Multilateral Initiative on Malaria (MIM) Pan-African Malaria Conference – 2024: Day 5

MESA Correspondents bring you cutting-edge coverage from the MIM 2024 Conference “Grassroots Mobilization to End Malaria: Invest, Innovate & Integrate”.

Plenary Session 9 – Data Science for Malaria Elimination

Maciej F. Boni (Temple University, United States) presented lessons learned from data-driven mathematical models of drug-resistance evolution. He began his talk with the remark that evaluating drug resistance studies often takes five to ten years), hence providing the rationale for utilizing mathematical models to project resistance outcomes. After rigorous validation, the models can be used to simulate future scenarios of drug resistance policies in different settings. Boni highlighted that the most effective strategies include combination therapy, multiple first-line therapies (MFT), or cycling. The modeling results indicated that a geographically stratified MFT approach slows down resistance only when deployed with at least annual rotations. Treatment strategies targeting resistance act on specific genotypes, necessitating an understanding of which genotypes to target. Therapeutic efficacy studies (TES) are conducted to utilize data jointly with P. falciparum data to understand which genotypes to suppress. Towards the end of his talk, Boni emphasized the urgency of immediate action, as delaying a change in antimalarial treatment policy will result in more treatment failures.

Muhamed Semaku (Ministry of Health, Rwanda) delivered a talk titled ‘Malaria Data Analytics: Shaping the Future of Health Planning in Rwanda’. According to the WHO, several significant factors, including a lack of health information and data gaps, may lead to a fragile health system. Weak health information systems, which include data collection, analysis, and reporting, can hinder a health system’s ability to respond to health crises and plan for the future, making data analytics pivotal for shaping public health strategies. Spatiotemporal models and frameworks can be used effectively to integrate routine clinical data into public health decision-making processes, bridging the gap between data availability and practical use. The Bayesian spatio-temporal modeling mapping model was done following three major stages: first, data specification and formulation of a linear predictor equation; second, assigning prior distributions to latent fields based on second order differences; and last, allocating hyperpriors to hyperparameters. This approach enables us to generate maps that show the probability and uncertainty of reaching the targets, as well as the spatial contributions to the malaria burden in the country. Semaku concluded his talk by recommending the use of both household survey data and routine data in a two-step modeling framework for monitoring malaria trends, prediction of new cases, and evaluation of malaria incidence.

Symposium 60 – Symposium on the current status of biological threats in malaria and the interplay amongst them

Charlotte Rasmussen (Global Malaria Programme WHO, Switzerland) discussed biological threats to malaria control and elimination, including insecticide resistance, parasite Pfhrp2/3 gene deletions, and antimalarial drug resistance. Insecticide resistance jeopardizes major vector control tools like insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS), with growing concerns about the efficient vector Anopheles (An.) stephensi spreading in African cities. Thus, this vector is breeding in human-made water storage containers, and adapting to local environments. The World Health Organization (WHO) issued a vector alert for An. stephensi in 2019, extending the malaria threats map and launching a regional initiative in 2022 to halt its spread in Africa. Pfhrp2/3 gene deletions pose challenges for rapid diagnostic tests (RDTs) detecting P. falciparum malaria, as parasites not expressing these antigens evade detection. WHO recommends surveillance and, at the moment, there is no recommendation to switch RDTs due to limited options and supply security issues. Artemisinin-based combination therapies, used to treat malaria, face partial resistance, with delayed parasite clearance linked to Pfkelch13 mutations. WHO’s response strategy includes strengthening surveillance, regulating diagnostics and therapies, limiting parasite spread, and promoting research and innovation against antimalarial drug resistance in Africa.

Fitsum G. Tadesse (Armauer Hansen Research Institute – AHRI, Ethiopia and London School of Hygiene & Tropical Medicine – LSHTM, United Kingdom) highlighted An. stephensi as an emerging threat, echoing Charlotte’s concerns in the previous talk, about insecticide resistance, parasite gene deletions, and antimalarial drug resistance. He noted its expanding distribution in African countries, particularly in Ethiopia’s eastern region. An. stephensi’s unique characteristics, including its breeding in containers, resistance to insecticides, and adaptability, pose the main challenges to control efforts. An. stephensi is more efficient in sporozoite formation and transmission of P. falciparum and P. vivax and it is the dominant species in breeding and resting sites, therefore all these factors contributed to an increase of malaria transmission in Djibouti and Dire Dawa.  Spatially overlapping with P. falciparum infections, it harbors genetic signatures of partial artemisinin resistance and gene deletions. Efforts are underway to address this challenge, including a new study on malaria molecular surveillance in the Horn of Africa, aimed at tackling the convergence of these biological threats.

Abebe Fola (Brown University, United States) noted progress in malaria control since the early 2000s but highlighted a stall since 2015, with rising cases and no decrease in deaths. Artemisinin resistance (ART-R), among other challenges, poses a significant threat in that picture and then, she discussed the rise of P. falciparum strains showing partial resistance to artemisinin in East Africa and the Horn of Africa. Various mutations in the kelch 13 gene, which are markers for ART-R, have been recorded. Partial ART-R was first confirmed in Rwanda and now in Uganda, Tanzania, and Ethiopia, endangering malaria control efforts not only in these countries but on a global scale. Fola stressed the need for robust surveillance through both phenotype and genome analysis across different regions, emphasizing cross-border collaboration due to parasite movement. Fola also suggested using multiple artemisinin-based combinations (ACTs) and rotating drugs every four or five years to combat resistance. She also emphasized that mapping partner drug resistance needs to be expedited as their efficacy is a key reason why ACTs remain effective in regions affected by ART-R P. falciparum.

Dorothy Fosah Achu (World Health Organization Afro, Republic of Congo) discussed key strategies for monitoring and responding to biological threats to malaria control in Africa. She highlighted insecticide resistance, the spread of An. stephensi, artemisinin resistance (ART-R), and Pfhrp2/3 deletions as major threats. Achu noted the presence of global and local frameworks such as the World Health Organization (WHO) manual for monitoring insecticide resistance in mosquito vectors and selecting appropriate interventions, response plans to pfhrp2 gene deletions, and the initiative to stop the spread of An. stephensi in Africa to address these challenges. In that regard, WHO will collaborate closely with partners and regions for a unified approach, considering local contexts. Future efforts will focus on enhancing member states’ capacity with standardized protocols, strengthening laboratory capabilities, and identifying research areas. This includes exploring innovative methods to optimize current tools, test new approaches, and improve knowledge of the malaria drugs’ mode of action.

Symposium 64 – Counteracting pfhrp2/3 deletion threats: From survey and modeling research to forecasting and market shaping

Agaba Bosco (National Malaria Control Program – NMCP, Uganda) presented data on two surveys conducted in Uganda to detect PfHRP2/3 deletions. The first survey was conducted in east and west Uganda, where malaria transmission is low. Malaria detection involved the use of RDTs, microscopy, and PCR of HRP2 and 3. Results showed that 3.3% of parasites had HRP2/3 double deletions. Statistical analyses revealed clustering of these double-deleted parasites both within the eastern and western regions. In contrast, the second survey was conducted in northern Uganda, a high transmission setting, where real-time multiplex PCR was utilized to detect HRP2/3 deletions, with 0.2% of parasites found to have HRP2/3 double deletions. This difference in prevalence of pfhrp2/3 deletions between regions may be explained by the differences in the volumes of RDTs and the duration within which the RDTs have been in use since introduction. Bosco emphasized the importance of training and capacity building for continued surveillance studies using molecular testing. Additionally, he urged the harmonization of molecular surveillance methods across countries and increased communication of HRP2/3 deletion survey results.

Oliver J. Watson (Imperial College London, United Kingdom) discussed the use of Imperial College London’s mathematical malaria model ‘malariasimulation’ to project the selection of hrp2-deleted parasites and pfhrp-based RDT failure. The model results aided in the strategic placement of future surveillance efforts by projecting the risk of hrp2 deletion spread geographically and over time. Key risk factors for selecting hrp2-deleted parasites are low malaria prevalence and a high proportion of people seeking treatment. Watson highlighted the innate risk of selecting deletions when using hrp2 RDTs and the prospective risk of reaching a certain threshold of deletions in the following years. Regions with a prevalence below 0.05% are at higher risk of selecting deletions more quickly, emphasizing the need for continuous surveillance and proper utilization of diagnostic tools. Finally, he pointed towards the Deletion Risk Explorer tool, available on the WHO website, as a valuable resource for monitoring and planning malaria control strategies.

Salome Muchiri (Clinton Health Access Initiative – CHAI, Kenya) highlighted facts and forecasts on the need for non-HRP2-only RDTs. The method was based on the admin 1, a 5% threshold, slower’ and faster’ switching strategies, estimated public sector volumes, and Africa forecast on Pfhrp2/3 deletions. The projected prospective risk of hrp2 deletions from Imperial College London’s mathematical malaria model and CHAI’s RDT forecasting were used to estimate the time taken to reach the 5% threshold and the required volumes. Their switching strategies identified those countries that will reach 5% in at least 10% or 25% of their admin-1 units under the central estimates from the mathematical model in the next five to ten years. Their forecasts suggested that non-HRP2-only RDTs could be needed in countries that make up 35-56% and 45-58% of the public sector RDT market in Africa within the next five years and the next ten years, respectively. Muchiri concluded that the total RDT public sector volume forecasts in Africa assume switching begins when the 5% threshold is reached in 10% of admin 1 units.

Spike Nowak (PATH, United States) presented results from  48 stakeholder interviews aiming to address market uncertainties and market-shaping solutions for non-HRP2-only RDTs. Interviewees included representatives from national malaria programs, donors, market shapers, researchers, RDT manufacturers, and PATH staff. National control program staff emphasized idiosyncratic processes for switching RDTs and their reluctance to adopt LDH/HRP2 RDTs without evidence. Interviewed manufacturers expressed concerns about uncertain demand hindering investment decisions, while interviewed donors are aware of opportunity costs, researchers highlighted the uncertainty in HRP2/3 deletion spread. Interviewed implementers have foreseen increasing RDT demand but expressed uncertainty about new RDTs. On the supply and demand side, interviewers acknowledged existing risks for uncertainty in the market for non-HRP2-only RDTs, necessitating market-balancing strategies like volume guarantees, as recently explored by MedAccess and Gates Foundation. LDH/HRP2-based RDTs offer benefits in hrp2/hrp3 deletions high-risk areas by decreasing transmission and improving health outcomes, though more budget is required. Finally, large donors also signaled the crucial role of support for LDH/HRP2-based RDT procurement for a healthy market transition.

Symposium 67 – Transforming Pregnant Women and Access to MiP Prevention: Tools & Experiences to Support Scaling c-IPTp

Dorothy Fosah Achu (World Health Organization – WHO, Republic of Congo) presented the implementation of a community-based intermittent preventive treatment of malaria for pregnant women (c-IPTp) delivery approach guidelines. Overall, 13 million pregnant women are exposed to malaria infections in 33 high burden malaria countries which are eligible for IPTp treatments. A country is eligible to implement the c-IPTp guidelines only when IPTp coverage is low and when there is a gap between IPTp3 coverage and antenatal care (ANC) attendance. Firstly, for this strategy to be put in place there has to be a favorable policy, with programmatic factors permitting the use of IPTp, the possibility of community health workers to administer chemoprevention and establish case management. Secondly, there should be a good collaboration between the malaria program, maternal and child services, and community health workers of the Ministry of Health. Thirdly, a functional supply chain management to maintain drug disponibility is needed. Lastly, as Achu emphasized, the intervention has to be accepted by the community and all stakeholders. This is the first time this intervention is taking place and evidence shows it’s feasible and will improve IPTp coverage.

Tahima Razafiarijaona (Johns Hopkins Program for International Education in Gynecology and Obstetrics – Jhpiego, Madagascar) talked about the experience of piloting and scaling up c-IPTp in Madagascar, which is one of eight countries that completed the piloting phase under WHO direction before going on to the scaling phase. The antenatal care (ANC) attendance rates were 51% and 28.9% for the first and fourth visits, respectively. This relatively low attendance may explain the high maternal mortality observed in the country. Seventy percent of those who went for ANC1 received IPTp1, while only 40.4% of those who went for ANC4 received IPTp3. With a delivery coverage of 25.8%, the malaria cases increased from 36.9 per thousand in 2018 to 81.3 per thousand in 2021. This trial used a single dose of sulfadoxine-pyrimethamine (SP) per visit as the IPTp medication. The piloting results showed that IPTp3 coverage increased from 20% to more than 80%, and ANC4 from 20% to 65%. Razafiarijaona also mentioned some of the challenges encountered during the study, including women’s reluctance to change, working with local associations, SP misuse, and challenges related to scaling up from the piloting to the scale-up phase. 

Sidzabda Christian Bernard Kompaore (Ministry of Health, Burkina Faso) presented on IPTp in Burkina Faso. This was a quasi-experimental pre-/post-mixed-methods implementation research study that aimed to determine the effect of community-based intervention on IPTp in three different districts of Burkina Faso (Ouargaye, Po, and Batie), with support from Jhpiego. The strategy involved several steps including basic evaluation, actor training, community involvement (advocacy), consultation and planning meetings, and drafting of the feasibility study protocol. Kompaore highlighted the challenges faced and mitigation strategies for the approach. The project indicated that c-IPTp is a major strategy for reducing malaria morbidity and mortality in pregnant women. The involvement of key stakeholders at all levels of the intervention was identified as a critical success factor for the approach. Kompaore finished the talk by stating that the prospects for optimal implementation of this intervention can be leveraged for the benefit of the population.

Chonge Kitojo (President’s Malaria Initiative – PMI, Tanzania) presented PMI’s technical guidance regarding community-based intermittent preventive treatment of malaria for pregnant women (c-IPTp). She explained that the strategies are aligned with WHO recommendations and the WHO’s Field Guide on c-IPTp. PMI’s technical guidance includes training community health workers (CHWs) on IPTp-SP and promoting antenatal care (ANC), consultation with the National Malaria Plan (NMP), reproductive health, and community health programs before implementation. Gender considerations for CHWs working with pregnant women were emphasized, and she made clear that the PMI team is available to provide technical assistance such as virtual workshops or discussions on the Malaria Operation Plan, in partnership with countries interested in initiating c-IPTp, which includes recommendations on the selection of sites, supplies, required skills, salaries and supervision to countries to scale up CHWs for c-IPTp.

Symposium 70 – Relapsing malaria in Africa, diagnosis and treatment considerations

Isaac Quaye (Regent University College of Science and Technology, Ghana on behalf of Pan African Vivax and Ovale Network – PAVON) delved into the complex burden of malaria relapse in Africa, focusing on P. vivax strains. He highlighted two main strains: the Chesson strain, prevalent in tropical regions with a latency period of 3-6 weeks, and the St. Elizabeth strain, common in temperate areas, which exhibits a longer latency period of 3-9 months or more. Quaye examined various aspects of malaria including infection volume, clinical manifestations, recurrence, and new infections identified through surveillance. He discussed how recurrence differs from seasonal reinfection and explored cryptic infections hidden in the spleen and bloodstream, contributing to relapse. Quaye attributed malaria relapse to liver hypnozoites, while recurrence stems from blood-stage asexual parasites and cryptic infections, often asymptomatic. Additionally, he briefly touched on P. ovale, noting minimal data on its strains; and explained how the behavior of P. ovale curtisi and P. ovale wallikeri is influenced by environmental and host factors.

Arsène Ratsimbasoa (University of Fianarantsoa, Madagascar) gave a comprehensive talk on the epidemiology of P. vivax in Madagascar and introduced innovative strategies aimed at addressing the hidden reservoirs of this parasite. In his presentation, he shared the results of a study on malaria rapid diagnostic tests (RDT) conducted from 2021 to 2024 in Madagascar. The data from 2024 showed that P. falciparum had a prevalence of 54.4%, P. vivax was found in 10.04% of cases, and mixed infections accounted for 35.09%. Ratsimbasoa also provided insights into the structure of Madagascar’s health system, where RDTs are used at the community service level, microscopy at health centers, and polymerase chain reaction (PCR) at central laboratories. He highlighted the limitations of microscopy in detecting P. vivax due to its lower sensitivity compared to other methods. To enhance the detection rates, he advocated for the increased use of PCR and serological testing, stressing their effectiveness in identifying malaria infections more accurately.

Daniel Yilma (Jimma University, Ethiopia) discussed ways of improving the radical cure of Plasmodium vivax malaria. In his discussion, he focused on two drugs: Primaquine (PQ) and Tafenoquine (TQ). PQ has been used since 1950 for people over six months of age with Glucose-6-phosphate dehydrogenase (G6PD) levels above 30%. PQ can be taken with artemisinin combined therapies (ACTs) or chloroquine at different doses and durations based on specific case requirements. On the other hand, TQ, which was approved in 2018, is prescribed for individuals over 16 years with G6PD levels above 70%, and can only be used with chloroquine at a single dose. Yilma highlighted the risk of severe hemolysis that these drugs pose to individuals with G6PD deficiency, underscoring the importance of precise G6PD status assessment. He also stressed the necessity of understanding the overall case burden and the risk of relapse to effectively implement these radical cures for malaria.

Tamiru Shibiru (Arba Minch University, Ethiopia) evaluated new radical cure treatments in Ethiopia to reduce relapse risk of malaria infection. In this country, malaria cases are primarily caused by P. falciparum (approximately 70%), with P. vivax (approximately 30%) and P. ovale being rare. Primaquine (PQ) is used in low (3.5mg/kg) or high (7mg/kg) doses, the latter given for seven days (not yet WHO-approved but under consideration) and it requires supervision Results showed that without PQ there was a higher recurrence risk and with a high dose there was a low recurrence risk. In concordance with this, another study revealed higher P. vivax risk in placebo-treated patients compared to those receiving PQ for 14 days. Shibiru at the end talked about two studies, the EFFORT study, a randomized 3-arm trial to assess P. vivax incidence risk, as well as the effectiveness, safety, cost-effectiveness, and feasibility of a 7 or 14 PQ treatment.  And the TADORE study aims to revise tafenoquine dosing, optimizing duration and dosage.

Scientific Session 45 – Drug efficacy 2

Christian Nsanzabana (Swiss Tropical and Public Health – SwissTPH, Switzerland) presented a study that compared the sensitivity of microscopy and qPCR which evaluated the efficacy of Ganaplacide/Lumefantrine solid formulation in an open-label, multicentre, parallel-group, randomised, controlled, phase 2 trial. Results showed a good correlation between microscopy and qPCR at baseline, a higher positivity rate of qPCR, and the highest predictive value of recrudescence in patients. He concluded that qPCR detects submicroscopic infections at all time points and there is a linear correlation between microscopy and qPCR. However, he highlighted the need for further studies such as using other markers other than 18S rRNA to check if they could improve the accuracy of PCR.

Anyirekun Fabrice (Research Institute of Health Sciences – IRSS, Burkina Faso) presented on ex vivo drug susceptibility and resistance mediating genetic polymorphisms of Plasmodium falciparum in Bobo-Dioulasso, Burkina Faso, where  H malaria remains a leading cause of morbidity and mortality. The country has utilized various antimalarials, including artemisinin-based combination therapies (ACTs) and sulfadoxine-pyrimethamine plus amodiaquine (SPAQ) for seasonal malaria chemoprevention (SMC) in children, interventions which seem to be effective. However, while resistance to certain drugs like AQ remains low, concerns persist regarding emerging resistance, particularly to artemisinin. In this particular studio presented, Ex vivo assays demonstrated overall good drug potency, with some exceptions. Genetic analyses revealed trends consistent with West Africa but raised concerns about increasing resistance mutations. He stressed that despite the current stability, continued surveillance is crucial to monitor and manage potential resistance developments effectively.

Scientific Session 47 – Vector Biology and control 8

Carol Tasiano (Malaria Alert Centre – MAC, Malawi) presented findings from field experiments that compared various larvicides commonly used in Africa and the USA. The objective was to assess the effectiveness of those commonly used larvicides on wild-caught mosquito larvae, as well as their retention and survival rates. Mosquito larvae were intentionally collected from a specific area. The larvicides tested included NatularⓇ formulations XRT, T30, and DT from the USA, compared to Bacillus thuringiensis israelensis (Bti), commonly used in Africa for larval source management. Results showed that both Natular formulations DT and Bti achieved 100% mortality within the first week, while Natular formulations XRT and T30 exhibited lower mortality rates. In conclusion, integrating larviciding into existing intervention strategies in the country would be highly beneficial to fighting malaria.

Kwi Pilate Nkineh (University of Buea, Cameroon) outlined the diversity and transmission dynamics of malaria across various altitudes along Mount Cameroon’s slope. Nkineh and colleagues conducted a cross-sectional study to investigate the distribution and genetic variability of An. gambiae complex siblings at different altitudes and their resistance to pyrethroids and carbamates in the vicinity of Mount Cameroon. The study findings revealed that An. gambiae complex and An. funestus were prevalent along the mountain’s slopes, predominantly at lower and intermediate elevations. The study further identified two distinct strains of An. coluzzii and geographical isolation were observed among An. gambiae and An. coluzzii populations from different locations. The final result shared was that An. gambiae complex mosquitoes exhibited resistance to both, deltamethrin and bendiocarb insecticides in all genotyped specimens.

Anna Trett (Clinton Health Access Initiative – CHAI, United States) presented general long-term projections for vector control strategies, including insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS), aimed at anticipating market challenges, trends, and opportunities. The forecasted quantities and budget allocations rely on historical data, anticipated population shifts, and country-specific strategy adjustments. The available budget for ITNs dictates the pace of transition to dual active ingredient (DAI) nets and influences achievable ITN coverage levels. Recently, IRS application rates have stabilized, with resources redirected toward DAI coverage. The global vector control commodities market faces various threats, including financial constraints, emerging competitors, evolving epidemiological patterns, and updated control guidelines.

Jésukèdè Constantin Adoha (University of Abomey-Calavi, Benin) presented on utilizing systems distribution models (SDM) to assess the composition, distribution, and ecological preferences of mosquito species in Southern Benin. Mosquito species were captured using human landing catch (HLC) methods, identified, and their GPS coordinates recorded for sampled locations. Ecological indices were applied to evaluate species diversity, and ecological niche models were employed to analyze bioclimatic and environmental data. A notable increase in both the abundance and diversity of mosquito species was observed during the wet season compared to the dry season, with ecological preferences exhibiting seasonal variation.

Boulais Yovogan’s (University of Abomey-Calavi, Benin) study assessed the efficacy of Royal GuardⓇ (alphacypermethrin-pyriproxyfen) and Interceptor G2Ⓡ (alpha-cypermethrin-chlorfenapyr) long-lasting insecticidal nets (LLINs) compared to Interceptor® nets (treated with alpha-cypermethrin using long-lasting technology) LLINs on primary malaria vectors in Benin. Both pyrethroid-chlorfenapyr and pyrethroid-pyriproxyfen LLINs effectively reduced An. gambiae and An. coluzzii density. Mosquitoes species composition, vector density and parity rate were analyzed at baseline and after the 2-year intervention. Results showed that both pyrethroid-chlorfenapyr LLINs and pyrethroid-pyriproxyfen LLINs were found to reduce the density of An. coluzzii and An. gambiae s.s. at a broadly similar magnitude, both indoors and outdoors. Combining chlorfenapyr and pyriproxyfen with pyrethroid insecticides in LLINs could yield similar effects. The research informed policy decisions for vector control intervention selection and deployment in malaria-endemic regions, highlighting the importance of complementary indoor and outdoor strategies for effective malaria prevention and control. 

Jacques Gnambani (Western Regional Directorate of the Institute of Research in Health Sciences – IRSS, Burkina Faso) presented an entomopathogenic study on utilizing novel biological control interventions for managing mosquito vectors. His research focused on leveraging emerging technologies that harness mosquito symbiotic bacteria to tackle challenges and explore opportunities in vector control. These challenges included the suboptimal effectiveness of the RTS,S malaria vaccine against clinical and severe malaria, the limited efficacy of most antimalarial drugs against gametocytes, and the altered ecology and behavior of vectors. The study identified a promising candidate in Chromobacterium anophelis sp. nov., a native strain from Burkina Faso, whose bioactive cell-free supernatant demonstrated significant impacts on key determinants of vector capacity and disease transmission. Gnambani recommended incorporating biocontrol strategies into mosquito-borne disease management to reduce reliance on existing interventions. The selective mosquito-killing abilities of the pathogenic bacteria showed exciting prospects for more effective and sustainable approaches to combat mosquito-borne diseases.

Sandrine Eveline Nsango (Pasteur Center for Cameroon and University of Douala, Cameroon) shared in her talk findings from a study conducted in the western region of Cameroon, that characterized malaria vectors and their role in local transmission. Adult mosquitoes were collected by indoor residual spraying and identified morphologically and molecularly. Blood samples were collected from symptomatic malaria patients at three health facilities, whereas samples from asymptomatic individuals were taken from eight sites in Tibati’s neighborhood, aligning with mosquito collection sites. Results identified six Anopheles species, with An. gambiae emerging as the predominant and most competent vector across different study sites in Tibati between 2015 and 2017. The diversity of mosquito species and abundance varied with altitude. Urging further research into malaria vector dynamics, species behavior, and resistance profiles, the study underscores the importance of understanding local ecological and socio-economic factors for targeted malaria interventions in Adamawa, the West region of Cameroon.

Scientific Session 52 – Social and health economics 2

Abiola O. Oluwagbemiga (Malaria Consortium, Nigeria) presented on the cost of delivering pyrethroid-piperonyl butoxide (P-PBO) insecticide-treated nets (ITNs) to households in Ondo and Anambra in Nigeria through universal campaigns. Data from 48 wards in each of the two states were collected using a multi-stage cluster sampling design to identify financial and opportunity costs associated with the campaigns to provide data on costs per ITN delivered to households. The findings revealed that delivering an ITN to a household costs 3.33 USD in Ondo and 3.19 USD in Anambra, with opportunity costs of 1.9% and 2.6%, respectively. The main cost driver was the cost of purchasing ITNs, including freight and insurance, which constituted 77% of total expenses in Ondo and 82% in Anambra. Oluwagbemiga highlighted that these results would aid economic assessments of P-PBO ITNs distributed through universal campaigns and enhance value-for-money evaluations.

Edward Thomsen (University of California, United States) talked about insecticide-treated nets (ITNs) market trends from 2004 to 2021 and the monetary value of extending ITN lifespan. The research aimed to understand overall market trends and factors affecting ITN prices during this period. It also estimated the premium price that the market should offer for ITNs with longer lifespans. Findings revealed that ITN prices are largely influenced by a small number of buyers and manufacturers. The market incentivizes innovation when both buyers and sellers value product improvements. Value premium for ITNs with a longer life span is context-dependent but not yet captured in the market. Recognizing resistance to damage could assist buyers in selecting more suitable products and encourage innovation through added value.

Hamidou Niangley (Malaria Research and Training Centre – MRTC, Mali) gave a presentation under the title ‘Impact and cost-effectiveness of a school-based intervention to improve malaria treatment compliance: Randomized controlled trial in peri-urban village of Mali, Tienfala’. The randomized controlled trial aimed at assessing the training of school children to enhance malaria treatment compliance. The study results indicate improved adherence, with 90% in the intervention group versus 88.9% in the control group. The intervention proved effective, echoing findings by Cohen and Saran regarding the efficacy of targeted messaging. A cost-effectiveness analysis from the government perspective suggests promising outcomes. Such interventions that leverage schools for health promotion, as Niangley concluded, offer a viable strategy for combating malaria and reducing healthcare burdens.

Epaphrodite Habanabakize (Rwanda Biomedical Center – RBC, Rwanda) presented on the ‘Role of CSOs in enhancing SBC implementation and fostering the uptake of malaria interventions in Rwanda’. He highlighted the instrumental role of Civil Society Organizations (CSOs) in advancing Social Behaviour Change (SBC) interventions for malaria in Rwanda. Deployed strategically across provinces and targeting high-risk groups, CSOs significantly reduced malaria cases. Additionally, the incidence rate dropped from 114/1000 people per year to 47/1000. Their collaborative efforts with government initiatives facilitated community awareness, behavioral change, and malaria prevention, fostering a decline in malaria incidence. He highlighted the vital partnership between CSOs and governmental efforts, emphasizing the sustained impact of their collaborative action.

Scientific Session 53 – Bioethics and diversity 1

Paulina Onvomaha Tindana (University of Ghana, Ghana) presented findings from a qualitative study on integrating molecular and genomic data into malaria elimination programs in Africa.  The study sought perspectives from genomic researchers in Africa and revealed extensive engagement between principal investigators and policymakers, akin to collaborative efforts seen during the COVID-19 response. However, policymakers’ limited capacity to grasp genomic data poses a challenge. Simplifying scientific language and developing innovative communication strategies emerged as crucial solutions. Transitioning and utilizing genomic data faces obstacles such as aligning research funders’ interests with NMCP needs and bureaucratic complexities. Researchers expressed a need for training in policy engagement and effective communication with policymakers. Tindana emphasized at the end of her presentation the pressing need to address these challenges for enhancing the integration of genomic data into malaria control strategies across Africa.

Kaddyijatou F. Jallow (Ministry of Health, The Gambia) presented the study examining caregivers’ health-seeking behavior for children aged 24 to 59 months, focusing on pneumonia, diarrhea, and malaria in The Gambia. While caregivers generally seek medical care promptly, knowledge gaps exist, particularly in rural and less educated communities, regarding pneumonia and diarrhea. Appropriate health-seeking behavior varies across diseases, with malaria showing the highest rate of proper care, followed by pneumonia and diarrhea. Younger caregivers and urban residents tend to seek care more effectively, as also do married caregivers. Future recommendations include performing qualitative research to understand underlying reasons for health-seeking behaviors, policy measures to discourage inappropriate practices, and support for caregivers through education and employment opportunities. Implementing these recommendations could improve caregivers’ ability to seek timely and appropriate care, thereby enhancing the health outcomes of children in these communities.

Christina Sudi (Pan-African Mosquito Control Association – PAMCA, Kenya) presented the proactive steps taken by PAMCA through the Women in Vector Control (WiVC) initiative to recognize and uplift the contributions of African women in the fight against malaria and to rectify the oversight of not recognizing their pivotal roles through the PAMCA Excellence Awards, increasing their social visibility. With rigorous pre-determined criteria and a transparent selection process, the awards honor women’s dedication, creativity, mentoring, and career progression. The initiative’s impact is evident, with awardees training pupils, students, and researchers, conducting studies, and advocating for vector-borne disease control. However, challenges like competitiveness, limited implementation time, and inadequate monitoring persist. Securing additional funding can help address these issues and expand the initiative’s reach, ensuring more women are recognized and supported in their crucial roles in vector control.

John Mwangi (The Kenya Malaria Youth Corps, Kenya) presented the Kenya Malaria Youth Corps (KeMYC) program, engaging youth affected by malaria to combat the disease. He evaluated its impact on Kenya Vision 2030 and emphasized youth agency in public health decision-making. The KeMYC not only addresses immediate health challenges but also fosters leadership and community resilience. The program prioritizes equity, gender inclusion, and meaningful participation, harnessing the transformative potential of youth engagement in public health. Through empowering young leaders, the program contributes to achieving broader health goals, demonstrating the vital role of youth-led initiatives in tackling malaria and building healthier futures for all.

Bayala Ipéné Mylène Carenne (National Center for Research and Training on Malaria – CNRFP, Burkina Faso) presented on the evaluation of the reliability of rapid diagnostic tests (RDTs) targeting histidine-rich protein 2 (HRP2) for malaria diagnosis, amid concerns of strains lacking the pfhrp2 antigen. Despite worries, RDTs showed good agreement with microscopy results. The study also found a low pfhrp2 gene deletion rate of 2.6%, below the WHO’s 5% threshold for changing RDT types. This supports the continued use of HRP2 RDTs for malaria diagnosis in Burkina Faso. However, ongoing surveillance is recommended to monitor the dynamics of P. falciparum strains lacking the pfhrp2 antigen. Overall, the study findings suggest that current RDTs remain effective for malaria diagnosis in Burkina Faso, but vigilance is essential to ensure diagnostic accuracy amid evolving strain dynamics.

Scientific Session 56 – Drug resistance 5

Helle Hanson (University of Copenhagen, Denmark) presented the characterization of Illumina amplicon sequencing for determining resistant profiles in mixed malaria infections. Data analysis was conducted using the web-based platform ‘usegalaxy.org’, a user-friendly tool for non-bioinformaticians. The methodology involved conducting a range of mixed infection experiments with lab strains, followed by sequencing and analyzing full and partial haplotype data. Notably, emphasis was placed on the ability to specify minor haplotypes, with a 10% cutoff for determining the haplotype in the infection. The presentation also discussed separating infections with mixed drug resistance profiles into major and minor haplotypes, requiring a 20% difference from a 50:50 distribution. In her future work, Hanson will utilize this method with patient samples collected from various malaria-endemic nations in Africa.

Martin Okitwi (Infectious Diseases Research Collaboration, Uganda) presented findings from a study comparing the dihydroartemisinin (DHA) survival phenotypes of 122 samples using both ring-stage survival assay (RSA) and extended RSA (eRSA) methods. The study also examined the relationship between RSA survival and fold changes in eRSA, utilizing dried blood spots (DBS) for quantitative polymerase chain reaction (qPCR) analysis and sequencing via molecular inversion probes (MIPs). Results indicate a 30% joint prevalence of K13 markers and similar correlation coefficients across various growth levels of parasite cultures. The eRSA fold changes demonstrate a strong correlation with RSA outcomes, suggesting potential interchangeability. Moreover, comparable dihydroartemisinin (DHA) susceptibility patterns were observed in eRSA and RSA, particularly concerning the C469Y and A657V mutations. Okitwi highlighted the importance of the study and underscored the feasibility of obtaining reliable outcomes in low-resource settings through sample storage in DBS samples.

Maciej Boni (Temple University, United States) presented the future effectiveness of artemisinin treatment in Rwanda, Uganda, and Tanzania. The mathematical modeling results indicate that combination therapies followed by multiple first-line therapies and drug cycling are the most effective strategies for delaying or preventing artemisinin resistance. The modeling study projected incidence, prevalence, and resistance to treatment, as well as evaluated the most effective strategies using real-life data. For instance, the model estimated a 30% treatment failure rate in Uganda by 2029 if the current situation remained unchanged. In his presentation, Boni stressed the importance of rapid-turnaround molecular surveillance to inform these models and comprehend the future trajectory of piperaquine resistance in Africa, particularly concerning the deployment of dihydroartemisinin-piperaquine (DHA-PPQ) as a treatment. 

Stephen Tukwasibwe (Makerere University, Uganda) presented on antimalarial drug resistance in different populations of newly arrived refugees in Uganda, emphasizing the threat posed by antimalarial drug resistance in Africa, particularly in conflict zones such as East Africa and the Horn of Africa. Collaborating with Ugandan authorities and international organizations, Tukwasibwe’s team conducted surveys among newly arrived refugee populations from South Sudan and the Democratic Republic of Congo (DRC). Their findings revealed varying resistance markers between populations, indicating diverse treatment practices and local resistance profiles. Utilizing molecular surveillance techniques, they identified common resistance markers with Ugandan populations, thereby enhancing the understanding of resistance transmission. This approach provides valuable insights into malaria management in conflict-affected regions where traditional surveillance methods face challenges.

Denis Niyomwungere (National Institute of Public Health, Burundi)  presented on artemisinin partial resistance (ART-R) in Eastern Africa, with a focus on the situation in Burundi. Despite the effective use of artemisinin-based combination therapy (ACT) (specifically artemether-lumefantrine) in Burundi, concerns have arisen due to the emergence of artemisinin resistance in neighboring countries. Their study aimed to assess the presence of ART-R e in northern Burundi, particularly at the border with Rwanda and Tanzania. Analysis revealed persistent parasitemia on day three and pfkelch R561H mutations in specific regions. He recommended surveillance, continuous evaluation of ACT efficacy, and the implementation of new strategies to combat ART-R. Collaboration at national and regional levels is essential for effective intervention. 

Edwin Kamau (United States Army Medical Research Unit Kenya – USAMRU-K, Kenya) explored the emergence of Plasmodium falciparum Kelch 13 (PfK13) mutations and their association with artemisinin resistance in Kenya. Across six distinct locations, 14 mutations, including PfK13 675V, were detected, indicating significant genomic activity. Notable mutations such as A675V, linked to artemisinin resistance, were also identified. Kamau emphasized the necessity of continuous surveillance to promptly detect and address these genomic changes. Such vigilance enables effective preventive and curative measures against resistant parasites, underscoring the urgency of intervention strategies to effectively combat malaria drug resistance in Kenya.

Scientific Session 62 – Diagnosis and Reagent 3

Felix Habarugira (University Teaching Hospital of Butare – CHUB, Rwanda) reported on a clinical study that validated a chip-based real-time duplex PCR test for P. falciparum, the TruenatⓇ by Molbio, a novel malaria diagnostic tool designed for point-of-care testing. The aim was to improve diagnostic accuracy and enable prompt interventions for malaria infections. Samples from a cross-sectional study were analyzed and compared with the gold standard microscopy. The Truenat device demonstrated good diagnostic performance, with a sensitivity of 96.1%, specificity of 97.3%, and a Receiver Operator Characteristic (ROC) area of 0.99, indicating high reliability. Habarugira recommended the use of the Truenat device for detecting malaria parasites on a larger sample size to further validate its efficacy. Implementing such tools has the potential to enhance malaria diagnosis and significantly contribute to effective management strategies, particularly in resource-limited settings.

Eric Saraba (University of Rwanda, Rwanda) presented findings from a study on the prevalence of non-falciparum and mixed species infections in malaria-endemic areas in Rwanda. The study utilized microscopy and nested PCR tests to detect various Plasmodium species including P. malariae, P. ovale (P. ovale curtisi and P. ovale wallikeri), and P. falciparum in the study population. The results revealed that non-falciparum species accounted for more than 46% of malaria infections. Additionally, more than 15% of non-falciparum infections were missed, while 23% of mixed infections were misdiagnosed by microscopy. In malaria-endemic areas, a significant number of non-falciparum Plasmodium spp infections are either missed or misdiagnosed, potentially contributing to the persistence and/or resurgence of malaria. Saraba emphasized the importance of introducing more accurate, accessible, and sensitive diagnostic methods and tools in routine clinical laboratory services to effectively eliminate malaria.

Jean Modesta Harerimana (Johns Hopkins Program for International Education in Gynecology and Obstetrics – Jhpiego, United States & US President’s Malaria Initiative – PMI, Rwanda) presented a study with the primary aim of the study was to evaluate laboratory technicians’ performance in identifying malaria species and quantifying malaria parasites. A total of 308 lab technicians participated in the study, receiving pre-training assessments, followed by training sessions, and then post-training follow-up assessments. The training structure established for laboratory technicians, which included clear post-training mandates and follow-up mechanisms, demonstrated an increase in malaria diagnostic tests and the retention of skills and knowledge at their respective workplaces.

Scientific Session 63 – Pathogenesis and co-morbidities 2

Tchoutang Ange Maxime (University of Yaoundé I, Cameroon) presented a study that aimed to fill the knowledge gap regarding malaria, typhoid fever, and their co-infection. Blood samples from 288 fever patients at Etoug-Ebe Baptist Hospital were collected and categorized into groups: unknown fever (positive control), malaria-positive, typhoid-positive and co-infected, together with samples from healthy individuals. Malaria was diagnosed using rapid diagnostic tests (RDT), and typhoid fever with traditional Widal slide and tube tests. Prevalence rates were found to be 25% for malaria, 17.36% for typhoid fever, and 19.79% for co-infection. The study also assessed oxidative stress and immune response through various assays, revealing heightened stress levels, reduced antioxidant capacity, and a shift towards a TH1-cytokine profile in co-infected patients. He concluded by pointing out the need for further research to understand the specific pathological consequences of co-infection, particularly the interaction between Plasmodium and Salmonella, to improve diagnostic and therapeutic approaches for managing these conditions

Ruth Namazzi (Makerere University, Uganda) explored the link between circulating immune complexes, G6PD deficiency, and severe malaria outcomes in children, focusing on blackwater fever (BWF) and severe anemia. Serum samples from 600 children with severe malaria and 120 community children were analyzed using ELISA to measure immune complex levels and markers of hemolysis in a prospective cohort study. About 9% of children had G6PD deficiency for the African allele. Regional and gender-specific differences were also noted, with higher immune complex levels in Jinja compared to Kampala, and more severe malaria cases in Kampala. Circulating immune complexes were associated with hemolytic events, with variations based on sex and location. These findings suggest a potential role for circulating immune complexes in mediating hemolysis and malaria complications, particularly in G6PD-deficient individuals. Insights from this study may inform targeted interventions for improving severe malaria outcomes in regions like Eastern Uganda.

Samuel B. Anyona (Maseno University, Kenya) presented a previously unexplored aspect of severe malarial anemia (SMA) in Kenyan children, focusing on the differential ubiquitination protein expression. Ubiquitination is a fundamental process in cells, regulating protein degradation, signaling, and immune responses. Understanding how ubiquitination is altered in SMA could offer insights into the disease mechanisms and aid in developing targeted treatments. The findings from a prospective observational study indicated that dysregulation of ubiquitination affects various pathways crucial in SMA pathogenesis. These include cellular stress responses, inflammatory pathways, and tissue repair mechanisms. Malaria infection triggers inflammatory responses, which in turn activate downstream pathways. The intersection of inflammatory responses with cellular stress and immune regulation pathways suggests a complex interplay between inflammation, cellular stress, and immune responses in SMA. Disruptions in these pathways and associated proteins likely contribute to the pathophysiology of SMA, leading to inflammation, impaired erythropoiesis, tissue damage, and organ dysfunction. This study opens avenues for targeted interventions aimed at restoring proper pathway function and alleviating the severity of the disease.

Closing Ceremony

The Multilateral Initiative on Malaria (MIM) 8th Pan African Malaria Conference, held in Kigali, Rwanda, from the 21st to the 27th of April 2024, concluded with a closing ceremony where distinguished individuals, including outstanding leaders in the field of malaria research, poster presenters, and contributors to MIM and malaria research in general, as well as distinguished institutions, were recognized for their remarkable contributions. Additionally, an invitation was extended to East African research institutions or consortiums engaged in malaria research to apply to host the 9th Pan African Malaria Conference. The Minister of Health in Rwanda took the opportunity of the closing ceremony to thank all who made possible the MIM conference and acknowledged the contributions of all the scientists who presented. During her closing speech, Emeritus Rose GF Leke, Chair of the Multilateral Initiative on Malaria Secretariat, expressed gratitude to sponsors, partners, and the Government of Rwanda for their role in making the event successful. She emphasized the importance of united efforts to accelerate progress in ending malaria. Finally, the MIM Society welcomed its new chair Professor Abdisalan Noor and he gave a heartfelt speech on his vision for shaping the future of MIM.