Local scientists should lead the research to fight vector‐borne diseases in Africa

Le résumé fourni par la source

Vector-borne disease research in Africa achieved significance when the second Nobel Prize for Physiology or Medicine was awarded to Sir Ronald Ross in 1902 for his work on mosquito ecology and malaria transmission dynamics (M. J. Bockarie et al., 1999). Ross was the first to show that the bite of infected mosquitoes transmitted the malarial parasite, and the first to demonstrate this phenomenon in the field through vector ecology studies in Sierra Leone in 1899 (M. J. Bockarie et al., 1999). His fieldwork in Africa, including the application of source reduction to control malaria, helped to explain the previously observed effects of traditional malaria control measures, such as drainage of marshes, and informed the development of better approaches used to control malaria today. The life history of Onchocerca volvulus, the parasite that causes onchocerciasis, was also first demonstrated in Sierra Leone in 1926 by scientists from the Liverpool School of Tropical Medicine (Blacklock, 1926). Nevertheless, the local capacity for research on vector-borne diseases in many African countries remains underdeveloped. Building the capacity for medical entomology and parasitology in malaria-affected countries, through the training of local vector scientists, was critical to achieving the objectives of the malaria eradication programme in the 1950s and 1960s after the development of dichloro-diphenyl-trichloroethane (DDT) (Najera et al., 2011). The knowledge acquired from outside Africa, where DDT house-spraying interrupted malaria transmission, encouraged the initiation of field epidemiological studies, using local investigators, to determine factors affecting the intense transmission of malaria in many parts of the Africa. The Garki District in northern Nigeria was selected for the field studies, and the renowned Garki Project was launched in 1969 (Molineaux & Gramiccia, 1980). The main objectives of the project were to determine the impact of indoor residual spraying and mass drug administration and to construct and test a mathematical model of malaria transmission. The entomological investigations needed to achieve the expected outcomes included the determination of vectorial capacities and entomological inoculation rates for different malaria vectors. The project concluded that indoor spraying had a very limited impact on malaria transmission intensity because, through vector ecology studies, it was shown that the Anopheles gambiae s.l. population was mainly exophilic. The main lesson learnt from the Garki Project is that vector studies are very important in determining the impact of malaria control activities. In recent years, vector-borne diseases have been contained through medicines, vaccines, and the application of novel insecticide-based approaches, including the use of insecticidal nets. In a recent review of the importance of vector-based strategies for the control and elimination of vector-borne diseases, Wilson et al. (2020) suggested that vector control has contributed more to shrinking the map of vector-borne diseases than drugs or vaccines. However, vector control methods are being threatened by insecticide resistance and the challenges of producing insecticidal materials in affected countries. To mitigate these challenges in Africa, scientists using modern molecular tools should generate new knowledge about the vectors, vector-parasite relationships, and insecticide resistance in the affected countries. Unfortunately, major funding agencies supporting research and capacity building in Africa, including the European and Developing Countries Clinical Trials Partnership, do not currently fund vector studies (Nyirenda et al., 2021). Similar concerns were raised in Europe in 2013 when the European Commission released a draft agenda for funding research within the Framework Programme, the Horizon 2020, and there was no specific action to support research on vectors (Kohl et al., 2016). The local capacity for molecular entomology studies in Africa is minimal and this has led to parachute research (M. Bockarie et al., 2018) by scientists from the global north extracting data and knowledge from resource-poor communities in the Global South, leaving scientists in Africa unable to pursue their work and contribute to the scientific discourse in global health. The Global Fund to Fight AIDS, Tuberculosis, and Malaria (Global Fund) provides 56% of all international financing for malaria programmes (The Global Fund, 2022). It is the largest funder of malaria prevention and treatment, including the procurement and distribution of insecticide-treated bed nets. However, little funding is provided by The Global Fund to support vector monitoring that will generate data on the changing patterns in the ecology and behaviour of the malaria vectors as well as vector-parasite relationships and insecticide resistance. The United States President's Malaria Initiative (PMI) currently provides the largest funding for malaria entomological monitoring, which supports 24 malaria-affected countries in sub-Saharan Africa and three additional countries in Southeast Asia to reduce malaria transmission intensity and progress towards malaria elimination (PMI, 2021). PMI works closely with national malaria programs and global partners including the World Health Organization and Global Fund. In 2020, the U.S. Congress appropriated $746 m for PMI activities (PMI, 2021). Nevertheless, some malaria-affected countries in Africa have raised concerns over how PMI supports its activities in the continent. In an open letter published in Nature Medicine in May 2021, scientists from Nigeria, Kenya, and Tanzania among other countries, expressed dissatisfaction about how international funders of science and development in Africa were not supporting the strengthening of local capacities for science (Erondu et al., 2021). A US$30 million grant awarded to the non-profit health organization PATH by PMI funded a consortium of seven institutions in the USA, the UK and Australia to support African countries to control and eliminate malaria. Not one African institution was named in the press release. Many African scientists expect that partnership support to Africa should be led from Africa by African scientists. In Sierra Leone, 124 years after the first studies by Ronald Ross, not a single Sierra Leonean doctoral vector scientist is working with the National Malaria Control Programme supported by PMI. The Partnership for Increasing the Impact of Vector Control (PIIVeC) has brought together researchers and policy makers to stimulate the vector control research pipeline in many African countries. PIIVeC's investment in promising future leaders of vector-borne disease research is filling knowledge gaps in molecular entomology and ensuring the sustainable use of evidence in decision-making for disease control. This has been clearly demonstrated in the African-led papers submitted by the members of the PIIVeC team in this special issue. We have here the proof of principle that African scientists can lead state-of-the-art vector research in resource-poor countries like Burkina Faso, Cameroon, and Malawi. However, few African scientists can lead large grant applications that can deliver outputs on the scale of the PIIVeC project because of restrictions inherent in many calls from funding agencies in the global north. Moreover, some high impact research institutions in countries like The Gambia, Malawi, Tanzania, and Uganda have been shaped by longstanding traditions of colonialism in global health research including entomology (Campbell et al., 2021). Africa needs a new public health order to be resilient and to cope with current challenges including colonization of research in global health. The new order will need strengthened continental and national public health institutions; local funding, training, and retention of a public health professionals including entomologists; and fostering of respectful incl

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