Dengue

DENGUE

There would be three types of virus related to Flavivirus I am going to talk about in the website. But In this post I would be talking about one particular disease that is cause by the Flavi family that greatly affects the lives of humans.

The Dengue virus is a member of the virus family Flaviviridae and is transmitted to people through the bite of the mosquitos Aedes aegypti and Aedes albopictus. Dengue is mainly found in the tropics because the mosquitoes require a warm climate. A major fear of epidemiologists is that the mosquitoes will develop resistance to cooler climates and then be able to infect people in the United States and other temperate climates. The virus is transmitted when a mosquito of the Aedes genus bites an individual infected with dengue virus.

http://www.nd.edu/~lumen/2007_06/images/aedes_aegypti_lumen.jpg

The Dengue virus has been shown to have 4 subtypes. These 4 subtypes are different strains of dengue virus which are DEN-1, DEN-2, DEN-3 and DEN-4.

Symptoms and outcome:

After a person is infected with dengue, they develop an immune response to that dengue subtype. However, if another subtype of dengue virus infects the individual, the virus will activate the immune system to attack it as if it was the first subtype as it have very similar surface antigen.

Dengue fever:

• Many infections asymptomatic
• Acute infection resulting in fever, severe headache, retro-orbital pain, nausea and vomiting.
• Severe muscle and bone pain
• Severe arthralgia
• Maculopapular rash

Dengue haemorrhagic Fever:

• Severe prostration, hypotension, circulatory collapse, bleeding and shock
• Bleeding-petechiae in skin, mucous membrances, injection and punction sites, Gastrointestinal bleeding and haemorrhagic pneumonia.

Prevention and management

Primary prevention of dengue mainly resides in mosquito control. There are two primary methods: larval control and adult mosquito control. In urban areas, Aedes mosquitos breed on water collections in artificial containers such as plastic cups, used tires, broken bottles, flower pots, etc. Periodic draining or removal of artificial containers is the most effective way of reducing the breeding grounds for mosquitos. Larvicide treatment is another effective way to control the vector larvae. Prevention of mosquito bites is another way of preventing disease. This can be achieved by using insect repellent, mosquito traps or mosquito nets.





This graph shows the number of cases in people in Singapore that had been infected with dengue from 2007 to the beginning of 2009.


http://www.dengue.gov.sg/

This video would explain on how the mosquito breed and infect host to spread the virus.