Controlling the Spread of the Zika Virus Through Genetic Modification

Aedes aegypti feeding.
Aedes Mosquito feeding.
Muhammad Mahdi Karim

The World Health Organization this month declared the Zika virus a global health emergency. Can anything be done to stop it?

Zika is spread by Aedes mosquitoes, which are also responsible for the spread of dengue fever, and thus far efforts to minimize their contact with human beings has been quite difficult. This has forced public health officials to take an innovative approach to the problem.

One proposed solution is to introduce genetically-modified mosquitoes (transgenic mosquitoes) into the wild population, an approach that’s been used in the past to control the spread of dengue fever. Genetic modification can attack the problem in many different ways. It can minimize the mosquitoes’ ability to transmit the virus. It can increase the insect’s resistance to the virus. Or, it can reduce a mosquitoes’ interest in biting humans.

Unfortunately, merely introducing a modified gene into a wild population is not enough. In order to become sufficiently widespread, the modified gene must spread through the population rapidly and remain active. Given these difficulties, it took years to develop large-scale transgenic mosquito tests. Thus far they seem promising: a recent test on dengue fever in Brazil seems to have been a big success. So there’s hope that this might work on the Zika virus as well. However, some scientists and anti-GMO activists caution that without careful management, transgenic mosquitoes might increase the virulence of pathogens like dengue and Zika.

Of course, introducing transgenic mosquitoes is just one way of tackling mosquito-born illness. Another involves controlling the mosquito population at the source. For instance, a research team in Iquitos, Peru, dusted attractive resting spots for adult female Aedes mosquitos with a toxic Juvenile Hormone Analog (JHA). Whenever the females lay eggs, the hormone guarantees that none of the hatchlings survive, thereby curtailing the growth of the mosquito population. Mosquito control is not a cure-all, but with luck, exploring cutting edge approaches like this and genetic modification, alongside established, low cost efforts (e.g., window screens) to prevent human contact with the disease-carrying mosquitoes will pay off.

 


JSTOR Citations

Transgenic mosquitoes sometimes have a risk of increased virulence: The Impact of Transgenic Mosquitoes on Dengue Virulence to Humans and Mosquitoes

By: Jan Medlock, Paula M. Luz, Claudio J. Struchiner and Alison P. Galvani

American Naturalist, Vol. 174, No. 4 (October 2009), pp. 565-577

University of Chicago Press for the American Society of Naturalists

Using Adult Mosquitoes to Transfer Insecticides to Aedes Aegypti Larval Habitats

By: Gregor J. Devine, Elvira Zamora Perea, Gerry F. Killeen, Jeffrey D. Stancil, Suzanne J. Clark, Amy C. Morrison and Barry J. Beaty

Proceedings of the National Academy of Sciences of the United States of America, , Vol. 106, No. 28 (Jul. 14, 2009), pp. 11530-11534

National Academy of Sciences

James MacDonald

James MacDonald received a BS in Environmental Biology from Columbia and a PhD in Ecology and Evolution from Rutgers University, spending 4 years in Central America collecting data on fish in mangrove forests. His research has been published in scholarly journals such as Estuaries and Coasts and Biological Invasions. He currently works in fisheries management and outreach in New York.

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