Malaria Consortium

BackgroundRespiratory rate is an important part of assessing the clinical state of children, and various methods exist to measure it. However, there is a lack of a universally accepted reference standard to validate the performance of these methods.AimTo identify different reference standards that have been used to evaluate respiratory rate measurement methods in children under 5 years of age and describe their perceived strengths and limitations.MethodsMEDLINE and Web of Science were searched for studies in English. Studies of children under 5 years of age, published between 2013 and 2024, in which a method for measuring respiratory rate was compared against a reference standard, were included. Deductive content analysis was used to map perceived strengths and limitations of each standard, and a forest plot analysis was used to compare agreement between the reference standard and the index tests.ResultsFrom 992 retrieved studies, 56 were included. The most common reference standard was impedance pneumography (22/56), primarily used in high-income settings, followed by manual counting (19/56), mostly employed in low- and middle-income settings, and capnography (9/56). Child age, clinical condition, setting, training of personnel and the ease of implementation were all important factors in which the reference standard was used and how it performed.ConclusionThree different reference standards were used for most studies; however, their relative performance to each other is unclear. There is a need for research that directly compares the performance of these reference standards across different age strata and settings in order to confidently recommend a reference standard for respiratory rate measurement methods.

Nearly 5 million children die each year of preventable causes, with pneumonia being a key contributor. The Integrated Management of Childhood Illnesses guidelines improve health care workers' diagnostic and management capabilities by relying mostly on clinical signs. Though there have been successes, challenges in the consistent application of IMCI and the accurate diagnosis of conditions like hypoxemia remain. Next generation pulse oximeters add functionality to stand alone pulse oximeters, like measurement of respiratory rate, temperature, and hemoglobin. While the TIMCI project sought to address gaps in the introduction of pulse oximetry in India, Kenya, Senegal, and Tanzania, research was also conducted to strengthen the market for multimodal pulse oximetry (PO) devices by filling evidence gaps around ideal product attributes and the validation of available and near to market photoplethysmography-derived clinical measurement tools (medical device and smartphone-based). A mixed-methods evaluation measured usability and diagnostic accuracy using multimodal PO devices among primary care providers in the four countries. Results showed good usability, minimal user errors, and high satisfaction and system usability scores across all devices. Additionally, across all age categories, device performance for hypoxemia, tachycardia, and fever exceeded 80% agreement; respiratory rate measurements exhibited greater variability in percent agreement between devices. A target product profile and an open-source data repository were developed to further advance device development and market alignment. This research provided data on the performance of various multimodal PO devices, considering different form factors and product attributes. Technological progress continues to expand opportunities for the collection of clinical measurements and data. Supporting providers with decision support and automated documentation tools ensures that the information generated is actionable and utilized, while an emphasis on integrated technologies is essential to maximize provider capabilities and improve the diagnosis and management of childhood illnesses in low- and middle-income countries.

Advanced molecular technologies allow for the generation of reproducible, sequence-defined recombinant antibodies.As in all areas of science, time and resource constraints can slow a widescale transition; however, the rapid expansion of recombinant antibodies in commercial catalogs makes major progress achievable today.Here, practical opportunities to increase the use of sequenced antibodies are highlighted, aligning with a call from the scientific community for more reproducibility and less reliance on animals in research (Ayoubi et al., 2023;Bradbury and Plckthun, 2015).A review of CiteAb's compilation of the top 100 cited antibodies 1 , published in October 2025, reveals that numerous antibodies listed could be replaced with existing catalog recombinant options, as detailed in Table 1.Ten of the top 25 antibodies in CiteAb's 2024 list are polyclonal secondary antibodies.The composition of a polyclonal antibody varies depending on the individual immune response of the animal used for production, and this inherent variability has long led scientists to call for their replacement with more reproducible antibodies.Manufacturer catalogs offer a growing number of sequence-defined alternatives that are either entirely animal-free or, while using animals during development, eliminate animal use during production.These include individual monoclonal antibodies that can replace polyclonal antibodies, as well as multiclonal cocktails composed of defined monoclonals.Further, two of the top 25 antibodies are polyclonal primary antibodies, both of which have catalog recombinant options, as shown in Table 1.Monoclonal antibodies that have recombinant replacements are also frequently cited.Four of the top 25 antibodies in CiteAb's list are monoclonal antibodies produced via hybridomas, all of which have existing catalog recombinant options listed in Table 1, and five of the top 100 are monoclonals produced via the ascites method.This method inflicts such considerable suffering that scientific committees in Europe and the U.S. have discouraged its use for animal welfare reasons (NRC, 1999; EC, 2020) in addition to issues with reproducibility.More than 20 years ago, the European Commission's EU Reference Laboratory for alternatives to animal testing's (EURL ECVAM's) Scientific Advisory Committee concluded that alternative procedures were equal to or better than the ascites method.In 2020, the organization reaffirmed that the method should no longer be acceptable for use under any circumstances 2 .Sequence-defined alternatives for each of these five ascites antibodies, which do not involve the ongoing use of animals, are listed within Table 1.For consumers who have contracts with or have preferred antibody vendors, there are an increasing number of companies offering recombinant antibodies for the same targets as their traditional counterparts.As an example presented within Table 1, Abcam has numerous animal-production-free recombinant antibodies that can be used in place of their polyclonal primary antibodies.Such options effectively remove a potential logistical barrier and streamline the transition.The growing availability of recombinant antibodies allows scientists to select reagents that, with proper characterization, can enhance research quality while advancing animal welfare.The information presented here serves as a guide for scientists to identify sequence-defined antibodies ready for immediate use.Beyond these examples, myriad additional catalog recombinant antibodies are readily accessible through commercial catalogs and in the Recombinant Antibodies & Mimetics Database 3 -offering scientists a practical opportunity to incorporate more reliable reagents in their research today.

Seasonal malaria chemoprevention (SMC) using monthly sulfadoxine-pyrimethamine-amodiaquine (SPAQ) is being deployed East Africa, where antimalarial drug resistance levels are high. Dihydroartemisinin-piperaquine (DP) is a potential alternative. A prospective 28 day pharmacometric assessment of SMC was conducted in Karamoja, Northern Uganda. In two villages children received SPAQ and in a third were randomized to DP vs. no SMC The primary outcome was malaria infection defined by capillary blood sample qPCR positivity on day 28, or presentation with fever and slide or rapid test positivity after day 2. Baseline qPCR malaria parasitemia prevalence among 1250 enrolled children was 46% (575/1250); P. falciparum 85%, other malarias (mainly P. ovale) 25%. Breakthrough parasitemias occurred in 7% (33/496) of DP, 31% (158/504) of SPAQ, and 39% (98/250) of no drug recipients. Clinical malaria (all P. falciparum) developed in 17% of no drug (42/250; 1 severe), 8% of SPAQ (38/504; 2 severe) and 2% of DP (13/496) recipients. Adjusted protective efficacies against all malaria parasitemia, P. falciparum parasitemia, and clinical malaria were SPAQ; 56% (95%CI 35-70%), 46% (11-68%), and 60% (27-78%)and for DP; 84% (77-89%), 86% (75-92%) and 86% (74-92%) respectively. Some asymptomatic P. falciparum infections were not cleared by SPAQ. All 260 P. falciparum isolates genotyped were Pfcrt K76 (haplotype CVMNK, a marker of 4-aminoquinoline susceptibility) and most were quintuple Pfdhfr/dhps mutants (i.e. relatively SP resistant). The chemoprevention drug exposure-response relationship was strong for desethylamodiaquine, but weak for sulfadoxine. SPAQ SMC had low clinical and parasitological chemopreventive efficacy in Northern Uganda whereas dihydroartemisinin-piperaquine was effective.

BackgroundMalaria remains a significant public health challenge in sub-Saharan Africa (SSA), where vector control strategies, particularly insecticide-treated nets (ITNs) and indoor residual spraying (IRS), have played a critical role in reducing transmission. However, the emergence and spread of insecticide resistance among malaria vectors threatens to undermine these gains. In response, many countries in the region have developed national insecticide resistance management (IRM) plans. This study evaluates the adequacy and implementation of these plans in Cameroon, Côte d’Ivoire, and mainland Tanzania, aiming to identify key challenges and best practices, and to develop actionable recommendations applicable to these and other countries with similar contexts.MethodsA mixed-methods approach was employed, incorporating document reviews, epidemiological and entomological data analysis, and discussions with stakeholders and experts in 2023. The evaluation focused on the alignment of national IRM plans with national malaria control strategies, their operational effectiveness, and the ability to guide effective monitoring and management of insecticide resistance. The assessment was conducted before changes in the global aid funding landscape.ResultsEach country has developed a 5-year IRM plan; however, the plans for Côte d’Ivoire and mainland Tanzania were found to be outdated. While the plans align well with national malaria strategies and international guidelines, implementation has been hindered by inadequate domestic funding and heavy reliance on external donors. Sentinel site coverage for resistance monitoring remains limited, though ITN campaigns have increasingly adopted targeted approaches using varied net types based on local data. IRS is sparsely deployed, but where it is used, rotation of insecticides with differing modes of action is practiced. Despite existing strengths, such as subnational tailoring of interventions, major challenges persist, including inactive monitoring sites and limited data availability due to financial and logistical constraints. The assessment identified important recommended actions, including increased mobilization of domestic financing of resistance monitoring and management to offset shortfalls in external funding, updating of national IRM plans regularly by realistically aligning with available resources, and improved tailoring of effective vector control through high-quality and localized resistance and malaria risk data.ConclusionInsecticide resistance remains a significant threat to malaria control efforts across sub-Saharan Africa. Robust, adaptable IRM plans are essential to address this challenge. Case studies from Cameroon, Côte d’Ivoire, and mainland Tanzania reveal that such policy plans exist but implementation gaps, largely driven by funding shortages (a challenge that has increased since the study was completed), undermine the effectiveness of existing strategies. Strengthening domestic resource mobilization, enhancing multisectoral coordination, and investing in systematic entomological surveillance are critical to ensure evidence-based, sustainable vector control programmes.

IntroductionSeasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine (SPAQ) has been delivered in sub-Saharan Africa since 2014, reaching over 40 million children in 2022. New questions are emerging related to SMC’s sustainability, integration with other interventions and introduction to new regions. Meanwhile, new WHO malaria guidelines have substantially increased flexibility for tailoring malaria strategies to local contexts. The SMC Alliance, bringing together researchers and implementers, commissioned a consultation to identify medium-term SMC research priorities.MethodsThe consultation was conducted online from September 2022 to September 2023 using the eDelphi methodology. An initial list of 46 research priorities was compiled during a workshop with SMC implementers. The wider expert consultation comprised three waves of online surveys available in English, French and Portuguese. Respondents rated research priorities on their importance, feasibility and degree to which they had already been addressed; responses determined elimination or retention of research priorities after each survey wave. Respondents suggested their own research priorities for rating. We also collected anonymised data on respondents’ characteristics. A final ranking exercise was conducted to reach consensus on a top 10 list of research priorities.ResultsA total of 67 unique respondents residing in 20 countries provided 96 survey responses. The surveys achieved balanced representation of respondents by gender, country of residence and professional background. Of the 25 research priorities retained for ranking, the highest-ranked included ‘evaluate duration of prophylactic protection offered by SPAQ and other SMC medicines’ and ‘evaluate the effect of integrating SMC with other malaria prevention interventions on development of antimalarial resistance’.ConclusionsResearch priorities related to sustainability, antimalarial resistance, integration with other interventions and improving quality of SMC delivery featured prominently among the highest-ranked research priorities. It is hoped the results of this consultation can encourage research uptake, guide new research and inform programme adaptation.

Background: Human immunodeficiency virus (HIV) affects more than 39 million people worldwide, with Uganda ranked 10th among countries with the highest number of cases. As new preventative HIV injectables emerge, it is vital to think about how best to tailor strategies to promote these injectable drugs, like PrEP and vaccines, when available, to the different populations most in need. Discrete choice experiments (DCEs) are economics-derived methods used to determine factors that influence engagement in a certain behavior. Objective: This study used a DCE to determine the preferences for a preventative HIV injectable drugs/vaccines among people at risk of HIV acquisition in urban and peri-urban areas of Uganda. Methods: In June 2024, we implemented a cross-sectional DCE survey in three urban sites in Uganda in English and Luganda. The survey collected information on demographics, HIV risk, vaccine confidence and responses to the 13 injection product choice tasks presented to determine preferences. We used community-based, respondent-driven sampling methods to recruit participants from three key populations: (1) female sex workers; (2) people who identify as lesbian, gay, bisexual or transgender; and (3) young women (18–24 years). We collected the data on tablets using the Sawtooth Lighthouse Studio software (v. 19.15.6), taking into consideration privacy and confidentiality, given the sensitivity of the information and recent governmental policies in Uganda. Data were analyzed using a split-sample mixed logit regression analysis. The study was approved by local ethical regulatory bodies. Results: From the total of 406 participants screened for this study, 376 participants met the eligibility criteria and were included in the final analysis (85 young women, 159 female sex workers, and 132 who identified as lesbian, gay, bisexual or transgender). The average age was 23.7 (SD: 5.7). The majority of participants had received some secondary school or vocational school (202, 53.7%) The attributes that explained the preferences were primarily severe compared to mild side effects (β: −0.69, 95% CI: −0.78, −0.60), a 30% increase in vaccine/drug effectiveness (β: 0.39, 95% CI: 0.34, 0.44), and a 50,000 UGX (or USD ~13.64) increase in cost (β: −0.22, 95% CI: −0.27, −0.17). There were no significant differences between the preferences for different injectable types. The sensitivity analyses suggested potential differences in preferences by the amount of help participants received from research assistants when completing the survey, although not by income level. Conclusions: Side effects had the greatest impact on participants’ preferences for injectable HIV prevention methods, followed closely by effectiveness and cost. It is therefore essential to develop affordable or free prevention options with minimal side effects. Policymakers should focus on reducing the financial barriers to access and emphasize transparent communication about the effectiveness and safety of these injectables in health promotion campaigns to maximize adoption and improve public health outcomes.

BackgroundThe number of reports of arboviral outbreaks is increasing and, consequently, the need for effective surveillance and vector control plans for Aedes-borne diseases is becoming more urgent. To explore the current state of knowledge of Aedes arbovirus vectors in Africa, we reviewed studies published between 1980 and 2023 that involved Aedes vector surveillance, vector control or insecticide resistance, with the aim to synthesize information and identify knowledge gaps to guide future Aedes research and control in Africa.MethodsStudies conducted in Africa and published between 1980 and 2023 were retrieved from twelve electronic databases using search strings designed to capture relevant concepts. Articles that did not meet the eligibility criteria were excluded during relevance screening.ResultsOut of 17,337 publications identified, 877 full-text articles were reviewed, of which seven included information on vector surveillance, 56 on vector control and 57 on insecticide resistance. Publications reporting longitudinal data from sustained Aedes vector surveillance systems were only available for Senegal and La Réunion. Aedes vector control studies were principally controlled bioassays or small-scale studies conducted before and after entomological studies which lacked epidemiological outcomes. The most studied methods were larval control (n = 21 publications), integrated control combining different interventions (n = 7), topical repellents (n = 6), environmental management (n = 5) and spatial repellents (n = 3). Four publications described typical vector control responses during arbovirus epidemics in Africa: these often combined larviciding, ultra-low volume (ULV) space spraying and community engagement to reduce larval sites, alongside active source reduction. There was a lack of high-quality evidence generated through rigorous study design on the effectiveness of control measures in reducing arbovirus transmission in the African context. As a consequence, the scientific basis for evidence-informed decisions in Africa, both for routine Aedes vector control or for outbreak response, remains weak. Insecticide resistance studies focused on adulticides using WHO tube tests (n = 43 publications), with larval bioassays relatively less common (n = 13). Aedes aegypti (n = 53) and Aedes albopictus (n = 12) were the only Aedes species tested. The most commonly tested adulticides were permethrin and deltamethrin (pyrethroids); bendiocarb (carbamate); and dichlorodiphenyltrichloroethane (DDT; organochlorine), although the results were rarely reported in connection with decision-making about Aedes control. Results of the most relevant adulticides indicated that Ae. aegypti populations were generally susceptible to malathion (organophosphate), but resistance to permethrin and deltamethrin was detected in West and Central Africa. Most studies pre-dated the revised WHO guidance, and insecticide concentrations were mostly those recommended for Anopheles susceptibility testing that use relatively higher discriminating doses, and thus likely underestimate true Aedes resistance levels. Larval susceptibility bioassays were conducted with temephos (n = 12) and Bacillus thuringiensis israelensis (n = 6). Temephos resistance was only detected in Cabo Verde following several decades of use.ConclusionsGiven the increasing frequency of arbovirus epidemics in Africa, countries urgently need to develop plans for emergency response and robust control strategies that make use of evidence from good-quality studies to strengthen resilience.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13071-025-07049-7.

Effectiveness of currently deployed insecticide-based malaria vector control measures depends on continuous insecticide resistance monitoring and management. Urban malaria is becoming a serious health problem in Africa partly due to vector resistance in urban areas. To provide insecticide resistance trends information for effective resistance management, this study assessed insecticide susceptibility status and occurrence of knock down resistance mutation in Anopheles mosquitoes from urban Ilorin, Nigeria in two different years. Malaria vectors in urban Ilorin were assayed for susceptibility to WHO-recommended insecticides in 2017 and 2020 using WHO test kits. Sub-sets of exposed An. gambiae s.l. mosquitoes were PCR-assayed for sibling species and knock down resistance (kdr) mutation detection. Full mosquito susceptibility (98–100% mortality; Niger and Baruba) and suspected resistance (95–97% mortality; Shao garage and Edun) to alphacypermethrin were recorded in 2017. Significantly (p ≤ 0.010) reduced mosquito mortalities indicating increased alphacypermethrin resistance were recorded in 2020. Permethrin, lambda-cyhalothrin and DDT resistance increased significantly (p ≤ 0.03) from 2017 (42–89%) to 2020 (5.8–58%) but not deltamethrin (p ≥ 0.086). Mosquitoes tested were mostly susceptible to bendiocarb and pirimiphos-methyl. The kdr-L995F detected increased from 15 to 20% for An. arabiensis, 24–36% for An. gambiae and 0–18% for An. coluzzii from 2017 to 2020. For both 2017 and 2020, most of the pyrethroid resistant (≥ 80%) and susceptible (≥ 75%) mosquitoes from each site were identified as An. arabiensis. This study presents a first report on widespread occurrence of kdr-L995F mutation in An. arabiensis mosquito populations in urban Ilorin, Kwara State, Nigeria. The report of pyrethroid-resistant An. arabiensis prevalence in urban Ilorin triggered the switch from pyrethroid only to dual active ingredient ITN distribution in the city since 2020. Extension of dry season periods due to climate change may drive more preponderance of An. arabiensis in the study area. Therefore, the implementation of supplementary vector control measures targeted at An. arabiensis is required in this locality.