Log out
My profile and settings
My bookmarks
Comment history
Please complete your account verification. Resend verification email.
today
This verification token has expired.
today
Your email address has been verified. Update my profile.
today
Your account has been deactivated. Sign in to re-activate your account.
today
View all newsletters in the newsletter archive
today
You are now unsubscribed from receiving emails.
today
Sorry, we were unable to unsubscribe you at this time.
today
0
0
Back to profile
Comment Items
You have not left any comments yet.
title
you replied to a comment:
name
description
Saved Posts
You haven’t bookmarked any posts yet.

All lives have equal value. But some deaths seem particularly cruel.

read more
Become a Gates Notes Insider
Sign up
Log out
Personal Information
Title
Mr
Mrs
Ms
Miss
Mx
Dr
Cancel
Save
This email is already registered
Cancel
Save
Please verify email address. Click verification link sent to this email address or resend verification email.
Cancel
Save
Email and Notification Settings
Send me updates from Bill Gates
You must provide an email
On
Off
Send me Gates Notes survey emails
On
Off
Send me the weekly Top of Mind newsletter
On
Off
Email me comment notifications
On
Off
On-screen comment notifications
On
Off
Interests
Select interests to personalize your profile and experience on Gates Notes.
Saving Lives
Energy Innovation
Improving Education
Alzheimer's
Philanthropy
Book Reviews
About Bill Gates
Account Deactivation
Click the link below to begin the account deactivation process.
If you would like to permanently delete your Gates Notes account and remove it’s content, please send us a request here.

Releasing Hope

This factory breeds 30 million mosquitoes per week. Here’s why.

These mosquitoes are allies in the fight against dengue and other deadly viruses.

|
0

Inside a two-story brick building in Medellín, Colombia, scientists work long hours in muggy labs breeding millions and millions of mosquitoes. They tend to the insects’ every need as they grow from larvae to pupae to adults, keeping the temperature just right and feeding them generous helpings of fishmeal, sugar, and, of course, blood.

Then, they release them across the country to breed with wild mosquitoes that can carry dengue and other viruses threatening to sicken and kill the population of Colombia.

This might sound the beginnings of a Hollywood writer’s horror film plot.

But it’s not.

This factory is real.

And the mosquitoes being released don’t terrorize the local population. Far from it. They’re actually helping to save and improve millions of lives.

Here’s how they do it: The mosquitoes being produced in this factory carry bacteria called Wolbachia that block them from transmitting dengue and other viruses, such as Zika, chikungunya and yellow fever, to humans. By releasing them to reproduce with wild mosquitoes, they spread the bacteria, reducing virus transmission and protecting millions of people from illnesses.

I’ve written before about these amazing Wolbachia mosquitoes, including last year when a new study showed how effective they could be in preventing diseases. The randomized controlled trial conducted in Yogyakarta, Indonesia, found that Wolbachia-carrying mosquitoes reduced the number of dengue cases in the city by 77 percent and dengue hospitalizations by 86 percent. In a new study in Medellín, dengue cases have declined by 89 percent since Wolbachia mosquitoes started being released in 2015.

These results are a huge breakthrough, offering proof that this new technology will protect entire cities and countries against the threat of mosquito-borne diseases. The World Mosquito Program, which is leading the Wolbachia effort, is now releasing these mosquitoes in 11 countries: Brazil, Colombia, Mexico, Indonesia, Sri Lanka, Vietnam, Australia, Fiji, Kiribati, New Caledonia, and Vanuatu.

And what’s remarkable about the Wolbachia mosquitoes is that once enough of them are released to offer disease protection, it’s a solution that’s self-sustaining. Over time, families will be spared the heartbreak of losing loved ones and communities won’t need to spend money on prevention and treatment for these mosquito-borne diseases, freeing up funds for other health priorities.

The World Mosquito Program aims to spread Wolbachia among Aedes aegypti mosquitoes, a tropical mosquito that is a host for dengue, yellow fever, and other viruses. (Malaria is spread through a parasite carried by the Anopheles mosquito and is not a focus of the Wolbachia effort.) With climate change, there is an urgency to the World Mosquito Program’s work. As global temperatures rise, Aedes aegypti mosquitoes, are finding more regions of the world habitable, increasing the spread of these diseases. The biggest risk is posed by dengue, which infects more than 400 million people each year and kills 20,000.

The demand for these lifesaving mosquitoes continues to grow and that means the World Mosquito Program needs to produce hundreds of millions of Wolbachia mosquitoes. That brings us back to the factory in Medellín, which is currently the world’s largest mosquito breeding facility in the world, producing more than 30 million mosquitoes per week. Other World Mosquito Program sites around the world are also breeding Wolbachia mosquitoes, but Colombia’s is currently the largest.

Hundreds of Wolbachia mosquitoes feed on blood at the World Mosquito Program facility in Medellín, Colombia. These mosquitoes will be released to mate with the wild mosquito population, spreading the Wolbachia bacteria that blocks the transmission of dengue and other mosquito-borne diseases to humans.

Until now, killing or repelling mosquitoes with insecticides, bed nets, and traps has been the priority, not mass producing them. As difficult as it is to kill mosquitoes, raising them by the millions may be even harder. Mosquitoes must be bred, fed, and housed under ideal conditions for them to grow and reproduce. The factory in Medellín has been perfecting the process and improving its efficiency so they can breed and release Wolbachia mosquitoes on a large scale.

The centerpiece of the mosquito factory is a colony of Wolbachia mosquitoes, called the brood stock, from which all future populations of Wolbachia mosquito offspring are bred. The brood stock offspring are then raised to create millions of eggs, which hatch when put in water and become larvae. Fed with fish meal, the larvae grow to become pupae, which then become adults. To thrive, adults need sugar (check out this story about how researchers in Zambia are exploiting mosquito’s craving for sugar to create a new bait that will control the spread of malaria) and blood, which the team sources from expired stocks at blood banks. 

Once the factory has bred millions of eggs and adult mosquitoes, they are ready to be released. The eggs are packaged in small gelatin capsules, each containing 300 eggs, which are given to residents to drop in water to hatch. The advantage of egg releases like this is that the eggs can easily be transported long distances and they can be hatched as needed.  The factory also releases adult mosquitoes by the thousands from the back of motorcycles roving the city. The World Mosquito team is also experimenting with releases from drones. The adult releases allow the Wolbachia mosquitoes to immediately begin mating with the wild mosquito population and spreading the virus-blocking bacteria.

It’s exciting to see how far the World Mosquito Program has come. Years ago, the idea of releasing mosquitoes as an ally in the fight against diseases struck many people as crazy. But support for this innovative solution has caught on in communities around the world. These amazing mosquitoes are taking flight and saving lives.