Dengue "EMPOWER IAS"

In news:

• The Union Health Ministry has flagged the emerging challenge in 11 States across India of serotype 2 dengue, which it said is associated with “more cases and more complications” than other forms of the disease.

What is Dengue?

• Dengue is a mosquito-borne viral infection, found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas.
• It is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus.
• These mosquitoes are also vectors of chikungunya, yellow fever and Zika viruses.
• Dengue is widespread throughout the tropics, with local variations in risk influenced by rainfall, temperature, relative humidity and unplanned rapid urbanization.

Its transmission

• The virus is transmitted to humans through the bites of infected female mosquitoes, primarily the Aedes aegypti
• Other species within the Aedes genus can also act as vectors, but their contribution is secondary to Aedes aegypti.
• Mosquitoes can become infected from people who are viremic with dengue.

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.