Dengue and Wolbachia
So NPR has discovered the work of Scott O’Neill, and colleagues around the globe, to fight Dengue fever (also known as breakbone fever) by releasing mosquitos. Dengue is a painful viral flu-like disease now spreading from the tropics, thanks to global warming, which brings the mosquitoes north–France had its first case last year.
But why release mosquitoes? The mosquitoes are infected by an intracellular microbe called Wolbachia. This excerpt from my textbook explains how Wolbachia bacteria infect a different invertebrate, the filarial nematode that causes elephantiasis. Wolbachia have tiny genomes that shrink even more when the bacteria become ensconced in an invertebrate host, where they provide key amino acids while obtaining just about everything else from their host cells. Because of Wolbachia, we can treat elephantiasis with antibacterial antibiotics–the host invertebrates actually depend on their endosymbionts.
In insects, Wolbachia has all kinds of weird behavior, such as altering the sex of the offspring of infected eggs. In the mosquitoes that carry dengue, the behavior is less clear. Dengue fever is caused by a virus. How does Wolbachia exclude dengue virus? We don’t know, but apparently the exclusion is reliable enough that populations of Wolbachia-infected mosquitoes are free of dengue.
In The Highest Frontier, dengue is what Jenny was afraid of getting from the invading mosquitoes. And release of engineered mosquitoes was one proposal to address them. No doubt we’ll be hearing more about mosquito release in the future.
Which pests would you like to engineer for release, and why?