Most people lead their lives hoping to leave behind a legacy, hoping to imprint their footprints in the annals of history. Yet, few realize that their footprint impressions are actually propagating the legacy of a tropical disease that the World Health Organization deems only second in lethality (after malaria), dengue fever.1 Spread to humans via the bites of infected female mosquitos of the species Aedes aegypti, dengue fever is prominently found near pools of water (such as the watery imprint of a footstep), where mosquitos like to breed, in south Asian and Latin American countries.2 With the lack of an internationally approved vaccine for dengue fever, research and public health officials are scurrying to find appropriate vaccination options and contain the vectors that cause it.
As a viral, infectious disease that causes 50 to 100 million infections per year, dengue fever is considered one of the most aggressive mosquito-borne human pathogens in the world.3
Although the standard dengue fever has a low mortality rate of less than 1% with treatment, patients who become infected with a more deadly variant, dengue hemorrhagic fever, have a mortality rate of 26%.2 In recent years, the lethality of the disease has become a major concern as the disease incidence has increased thirty fold in the last fifty years, largely due to urbanization, population growth, and global warming.1 Outbreaks have spread beyond the expected scopes of Asia and Latin America. For example, 67 cases of dengue fever were reported in 2010 in Key West.1-2
Because of the severity of the issue, numerous investigations and studies are and have been conducted on the mechanism behind infection and the possible vaccines. Research conducted by the Dow University of Health Sciences in Pakistan have discovered that not only does dengue fever have genetic and evolutionary connections but also have viral targeting of specific lipids in humans.4 Concurrently, clinical studies in Cuba are being conducted to test the effectiveness of prototype vaccines.5 While preventative measures are still in development, many countries are resorting to antiquated methods of disrupting the habitats and life cycles of the mosquito vectors. In Islamabad, Pakistan, the Ministry of Health is heavily fumigating anti-mosquito larvicides in rural areas where mosquitos are known to breed.6 In South Asia, public health officials are dispersing and draining large bodies of water, such as ponds and lakes, to further eliminate breeding.1 Even genetic engineering of male mosquitos with radiation so that they produce infertile offspring have been carried out in countries like the Cayman Islands.7
While controlling outbreaks of dengue fever should be a primary concern of public health throughout the world, especially in tropical countries, some containment options are more holistically beneficial and practical than others. Elimination methods such as the eradication of the Aedes aegypti population only lead to significant ecological damage. While solving the direct problem of dengue fever, such methods would trickle down negatively along the ecological food web/chain. Niches will be disturbed as species that used to feed on the vectors will be forced to find new food sources, thus changing entire ecosystems. In fact, elimination of the species might incite new and perhaps even more deadly diseases to arise, of which there would be no vaccine or cure.
Other solutions, like dispersing large bodies of water, are not economically sound. With a myriad of bodies of water in the world, is there an end to the drainage? Even if all significant water sources were drained, dengue fever might still persist because of human factors like taking a step in rainy weather. In actuality, the mosquitos themselves cannot even be blamed for the rapid spread of dengue fever. Studies conducted by the Johns Hopkins Bloomberg School of Public Health have found that mosquitos carrying the dengue fever virus have operant hunger and olfactory genes that are turned on by the virus to make them hungrier for a blood meal and more sensitive to smells, thus increasing their feeding skills.3 Elimination of the mosquito population is unnecessary when they themselves are vectors of the disease.
Instead, an economical and ecological way of resolving the public health menace is to spend more funding on discovering vaccines and treatments for dengue fever. As approaches that only affects humans, not other species and ecosystems, vaccines and treatments spare the economic inefficiencies associated with widespread larvicide spraying and water drainage. Only when the root of the disease, the virus causing the symptoms, is eliminated will the disease submerge back into obscurity and no longer remain a concern in the minds of the public.
References
1. Krisberg, Kim. “Public Health vs. The Mosquito: Pushing Back Against Dengue Fever.” The Pump Handle. 29 Mar. 2012. Web. 02 Apr. 2012. <http://scienceblogs.com/thepumphandle/2012/03/public_health_vs_the_mosquito.php?utm_source=networkbanner>.
2. “Research Points to Possible New Route to Fight Dengue Virus.” R&D, 23 Mar. 2012. Web. 02 Apr. 2012. <http://www.rdmag.com/News/2012/03/Life-Sciences-Disease-Research-Points-To-Possible-New-Route-To-Fight-Dengue-Virus/>.
3. Walsh, Jennifer. “Dengue Virus Increases Mosquito’s Lust for Blood.” Mother Nature Network. 30 Mar. 2012. Web. 02 Apr. 2012. <http://www.mnn.com/earth-matters/animals/stories/dengue-virus-increases-mosquitos-lust-for-blood>.
4. Husain, Shahid. “Pakistani Scientists Find Genetic Connection to Dengue Fever Virus.” The International News. 21 Mar. 2012. Web. 02 Apr. 2012. <http://www.thenews.com.pk/Todays-News-4-98711-Pakistani-scientists-find-genetic-connection-to-dengue-fever-virus>.
5. “Cuba To Test Dengue Fever Vaccine On Humans.” Fox News Latino. 08 Mar. 2012. Web. 02 Apr. 2012. <http://latino.foxnews.com/latino/health/2012/03/08/cuba-to-test-dengue-fever-vaccine-on-humans/>.
6. “Dengue Fever Prevention Drive Starts in Capital.” The International News. 30 Mar. 2012. Web. 02 Apr. 2012. <http://www.thenews.com.pk/Todays-News-6-100220-Dengue-fever-prevention-drive-starts-in>.
7. Black, Richard. “GM Mosquitoes Show Fever Promise.” BBC News. BBC, 30 Oct. 2011. Web. 02 Apr. 2012. <http://www.bbc.co.uk/news/science-environment-15491228>.
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