Human-Mosquito Conflict

for Conservation Psychology class, 2016

The Issue

The conflict between humans and mosquitoes, in the form of mosquito-borne illnesses, constitutes far and away the deadliest (to humans) human-wildlife conflict in the world. Some researchers estimate that mosquito-borne illnesses are responsible for approximately half of human deaths since the Stone Age.[1] Nearly 700 million humans contract mosquito-borne illnesses each year, resulting in more than one million human deaths per year.

Diseases caused by bacteria, viruses, or parasites transmitted by mosquitoes include malaria, dengue, filariasis, West Nile virus, chikungunya, yellow fever, a variety of encephalitises, and Zika fever. Of these, the protozoan disease malaria is the deadliest, causing around half a million deaths a year, 90% of which occur in Africa. Zika, suspected of causing microcephaly in infants born to infected women, has been much in the news lately. Other mosquito-borne diseases are less deadly than malaria but still a concern for humans, especially dengue and yellow fever. Many of these diseases (though not malaria) are primarily spread by a single species, Aedes aegypti – most of the more than three thousand species of mosquito are not vectors for disease and are more or less harmless to humans.[2]

This is a two-sided conflict: mosquitoes transmit diseases which kill humans, and humans in turn try to kill mosquitoes. Therefore, at stake in this conflict are millions to hundreds of millions of human lives and well-being on one side and countless mosquito lives and livelihoods on the other. In addition to the direct stakes for humans and mosquitoes, there are also the indirect ecosystem effects of mosquitoes, such as the plants pollinated by mosquitoes and the larger animals that eat mosquitoes and their larvae. Additionally, other animals, such as insects other than mosquitoes, stand to be harmed by indiscriminate insecticide use and other environmentally harmful techniques.

The conflict takes place in most tropical and subtropical areas of the globe, primarily Africa, South and Central America, India, and the Pacific Islands.

Vaccines are available for some mosquito-transmitted diseases, but not all.[3] Even in cases where vaccines exist, getting them to the people at risk of mosquito-borne illnesses – many of whom live in areas with limited road infrastructure – in any sort of consistent way is easier said than done.

Using conventional insecticides, humans have made some progress in recent years exterminating disease-carrying mosquitoes in many areas. However, this can have unforeseen effects on the ecosystem, adversely affecting a wide variety of insects, including the many species of harmless mosquitoes. Moreover, mosquitoes evolve quickly to resist insecticides.[4]

Among the most promising solutions to this conflict, and the one this paper will focus on, was developed by Oxitec, a British company, and tested in Brazil, Malaysia, and the Cayman Islands on Aedes aegypti, the primary carrier of dengue and yellow fever. This technique involves breeding and releasing mass numbers of genetically-engineered (i.e., transgenic) male mosquitoes (which do not bite – only female mosquitoes bite, to nourish their eggs) that are effectively sterile – engineered such that their larvae produce a protein that quickly kills them so they never become adult mosquitoes. These mosquitoes breed with females (who only breed once or twice in a short lifetime), their larvae quickly die, and the next generation of A. aegypti is much smaller. This targets only one of many mosquito species in the area, and so is likely to have minimal impact on the ecosystem and on non-problematic mosquito species.[5]

Nonetheless, Oxitec’s technique has much opposition, as many people hate and mistrust the idea of transgenic organisms.

Target Audience

The audience, then, is those people who oppose Oxitec’s technique, especially those in governments and positions of power in affected nations, who have the ability to block and stymie or to fund and support Oxitec’s efforts. These people may object to the technique on the basis of the precautionary principle, lack of comprehension of how the technique works (in particular how releasing more pest animals into an area can ultimately reduce their prevalence), or simple emotional fear of transgenic organisms – “Dr. Frankenstein’s Monster, plain and simple,” in the words of Helen Wallace, executive director of the British environmental organization GeneWatch.[6] The goal is to overcome these fears through education and, where necessary, additional research to demonstrate the safety of these transgenic mosquitoes, without dismissing those fears that have basis in reality.

There are cross-cultural issues at play here. In particular, there may be a possible problem with scientific imperialism (or Rudyard Kipling’s “White Man’s Burden”), where a British company of mostly white people comes to use their Enlightenment values (i.e., science) to rescue the darker-skinned folks of South America, Africa, India, and the Pacific Islands from something they can’t handle themselves. For this reason, it may be best to operate primarily through local intermediaries – use locals to get everyone else on board.

Psychological Concepts

Objections to transgenic organisms take, broadly, two forms: the value of caution, and the emotion of fear.

Hesitation based on the precautionary principle – that the onus is on those proposing a course of action to demonstrate that the proposed action is safe – may indeed be warranted. For this reason, much research should be performed to demonstrate the safety of Oxitec’s technique. However, one problem with the precautionary principle is that it promotes inaction, and in many cases inaction may be riskier than action. Indeed, in this case, we know for sure that inaction causes millions of human deaths. Perhaps the onus should instead be on the naysayers to prove that the technique is more dangerous than allowing mosquito-borne illnesses to continue to claim human lives.

A risk assessment workshop predicted negligible risk to humans or the environment, but found four possible risk areas: Aedes aegyptus could be replaced in its niche by other mosquito species, such as Aedes albopictus, which could correspondingly increase disease transmission by A. albopictus; a risk of alteration of food chains or webs, thought to be a low risk because A. aegypti is not native to Asia or South America in the first place and is not the only local mosquito species; the possibility that transgenic mosquitoes could somehow be less susceptible to insecticide than wild mosquitoes; and the potential that soil and water quality could be affected by the protein by which the process functions. These four areas warrant further studies and research to assuage potential legitimate fears.[7]

Less rigorously rational fears, on the other hand, are more difficult to deal with. Objection to advances in science and engineering has a long history, most famously incarnated in Mary Shelley’s Frankenstein; or, The Modern Prometheus (1818) and the English Luddites of the early 19th century. Indeed, citing Frankenstein is a common refrain from opponents of transgenic organisms of all sorts.

It is difficult to fight fear, especially when the fearful don’t see their fear as misplaced. The scientific community’s attempts to educate the public through scholarly defenses of genetically-modified organisms have barely made a dent in the public’s fear of GMOs.[8]

Action

The key here is science and education.

Science is needed to demonstrate beyond all reasonable doubt that Oxitec’s technique is safe for humans, safe for the environmental ecosystem, and effective at combating the problem of mosquito-borne disease. Much progress has been made on this front, but more is needed. Ideally, this science would be independent and not funded or performed by Oxitec or other corporations involved in transgenic engineering, to quiet suspicion of conflicts of interest. This science is necessary to settle the reasonable problem of the precautionary principle.

Concurrently and subsequently, a mass education campaign is needed to convince the public of areas afflicted by mosquito-borne disease that Oxitec’s technique is safe for humans, safe for the environmental ecosystem, and effective at combating the problem. Some of the fearful may never be swayed by education, but if we can convince enough of the populace and enough members of local governments not to fear transgenic organisms, the way may be paved for successfully fighting mosquito-borne diseases. Ideally, this education would be performed by locals in the afflicted areas, not white people sailing in to play savior.

Success will be measured proximately by a reduction in popular opposition to transgenic solutions to the mosquito problem and by local governments choosing to fund Oxitec’s efforts – i.e., to buy the product Oxitec is selling. Success will be measured ultimately by a reduction of the Aedes aegypti population and, more importantly, a reduction in the incidence of mosquito-borne disease.

Conservation people may be brought on board by the solution’s several benefits: it should reduce human mortality, which is something that should appeal to many or most humans; when compared against the old-fashioned method of indiscriminate insecticide use, it is much less dangerous for the ecosystem and the environment; and it reduces the impact of an invasive pest (Aedes aegypti is invasive everywhere it is found except Africa) – though invasiveness is no longer universally considered as inherently bad as it once was.

Works Cited

Beech, C. J., Nagaraju, J., Vasan, S., Rose, R. I., Othman, R. Y., Pillai, V., & Saraswathy, T. (2009, July). Risk analysis of a hypothetical open field release of a self-limiting transgenic Aedes aegypti mosquito strain to combat dengue. Asia Pacific Journal of Molecular Biology & Biotechnology, 17, 99-111. Retrieved from http://www.msmbb.org.my/apjmbb/html173/173g.pdf

Boyer, P. (2004, November). Unwarranted Fear of GMOs Harms Us All. New Perspectives Quarterly, 21(4), 105-107. doi:10.1111/j.1540-5842.2004.00708.x

Hoi, A. G., & Roitberg, B. D. (2014). Mosquito Behavior and Disease Control. Evolution, Medicine, and Public Health, 162. doi:10.1093/emph/eou030

Specter, M. (2012, July 9). The Mosquito Solution. The New Yorker. Retrieved from http://www.newyorker.com/magazine/2012/07/09/the-mosquito-solution

Tolle, A. M. (2009, April). Mosquito-borne Diseases. Current Problems in Pediatric and Adolescent Health Care, 39(4), 97-140. doi:doi:10.1016/j.cppeds.2009.01.001

World Health Organization. (2016, January). Malaria Fact sheet. Retrieved March 2016, from World Health Organization: http://www.who.int/mediacentre/factsheets/fs094/en/

[1] (Specter, 2012)

[2] (Tolle, 2009)

[3] Ibid.

[4] Ibid.

[5] (Specter, 2012)

[6] Ibid.

[7] (Beech, et al., 2009)

[8] (Boyer, 2004)