Context

Dengue fever is spreading across regions such as southern Europe and the United States as the planet is getting warmer. 

• Aedes is increasing risk of getting dengue by 2bn people 

About Dengue fever

This fever is a mosquito-borne tropical disease.

• Transmission of disease: A bite from Infected Aedes can transmit dengue fever if the mosquito is carrying a flavivirus pathogen.
  • The Aedes species is a mosquito, such as Ae. aegypti or Ae. albopictus.
• Its symptoms typically begin 3 to 14 days after infection.

Statistics of Dengue fever

Dengue feveris common in tropical and subtropical regions due to various reasons

• The climatic conditions of Tropical and subtropical regions are warm and humid.
• Tropical and Subtropical regions are dense. 
• Increase in Dengue fever Deaths: In 2000, approximately 20,000 people died from dengue, as reported by the World Health Organization (WHO).
  • Current Year Data: This year, the death toll is expected to reach at least 40,000, marking a significant rise in fatalities.
• Contrast with Malaria:
  • In contrast, malaria deaths decreased by 30% between 2000 and 2022, according to WHO data.
• Impact of Dengue fever on India 
  • 1950 and 1960: Dengue fever was concentrated in southeast Asian countries. 

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• • • It started prevailing worldwide in 1970 
    • In India, This disease spread by 2012–13. 
  • Decade Trend
    • Over the decades from 1951–60 to 2012–21, the number of favorable months for dengue transmission in India increased annually by 1.69%.
      • It  reached 5.6 months.
    • Dengue cases in India: Each year, dengue cases surpass lakhs cases in India. 
      • It causes tremendous pressure on the Indian healthcare system. 
        • During pandemic 2020, dengue incidence had decreased by 56-60%. 
        • Highest Dengue cases: Dengue cases were highest in 2021. 
          • Again in 2022, the case declined 

Factors Contributing to Dengue fever Spread

• Climate Change and Mosquito Range:

  • Higher temperature sensitivity: Higher temperatures and humidity create favorable conditions for mosquito breeding.
    • Due to current climate trends, Aedes could spread to southern Europe and the United States.

• Urbanization:

  • Favorable condition: Urbanization facilitates the spread of dengue as mosquitoes find more hosts in densely populated areas.
    • Dengue cases are increasing in previously unaffected regions like Bangladesh, India, California, southern Europe, and subtropical Africa.

• Water Storage Practices:

  • Breeding in stagnant water: Aedes mosquitoes breed in stagnant water, which is commonly found in containers and water storage vessels.
  • Improper water storage practices, such as open containers and neglected water sources, create ideal breeding sites for mosquitoes, leading to higher dengue transmission rates.

• Lack of Effective Vector Control:

  • Inadequate vector control: lack of  measures, such as mosquito surveillance and elimination programs, contribute to the continued spread of dengue.
  • Limited resources and infrastructure: lack of proper infrastructure and limited resources in some regions hinder efforts to effectively control mosquito populations and prevent dengue outbreaks.

Innovative Approaches to Dengue Control

• Singapore’s Approach:
  • Singapore uses both traditional methods and innovative strategies like releasing mosquitoes infected with wolbachia bacteria.
    • Since 2016, Singapore has implemented a technologically advanced dengue program.
      • This method, combined with vaccine development, offers a promising alternative to traditional mosquito control.
• Vaccine in India: Currently, there is no approved vaccine in India. 
  • However, Initiatives are going on for “Dengusiil”. 
• Impact of Wolbachia:
  • Trials in Colombia: These trials have shown a significant reduction in dengue cases where wolbachia-infected mosquitoes were released.
  • largest wolbachia-mosquito factory: Brazil is set to host the world’s largest wolbachia-mosquito factory.
    • This initiative will help other regions to combat dengue.

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