University of Buea

The omicron lineage has been declared the fifth variant of concern (VOC) by the World Health Organization (WHO). This study aims to describe the genomic characteristics of omicron sequences from Cameroon and to discuss the potential implications of identified mutations for viral evolution and immune escape, based on existing literature. This study is a retrospective analysis of publicly available SARS-CoV-2 sequences from Cameroon submitted to GISAID (Global Initiative on Sharing Avian Influenza Data). Full-length omicron sequences from across Cameroon were retrieved from the GISAID database. Phylogenetic analyses were conducted using Nextstrain SARS-CoV-2 Workflow version 8.2.0, and mutation analysis was performed using the Nextstrain web tool, with the Wuhan-Hu-1/2019 strain as a reference. A total of 1,428 omicron sequences were analyzed, revealing eleven variants: BA.1 lineage (45.0%), B.1.1.529 (0.2%), BA.2 (7.7%), BA.4 (6.5%), BA.5 (16.3%), BE (12.2%), BF (6.3%), BN.2 (0.1%), BQ.1 (3.7%), XBB (0.5%) and JN.1 (1.5%). The sequences exhibited high number of mutations in the spike gene, with the JN.1 lineage showing the highest mutation count. All lineages contained mutations associated with neutralizing antibody evasion, including R346T, K417N, G446S, E484A, or Q493R. Ongoing monitoring of omicron lineages is crucial to detect emerging variants and adapt vaccine strategies. The significant mutations, particularly in the JN.1 lineage warrant further investigation to assess their potential impact on transmissibility or immune escape. Not applicable.

ABSTRACT Background Vaccination is a cost-effective intervention preventing causes of 48% of deaths among children Under-5 in sub-Saharan Africa. However, one in five African children still has not completed basic vaccination, and over six million children have not received a single dose of the Diphtheria, Tetanus and Pertussis vaccine, resulting in over half a million deaths annually. This study aims to understand the key factors influencing pediatrics health (vaccination) decision-making in sub-Saharan Africa. Methods A cross-sectional design using a multi-stage stratified sampling approach was used. Data were collected from 2,451 households with children Under-5 in three countries and analyzed using R. Correlation analysis was used to understand the associations between variables, while regression analysis was used to control for covariates and identify influences on one another. Results The findings show that beliefs in gender disparity, misinformation, and masculinity can undermine childhood vaccination outcomes. A child’s gender ( r = –0.33–0.40, p < 0.01) and misinformation ( r = –0.38–0.54, p < 0.01) impact vaccination intentions and behavior. Meanwhile, positive attitudes ( r = 0.36–0.49, p < 0.01), trust (r = 0.17–0.34, p < 0.01) and peer influence ( r = 0.27–0.33, p < 0.01) significantly improve uptake. However, regressions show that male caregivers had weaker attitudes (β = –0.31, p < 0.001), stronger beliefs about misinformation (β = 0.33, p < 0.001) and lower vaccination intentions (β = –0.12, p < 0.001). Country comparisons reveal that Kenyan and Malawian children are 3.6 (OR = 3.64, p < 0.001) and 13 (OR = 13.13, p < 0.001) times more likely to be vaccinated than Nigerian children, respectively. Furthermore, masculinity had a significant effect on men, Muslims and polygamous households. Conclusion To address low vaccination uptake in sub-Saharan Africa, context-sensitive strategies are required that incorporate gender norms, counter misinformation, and engage fathers.

Accurate and timely monitoring of soil nutrient concentrations, particularly nitrogen (N), phosphorus (P), and potassium (K), is crucial for optimizing agricultural productivity and minimizing environmental impact. In this study, we present the characterization of an optical sensor designed for the rapid and non-destructive assessment of N, P, and K levels in soil samples. The sensor employs Visible-Near Infrared (VIS–NIR) spectroscopy to analyse the spectral signatures of soil samples and extract quantitative information regarding nutrient concentrations. A total of 30 experimental samples classified into six distinct categories, comprising various soil-fertilizer mixtures, were prepared to calibrate the sensor's performance. These samples were made from four primary constituents: black soil (sourced from a farm in the Auvergne-Rhone-Alpes region of France), NPK (6:3:12) fertilizer, ammonium nitrate, and urea. The six categories were grouped into two sets: sample type 1 consisted of pure samples, while sample types 2 through 6 were mixtures of soil and fertilizer. The mixed samples were prepared with nutrient concentrations higher than those typically found in agricultural soils to enable controlled calibration of sensor performance. The pure sample, specifically Sample10, consisting of humus soil without fertilizer amendment, was included as a reference to approximate real-soil conditions. Laboratory experiments involved illuminating the samples with specific wavelengths of light and measuring the intensity of reflected light within a controlled environment. Calibration curves and equations specific to each macronutrient were developed through regression analysis using data collected from the experiments. Performance evaluation metrics, including Root Mean Square Error (RMSE), Coefficient of Determination (R2), Predicted Residual Error Sum of Squares (PRESS), and Standard Error (s), were employed to assess model accuracy. Results demonstrated satisfactory performance across all sample types, with average R2, RMSE, PRESS, and s values of 0.7835 V, 0.0097 V, 0.0003 V, and 0.0003 V, respectively. Statistical analyses further validated the sensor, indicating average standard errors of 0.003 V for repeatability and 0.001 V for reproducibility, along with a sensitivity of 7% and a linearity of R2 = 0.8. These findings validate the effectiveness of the optical sensor in accurately quantifying soil macronutrient concentrations.

HIV treatment has significantly improved with the introduction of potent antiretroviral therapy (ART), particularly dolutegravir (DTG)-based regimens. With suboptimal adherence reported in resource-limited settings (RLS), real-word evidence on DTG-effectiveness within ART clinics is limited. This study assessed virological response, drug resistance profiling and HIV-1 diversity among ART recipients at the Yaoundé Central Hospital (YCH), Cameroon. A facility-based study was conducted at YCH from May-2023 to February-2025. HIV plasma viral load (PVL) was measured by RT-PCR. Viral suppression (VS) was defined as PVL < 1,000copies/mL. Genotypic resistance testing (GRT) was performed for participants with PVL≥1,000copies/mL. Drug resistance mutations (DRMs) were interpreted using Stanford HIVdb v9.8 and statistics were performed with significance at p < 0.05. Among 6,364 participants enrolled (median-age: 50 [IQR:42–59] years; 71% women), 76% (4,811/6364) were on DTG-based regimens. Median ART-duration was 13 [IQR:9.03–17.4] years, including 3.4 [IQR:3–5] years of DTG-exposure in the DTG-based sub-group. Overall, 93.2% (5,932/6,364) participants achieved VS in 2025; 94% among DTG-based versus 91% among DTG-sparing regimens (OR = 1.66; p = 0.000002). Interestingly, VS was higher with age ≥50years (aOR = 1.44; p < 0.001), DTG-based ART (aOR = 1.65; p < 0.0001) and DTG-exposure ≥3.4years (aOR = 1.29; p = 0.044). Between 2021 and 2025 specifically, VS remained consistently high among participants; with those on DTG-based showing significantly higher and more durable VS compared to those on DTG-sparing therapies (relative risk of failure > 1 for DTG-sparing throughout). Furthermore, from those virally unsuppressed in 2025, 9% (39/432) were lost-to-follow-up, 22% (94/432) were transfer-out to other health facilities and 65% (232/432) re-suppressed after enhanced adherence counselling; leaving us with 17 participants eligible for GRT (PVL≥1000copies/mL). GRT was successful for 70.5% (12/17) and DRMs detected in 83% (10/12), including major DRMs to protease inhibitors (17%), to nucleoside reverse transcriptase inhibitors (75%) and to non-nucleoside reverse transcriptase inhibitors (83%). CRF02_AG (75%) was the prevailing HIV-1 group M clade, followed by A3, D, and CRF18_cpx (each 8.3%). These real-life data reveal viral suppression rates closer to the epidemic control (95%) among DTG-based recipients, especially with older age and DTG-exposure over three years. Considering the broad HIV diversity observed, these findings are essential for modelling the long-term effectiveness of DTG in RLS and beyond. Register on 10/05/2023; Ethical Clearance Number 2023/022045/CEIRSH/ESS/BC.

The COVID-19 pandemic was a global public concern and constitutes a future threat to the world population due to its indirect effect on the burden of non-communicable diseases. The pandemic manifested disruptions in healthcare delivery and access. However, there is limited data in Sub-Saharan Africa on the impact of COVID-19 on cardiovascular disease (CVD) admissions and outcomes. This study aimed to compare the trends of CVD admissions and outcomes before and during the COVID-19 pandemic in the Southwest Region of Cameroon. We carried out a retrospective study of patients suffering from CVDs admitted from March 11, 2018, to March 11, 2020 (Pre-COVID-19 pandemic period) and from March 11, 2020, to March 11, 2022 (COVID-19 pandemic period). A p-value < 0.05 was considered statistically significant. There were 483 admissions due to CVD during the COVID-19 pandemic and 518 during the pre-COVID-19 period. There was no significant difference in mean age before (57.97 ± 15.6 years) and during the pandemic (59.74 ± 16.1 years) (p = 0.44). There was also no significant change in the proportion of males and females during and before the pandemic: males (21, 4%, and 24.8%), and females (26.8% and 27%), (p = 0.28). There was a downward secular trend with random variation in the number of CVD admissions during the pandemic compared with the corresponding pre-COVID period, which had an upward trend. Rates of admissions of Acute Myocardial Infarction decreased the most (22.2%) during the first wave of the pandemic. The in-hospital mortality increased by 2.4% with a relative risk for Mortality of 1.18 (95% CI [0.87-1.61], p = 0.28). There was no change in median length of hospital stay (p = 0.936). This study provides evidence of a decreasing tendency in admissions due to CVD during the COVID-19 Pandemic at the BRH. The effects varied among the different types of CVDs. The in-hospital mortality of CVDs did not change significantly.

Abstract Background: Immunization remains a highly effective and affordable disease-prevention measure, yet sociopolitical unrest in Cameroon’s North West Region hampers vaccine uptake. In Nkambe Health District, limited knowledge persists regarding coverage and challenges to immunization. The objective of this study was to determine the trends in immunization coverage among children aged 0–11 months between 2013 and 2019 and identify the challenges faced by caregivers and healthcare providers in the uptake of immunization in Nkambe Health District, North West Region, Cameroon. Methods: A survey was conducted among caregivers of 385 children aged 0–11 months in the Nkambe Health District to determine the immunization status of children, the coverage, challenges and associated factors using a structured questionnaire. Review of hospital records was done to determine the trend of vaccination coverage. In-depth interviews were conducted among healthcare providers to explore challenges of vaccination coverage. Data was analyzed using Statistical Package for Social Sciences (SPSS) version 23. Logistic regression analysis was used to identify the predictors of complete immunization and triangulated with thematic analysis results. Results: Among 385 guardians, 68.8% of children had completed vaccination. Coverage peaked at 82.0% in 2017 but fell to 40.0% in 2019. Complete vaccination was significantly associated with living &lt;5 km from a vaccination site (aOR = 3.2, 95% CI: 1.81–5.82, p = 0.001), knowledge of the vaccination schedule (cOR = 2.57, 95% CI: 1.43–4.60, p = 0.001), antenatal care attendance (aOR = 10.5, 95% CI: 3.59–31.05, p = 0.001), and postponed vaccination sessions (aOR = 2.97, 95% CI: 1.66–5.32, p = 0.001). Challenges included staff shortages, lack of cold chain, and socio-political unrest. Conclusion: Vaccination coverage in Nkambe Health District has sharply declined in recent years due to the ongoing crisis and other challenges; improving coverage will require stronger community engagement, sensitization, and expanded outreach services.

Background: Chemotherapy remains central to cancer management in sub-Saharan Africa but is frequently complicated by treatment resistance and cumulative hepato-renal toxicity. Longitudinal biomarker monitoring may improve early detection of subclinical organ dysfunction and therapeutic response. This study evaluated longitudinal changes in hepatic, renal, inflammatory, and tumor-associated biomarkers to elucidate chemotherapy response and resistance patterns among cancer patients receiving systemic therapy in Cameroon. Materials and Methods: A longitudinal observational study was conducted among 120 cancer patients treated at the Cameroon Oncology Centre (February-July 2025). Serum liver enzymes (aspartate aminotransferase (AST), alanine aminotransferase (ALT)), albumin, urea, creatinine-derived estimated glomerular filtration rate (eGFR), C-reactive protein (CRP) measurement was done once at the end of the chemotherapeutic period were measured at baseline and over three follow-up time points at two-month intervals, while cancer biomarkers, namely carcinoembryonic antigen (CEA), and cancer antigen 15-3 (CA15-3) were screened within two interval periods. Non-parametric analyses (Kruskal–Wallis, Friedman tests) assessed group differences and monotonic trends, while Spearman’s correlation evaluated treatment–biomarker associations. Results: Participants were predominantly female (77.5%), with advanced-stage disease (Stage III–IV: 59.2%). Liver enzymes remained largely stable throughout follow-up, indicating preserved hepatocellular integrity. In contrast, albumin exhibited a significant monotonic decline (−1.20%, &amp;lt;i&amp;gt;p&amp;lt;/i&amp;gt; = 0.004), reflecting cumulative metabolic and inflammatory stress. Renal function showed a modest but significant decline in eGFR (−3.77%, &amp;lt;i&amp;gt;p&amp;lt;/i&amp;gt; = 0.044), particularly among platinum-based regimens, despite stable urea levels. Tumour marker analysis revealed a pronounced and consistent reduction in CA15-3 (−12.98%, &amp;lt;i&amp;gt;p&amp;lt;/i&amp;gt; = 0.006), whereas CEA showed no significant longitudinal trend. Drug-specific correlations supported time-dependent renal and hepatic effects, particularly with cisplatin and combination therapies. Conclusion: Longitudinal biomarker profiling reveals subclinical renal stress, systemic metabolic burden, and differential tumour marker responsiveness during chemotherapy. CA15-3 and eGFR emerged as sensitive indicators of treatment response and toxicity, underscoring the value of integrated biomarker monitoring in resource-limited oncology settings.