Detection of antibodies against the mosquitoes of the Ross River virus by means of engorgement of blood from animals and humans
According to preliminary results, 480 of the mosquitoes were engorged with blood, presented at the International Congress of Infectious Diseases in Kuala Lumpur. More than half of those had fed on people, some 9% on cows and 6% on kangaroos, among other animals. A lot of the blood samples included antibodies against Ross River virus, which she says is a high population. There was evidence of exposure for close to three-quarters of the animals.
“This is a novel and fascinating approach, which demonstrates innovative ways to use the environment around us to learn more about exposure to infection,” says Shelly Bolotin, a vaccine scientist at the University of Toronto in Canada.
The QIMR Berghofer Medical Research Institute in Queensland, Australia has a technique that can detect antibodies in blood from animals and people.
She focused on Ross River virus, a potentially debilitating mosquito-borne disease that is endemic to Australia and islands in the southern Pacific Ocean.
A scaled platform to test mosquito behavior in a bioengineering lab using 3D-printed gels and a computational vision algorithm
“It is really surprising that nobody else noticed this before,” says Patrizia d’Ettorre, an ethologist at Sorbonne Paris North University, France. “The pupae were considered useless [because] they are immobile, they spin a cocoon around them in some species, they don’t eat, they’re just moved around by the [ant] workers, so they [wouldn’t] contribute anything to ant society. But this paper shows that this is not true.”
A mechanism that binding all ants across the colony into a unified entity is identified by co-author Orli Snir.
A picky eater is the world’s deadliest animal. Because they transmit viral diseases like Zika and chikungunya, and the parasites that cause malaria, mosquitoes like blood-sucking Aedes aegypti are responsible for over 700,000 deaths worldwide every year.
But in Omid Veiseh’s lab at Rice University, his team of bioengineers was struggling to get mosquitoes to eat. Typically, researchers study mosquitoe feeding by letting them bite live animals—lab mice, or grad students and postdocs who offer up their arms for science. Lab animals can be expensive and impractical to work with, so their use can raise ethical issues. Student arms aren’t good for large tests.
At the least, theoretically. The insects wouldn’t bite. They had to use a straw-like proboscis. The team made enough changes and it happened. “It was a big eureka moment for us,” Veiseh says. The mosquito was biting on the gel and swallowing the blood.
Writing today in the journal Frontiers in Bioengineering and Biotechnology, the team describes their scalable platform for testing mosquito behavior. Real blood can be pumped through the zig-zagging channels in their 3D-printed hydrogels. To test the gels, the researchers pointed cameras at them and used a computer vision algorithm to quickly analyze how many mosquitoes dove mouth-first into the buffet. They showed in a proof of concept that mosquitoes don’t eat when the odors of chemicals are present.
This could become a low cost system for testing and inventing repellents. “The good thing about it is that it’s trying to mimic human skin—without using a real human,” says Perran Ross, a medical entomologist with the University of Melbourne, Australia, who was not involved in the work. It would be useful for looking at mosquito repellents. If it is not feasible to use a real person, then it is a good way to do it.
It’s important to invent a new mosquito spray because the health havoc these insects wreak. Though the current styles of repellents work, they are not perfect, and comfort is important if you want people to adopt disease prevention methods. DEET is the gold standard, but it doesn’t stay active for very long, it’s smelly, and it’s rough on sensitive skin. Veiseh says there have been no big-scale efforts to come up with better alternatives.