Despite the tremendous progress made over the past two decades, malaria continues to be a major public health concern, especially among the most disadvantaged members of the global community young children and pregnant women. Since the mid-1990s, the distribution of long-lasting insecticide-treated mosquito nets, or LLINs, has been the mainstay of malaria prevention. However, new technologies and strategies hold the promise of supplementing or even replacing mosquito nets. This article reviews modern malaria prevention methods that extend beyond mosquito nets, focusing on new technologies and strategies designed to protect mothers and children from the parasite.
Understanding Malaria and Its Impact
Malaria is a disease spread through the bites of infected Anopheles mosquitoes. The disease is caused by Plasmodium parasites and causes symptoms of fever, chills, and flu-like illness. Malaria is one of the leading causes of severe illness and death in children under the age of five and pregnant women worldwide.
The disease poses a significant public health issue in endemic zones, particularly in sub-Saharan Africa, where it accounts for 20 percent of preventable mortality in children under age 5. Estimates from the World Health Organization indicate that 241 million people suffered from malaria in 2020, which was a decrease from 247 million earlier in 2019.
The Role of Mosquito Nets in Malaria Prevention
Mosquito nets, particularly insecticide-treated nets or ITNs, are also effective in reducing malaria. In part, this is because a net is a physical barrier that reduces the likelihood of a mosquito’s contact with a person. But more importantly, an ITN can prevent or kill the mosquito, thanks to the insecticide. Mosquito nets are one of the most effective malaria control strategies ever developed, but with one shortcoming – they don’t work perfectly because there are any number of reasons why their efficacy can be reduced, including:
- Inconsistent Use: Inconsistent or incorrect use of mosquito nets reduces their effectiveness.
- Wear and Tear: Over time, nets can become damaged or lose their insecticidal properties.
- Accessibility Issues: In some areas, access to mosquito nets remains a challenge.
Emerging Innovations in Malaria Prevention
So, how can these limitations be mitigated, and how can malaria prevention be improved? Here are a selection of some of the most exciting developments on the horizon:
1. Long-Lasting Insecticidal Nets (LLINs)
Although not entirely new, products incorporating nets and insecticides have been manufactured since the 1950s. Long-lasting insecticide-treated nets (LLINs) feature insecticide treatments that remain effective for five to eight years, even after repeated washing, before requiring re-treatment. Newer versions employ dual insecticide-treated LLINs to help combat resistance.
2. Insecticide-Treated Clothing
This is another new approach to preventing malaria. Insecticide-treated clothes offer an added layer of protection for individuals, especially for those who work in the field, and who are exposed to more mosquito bites. It’s useful to protect pregnant women and the young (under five years old), who tend to be more susceptible to malaria.
3. Indoor Residual Spraying (IRS)
Indoor Residual Spraying (IRS): Spraying insecticide onto the walls and ceilings of homes with IRS kills mosquitoes as they fly to and from the space by disrupting their nervous system and forming a film on the walls. It is an often overlooked but valuable tool in integrated malaria control programs, especially in those areas where mosquito nets cannot be easily used. New formulations and application technologies are making these indoor treatments more effective and safer.
4. Genetically Modified Mosquitoes
Perhaps the most ‘disruptive’ innovation is the rapidly expanding use of genetically modified (GM) mosquitoes to prevent malaria transmission. For example, scientists have created malaria vectors with reduced ability to pass on the parasite, or mosquitoes deliberately sterile or incapable of transmitting the malaria parasite. GM mosquitoes are still experimental but show enormous potential for long-term control of malaria.
5. Vaccines
The most recent technological development in malaria prevention is vaccines. Mosquirix (RTS, S/AS01) is the first vector-based malaria vaccine to be approved for widespread use. Plasmodium falciparum, the most deadly malaria parasite, is the target because it is the main cause of mortality by malaria in children. The vaccine, RTS, S/AS01, has been tested in clinical trials and is being rolled out in several endemic regions. Additional research is improving vaccine efficacy and developing more vaccines.
6. Antimalarial Drugs for Prevention
Antimalarial drugs, taken on a preventive basis by people for whom there is a high risk of malaria infection, can be useful. Specific preventive medicines can be given to pregnant women and young children. Researchers are exploring new formulations and delivery mechanisms to improve adherence and effectiveness.
7. Community-Based Interventions
A key aspect of this effort will be community engagement and education. For instance, mobile phones can provide families and caregivers with essential information and advice. Local communities can come together to participate in prevention activities and receive guidance to track problem areas. Community health workers can become powerful local agents in the fight against malaria by taking the initiative, receiving training and support to deliver education, and distributing preventive measures and treatments.
8. Environmental Management
Environmental management tries to manipulate or control the environment to eliminate (or reduce) mosquito breeding sites. The invention has resulted in innovations such as biological control agents in the form of larvivorous fish and eco-friendly larvicides. Environmental sanitation and waste management also keep mosquito habitats to a minimum.
The Importance of Integrated Malaria Prevention
Any single method of malaria control is insufficient by itself; a combination is required to be effective. Integrated malaria prevention entails multiple interventions with different types of impact. For example, people can combine insecticide-treated nets with IRS and community education.
Challenges and Future Directions
While innovations in malaria prevention are promising, several challenges remain:
- Cost and Accessibility: The implementation of new technologies and interventions can be costly, and ensuring they are accessible to those who could benefit the most are enormous challenge.
- Resistance: For instance, resistance to insecticides and antimalarial drugs can seriously threaten prevention efforts. This is one area that requires ongoing research.
- Lack of infrastructure: In many malaria-endemic settings, structural challenges can hamper the availability and provision of new interventions.
These are challenges for future research and development and hopefully further refinement of current technologies. International cooperation between governments, multilateral organizations, bilateral donors, and local organizations will be key to promoting effective malaria control and, eventually, its eradication.
While prevention through the use of rudimentary mosquito nets remains the most widely used mitigation strategy for preventing malaria across the Tropics, substantial technological advancements since 2000 have led to the emergence of new malaria prevention tools such as long-lasting insecticidal nets, insecticide-treated clothing, genetically modified mosquitoes, and vaccines. To date, few communities are using all these prevention tools to achieve comprehensive malaria control and elimination. Still, the best prevention strategy depends on context and budget, but virtually every approach is a smart move in the fight against this devastating disease.
For mothers and children, these various strands of protection must be combined in ways that are tailored to their specific needs and circumstances. As long as we keep investing in and deploying these new yarns, and adding others, we will eventually be able to spin a web that will no longer allow malaria to catch its prey.
