Dengue and Climate Change Info
Background:
Dengue is a major public health concern. Worldwide, over 2.5 billion people are at risk of dengue. It is estimated that between 50 to 100 million cases of dengue fever and 250,000 to 500,000 cases of dengue hemorrhagic fever occur each year. Dengue is found in tropical and subtropical climates, in urban and semi-urban areas. It is found in over 100 countries. It is a virus spread by infected female mosquitoes (Aedes aegypti). There are four different viruses that cause dengue. After an infection, a person will develop lifelong immunity to that specific virus and transient immunity to the other three viruses.
There is no vaccine, cure, or specific treatment for dengue fever. However, dengue can be prevented through the control of the mosquito population with biological, chemical, and environmental methods.
Clinically:
Humans bitten by a mosquito infected with dengue usually develop dengue fever, a severe flu-like illness; however, they could also develop a deadly form called dengue hemorrhagic fever.
Infants and young children infected with dengue develop fevers and rashes. Adults may develop high fevers, severe headaches, pain behind the eyes, muscle and joint pains, rashes, and post-illness depression.
Game Scope: Vector-borne diseases and climate change.
Game Focus: Education of dengue risk factors, especially those related to climate change, and the consequences of human behaviors that impact its spread.
Game Target audience: Primary audience school aged children between the ages of 8-12. Secondary audience is UN Convention on Climate Change (UNFCC) participants, Red Cross/Red Crescent workers, parents and educators (teachers, nurses, and physicians).
This game is being developed for use in the field to educate children about dengue risk factors and climate change. The game will be played at the United Nations Climate Change Conference, Durban 2011 to showcase innovative teaching tools in the field. At this conferences there will be diplomats, NGO workers. The goal of this conference is to negotiate the implementation the Kyoto Protocol on climate change.
UNFCC. For more information about the conference please visit: <http://unfccc.int/meetings/durban_nov_2011/meeting/6245.php>.
Number of players: 5 – 15.
Time required to play game: 20 – 30 minutes.
Mosquito (Aedes aegypti):
• Mosquitoes acquire dengue virus from feeding on blood of an infected human
• Virus incubates in mosquito for 8-10 days
• Infected female mosquito transmits dengue back to humans by biting
• Daytime feeders
• Lives around humans
• In urban and semi-urban areas
• Prefers to lays eggs in artificial containers
• Mosquitoes lay their eggs on the surface of water.
Dengue is on the rise, for a variety of reasons related to climate change and human behavior.
Dengue risk factors related to climate change:
Higher temperature:
• Mosquitoes:
• Develop faster
• Fly further
• Survive longer
• BITE more
• The dengue VIRUS (inside the mosquito)
• Replicates faster
Increased Rain:
• Increase breeding sites for mosquitoes
Less rain:
• Can also increase breeding sites for dengue mosquitoes
• Low, stagnant river flow
• Water storage in homes in containers without lids
Human behaviors that impact the spread of dengue:
• Increased urbanization
• Increased air travel
• Improper storage of water
• Increasing use of non-biodegradable containers
• Lack of garbage disposal
• Inadequate supply of mosquito netting for sleeping areas
• Decreased mosquito control efforts
• Lack of knowledge about risks of transmission for Dengue
Dengue Control
• Biological Control
• Using guppies or small freshwater crustaceans to eat immature mosquitoes (larvae).
• Can eliminate mosquitoes from larger containers used to store potable water, open freshwater wells, concrete irrigation ditches, and industrial tanks.
• Environmental Control
• Using insecticidal spray over large areas and villages that is toxic to mosquitoes and larvae but benign to human health.
• Installing culverts and drainage systems to drain swampy areas where mosquitoes breed.
• Garbage management
• Garbage should be put in plastic bags.
• Disposed of 2X per week.
• Discard non-essential containers.
• Street cleaning
• Removes discarded water-bearing containers.
• Cleans drains to prevent stagnant breeding pools of water.
• Mosquito-proofing of water-storing containers
• Tight lids for water-storing containers.
• Mesh-screens for rainwater collected from roofs to keep mosquitoes out.
• Household Safety
• Distribution of nets for households for sleeping areas.
• Chemical Control
• Larvicides.
• Kills immature mosquitoes (larvae).
• Used as complimentary to environmental management.
• Treat containers that cannot otherwise be eliminated or managed.
• Adulticides
• Kills adult mosquitoes.
• Two methods of application:
• 1) Residual surface treatment
• Cannot be used on containers to store water.
• 2) Space treatment
• Only used in emergency situations.
• To mitigate an epidemic.
• Works in short-term to reduce mosquito population but long-term efficacy is unknown.
Additional resources:
http://www.who.int/mediacentre/factsheets/fs117/en/#
Distribution of Dengue in the World:
Nature Reviews Microbiology 5, 518-528 (July 2007) | doi:10.1038/nrmicro1690