FrankenFungus Armed With Venom Toxins Could Join The War Against Malaria

One of the world's deadliest venomous animals—a female Anopheles gambiae—demonstrating the behavior that makes her so lethal. Photo Credit: CDC/ James Gathany
One of the world’s deadliest venomous animals—a female Anopheles gambiae—demonstrating the behavior that makes her so lethal. Photo Credit: CDC/ James Gathany

People are often surprised when I say that mosquitoes are the deadliest venomous animal in the world (the deadliest animal period, really, if we don’t count ourselves). Mosquito bites—and the venoms delivered by them—kill upwards of 750,000 people worldwide every year thanks to the lethal beasties harbored within them. Most of those are due to microscopic parasites in the genus Plasmodium, which are responsible for the diseases collectively called malaria. Malaria accounts for around 500,000 of those mosquito-caused deaths, according to the World Health Organization—only a fraction of the over 210 million cases of malaria reported every year. Not surprisingly, there is a lot of time, money, and intellectual capital being invested into finding ways to reduce those numbers. And as the vectors, mosquitoes—especially the few species that carry the most devastating diseases—are a key target.

While killing mosquitoes seems like a simple objective, it can be quite complicated in practice. Mosquitoes are hardy little buggers, and rapidly evolve resistance to pesticides. And when effective pesticides can be found, such as DDT, they tend to be a little too effective, killing a wide diversity of insects and causing ecological harm to local biodiversity. In the hope of wiping out disease-carrying mosquito populations, scientists have tried all sorts of methods, from increasing natural predators to releasing sterile male mosquitoes in swarms. But the most recent approach sounds like it’s straight out of a science fiction thriller: an international team of scientists has genetically engineered a fluorescent fungus that wipes out mosquitoes using venom toxins from spiders and scorpions. Continue reading “FrankenFungus Armed With Venom Toxins Could Join The War Against Malaria”

Eau de Manipulation: Malarial Mosquitoes More Attracted To Human Scent

An Anopheles gambiae mosquito gorging herself on blood. Photo by Jim Gathany, from the CDC’s Public Health Image Library

By the time you realize what has happened, it’s too late. An Anopheles gambiae mosquito can land on your skin completely unnoticed. While you continue unaware, she stealthily walks over your exposed flesh, searching, probing the surface of your skin with her proboscis until she finds a blood vessel. She then situates her body perfectly at just the right angle, hunches down, and plunges her needle-like mouthparts into your skin. Tiny pumps pull the warm, protein-rich blood into her mouth.

With every millisecond increasing her chances of exposure, she drinks as quickly as she can. Your hand isn’t the only obstacle she faces: even as she sucks, your body senses the wound and attempts to plug the hole by forming a clot. She needs your warm, nutritious blood for her eggs, so she’s not about to let your protective mechanisms interfere. To ensure her meal keeps flowing, she pumps saliva laden with anti-coagulants and vasodilators  into the wound — and that’s when it happens. That’s when the Plasmodium falciprum sporozoites that have been waiting patiently in her salivary glands enter your bloodstream. Dozens can hitch a ride in her saliva, but it only takes one to cause malaria. One single, microscopic protozoan is enough to kill you. Continue reading “Eau de Manipulation: Malarial Mosquitoes More Attracted To Human Scent”