Bacteria Vs Viruses to Save the Human Race

The Human Race = One third of the world’s population at risk, 400 million people infected, and 22 thousand deaths annually. [CDC 2015]

The Virus = Dengue, any of four closely related viruses spread by mosquitoes that can cause symptoms as mild as fever and as serious as death with hemorrhagic fever in between. [CDC 2015]

The Bacteria = Wolbachia, bacteria found in up to 76% of insect species that when artificially introduced into Aedes aegypti populations inhibits the transmission of dengue viruses. [Iturbe-Ormaetxe, Walker, O’ Neill 2011]

Wolbachia is thought to work in two ways to interrupt the transmission of dengue:

First it shortens the life of the mosquito below the incubation period of the virus. It takes dengue 8-12 days from entering the mosquito to become infectious, if the mosquito doesn’t live that long it will not be able to transmit the virus. [Cook, McMeniman, O’Neill 2007]

Second it inhibits the multiplication of the virus within the cells of the mosquito. If the virus cannot replicate sufficiently it cannot be transmitted. [Ritchi 2014]

The beauty of using Wolbachia is that it has vertical transmission meaning that an infected female passes the bacterial infection to her offspring and if the female is uninfected but mates with an infected male she doesn’t produce viable offspring. Because of these traits the Wolbachia infection can spread very effectively through a population and remain in the population indefinitely. [Lambrechts et al. 2015]

Novel control measures such as this have the potential to overcome the pitfalls of classic control measures and save the lives of many of our fellow humans.

For further information here is video produced by Eliminate Dengue, the lead research organization behind Wolbachia as a dengue control measure.

What are your thoughts on Wolbachia or using bacteria in disease control in general?

Author’s Notes

I have worked in mosquito control for many years and have always thought that there has to be a more effective way to control mosquito borne diseases than the laborious application of insecticides, I had a lecture at the London School of Hygiene and Tropical Medicine about Wolbachia and the control of dengue and was immediately interested. Since I can’t help but talk about what I love my friends patiently listened to my ramblings and then became interested also; one suggested that I write an article in terms they could more easily understand and here it is.

If you are interested in the more technical details the Eliminate Dengue website has a publications page. And if you are already working with Wolbachia or other novel methods of mosquito control I would be very interested in conversation and collaboration.

Disclaimer: I do not work for Eliminate Dengue or have authorization to speak for them, any errors in this document are my own and should not be attributed to Eliminate Dengue.