Introduction
Malaria remains a major threat in Tanzania and Burkina Faso, requiring more innovative control approaches to help the countries advance towards elimination. Burkina Faso had an estimated 12.23 million cases (at an incidence rate of 569 cases per 1000 population) in 2021, resulting in 43,555 deaths (WHO Regional Office, 20231). Tanzania had a reported incidence of 106 cases per 1000 population in 2020 (Ministry of Health, 20202); in the 2022 demographic and health survey, 8% of children aged 6–59 months in the survey tested positive for malaria, (Ministry of Health et al, 20223). In 2023, the World Health Organisation estimated that four percent of deaths in the world attributed to malaria occurred in Tanzania, and 2.7% in Burkina Faso (WHO, 20234).
Some of the challenges both countries face in the fight again the disease include poor bed net use – in the 2022 Tanzania demographic and health survey, only 59% of respondents in all households had slept under a mosquito net the night before the survey. In Burkina Faso in 2021, only 61% of the population had slept under a net the night prior to the survey. Both countries are also grappling with the emergence of mosquitos resistant to common insecticides. The two countries are exploring the use of different genetically based vector control technologies for malaria control.
Implementation
GBVC technologies, which include gene drives and genetically modified mosquitoes, are developed through genetic manipulation techniques to control the population of disease-carrying vectors. Gene drives technology enables scientists to alter the DNA of mosquitoes and incorporate genes that hinder their ability to transmit the disease, passing on ‘beneficial genes’ to suppress or eliminate the vector population. The technology is still at laboratory research stage in both countries.
In Tanzania, one of the research projects being implemented is a study by the Ifakara Health Institute (IHI) and Tanzanian National Institute of Medical Research (NIMR), in collaboration with Transmission Zero, a global scientific programme of the Imperial College London. In 2023, the project generated a genetically modified mosquito strain, which carries in its genome genetic modifications that will allow scientists in the future to render mosquitoes unable to transmit malaria. IHI is also conducting other studies on gene drives, including one on stakeholder perceptions and support for the technology.
In Burkina Faso, the Institut de Recherche en Sciences de la Santé and Target Malaria project have been conducting research on genetically modified mosquitoes since 2012, researching two genetically modified strains - one to produce predominantly male offspring, and the second, to carry a gene that will cause females that inherit it to be sterile. The research has already released the first genetically modified mosquitoes in 2019 into field trials. The modified mosquitoes were sterile males and therefore unable to pass on their genes in the wild. They were released to enable the study to learn of their flight patterns, dispersal, and longevity, as part of the continuing research. The various aspects of this field study are still continuing.
In Burkina Faso, Target Malaria put in place a stakeholder engagement team, which links the study with the local community, and shares information from the study. In Tanzania, a technical working group in the Ministry of Health provides oversight to research activities, including biomedical and clinical trials, and ensures all relevant stakeholders are involved.
Policy and Regulation
Both Tanzania and Burkina Faso have policies, laws and regulations, and institutions that provide guidance and governance around public health research. In Tanzania, the current National Malaria Control Strategy (2021-2025) highlights the need to search for evidence-based vector control innovations as a key strategic priority. The Tanzania National Institute for Medical Research is responsible for coordinating all medical research. Burkina Faso also has environmental and biosafety regulations and institutions that guide such studies, including the Biosafety Law (2006), and a national biosafety authority, Agence Nationale de Biosécurité (ANB), that approves biotechnology research. Both countries also have data protection laws to govern management of personal information and information systems.
Impact
Gene drives and genetically modified mosquitoes can help reduce Africa’s burden of malaria disease and similar fevers and significantly improve the health of local populations. Although the technologies are still in research stage, the ability to decrease the population size of malaria vectors will have great impact in reducing the risk of malaria transmission. Given the increasing challenges posed by mosquitoes’ increasing resistance to conventional insecticides, these emerging technologies will be useful additions in the fight against malaria in Africa.
Lessons Learnt
To guide the application of gene drive technology for malaria control, policymakers in Africa should consider the following recommendations:
- Develop policies and regulations that support innovations for health and provide strategic direction.
- Invest in research infrastructure to support innovations for health.
- Engage all relevant stakeholders in planning and decision-making processes.
- Form teams with diverse expertise to address the complexities of gene drive projects.
- Provide training to enhance understanding of gene drive technology among policymakers and community representatives.
Conclusion
More work remains to be done on these experiments before gene drive mosquitoes can be considered for further study and eventual implementation in Africa. The technology holds much promise, if successful, as one of the many tools that the continent needs to fight malaria. By harnessing its potential benefits researchers and public health authorities have the opportunity to advance innovative, sustainable, and effective approaches to malaria control and elimination.