a live, attenuated dengue virus that must be given to children aged 9 to 16 who have had a previous dengue infection confirmed by a laboratory and who live in endemic areas.