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Purpose: The Democratic Republic of Congo has one of the highest burdens of malaria in the world, accounting for 12.3% of malaria cases and 11.6% of malaria deaths. The country has been scaling up various malaria control interventions, but how the malaria burden and risk factors have evolved remains unclear. This study aimed to estimate the trend in the burden of malaria in different settings in Kinshasa Province and assess factors contributing to the infection., Participants: From 2018 to 2022, a cohort study was conducted in three health areas in Kinshasa Province known to have varying malaria endemicities: Voix du Peuple (urban), Kimpoko (peri-urban), and Bu (rural) health areas in Kinshasa Province. Participants 6 months of age and older were recruited and followed biannually through household visits and encouraged to visit study health centres whenever they felt ill. The participants' sociodemographic data, illness history and access to malaria interventions were collected along with blood specimens. During the same study period, mosquitoes and larvae were collected to study entomological characteristics that may contribute to malaria transmission., Findings: A total of 1635 participants were recruited from 239 households. The median number of participants per household was 6 (IQR, 5-9). Over half (54.7%) of the participants were female, 14.6% were under-5 children, and 33.3% were 5-14 years old. Household net ownership and reported use the previous night were 77.8% and 79.1%, respectively. Overall, malaria prevalence by rapid diagnostic test at baseline was 33.4%. Of the recruited participants, 1390 (85%) completed the 4 years of follow-up., Future Plans: Planned analyses include calculating malaria prevalence and incidence trends at follow-up as well as risk factors for infection. Continued analyses will link epidemiological and entomological data to understand malaria transmission evolution and the sustained high prevalence of malaria over time in various settings., Competing Interests: Competing interests: JBP reports research support from Gilead Sciences, non-financial support from Abbott Laboratories, and consulting for Zymeron Corporation, all outside the scope of this work, (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Reports suggest non-falciparum species are an underappreciated cause of malaria in sub-Saharan Africa but their epidemiology is ill-defined, particularly in highly malaria-endemic regions. We estimated incidence and prevalence of PCR-confirmed non-falciparum and Plasmodium falciparum malaria infections within a longitudinal study conducted in Kinshasa, Democratic Republic of Congo (DRC) between 2015-2017. Children and adults were sampled at biannual household surveys and routine clinic visits. Among 9,089 samples from 1,565 participants, incidences of P. malariae, P. ovale spp., and P. falciparum infections by 1-year were 7.8% (95% CI: 6.4%-9.1%), 4.8% (95% CI: 3.7%-5.9%) and 57.5% (95% CI: 54.4%-60.5%), respectively. Non-falciparum prevalences were higher in school-age children, rural and peri-urban sites, and P. falciparum co-infections. P. falciparum remains the primary driver of malaria in the DRC, though non-falciparum species also pose an infection risk. As P. falciparum interventions gain traction in high-burden settings, continued surveillance and improved understanding of non-falciparum infections are warranted., (© 2023. Springer Nature Limited.)

Malaria programs rely upon a variety of diagnostic assays, including rapid diagnostic tests (RDTs), microscopy, polymerase chain reaction (PCR), and bead-based immunoassays (BBA), to monitor malaria prevalence and support control and elimination efforts. Data comparing these assays are limited, especially from high-burden countries like the Democratic Republic of the Congo (DRC). Using cross-sectional and routine data, we compared diagnostic performance and Plasmodium falciparum prevalence estimates across health areas of varying transmission intensity to illustrate the relevance of assay performance to malaria control programs. Data and samples were collected between March-June 2018 during a cross-sectional household survey across three health areas with low, moderate, and high transmission intensities within Kinshasa Province, DRC. Samples from 1,431 participants were evaluated using RDT, microscopy, PCR, and BBA. P. falciparum parasite prevalence varied between diagnostic methods across all health areas, with the highest prevalence estimates observed in Bu (57.4-72.4% across assays), followed by Kimpoko (32.6-53.2%), and Voix du Peuple (3.1-8.4%). Using latent class analysis to compare these diagnostic methods against an "alloyed gold standard," the most sensitive diagnostic method was BBA in Bu (high prevalence) and Voix du Peuple (low prevalence), while PCR diagnosis was most sensitive in Kimpoko (moderate prevalence). RDTs were consistently the most specific diagnostic method in all health areas. Among 9.0 million people residing in Kinshasa Province in 2018, the estimated P. falciparum prevalence by microscopy, PCR, and BBA were nearly double that of RDT. Comparison of malaria RDT, microscopy, PCR, and BBA results confirmed differences in sensitivity and specificity that varied by endemicity, with PCR and BBA performing best for detecting any P. falciparum infection. Prevalence estimates varied widely depending on assay type for parasite detection. Inherent differences in assay performance should be carefully considered when using community survey and surveillance data to guide policy decisions., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: JBP reports financial support from Gilead Sciences, non-financial support from Abbott Diagnostics, and consulting for Zymeron Corporation, all outside the scope of this work. All other authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Histidine-rich protein 2- (HRP2-) based rapid diagnostic tests (RDTs) are widely used to detect Plasmodium falciparum in sub-Saharan Africa. Reports of parasites with pfhrp2 and/or pfhrp3 (pfhrp2/3) gene deletions in Africa raise concerns about the long-term viability of HRP2-based RDTs. We evaluated changes in pfhrp2/3 deletion prevalence over time using a 2018-2021 longitudinal study of 1,635 enrolled individuals in Kinshasa Province, Democratic Republic of the Congo (DRC). Samples collected during biannual household visits with ≥ 100 parasites/µL by quantitative real-time polymerase chain reaction were genotyped using a multiplex real-time PCR assay. Among 2,726 P. falciparum PCR-positive samples collected from 993 participants during the study period, 1,267 (46.5%) were genotyped. No pfhrp2/3 deletions or mixed pfhrp2/3-intact and -deleted infections were identified in our study. Pfhrp2/3-deleted parasites were not detected in Kinshasa Province; ongoing use of HRP2-based RDTs is appropriate.

Background: The Democratic Republic of the Congo (DRC) remains one of the countries most impacted by malaria despite decades of control efforts, including multiple mass insecticide treated net (ITN) distribution campaigns. The multi-scalar and complex nature of malaria necessitates an understanding of malaria risk factors over time and at multiple levels (e.g., individual, household, community). Surveillance of households in both rural and urban settings over time, coupled with detailed behavioral and geographic data, enables the detection of seasonal trends in malaria prevalence and malaria-associated behaviors as well as the assessment of how the local environments within and surrounding an individual's household impact malaria outcomes., Methods: Participants from seven sites in Kinshasa Province, DRC were followed for over two years. Demographic, behavioral, and spatial information was gathered from enrolled households. Malaria was assessed using both rapid diagnostic tests (RDT) and polymerase chain reaction (PCR) and seasonal trends were assessed. Hierarchical regression modeling tested associations between behavioral and environmental factors and positive RDT and PCR outcomes at individual, household and neighborhood scales., Results: Among 1591 enrolled participants, malaria prevalence did not consistently vary seasonally across the sites but did vary by age and ITN usage. Malaria was highest and ITN usage lowest in children ages 6-15 years across study visits and seasons. Having another member of the household test positive for malaria significantly increased the risk of an individual having malaria [RDT: OR = 4.158 (2.86-6.05); PCR: OR = 3.37 (2.41-4.71)], as did higher malaria prevalence in the 250 m neighborhood around the household [RDT: OR = 2.711 (1.42-5.17); PCR: OR = 4.056 (2.3-7.16)]. Presence of water within close proximity to the household was also associated with malaria outcomes., Conclusions: Taken together, these findings suggest that targeting non-traditional age groups, children >5 years old and teenagers, and deploying household- and neighborhood-focused interventions may be effective strategies for improving malaria outcomes in high-burden countries like the DRC., (Copyright © 2021 Elsevier Ltd. All rights reserved.)