Surge in Dengue Cases

Why in the news?

Dengue cases have surged globally, with over 12 million infections reported in 2024, driven by urbanisation, climate change, and increased movement of people, raising concerns in countries like India.

Global Context:

  • Record Cases: Over 12 million dengue cases reported globally in 2024, more than double last year’s total of 27 million.
  • Deaths: Approximately 6,991 deaths linked to dengue this year, indicating severe outbreaks, especially in Brazil and other South American nations.
  • Underreporting: Experts believe actual numbers may be higher due to incomplete data reporting by various countries.

Situation in India:

  • Rising Cases: India has reported over 32,000 dengue cases and 32 deaths as of June 2024, with a 504% increase compared to the same period in 2023.
  • Geographical Spread: Dengue cases have expanded from eight states in 2001 to multiple regions, including Ladakh, which reported its first cases in 2022.

Contributing Factors:

  • Urbanisation: Dense populations in urban areas provide ideal breeding conditions for Aedes aegypti mosquitoes.
  • Climate Change: Rising temperatures expand the mosquitoes’ habitat and enhance virus transmission capabilities.
  • Global Movement: Increased movement of people and goods contributes to the spread of infections.
  • Prevention: Preventing mosquito breeding, protecting against bites, and strengthening public health surveillance are essential for controlling outbreaks.
  • Vaccines like Sanofi’s Dengvaxia and Takeda’s Qdenga are recommended, with ongoing development of new vaccines in India.

About Dengue:

  • Definition: A self-limiting febrile illness ranging from asymptomatic to severe.
  • Cause: Mosquito-borne disease caused by the dengue virus (Genus Flavivirus) transmitted by Aedes mosquitoes, mainly Aedes aegypti.

Serotypes and Symptoms:

  • Serotypes: Four distinct serotypes (DEN-1, DEN-2, DEN-3, DEN-4).
  • Symptoms: Sudden high fever, severe headaches, pain behind the eyes, and severe muscle/joint pain.

Vaccines and Control:

  • Dengvaxia: Approved by the FDA in 2019; a live attenuated vaccine for ages 9-16 with prior dengue infection.
  • DNA Vaccine: India’s first DNA vaccine candidate shows promise in mice.
  • Wolbachia Method: Infection of mosquitoes with Wolbachia led to a 77% reduction in dengue cases in Indonesia.

Associated Article:

https://universalinstitutions.com/dengue-control-the-unrealised-promise-of-wolbachia-infected-mosquitoes/