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Effects of vector control interventions on spatio-temporal changes of Falciparum malaria risk in children aged 2-10 in sub-Saharan African regions during 2011-2020
Chol, Changkuoth Jock; Belay, Denekew Bitew; Fenta, Haile Mekonnen; Chen, Ding-Geng (Din) (Frontiers Media, 2025-07-02)
BACKGROUND : Sub-Saharan Africa (SSA) has a disproportionately high malaria fatality rate globally, with young children accounting for the majority of fatalities. The objective of this study is to investigate the spatiotemporal dynamics of malaria infection risk and assess the effect of vector control interventions on malaria infection rates in SSA nations. METHODS : We utilized data from the Malaria Atlas Project regarding the prevalence of Plasmodium falciparum malaria infections and vector control interventions across 634 administrative areas in 45 SSA countries over a decade. This study adopted spatiotemporal regression models using Markov-chain Monte Carlo methods with a Bayesian setup. RESULTS : Between 2011 and 2020, the average annual prevalence rates of malaria infection among children aged 2 to 10 in SSA diminished from 21.32% in 2011 to 16.75% in 2016, with a slight resurgence observed in 2017. Each unit increase in the number of individuals utilizing insecticide-treated nets (ITN) annually correlates with a 34.07% reduction in the risk of malaria infection. A rise in malaria cases has prompted SSA to undertake serious control measures. The auto-regressive process reveals a highly significant temporal correlation, while the global spatial dependency parameter indicates a modest spatial correlation. The highest risk of malaria infection prevalence among children aged 2 to 10 was indicated in states in the West-central, Central, and certain Eastern regions. CONCLUSION : Given that the West-central, Central, and select Eastern states exhibit the highest rates of malaria infection, the global end malaria councils and the malaria control and elimination program should prioritize interventions in these regions, enhancing vector control measures and providing comprehensive training on their effective utilization to mitigate malaria risk in these areas.
“I will take PrEP because that’s what will help me not to get infected with HIV” : barriers to and facilitators of pre-exposure prophylaxis and condom use among adolescent girls and young women enrolled in a school-based HIV prevention program in South Africa
Bergh , Kate; Jonas, Kim; Toska, Elona; Abdullah, Fareed; Blom, Nomtopi; Mathews, Catherine; Mthanti, Ngkatiseng; Slingers, Nevilene; Van Blydenstein, Nathanael; Duby, Zoe (Frontiers Media, 2025-11-20)
INTRODUCTION : The Imagine programme is a school-based HIV prevention program offering preexposure prophylaxis (PrEP), condoms and other social and structural interventions to adolescent girls and young women (AGYW) in South Africa. PrEP uptake and adherence together with the provision of condoms has not been extensively studied in the school context. We explored the barriers to and facilitators of PrEP and condom usage among Imagine programme beneficiaries using the HIV prevention cascade framework. METHODS : Sixteen AGYW aged 16–20 years who had never taken PrEP, were on PrEP or had stopped PrEP were interviewed between November 2023 and March 2024. Interviews were audio-recorded, and transcripts were deductively coded according to the HIV prevention cascade steps: (1) Knowledge, (2) Motivation, (3) Access and (4) Effective use. RESULTS : HIV and pregnancy risk awareness was high. For condom use, the risk of HIV transmission and pregnancy was outweighed by fear of sexual or physical violence from male partners and a desire to maintain relationships, as asking to use condoms demonstrated a lack of trust. High levels of PrEP knowledge motivated participants to use PrEP, especially if their partner refused to use condoms. Fear of side effects and daily pill taking were barriers to PrEP uptake. PrEP and condom services in school were highly acceptable, while anticipated stigma remained a challenge at the community clinic. DISCUSSION : Barriers to condom use persist in South Africa, but positive attitudes toward PrEP described in this study suggest that opinions about PrEP are still forming and can be strongly influenced by youth-friendly HIV programming in schools.
Examining suicide risk among people with schizophrenia, focusing on the role of anosognosia and the ethical considerations for future research directions
Kotze, Carla; Roos, J.L. (Johannes Louw) (Frontiers Media, 2025-10-20)
This perspective paper discusses the primary risk factors consistently identified in systematic reviews of suicide among individuals with schizophrenia. Particular attention is given to the intricate relationship between anosognosia (lack of insight into one’s illness) and suicide risk in this population. This paper explores how anosognosia may influence other established risk factors and potentially contribute to suicidal behavior in patients with schizophrenia. By analyzing this complex interplay, this paper aims to provide a more comprehensive understanding of suicide risk in schizophrenia, potentially informing more effective prevention strategies and interventions for this vulnerable group. Future research in this area should carefully consider the ethical implications, including the potential impact of interventions on individuals with varying levels of insight into their condition. Researchers must prioritize participant safety and well-being while balancing the need to advance knowledge in this critical field.
A latent invader : transcriptomics reveals Cercospora zeina's stealth infection strategy of maize and immune-activating effectors
Nadasen, Trystan; Buitendag, Carla; Visser, Rode´; Welgemoed , Tanya; Hein, Ingo; Berger, David Kenneth (Frontiers Media, 2025-11-07)
Cercospora zeina is a fungal pathogen that causes gray leaf spot (GLS) disease on maize (Zea mays L.). Upon landing on a leaf, the pathogen enters through the stomata and continues to develop asymptomatically for up to 28 days before symptoms appear. As previous work has yet to adequately determine how the pathogen behaves during its infective period, we used transcriptomics to gain insights about the in-planta development of the pathogen and explore its use of effectors to facilitate this process. Samples from B73 maize inbreds inoculated with an African reference strain of C. zeina (CMW25467) were harvested in a time course experiment and used for deep RNA sequencing. We used reads mapped to an improved assembly and annotation of the C. zeina CMW25467 genome as a proxy for biomass accumulation. Following the latent period, C. zeina was found to rapidly accumulate biomass and showed a nearly 50-fold increase in biomass as symptoms appeared. Two distinct transcriptional waves occurred across the infection period. The first wave showed expression of genes for cellular growth, maintenance and immune avoidance, whereas the second wave was enriched with genes involved in detoxification and carbohydrate catabolism. A total of 140 putative effector genes were differentially expressed over the time course, with most upregulated during the mid stage when the switch to necrotrophy occurred. Transient expression of three of these C. zeina effectors (CzEcp2, CzNIS1a, CzNIS1b) induced plant immunity in Nicotiana spp. resulting in the development of cell death. The CzNIS1a effector required a signal peptide for activity in Nicotiana benthamiana, indicating that it is most likely secreted into the apoplast for this function. The previously undescribed CzNIS1b family member has an N-terminal domain with high sequence and structural identity to CzNIS1a plus a C-terminal domain made up of four alpha helices. Orthologues of CzNIS1b appear to be limited to the Mycosphaerellaceae. This study suggests that a cohort of C. zeina effectors expressed during the mid-stage of infection have functions for which receptors are present in non-host species like tobacco. Altogether, this work suggests C. zeina behaves as a latent necrotroph and provides a foundation for future research into the infection biology of C. zeina.
Beyond prescriptions : chronic medication adherence predicts mortality risk in a large-scale cohort study
Blanco, Jessica Hamuy; Janse van Rensburg, Dina Christina; Jansen van Rensburg, Audrey; Uys, Corrie; Schellack, Natalie (Frontiers Media, 2025-11-25)
OBJECTIVES : The Medication Adherence Risk Score (MARS) is a calculated score using pharmacy transactional data spanning 50% of the South African private pharmacy market. This study aims to demonstrate that the existing MARS model enhances risk stratification by identifying individuals at increased risk of mortality related to non-adherence to chronic medication. METHODS : This was a retrospective cohort study in which an analysis of the relative mortality experience was compared to a standard fully underwritten base was performed for each of the MARS categories (low, medium, high and very high). The actual-to-expected ratio (AER) and relative risk (RR) for each category were compared across age groups and gender. The least absolute shrinkage and selection operator (LASSO) regression analysis method was applied to determine the most important variables within the dataset, providing insight into whether MARS offered more benefit than traditional risk rating factors. A time-to-event analysis by MARS categories was performed using the Cox proportional hazards model. RESULTS : The mortality experience of the study population was higher than the expected fully underwritten base (AER = 175%). For the overall sample, increasing AER and RR did not correlate with increasing MARS categories. However, use of the MARS in addition to age band allowed for differentiation of risk within the 25 to 55 age bands, with a higher MARS score indicating a higher AER and RR. The time-to-event analysis showed a statistically significant difference in the mean number of months before death occurred between the different MARS categories (low = 26.53; medium = 8.93; high = 7.02; very high = 6.92; p < 0.001). CONCLUSION : The MARS is not generalisable across all groups, as evidenced by the absence of a monotonic trend in the overall sample. However, when combined with age, it effectively differentiated mortality risk for individuals aged 25–55. The standard fully underwritten model underestimated the number of deaths within this pharmacy population. The time-to-event analysis showed a significant inverse relationship between MARS category and survival time.