Posted on December 05, 2023
Malaria, a complex vector-borne disease, requires a comprehensive research-based approach for effective control and elimination. Due to its complexity, researchers follow a step-by-step method called scientific inquiry to study malaria. Researchers formulate hypotheses from research questions, test ideas through controlled experiments, and collect valuable data to unravel the intricacies of the parasite, its vectors, and transmission dynamics. This approach deepens researchers’ knowledge of the disease, guiding the development of effective, evidence-based interventions towards achieving malaria elimination.
The University of Pretoria Institute for Sustainable Malaria Control creates a platform for diverse experts to bring their unique skills and knowledge to the table and join forces to address malaria holistically.
Research disproved malaria fallacies over time
Historical malaria fallacies include misconceptions about its cause, transmission, and remedies. The concept of miasma—the belief that diseases were caused by noxious air—was prevalent in many cultures. In the case of malaria, residents or people near marshy or swampy areas with high mosquito populations were observed to have a higher likelihood of contracting the disease. People, lacking knowledge of microscopic organisms and the role of mosquitoes as vectors, attributed the cause to the "mala aria” (“bad air” in Italian), or miasma arising from these locations.
Acacia xanthophloea, commonly known as the "fever tree", is native to eastern and southern Africa. These trees are often found in areas where malaria is prevalent. Early inhabitants noted that these areas coincided with bouts of fever. An association between the prevalence of these trees and the prevalence of malaria in these areas leads to misconceptions about the trees causing the disease.
The cinchona tree (Cinchona species), on the other hand, is historically associated with the treatment of malaria due to its quinine content. Yes, tonic water contains quinine. No, drinking gin and tonic (or tonic alone) cannot cure malaria. The concentration in tonic water is much lower than therapeutic doses. Besides, quinine's efficacy has been challenged by the emergence of drug-resistant strains of the parasite. Additionally, its side effects and the need for prolonged treatment also raised concerns.
Other fallacies include beliefs in specific foods causing or preventing malaria. Traditional herbal remedies are used to treat malaria, but relying solely on them can lead to complications. Some cultures associate malaria with the supernatural, stigmatising patients and hindering effective medical interventions. There are misconceptions about casual contact spreading malaria or that malaria is exclusive to tropical regions. Dispelling these myths is crucial for effective malaria control.
A summarised history of malaria research
Researching malaria delivers insight into vector and parasite biology, behaviour, and genetic characteristics. Knowledge of the mosquito's life cycle, feeding habits, and breeding patterns aids in developing effective control interventions beyond insecticides. Understanding the parasite’s complex life cycle and identifying potential parasite drug and vaccine targets leads to drug and vaccine development.
The discovery that malaria is caused by Plasmodium parasites and transmitted by Anopheles mosquitoes, through the collaborative efforts of Sir Ronald Ross and Sir Patrick Manson, revolutionised the understanding of disease dynamics, creating new possibilities for control. Manson, a British physician, proposed the theory that mosquitoes were involved in the transmission of malaria. Ross, a British Army surgeon, conducted ground-breaking experiments in 1897 in India, demonstrating the parasite’s complete life cycle within Anopheles mosquitoes, earning him the Nobel Prize in Physiology or Medicine in 1902. Early 20th-century efforts targeted mosquito breeding sites, while the 1950s saw the introduction of DDT for indoor residual spraying (IRS). Over time other insecticides were developed for IRS, with mosquitoes developing resistance to many, including DDT. In the 1980s, insecticide-treated bed nets gained importance, evolving into long-lasting insecticidal nets in the 2000s. In the 21st century, integrated vector management (IVM), and genetic approaches are explored to control vector populations and interrupt transmission.
The emergence of drug-resistant parasite strains over the years has posed a significant challenge. Malaria drug discovery started with quinine's 17th-century use, followed by 19th-century synthesis of chloroquine-like compounds. In the early 1970s, Chinese scientist Tu Youyou and her team discovered artemisinin, extracted from the sweet wormwood plant (Artemisia annua). Youyou's work on artemisinin and its subsequent development into artemisinin-based combination therapies (ACTs) revolutionised malaria treatment. She received the Nobel Prize in Physiology or Medicine in 2015. Chloroquine, a 20th-century development, was widely used until resistance emerged. Antifolate drugs appeared in the mid-20th century, while ACTs gained importance in the 2000s. Other drug types were also introduced in the 2000s and 2010s. The concerning drug resistance, especially to ACTs in various regions has prompted the need for new drug candidates with novel mechanisms of action.
Malaria vaccine research started in the mid-20th century. The development process faced challenges due to the parasite's ability to evade the immune system and the complexity of its life stages. After several decades of hard work, two vaccines are now available: RTS,S/AS01 since 2021, followed by R21/Matrix-M in 2023. Both vaccines demonstrate safety and efficacy in preventing malaria in children and are anticipated to yield substantial public health benefits when widely implemented.
Research helps in understanding malaria's distribution, transmission, and risk factors, informing targeted interventions, and allocating resources efficiently. Research supports robust monitoring for outbreak detection and intervention assessment. Research encourages collaboration, facilitating data and resource sharing. With research comes the knowledge of how malaria is evolving.
Research towards elimination
Funding is the lifeblood of malaria research. Investment catalyses breakthroughs that could become game-changers. Innovation transforms knowledge into actionable solutions and drives progress. Researchers harness cutting-edge technologies to decode the genetic mysteries of the parasite and vector, allowing for targeted control strategies. Innovation creates better, faster, and more accurate diagnostic tools, and it produces environmentally sustainable and community-centric ideas towards control.
Ideas must translate into tangible interventions, where implementation is key to actual impact. Effective implementation is a collective pursuit, requiring collaboration between scientists, healthcare providers, policymakers, and communities, ensuring that findings really do make a difference.
Research uses the complexity of malaria and creates the possibility of ending it for good.
For more information, visit the webpage of the University of Pretoria Institute for Sustainable Malaria Control, a multi-disciplinary research institute making a substantial contribution towards the creation of a malaria-free Africa.
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