Tag Archives: Zika

How Local Drone Pilots Are Reducing Dengue Fever

The dengue fever outbreak in Fiji in 2014 was one of the region’s largest known outbreaks of the mosquito-borne infection. Scientists studying the outbreak believe climate change was a contributing factor: more flooding results in more areas of standing water for longer periods—perfect breeding grounds for mosquitos. According to the World Health Organization’s Regional Office, the islands of the South Pacific are “some of the most vulnerable places on the planet to health effects of climate change.” Unfortunately, existing tools to control these mosquitoes such as insecticide spraying are not efficient and have failed to eliminate dengue as a public health concern. Worldwide, an estimated 390 million human dengue infections occur every year. This explains why ministries of health in the South Pacific expect larger outbreaks. In fact, Fiji experienced another outbreak of dengue fever this year, which once again prompted urgent calls for more effective and preventative solutions.

One such solution may be the use of Wolbachia-treated mosquitos. Wolbachia is a naturally occurring bacteria that prevents mosquitos from transmitting diseases like Zika and dengue. This explains why our partners at the World Mosquito Program (WMP) and the Ministry of Health and Medical Services have been releasing Wolbachia-carrying mosquitos in Fiji. This is done be driving around a town or village with canisters of Wolbachia mosquitoes (W-mosquitoes for short). The driver pulls over by the side of the road every few minutes to release one canister at a time. Over time, Wolbachia becomes established in the local mosquito population. When most of the mosquito population have Wolbachia, local communities in Fiji should be at lower risk of getting dengue, Zika and chikungunya.

Releasing Wolbachia mosquitos “by car” presents a number of challenges, however. First, during the rainy and cyclone seasons, many roads become unusable while pools of standing water breed more mosquitos. What’s more, mosquitos that are released by car may not be uniformly distributed over an area but rather constrained by the local road network. As such, a significant amount of work and time has to go into planning the best routes for cars given these fixed constraints. Lastly, not everyone lives next to a road and so are potentially excluded from public health interventions.

Countries in the region experience severe flooding during Cyclone season

This explains why WMP teamed up with WeRobotics earlier this year. WeRobotics engineers have been busy developing an aerial release mechanism that can be attached to a drone. Combining both the aerial and ground-based release of W-mosquitos is expected to be a lot more effective. The aerial release mechanism can store up to 160,000 W-mosquitos at 5 degrees Celsius and release 200 mosquitos at a time every 50 meters. This is enough to cover an area of four square kilometers. Aerial releases are much faster than ground releases (no traffic, stop lights, pedestrians, etc.) and, unlike cars, drones don’t burn fossil fuels. A drone can cover an area of 10km2 in a couple hours while mosquito releases by car over the same area would require several days. In addition, the use of drones provides far more homogeneous releases and better coverage. Another bonus: drone routes are much easier to plan than car routes.

The mechanism is airborne and ready to release 200 W-mosquitos at a time

A fully operational prototype of the release mechanism is currently being piloted in the South Pacific after 5 months of local community engagement and awareness raising. WeRobotics engineers have already trained local drone pilots with South Pacific Flying Labs and Drone Services Fiji on how to operate the drone and the release mechanism safely and effectively. As such, the local team at Pacific Flying Labs is now taking the lead in piloting the drone and aerial releases as part WMP’s public health intervention in Fiji.

Building local capacity is central to the mission of WeRobotics as is creating local ownership of health, humanitarian, development and environmental projects. The localization of this expertise and technology through the global Flying Labs network leads to more sustainable and impactful projects.

An aerially-released mosquito finds their way to the arm of a WMP colleague

When the pilot project completes this week, South Pacific Flying Labs and partners will have released around half-a-million W-mosquitos. WMP has engaged the help of local community members to host a large network of mosquito traps across the release area to determine how widely, quickly and uniformly these mosquitos have dispersed compared to ground-released mosquitos. W-mosquitos can be distinguished from others because the former have each been dusted with yellow-colored dye. Once our friends at WMP complete their evaluation following of trial, we’ll be able to quantify the added value of complementing ground-based releases with aerial releases. Future trials will seek to optimize the release methods so that mosquito deployments can be achieved across larger areas.


South Pacific Flying Labs is funded by Australia’s Department of Foreign Affairs and Trade (DFAT). The drone component of the mosquito project is funded by the United States Agency for International Development (USAID) through the Combating Zika and Future Threats Grand Challenge. Earlier this year, WeRobotics tested the use of drones for mosquito release in Brazil using a completely different prototype release mechanism.

 

How Mosquitos are Hitching a Ride on Drones to Reduce Zika

I had the distinct honor of serving on the expert panel of judges for the prestigious International Drones and Robotics for Good Awards in Dubai for 2 years. It was there that I first came across the path-breaking work of the Insect Pest Control Laboratory (IPCL) of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture (NAFA). Their proposed solution: to fight Zika and other mosquito-borne diseases by using drones. I was impressed with their innovative approach and pleased that their pitch was recognized as such by my fellow judges in Dubai: the FAO/IAEA team was selected as one of 10 semi-finalists from over 1,000 competing teams.

I therefore reached out to IPCL when USAID launched their Grand Challenge on combating Zika and related diseases. I was keen to explore whether WeRobotics could help translate IPCL’s pitch in Dubai into reality. To be sure, combining FAO/IAEA’s world renowned expertise in pest control with our demonstrated expertise in the application of robotics for positive social impact could really make a difference. Thankfully, USAID was equally excited and kindly awarded us with this grant to design, prototype and field-test a mosquito release mechanism specifically for drones.

Mosquitoes are one of the world’s biggest killers, responsible for spreading deadly diseases including Zika, dengue and malaria. Among the many ways being researched to combat this threat is the Sterile Insect Technique (SIT) – flooding the environment with non-biting, sterile male mosquitoes, which after mating produce sterile eggs and a reduction in the local mosquito population. SIT is a complementary tool in pest-control efforts. This form of insect birth control has been used successfully for decades to combat insects, including the Mediterranean fruit fly, the screwworm and the tsetse fly, and is now being adapted to help fight disease-transmitting mosquitos. One of the challenges for the potential use of this technique is efficiently spreading millions of sterile mosquitoes – this is where drones come in. So for the past year we have been working together with IPCL on a drone-based mosquito dispersion mechanism, as part of USAID’s Grand Challenge on combating Zika and related diseases.

You can read here about the motivations behind using mosquito-releasing drones for vector control. As we’ve recently received some media coverage on our joint project (e.g., BBC, IEEE Spectrum, TechExplore, DigitalTrends, Interna-tional Business Times and Internet of Business) we wanted to share the latest developments on our prototype.

While release mechanisms exist for fruit flies (in particular for manned aircraft), mosquitoes are alas far more fragile. Developing a release mechanism for mosquitoes is a lot more difficult, presenting a number of design challenges ranging from the shape of the mosquito storage unit and its nozzle, to the type of ejection unit used to physically disperse them. Quality of the mosquitoes as they exit the mechanism is paramount; the mosquitoes must be able to find mates, and any damage to their wings or body can prevent them from successfully competing with non-sterile males.

In addition, the mosquitoes need to be kept between 4-10 °C to keep them in a sleep-like state so that they don’t get “active” and hurt each other when placed into the small release mechanism. So the challenge here is to maintain the cold-chain as efficiently as possible; not only during the drone flight, but also during transportation to the takeoff site and setup of the drone platform.

Our immediate direct goal is to release 50,000-100,000 mosquitoes over one square kilometer in a single drone flight. While a range of ejection solutions were considered, we’re currently using a mechanism based on a simple rotating cylinder with small slots that transfers mosquitoes in small batches. This mechanism was developed for other fragile insects within the ERC REVOLINC project (PCT/EP2017/059832). To chill the mosquitoes we’re using a passive cooling technique based on phase change materials.

The first step in validating the system is lab tests. Our partners at IPCL have reared hundreds of thousands of mosquitoes (photo above) and passed them through the device in various configurations, measuring their resistance to the mechanical stress of the mechanism, wind resistance and various other details. The release mechanism was extensively tested with real mosquitoes (Aedes aegypti) at IPCL in Vienna with further tests scheduled for early December.

Lab tests help us characterize our mechanism in controlled conditions, but the real proof of the mechanism’s efficacy must be done in the mosquito’s natural habitat. We are thus finalizing our plans to field test the release mechanism with live mosquitoes in Latin America in early 2018. IPCL will be using mosquito traps during these tests to evaluate the survival and dispersal of mosquitoes from the mechanism, comparing it to ground-based release and giving us clues on the impact of aerially-released sterile mosquitoes on the overall mosquito population.

Stay tuned for the results of our field tests in coming months!

How to Defeat Zika with Flying Robots

Cross-posted from WeRobotics

Mosquitos kill more humans every year than any other animal on the planet and conventional methods to reduce mosquito-borne illnesses haven’t worked as well as many hoped. So we’ve been hard at work since receiving this USAID grant six months ago to reduce Zika incidence and related threats to public health.

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Our partners at the joint FAO/IAEA Insect Pest Control Lab in Vienna, Austria have been working to perfect the Sterile Insect Technique (SIT) in order to sterilize and release male mosquitos in Zika hotspots. Releasing millions of said male mosquitos increases competition for female mosquitos, making it more difficult for non-sterilized males to find a mate.

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We learned last year at a USAID Co-Ideation Workshop that this technique can reduce the overall mosquito population in a given area by 90%. The way this works is by releasing millions of sterilized mosquitos using cars, helicopters and/or planes, or even backpacks.

Our approach seeks to complement and extend (not replace) these existing delivery methods. The challenge with manned aircraft is that they are expensive to operate and maintain. They may also not be able to target areas with great accuracy given the altitudes they have to fly at.

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Cars are less expensive, but they rely on ground infrastructure. This can be a challenge in some corners of the world when roads become unusable due to rainy seasons or natural disasters. What’s more, not everyone lives on or even close to a road.

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Our IAEA colleagues thus envision establishing small mosquito breeding labs in strategic regions in order to release sterilized male mosquitos and reduce the overall mosquito population in select hotspots. The idea would be to use both ground and aerial release methods with cars and flying robots.

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The real technical challenge here, besides breeding millions of sterilized mosquitos, is actually not the flying robot (drone/UAV) but rather the engineering that needs to go into developing a release mechanism that attaches to the flying robot. In fact, we’re more interested in developing a release mechanism that will work with any number of flying robots, rather than having a mechanism work with one and only one drone/UAV. Aerial robotics is evolving quickly and it is inevitable that drones/UAVs available in 6-12 months will have greater range and payload capacity that today. So we don’t want to lock our release mechanism into a platform that may be obsolete by the end of the year. So for now we just using a DJI Matrice M600 Pro so we can focus on engineering the release mechanism.

Screenshot 2017-06-09 13.24.22

Developing this release mechanism is anything but trivial. Ironically, mosquitos are particularly fragile. So if they get damaged while being released, game over. What’s more, in order to pack one million mosquitos (about 2.5kg in weight) into a particularly confined space, they need to be chilled or else they’ll get into a brawl and damage each other, i.e., game over. (Recall the last time you were stuck in the middle seat in Economy class on a transcontinental flight). This means that the release mechanism has to include a reliable cooling system. But wait, there’s more. We also need to control the rate of release, i.e., to control how many thousands mosquitos are released per unit of space and time in order to drop said mosquitos in a targeted and homogenous manner. Adding to the challenge is the fact that mosquitos need time to unfreeze during free fall so they can fly away and do their thing, ie, before they hit the ground or else, game over.

We’ve already started testing our early prototype using “mosquito substitutes” like cumin and anise as the latter came recommended by mosquito experts. Next month, we’ll be at the FAO/IAEA Pest Control Lab in Vienna to test the release mechanism indoors using dead and live mosquitos. We’ll then have 3 months to develop a second version of the prototype before heading to Latin America to field test the release mechanism with our Peru Flying Labs. One of these tests will involve the the integration of the flying robot and the release mechanism in terms of both hardware and software. In other words, we’ll be testing the integrated system over different types of terrain and weather conditions in Peru specifically.

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We are already developing the mission control app pictured above to program our autonomous flights. The app will let the operator decide how many sterilized mosquitos to release at any given time and location. Our field tests in Peru will also seek to identify the optimal flight parameters for the targeted and homogenous delivery of sterilized mosquitos. For example, what is the optimal speed and altitude of the flying robot to ensure that the mosquitos are released over the intended areas?

Our Peru Flying Labs has already developed expertise and capacity in cargo drone delivery, most recently in projects in the Amazon Rainforest with the Ministry of Health (more here). This new Zika reduction project –and in particularly the upcoming field tests — will enable us to further build our Peruvian team’s capacity in cargo space. The plan is for Peru Flying Labs to operate the flying robots and release mechanisms as need once we have a more robust version of the release mechanism. The vision here is to have a fleet of flying robots at our Flying Labs equipped with release mechanisms in order to collectively release millions of sterilized mosquitos over relatively large areas. And because our Peruvian colleagues are local, they can rapidly deploy as needed.

For now, though, our WeRobotics Engineering Team (below) is busy developing the prototype out of our Zurich office. So if you happen to be passing through, definitely let us know, we’d love to show you the latest and give you a demo. We’ll also be reaching out the Technical University of Peru who are members of our Peru Flying Labs to engage with their engineers as we get closer to the field tests in country.

As an aside, our USAID colleagues recently encouraged us to consider an entirely separate, follow up project totally independently of IAEA whereby we’d be giving rides to Wolbachia treated mosquitos. Wolbachia is the name of bacteria that is used to infect male mosquitos so they can’t reproduce. IAEA does not focus on Wolbachia at all, but other USAID grantees do. Point being, the release mechanism could have multiple applications. For example, instead of releasing mosquitos, the mechanism could scatter seeds. Sound far-fetched? Think again.