CABI scientists have joined an international team of experts who suggest that the large-scale management of a range of some invasive plants could hold the key to reducing the spread of deadly malaria.
Dr Arne Witt and Dr Sean Murphy worked with scientists from the University of Illinois, The Ohio State University and the Fundación para el Estudio de Especies Invasivas (FuEDEI) in Argentina, to conduct a review of existing studies which looked at how mosquitoes are attracted to both land and water-based invasive plants such as water hyacinth, floating pennywort and prosopis and how best these invasive plants can be managed.
The review paper ‘Would the control of invasive alien plants reduce malaria transmission’, funded by the Bill & Melinda Gates Foundation and published in the journal Parasites & Vectors, maintains that an integrated management strategy would contribute to the control of malaria which in 2013 in Sub-Saharan Africa caused around 855,000 deaths.
They found that certain invasive plants provide shelter or resting sites and produce copious amounts of rich nectar, a source of energy which significantly increases their ability to transmit this deadly disease.
The scientists argue that an accumulating body of evidence suggests that these plants can affect the spread and transmission intensity of sleeping sickness as well as various tick-borne diseases. The paper also provides evidence that the presence of these plants may increase malaria transmission rates in certain environments, though many questions still need to be answered to determine how often this conclusion holds.
Dr Arne Witt, Coordinator: Invasive Species, CABI, said, ‘Invasive alien plant species are a major problem in Africa and affect crop and pasture production, human and animal health, water and other natural resources’.
‘This review paper provides additional evidence that invasive plants have cross-cutting impacts across multiple sectors, from human health to biodiversity, and as such require a multisectoral management approach, one that can probably only be achieved by establishing a biosecurity unit or similar, which is funded directly from the treasury and not via any particular Ministry. It is obvious that invasive species cannot be managed in isolation within a country or by only one country within a region – we need to better coordinate our activities in order to protect biodiversity and improve livelihoods, including human health.’
The team, in advocating an integrated management strategy to control invasive plants to curb the spread of malaria, suggest that a combination of cultural, physical, chemical and biological methods should be implemented followed by rehabilitation or restoration of natural ecosystems.
Dr Sean Murphy, Global Scientific Advisor, IPM and Modelling, CABI, said, ‘In the case of aquatic invasive plants, available evidence suggests that the management of these plants would contribute to malaria control and we maintain that this is best achieved in an integrated way.’
The scientists conclude that while a number of studies indicate that in areas with more abundant or richer nectar sources, Anopheles mosquitoes will live longer and greater populations can be sustained, the effects on human biting behaviour are less clear.
In recommending areas for further research, the scientists believe that where there is high exposure to Plasmodium, enhanced by the presence of invasive plants, there is potential for invasive plant management to contribute to an integrated malaria control strategy. However, many further experiments on mosquito foraging behaviour and its implications for malaria transmission potential and mosquito population growth and spread would be required to inform what such a strategy would look like.
Full paper reference
Christopher M. Stone, Arne B.R. Witt, Guillermo Cabrera Walsh, Woodbridge A. Foster and Sean T. Murphy, ‘Would the control of invasive alien plants reduce malaria transmission? A review’, in Parasites & Vectors (2018) DOI: 10.1186/s13071-018-2644-8
The paper is available as an open access document here.
About CABI
CABI is an international not-for-profit organization that improves people’s lives by providing information and applying scientific expertise to solve problems in agriculture and the environment.
Through knowledge sharing and science, CABI helps address issues of global concern such as improving global food security and safeguarding the environment. We do this by helping farmers grow more and lose less of what they produce, combating threats to agriculture and the environment from pests and diseases, protecting biodiversity from invasive species, and improving access to agricultural and environmental scientific knowledge. Our 48 member countries guide and influence our core areas of work, which include development and research projects, scientific publishing and microbial services.
We gratefully acknowledge the core financial support from our member countries (and lead agencies) including the United Kingdom (Department for International Development), China (Chinese Ministry of Agriculture), Australia (Australian Centre for International Agricultural Research), Canada (Agriculture and Agri-Food Canada), Netherlands (Directorate-General for International Cooperation, and Switzerland (Swiss Agency for Development and Cooperation). Other sources of funding include the fees paid by our member countries and profits from our publishing activities which enable CABI to support rural development and scientific research around the world.
Media contact
Wayne Coles
Communications Manager
Tel: +44 (0)1491 829395 Email: w.coles@cabi.org
Related News & Blogs