Blood donors as a sentinel population for real-time malaria surveillance using the Sysmex XN-31: a one-year review from the National Blood Transfusion Centre in Burkina Faso

(2025) 24:288 Sawadogo et al. Malaria Journal https://doi.org/10.1186/s12936-025-05588-z Malaria Journal Open Access RESEARCH Blood donors as a sentinel population for real‑time malaria surveillance using the Sysmex XN‑31: a one‑year review from the National Blood Transfusion Centre in Burkina Faso Salam Sawadogo1,2, Talent Hwandih3, Jarob Saker3, Thérèsa L. Coetzer3,4, Anna Paszkowska5, Sidzabda C. B. Kompaoré6 and Marion Münster3* Abstract Background The World Health Organization malaria burden estimates produced from incomplete clinical case reporting and often outdated household asymptomatic parasitaemia surveys in children < 5 years old, are unreliable. Surveillance target groups need to be expanded in line with the epidemiological shift in malaria-eliminating countries towards adults, and particularly men. Furthermore, new tools that can provide granular and timely data, critical to understanding geographic heterogeneity and enabling timely decision-making at the operational level, are needed. This prospective study aimed to demonstrate that blood donor malaria screening could serve as a timesensitive complementary source of highly detailed malaria surveillance data. Methods Consecutive blood donations received from 16 August 2023 to 31 August 2024 at the Ouagadougou and Bobo-Dioulasso Regional Blood Transfusion Centres in Burkina Faso, covering 5 of 13 regions, were screened for malaria using the Sysmex XN-31 automated analyser. XN-31 results, donor age, sex, place of residence, collection date, were analysed using descriptive statistics, chi-squared, and logistic regression tests. Seasonal malaria patterns were compared with publicly available rainfall data. Results Donor malaria prevalence was 5.91% (3164/53575) overall. Key predictors of malaria identified were age ≤ 30 years (odds ratio (OR) 2.85, p < 0.001), male sex (OR 1.47, p < 0.001) and rural residency (OR 2.40, p < 0.001), with regional location having a strong influence on the latter. Strong seasonal variability, mirroring that of rainfall with a 3-month lag, was observed with different peak periods and rate of change over time at provincial level. Hotspots were observed within both Bobo-Dioulasso and Ouagadougou. There were no age or sex-based differences in parasite density or gametocyte carriage, and both measures were directly proportional to malaria prevalence. Only males showed striking seasonal variability in gametocyte carriage (low season 1.39%, 14/1006; high season 4.42%, 66/1494; p < 0.001). *Correspondence: Marion Münster Full list of author information is available at the end of the article © The Author(s) 2025. 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To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. Sawadogo et al. Malaria Journal (2025) 24:288 Page 2 of 19 Conclusions The large data set and spatiotemporal malaria prevalence information, not possible with episodic household malaria surveys, facilitated highly granular analysis and demonstrated the potential to provide dynamic real-time information on the malaria burden using automated XN-31 blood donor malaria screening. Keywords Malaria surveillance, Asymptomatic blood donors, Burkina Faso, XN-31, Automated malaria detection Background High quality surveillance data, which accurately reflects the heterogeneity of malaria prevalence trends within a geospatial framework over time, is an essential component of a comprehensive malaria elimination strategy. The World Health Organization (WHO) has emphasized the importance of surveillance and recommended that it be transformed into a core intervention [1]. Country-specific malaria burden estimates are generally determined using two sources: (1) passive surveillance data derived from clinical case reporting and (2) active surveillance data from periodic community-based surveys where malaria parasitaemia screening is undertaken in randomly selected households [2]. Epidemiological characteristics of asymptomatic infections may differ from those of clinical malaria, thus both forms of surveillance are needed for effective monitoring of malaria trends and intervention planning. The reliability of clinical case reporting as a malaria-metric is dependent on equity in access to healthcare facilities, febrile patient health-seeking behaviour, the sensitivity of the diagnostic method utilized for malaria confirmation, and the completeness of reporting, amongst others [3–6]. Household surveys, such as malaria indicator surveys (MIS) in turn, are limited by their high cost, inherent logistic complexity, and infrequent occurrence. Although malaria screening in MIS is intended to target household members most at risk—namely pregnant women and children under five years of age—all MIS reports published since 2020 have reported malaria prevalence data exclusively for the latter group [7]. Many malaria-endemic countries in subSaharan Africa have weak surveillance systems, thus data generated using these traditional means are often incomplete and may not represent the complete malaria burden picture [8, 9]. In this regard, it has been highlighted that complementary data sources, such as the routine screening of pregnant women attending antenatal clinics [10] or school children [11] would fill some of these gaps. Many individuals in malaria-endemic countries, including children, the primary target of MIS, are parasitaemic but show no clinical signs of infection. Besides being at risk of becoming anaemic, asymptomatic carriers, who mostly outnumber those with clinical malaria in malaria-endemic regions, are a major factor in perpetuating the transmission of malaria [12]. Targeting these populations and being able to rapidly identify changing trends in malaria prevalence is of particular importance, especially in the context of climate change, as well as in situations of declining prevalence when reservoirs of infection become increasingly geographically clustered [13–15]. Consequently, as countries switch their attention from malaria control to possible elimination, surveillance act (...truncated)