Fighting malaria in Africa
Some grim statistics to commemorate this year’s April 25.
It is World Malaria Day last Sunday; and Africa has not covered itself in glory when it comes to fighting the disease that has caused untold suffering among its citizens.
As we even write this, one of our greatest football exports, Pierre-Emerick Aubameyang has missed a few important matches for his Premier League club, Arsenal – because he caught the parasitic disease after travelling to his home in Gabon at the last international break.
And if a well-protected professional of the calibre of Pierre-Emerick Aubameyang can catch malaria, what hope is there for Africa’s rural populations, far removed as they are from medical access and other preventive measures?
But not all African countries have had bad numbers though – some have given a really good fight and protected the majority of their citizens from malaria infections in recent years.
But claiming 200million annual infections out of a world total of 219million paints a grim picture of the situation on the ground. That is about 93 percent of all infections being concentrated in Africa; in ten countries specifically – Burkina Faso, Cameroon, Democratic Republic of the Congo, Ghana, Mali, Mozambique, Niger, Nigeria, Uganda and Tanzania. Along with India, these countries recorded 155million malaria cases in 2017, about 22million cases less than the previous year’s figures.
A notable reduction of course. But still worryingly high numbers nevertheless.
Also, at 93 percent, the countries also take the lion’s share of the 409,000 people – most of them women and children – who lost their lives to malaria in 2019.
Which was why in 2018, the World Health Organisation launched the High Burden High Impact response, an aggressive, country-driven approach to jump-start preventive progress against malaria. The project has done its part in reducing the infection and death rates due to malaria – and in some of the affected countries, drone technology has played a part in this regard.
In Tanzania, which is one of the country worst affected by the disease, the country has been using drone technology to map out mosquito breeding sites areas and conduct targeted spraying, using Aquatain AMF, a silicone-based liquid manufactured by Australian insecticide company, Aquatain.
But, according to this Reuters report, researchers, led by Bart Knols from Radboud University in The Netherlands, were not only targeting the breeding sites for wholesale spraying, as was done in Malawi before. Their plan was to sample the larvae and the mosquitoes in the fields before, during and after spraying; because they believe preventing pupae and larvae from attaching themselves to the surface of the water would take the malaria fight to the next level.
“By controlling mosquitos right at the source, we hope to have an impact ultimately on the transmission of malaria,” Knols said.
The research work is being done through Anti-Malaria Drones, an initiative, which brings together efforts from drone maker DJI (because of their Agras crop-spraying drone generations); Aquatain; the Dutch Malaria Foundation and drone services start-up, Tanzania Flying Labs, which would chip in with other drone services like mapping.
Also joining the initiative is Zanzibar Malaria Elimination Program (ZAMEP), which is responsible for the development, implementation, monitoring and evaluation of malaria control interventions and coordination of stakeholders of malaria elimination interventions at all levels of the health care delivery system. In pursuing this goal, the program is coordinating with various stakeholders and receives financial and technical support from many partners.
The initiative chose drone because, unlike helicopters, drones are way, way, way less expensive and they also take way less time and are less invasive, when compared to humans with spray containers on their backs.
And Knols and fellow researchers chose Tanzania’s Zanzibar archipelago for the pilot tests, partly due to its progressive laws on the use of drones for research.
“It is very difficult to just walk through the paddies and apply the chemicals, so you want to have something that can just spray it on the water surface. It spreads, does the job and that’s it,” said one of the researchers, Wolfgang Richard Mukabana from the University of Nairobi, speaking of the effectiveness of the chemical spray used in the project.
The way the process works is that the DJI Agras drones would be flown over malaria breeding sites, spraying the biological control agent over them. The control agent forms a thin layer over the breeding sites, which would prevent the larvae from getting oxygen, and eventually suffocate them.
Aquatain says their liquid product is highly permeable to gases so does not prevent the water from being oxygenated. It is just lethal to mosquitos.
And like Mukabana intimated, the process worked. A few days after carrying out the sprays, the researchers went back to check whether their nets had caught any mosquitos that had developed into adults with a potential to spread diseases among the farmers on whose rice paddies they had made a home.
They found none; and the situation remained the same for weeks after the sprays were done.
When it comes to drone technology’s involvement in fighting malaria, targeted spraying at the source seems to be the solution of choice because that is exactly what drone start-up company, Charis UAS are also doing in Rwanda.
“We use Artificial Intelligence models to detect mosquito breeding sites, develop “signatures” of these sites, and collect data for deep analysis,” the company says, adding that the information gathered will be transmitted to authorities for further action and investigation.
“The final and most important step in this technologically advanced malaria eradication program is targeted spraying. UAVs are equipped with the necessary larvicide tools to spray multiple hotspots quickly and safely. By targeting disease-carrying mosquitoes at their inception point, drones eliminate their numbers as well as reduce the need for interventions such as home and indoor spraying.
“Eradicating the number of disease-carrying pests leads to a lower infection rate, saves lives, and contributes to the positive development of national economies. Drone technology also has knock-on effects; as governments would be able to use mosquito breeding ground mapping to not only attack hotspots but also incorporate this knowledge into agriculture and land management planning.”
According to this report from the Daily Maverick, the South African Medical Research Council (SAMRC) is currently exploring the possibility of using drone technology in the fight against malaria.
The paper quoted Professor Rajendra Maharaj, Director of the SAMRC’s Office of Malaria Research saying his organisation was looking to also control mosquito larvae while they were still fledgling in their nests, and before they leave to cause destruction and suffering in people’s homes.
Maharaj says they would also be conducting indoor spraying as well.
“Traditionally this has been done by control staff walking through areas where malaria cases have been identified to identify and geo-locate (using a GPS) them for treatment with insecticides, Professor Maharaj said. “However, this was not an effective method since people usually walk along roads and pathways whereas the breeding site may be a small puddle under a bush of an indentation in the ground that has filled with water and would not be noticed by an individual not straying from the usual paths.
“Drones can hover over an area and take photographs of breeding sites, geo-locate the breeding sites and potentially apply the insecticide to the water body with mosquitoes breeding in it. This helps to decrease the mosquito populations and therefore limits malaria transmission.”
He says a microcosm project is underway in the Ndumo area in northeast KwaZulu-Natal to use drones to inspect houses for openings that could either serve as an entry point for mosquitoes or – in the case of flat roofs – identify mosquito breeding sites that contribute to the available pool of mosquito vectors.
If the project is successful, the SAMRC plans to introduce drones into the malaria control programmes the whole province of KwaZulu-Natal, and also in Limpopo, and Mpumalanga.
Breeding sterile mosquitos in Brazil
While controlling baby mosquitos at the source seems wide spread, what has yet to be tried on the continent is setting sterile male mosquitos on the loose to breed with their malaria-causing female counterparts, so they produce eggs that will not hatch.
This method – which also used a drone to release the sterile mosquitos around malaria breeding sites – was tried by scientists in Brazil since 2018, and the results were published in a research article on Science Robotics last year.
“After just three drone releases of sterile male mosquitoes, a peak of 50 percent unviable eggs was observed in the following two weeks in the test areas,” the researchers said of their project. “The results look very promising for controlling the diseases transmitted by these insects.
“This is the first scientific publication on sterile insect releases from uncrewed aerial vehicles, and also the first field analysis of the sexual competitiveness of sterile male mosquitoes. It has taken two years for the researchers involved to draw their conclusions on the trial in Brazil in 2018, and the results look very promising for controlling the diseases (malaria, Zika, dengue or chikungunya) transmitted by these insects.”
Researchers praised the effectiveness of the sterile male mosquitoes – which were sterilised in a laboratory before being unleased into the environment to mate with females – saying the modified mosquitos held their own in competition against their virile counterparts, and had a great hand in the fight to reduce disease-causing mosquitos to levels below their potency.
And they released the mosquitos using a drone too, to give them a greater chance of survival and also spread them over a wider area, at twenty times less the cost of terrestrial releases.
“Drone releases can be used to treat large areas more uniformly than terrestrial releases,” the researchers concluded. “Above all, they save a lot of time, and a recent study in China estimated that they cost up to 20 times less. Technological advances in recent years have improved the efficacy of such treatments even further. The drone we used in 2018 (a DJI M600) weighed around 12 kg; but new trials are planned in Brazil this (last) year with devices that weigh a tenth of that. The new, smaller devices can be used to treat urban areas safely.”