Malaria places a crushing burden on Uganda’s health system, as it does in many African countries.
The disease accounted for 30-40% of Ugandan outpatient visits in 2023, states the World Health Organization. It kills 16 people daily, according to Jimmy Opigo, malaria control programme manager for the Ministry of Health. Children under five and pregnant women are especially vulnerable.
Incidence of the disease had been reduced in the 2010s by distributing mosquito nets and spraying insecticide, but there has been a resurgence since 2020, and climate change is boosting mosquito numbers.
In order to stem the tide, researchers at the Uganda Virus Research Institute (UVRI) have been working on a “gene drive” initiative to release genetically modified male mosquitoes into the wild. They carry a gene which spreads rapidly through the mosquito population, reducing its ability to reproduce.
“Gene drives could complement existing strategies by addressing the root cause – the mosquito population itself,” Jonathan Kayondo, head of entomology at the UVRI, tells Dialogue Earth.
Beating back the resurgence
From 2013, Uganda’s government managed to lower rates of malaria largely by distributing nets treated with insecticide and carrying out spraying campaigns, researchers described in a 2022 study. However, in 2020 and 2021, there was a resurgence of the disease to levels not seen since before the insecticide spraying begun.
It is not known what caused this, though possible reasons given by the researchers include the changing in 2019 of the active ingredient in the spray, in order to beat mosquito resistance to it, and the Covid-19 pandemic, which affected vector-control measures.
Gene-drive technology is powerful because it is self-sustaining. But that also raises questions about control. Once released, the altered genes cannot be recalled, and their spread across ecosystems – and borders – may be inevitable.
As of September 2025, Uganda was still conducting work on the gene-drive mosquitoes in contained laboratory settings with none yet released ino the environment, an official from the Uganda National Council for Science and Technology told the journal Nature Africa.
In 2023, 569,000 people died in Africa due to malaria. By the middle of this century, climate change will cause half a million more to die from the disease than would under a stable climate, according to a model developed by the Boston Consulting Group and the Malaria Atlas Project. The additional deaths are largely the result of extreme weather events that do damage to mosquito nets and other barriers to mosquitoes, like windows, as well as reduce access to healthcare.
Targeting the fertility gene
Birungi Krystal is an entomologist working on the Target Malaria project at the UVRI. Target Malaria is a not-for-profit aiming to use genetic modification to reduce malaria-transmitting mosquitoes in Sub-Saharan Africa.
Krystal tells Dialogue Earth it is working on doing this by “modifying the mosquito so that instead of laying up to 300 eggs [each time] it would lay maybe 10 or less”.
She says the challenge becomes making sure that that modification is maintained. Normal genetics dictate that a particular gene is passed down 50% of the time. “And when you have a modification like this, which … the mosquitoes do not benefit from, that modification is usually wiped out even faster than regular genes … which means you’d have to release large numbers of mosquitoes to compete with the [ones] we have in the wild,” Krystal says. Gene drives attempt to design a trait that is inherited far more than 50% of the time, greatly increasing the rate of its spread.
Changing climate, changing mosquito behaviour
As of 2023, Uganda has the third highest number of malaria cases globally, with more than 15,000 deaths that year. The five countries with the highest malaria cases, which are all in Africa, account for around half of all the 246 million cases.
Herbert Nabaasa, Uganda’s health commissioner, champions the country’s work on gene drives, saying that “research and possible interventions to control malaria are highly commended”.
“I welcome the move to bring on board that additional science, managing the mosquito population by checking on the sex or fertility capacity of the mosquitoes, eventually pulling down the biting capacity and biting rate,” Nabaasa says.
He observes that with climate change, Uganda has seen the growth rate of the mosquito population more than double, and that warming temperatures are changing their behaviour too.
“We see that the mosquitoes that would bite at night now can bite during the day. And so the characteristics and the behaviour of the mosquito, especially the female Anopheles that spreads malaria, have drastically changed due to environmental factors and climate change,” Nabaasa says.
“The rising temperatures, the warmth provided, are [also] fertile grounds for breeding of the mosquito and larvae.”
The ecological question
Opakrwoth Caysie, a graduate environmental scientist from Makerere University, explains the potential ecological impacts that could arise if the gene drive crashes mosquito numbers, or eliminates Anopheles in Uganda.
“Suppressing a mosquito [genus] like Anopheles could trigger a range of unintended consequences within Uganda’s ecosystems,” Caysie tells Dialogue Earth. “Mosquitoes are often perceived only as disease carriers, but they really play important roles for nutrient cycling – their larvae feed on organic matter in water, help break it down and recycle nutrients – and maintaining water quality in wetlands and other aquatic habitats.”
Female Anopheles mosquitoes, known carriers of malaria, are the object of Target Malaria’s proposed gene-drive initiative in Uganda (Image: CDC / James Gathany / Alamy)
Caysie further notes that by existing in large numbers, mosquitoes influence population dynamics of their predators.
“If [mosquito numbers are] drastically reduced, predators may decline or shift diets, which can cause cascading effects in ecosystems,” he says. “Altering or removing them may create far-reaching effects that could extend beyond the immediate goal of malaria control, potentially leading to disruptions in biodiversity, shifts in ecosystem dynamics, and unforeseen environmental risks.”
Lessons from Burkina Faso
In 2019, Burkina Faso became the first African country to release genetically modified male mosquitoes into the wild. The mosquitoes were sterile and were released in small numbers under the supervision of researchers at Target Malaria. Because the sterility could not be passed on to subsequent generations, this is different to a gene drive which is self-perpetuating.
The trial ended without visible ecological harm, but it was temporary by design. It nonetheless sparked intense debate, with critics accusing researchers of “medical colonialism”.
“The key lesson from Burkina Faso is that local communities must be fully informed and consent clearly established,” says Noumechi Rochel, a regional health advocate. “Otherwise, trust erodes quickly, and the science becomes entangled in politics.”
This, along with health and ecological concerns, appears to have been partly the case in the gene-drive initiative launched in the country on 11 August this year. Target Malaria released 16,000 mosquitoes genetically modified to produce male offspring almost exclusively but suspended the programme just a week later. The Burkina Faso government dispatched a team to spray insecticide in the release area and kill insects still in the lab. The outlet Science reported that anti-Western disinformation campaigns and false accusations had in part led to public opposition to the project, including unfounded claims that the NGO was using the modified mosquitoes to spread disease and sterilise people.
In Uganda, Target Malaria has been holding community meetings in potential trial districts to explain the research on gene drives. Visual aids and local-language sessions are used to demystify the science.
But campaigners question the efficacy of such meetings, given that rural communities may not be able to truly grasp the long-term implications of gene drives. “You cannot simplify this technology enough to guarantee full understanding,” says a Kampala-based human rights activist. “That creates an imbalance of power between foreign funders, local scientists, and communities who will live with the consequences.”
Concerns also extend to consent. In tightly knit rural areas, decisions are often made by local leaders, leaving ordinary residents with little influence. Critics worry that consent obtained under such circumstances cannot be considered free and informed.
Developments in Uganda are being closely watched by other African nations, including Kenya, where malaria remains a major public health burden. Scientists at the Kenya Medical Research Institute have been exploring similar genetic approaches, though public acceptance and regulatory approval remain hurdles.
Health experts say Uganda’s move could provide valuable lessons for countries across Africa. “If Uganda demonstrates that gene-drive mosquitoes can be tested safely and ethically, this may pave the way for regional harmonisation of biotechnology regulation,” says a Nairobi-based malaria researcher who was not involved in the project.
Policy dilemma
Uganda’s National Biosafety Committee is drafting regulations to cover genetically modified organisms, including gene drives. But without comprehensive biosafety legislation in place, the legal path to a release remains uncertain.
For now, gene-drive mosquitoes in Uganda remain confined to laboratories in Entebbe, the country’s second largest city. But the debate surrounding them is no longer academic. It touches on livelihoods, sovereignty and the balance between human survival and ecological stewardship.
As Uganda weighs its next steps, especially in light of the setbacks faced by Burkina Faso’s gene-drive initiative, one question looms large: can Uganda fight malaria with cutting-edge science without crossing a line that nature cannot redraw?
