Biology subjects

Nyirenda, M.

Publications and source records attributed to Nyirenda, M..

4 recordsLinked to original sources

bioRxiv2025

Antibiotic Use and Resistance in Zambia's Aquaculture Sector: Assessing Knowledge, Attitudes, and Practices Among Fish Farmers

Aquaculture in Zambia is rapidly growing, contributing significantly to food security and income generation. However, the intensification of fish farming raises concerns about antimicrobial use (AMU) and the emergence of antimicrobial resistance (AMR). This study assessed the knowledge, attitudes, and practices (KAP) of fish farmers regarding AMU and AMR across 25 districts in Zambias ten provinces. Data were collected from fish farmers using a structured questionnaire distributed via district fisheries officers and analyzed through descriptive and inferential statistics, including logistic regression. The results revealed significant gaps in knowledge, with only 17.4% of farmers classified as knowledgeable about AMU and AMR. Attitude assessments showed that 60.5% exhibited positive attitudes toward responsible AMU practices, while the remaining 39.5% displayed negative perceptions. In terms of practices, 76.5% adhered to good practices, including consulting veterinary professionals and responsible antibiotic use, whereas 23.5% engaged in poor practices. Key factors influencing KAP outcomes included age, farming experience, and annual production capacity. Farmers aged 30-39 years and those with 1-5 years of experience demonstrated significantly more positive attitudes (p < 0.05), while those with higher production capacities (501-1000 kg) exhibited better practices (p < 0.001). The findings highlight critical knowledge gaps and inconsistent practices regarding AMU and AMR among Zambian fish farmers. Targeted interventions, including education programs, enhanced access to veterinary services, and strengthened regulatory frameworks, are essential to promote responsible AMU, mitigate AMR risks, and ensure the sustainability of aquaculture in Zambia.

scientific communication and education↗

bioRxiv2024

EDTA tubes are suitable for insulin and C-peptide measurement in resource-limited settings and can be stored at room temperature for up to 24 hours

IntroductionInsulin and C-peptide assessment are important in characterization and management of diabetes. However, their adoption and increased clinical use in low resource settings (LRSs) is partly hindered by logistical factors including supplies required for pre-analytical sample handling and limited infrastructure. We aimed to determine the effects of altered sample processing conditions on stability of insulin and C-peptide at the pre-analytical stage. MethodsWe investigated the stability of C-peptide and insulin in serum and plasma collected, preservative type, time to centrifugation, storage conditions and duration of storage on the stability of C-peptide and insulin over 24 hours. ResultsBoth C-peptide and insulin levels remained stable above 90% from baseline p=1.000 & p=0.776 over 24 hours for samples stored in K2EDTA tubes, whether at room temperature or in a cooler box, both as centrifuged and uncentrifuged whole blood. In contrast, samples collected in plain serum tubes kept at room temperature and uncentrifuged C-peptide and insulin levels decreased significantly to 51%, p=0.006 and 62%, p=0. 083 respectively, similarly insulin levels for centrifuged samples declined to 64%, p=0.083 All iced and centrifuged serum samples remained above 90% of baseline concentration. ConclusionsIn resource limited settings where insulin and c-peptide tests are limited to central laboratories and highly dependent on sample referral systems, these tests can be reliably measured without the need for immediate centrifugation or processing from samples collected in whole blood K2EDTA tubes uncentrifuged kept at room temperature and processed within 24hours. MessageK2EDTA tubes can be used for sample collection in resource limited setting kept at room temperature for up to 24hrs for insulin and c-peptide assays. K2EDTA plasma is more stable than serum for insulin and c-peptide measurement and should be used in resource limited settings

biochemistry↗

bioRxiv2024

The CSF transcriptome in pneumococcal meningitis reveals compartmentalised host inflammatory responses associated with mortality.

AbstractO_ST_ABSBackgroundC_ST_ABSPneumococcal meningitis (PM) has persistently poor clinical outcomes, especially in sub- Saharan Africa. To better characterise the inflammatory response and identify factors associated with mortality we compared paired peripheral blood and cerebrospinal fluid (CSF) transcriptomes before the initiation of antibiotics in Malawian adults with proven PM. ResultsBlood transcriptional profiles were obtained in 28 patients with PM, with simultaneous paired with CSF profiles available for 13 patients. 15/28 (52%) patients died. Comparison of the transcriptome between CSF and blood compartments showed upregulation of 2293 differentially expressed genes in CSF and 909 in blood; enriched pathways in CSF included inflammasome activity and neutrophil migration/activation in the CSF, contrasting with enrichment for pathways including platelet and endothelial activation, cell cycle, cytokine release and oxidative stress in the blood transcriptome. Comparison of CSF profiles between survivors and non-survivors revealed 1829 differentially expressed genes, non- survivor CSF was enriched for multiple innate inflammatory pathways, including IL-17A and Type 1 interferons and proteolysis. In contrast, minimal transcriptomic differences between outcome groups were detected in blood. ConclusionInflammation in PM is characterised by compartmentalised responses in blood and CSF. Poorer outcomes are associated with an dysregulated innate immune host response to S. pneumoniae in the CSF compartment.

immunology↗

bioRxiv2020

Discovery and fine-mapping of kidney function loci in first genome-wide association study in Africans

Genome-wide association studies (GWAS) for kidney function have uncovered hundreds of risk loci, primarily in populations of European ancestry. We conducted the first GWAS of estimated glomerular filtration rate (eGFR) in Africa in 3288 Ugandans and replicated the findings in 8224 African Americans. We identified two loci associated with eGFR at genome-wide significance (p<5x10-8). The most significantly associated variant (rs2433603, p=2.4x10-9) in GATM was distinct from previously reported signals. A second association signal mapping near HBB (rs141845179, p=3.0x10-8) was not significant after conditioning on a previously reported SNP (rs334) for eGFR. However, fine-mapping analyses highlighted rs141845179 to be the most likely causal variant at the HBB locus (posterior probability of 0.61). A trans-ethnic GRS of eGFR constructed from previously reported lead SNPs was not predictive into the Ugandan population, indicating that additional large-scale efforts in Africa are necessary to gain further insight into the genetic architecture of kidney disease.

genetics↗