School-wide publications
Permanent URI for this collectionhttps://dspace.njala.edu.sl/handle/20.500.144402/152
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Item Genetic diversity of coffee germplasm in Sierra Leone: implications for conservation and breeding programs(Maximum Academic Press, 2023) Lahai, Paul MusaGlobal coffee production is dominated by Coffea arabica (Arabica coffee) and C. canephora (Robusta coffee) due to their relatively high-yielding and quality attributes as opposed to other coffee species. Despite these advantages, production of Arabica and Robusta coffee is facing mounting challenges though not limited to increasing prevalence and severity of biotic and abiotic stresses. These challenges bring forth an indication that the global coffee crop portfolio requires diversification to ensure resilience to the key challenges for sustainable production.Sierra Leone is in the center of genetic diversity of genus Coffea, and the countryhosts rich coffee genetic resources. The C. stenophylla, C. affinis and possibly other wild relative species are indigenous to Sierra Leone and these species offer great potential for a new coffee market and income generation. However, moreefforts of conservation and genetic improvement on these species, are needed to realize these opportunities.The objective of this paper is to review the coffee genetic resources in Sierra Leone with an emphasis on the wild coffee species including their conservation status, and the phenotypic and molecular characterization. We also presented perspectives for future genetic improvement of C. stenophylla, and discussed breeding methods,combiningability, and molecular marker-assisted prediction of hybrid vigor. Moreover, with the availability of recently developed single nucleotide polymorphisms (SNP) markers on C. stenophylla, we suggest that new technologies of molecular breeding, such as genomic selection can significantly accelerate the breeding progress and deliver improved varieties with high yield, good adaptability, and disease resistance.Item Lockdown measures in response to COVID-19 in Sub-Saharan Africa: A rapid study of nine countries(openRxiv, 2020-07-11) Haider, NajmulLockdown measures have been introduced worldwide to contain the transmission of COVID-19. This paper defines the term lockdown and describes the design, timing and implementation of lockdown in nine countries in Sub Saharan Africa: Ghana, Nigeria, South Africa, Sierra Leone, Sudan, Tanzania, Uganda, Zambia and Zimbabwe. It also discusses the manner in which lockdown is enforced, the need to mitigate the harms of lockdown, and the association between lockdown and the reported number of COVID-19 cases and deaths. While there are some commonalities in the implementation of lockdown, a more notable finding is the variation in the design, timing and implementation of lockdown measures across the nine countries. We found that the number of reported cases is heavily dependent on the number of tests done, and that testing rates ranged from 9 to 21,261 per million population. The reported number of COVID-19 deaths per million population also varies, but is generally low when compared to countries in Europe and North America. While lockdown measures may have helped inhibit some community transmission, the pattern and nature of the epidemic remains unclear. Of concern are signs of lockdown harming health by affecting the functioning of the health system and causing social and economic harms. This paper highlights the need for inter-sectoral and trans-disciplinary research capable of providing a rigorous and holistic assessment of the harms and benefits of lockdown.Item Implications of Prevalence and Intensity of Soil-Transmitted Helminthes (STHs) on Rural Farmers’ Productivity in Selected Districts of Sierra Leone(Warsaw University of Life Sciences, 2023-03-31) Ngegba, Mohamed PaulSoil-transmitted Helminths (STH) are among the most prevalent parasitic diseases that impair childhood physical and mental growth, hence hindering economic development. The study was a cross-sectional-designed survey, conducted in three districts in Sierra Leone between December and March 2022 on 625 individual farmers to determine: 1) the prevalence of soil-transmitted helminths; 2) the intensity of soil-transmitted helminths; 3) the effect of the prevalence and intensity on farm productivity, and 4) the implication of these effects on agricultural extension service delivery and the rural livelihood of the selected districts. Stool samples were collected from male and female farmers in fifteen chiefdoms in the selected districts and analyzed using the Kato-Katz technique. A total of 625 individuals were included, among whom 172 (27.0%) were vegetable farmers, 224 (35.8%) were tree-crop farmers and 226 (36.2%) were rice farmers. The result indicates a prevalence of parasitic infection among farmers shown by 58.4% eggs/ova in stool from the three districts. STH prevalence is higher in Bo (64.0%), Koinadugu (56.9%), and Kailahun (51,7%). STH infections, in various ways, affected extension services, delivery and the livelihoods of individual farmers. The recommendation is that farmers and children be periodically dewormed for STH infection in rural areas.Item Rabies Virus in Sierra Leone: Challenges and Recommended Solutions for Elimination by 2030(IntechOpen, 2021-09-21) Suluku, RolandThe objective of this write-up is to find possible solution control canine rabies virus in Sierra Leone and other low-income countries in the world. Rabies is a viral disease affecting both humans and animals in Sierra Leone. The country has no policy on dog ownership and management, two veterinarians, limited access to rabies vaccines and human immunoglobin, and a lack of information about the disease in the country despite increasing dog bite cases and death. There is no wildlife specialist to initiate wildlife vaccination. Continuous vaccination increased awareness, trained personnel in veterinary and wildlife, development of policies on responsible dog ownership and by-laws and increase financial support from the government and private sector will help Sierra Leone eliminate rabies in the first half of the twenty-first century.Item Measuring coverage of maternal and child health services using routine health facility data: a Sierra Leone case study(BioMed Central, 2021-09-01) Maïga, AbdoulayeBACKGROUND: There are limited existing approaches to generate estimates from Routine Health Information Systems (RHIS) data, despite the growing interest to these data. We calculated and assessed the consistency of maternal and child health service coverage estimates from RHIS data, using census-based and health service-based denominators in Sierra Leone. METHODS: We used Sierra Leone 2016 RHIS data to calculate coverage of first antenatal care contact (ANC1), institutional delivery and diphtheria-pertussis-tetanus 3 (DPT3) immunization service provision. For each indicator, national and district level coverages were calculated using denominators derived from two census-based and three health service-based methods. We compared the coverage estimates from RHIS data to estimates from MICS 2017. We considered the agreement adequate when estimates from RHIS fell within the 95% confidence interval of the survey estimate. RESULTS: We found an overall poor consistency of the coverage estimates calculated from the census-based methods. ANC1 and institutional delivery coverage estimates from these methods were greater than 100% in about half of the fourteen districts, and only 3 of the 14 districts had estimates consistent with the survey data. Health service-based methods generated better estimates. For institutional delivery coverage, five districts met the agreement criteria using BCG service-based method. We found better agreement for DPT3 coverage estimates using DPT1 service-based method as national coverage was close to survey data, and estimates were consistent for 8 out of 14 districts. DPT3 estimates were consistent in almost half of the districts (6/14) using ANC1 service-based method. CONCLUSION: The study highlighted the challenge in determining an appropriate denominator for RHIS-based coverage estimates. Systematic and transparent data quality check and correction, as well as rigorous approaches to determining denominators are key considerations to generate accurate coverage statistics using RHIS data.Item COVID-19—Zoonosis or Emerging Infectious Disease?(Frontiers Media, 2020-11-26) Haider, NajmulThe World Health Organization defines a zoonosis as any infection naturally transmissible from vertebrate animals to humans. The pandemic of Coronavirus disease (COVID-19) caused by SARS-CoV-2 has been classified as a zoonotic disease, however, no animal reservoir has yet been found, so this classification is premature. We propose that COVID-19 should instead be classified an “ emerging infectious disease (EID) of probable animal origin .” To explore if COVID-19 infection fits our proposed re-categorization vs. the contemporary definitions of zoonoses, we reviewed current evidence of infection origin and transmission routes of SARS-CoV-2 virus and described this in the context of known zoonoses, EIDs and “spill-over” events. Although the initial one hundred COVID-19 patients were presumably exposed to the virus at a seafood Market in China, and despite the fact that 33 of 585 swab samples collected from surfaces and cages in the market tested positive for SARS-CoV-2, no virus was isolated directly from animals and no animal reservoir was detected. Elsewhere, SARS-CoV-2 has been detected in animals including domesticated cats, dogs, and ferrets, as well as captive-managed mink, lions, tigers, deer, and mice confirming zooanthroponosis. Other than circumstantial evidence of zoonotic cases in mink farms in the Netherlands, no cases of natural transmission from wild or domesticated animals have been confirmed. More than 40 million human COVID-19 infections reported appear to be exclusively through human-human transmission. SARS-CoV-2 virus and COVID-19 do not meet the WHO definition of zoonoses. We suggest SARS-CoV-2 should be re-classified as an EID of probable animal origin.Item Evaluating the cascade of care for hypertension in Sierra Leone(Wiley, 2021-08-04) Geraedts, Tessa J. M.OBJECTIVE: To assess the care for hypertension in Sierra Leone, by the use of a cascade-of-care approach, to identify where the need for healthcare system interventions is greatest. METHODS: Using data from a nationwide household survey on surgical conditions undertaken in 1956 participants ≥18 years from October 2019 to March 2020, a cascade of care for hypertension consisting of four categories - hypertensive population, those diagnosed, those treated and those controlled - was constructed. Hypertension was defined as having a blood pressure ≥140/90 mmHg, or self-reported use of antihypertensive medication. Logistic regression analysis was used to investigate factors associated with undiagnosed hypertension. RESULTS: The prevalence of hypertension was 22%. Among those with hypertension, 23% were diagnosed, 11% were treated and 5% had controlled blood pressure. The largest loss to care (77%) was between being hypertensive and receiving a diagnosis. Male sex, age and living in a rural location, were significantly associated with the odds of undiagnosed hypertension. There was no significant difference between men and women in the number of patients with controlled blood pressure. Adults aged 40 or older were observed to be better retained in care compared with those younger than 40 years of age. CONCLUSION: There is a significant loss to care in the care cascade for hypertension in Sierra Leone. Our results suggest that increasing awareness of cardiovascular risk and risk factor screening for early diagnosis might have a large impact on hypertension care.Item Insights into canine rabies vaccination Disparities in Sierra Leone: A cross-sectional household study(Public Library of Science, 2024-07-19) Mshelbwala, Philip PAnnually, Sierra Leone records an estimated 301 human fatalities due to rabies. Canine vaccination is crucial for rabies prevention and control efforts. However, considerable variability exists in vaccination rates. Reasons for this variation remain unclear. We conducted a cross-sectional study across 2,558 dog-owning households (HHs) to provide insights into factors influencing canine vaccination for targeted prevention and control towards elimination by 2030. First, we described dog ownership practices, then built a probabilistic model to understand factors associated with dog vaccination, and finally used a spatial scan statistic to identify spatial clusters where vaccination rates were low. Our results indicated that only 14% (358/2,558) of participating HHs had fully vaccinated their dogs against rabies. The probability of dog vaccination increased when comparing civil servants to private workers/artisans, with an Odds Ratio(OR) of 1.14 (95% credible interval (Crl) of 0.82-1.56), residing in locations with a veterinary establishment vs. none (OR = 6.43, 95% Crl (4.97-8.35), providing care to dogs vs. allowing dogs to roam freely (OR = 2.38, 95% Crl(1.80-3.17) and owning a single dog vs multiple dogs (OR = 1.20, 95 Crl (0.92-1.56). Conversely, there was a decrease in the estimated probability of vaccination when comparing dog owners located in rural vs. urban areas (OR = 0.58, CrI 95% (0.43-0.78). Latent understanding, a measure of overall understanding of rabies virus, which we estimated using participant education levels and responses to questions about rabies epidemiology, was also an important predictor of vaccination probability (OR = 1.44, 95% Crl (1.04-2.07). The spatial analysis identified high-risk clusters for low vaccination in the cities of Moyamba, with a radius of 40 km, a relative risk (RR) of 1.10, and Bo, with a radius of 19.9 km with RR of 1.11. These data do not support Sierra Leone reaching the 2030 goal of human rabies elimination caused by dogs. Our study highlights a critical need for public outreach and education, improved vaccination rates, increased accessibility to veterinary services, and targeted interventions in Bo and Moyamba to support rabies prevention and control efforts.Item Integrated Strategies Addressing Predisposing, Enabling, and Illness-Level Factors Influencing Healthcare-Seeking Behavior among Pregnant Women and Newborn Mothers: Insights from Sierra Leone(Springer Science and Business Media LLC, 2025-08-27) Viah, RennieBackground Maternal and newborn health outcomes in Sierra Leone remain among the poorest globally, driven by a complex interplay of socio-demographic, systemic, and behavioral factors. Understanding how integrated strategies influence healthcare-seeking behavior is critical for tailoring interventions that reduce delays and improve maternal outcomes. This study aimed to identify high-impact strategies addressing predisposing, enabling, and illness-level factors that affect maternal and newborn healthcare-seeking behavior in Bo District, Sierra Leone. Methods A descriptive cross-sectional study was conducted at Bo Government Hospital (urban) and Tikonko Maternity Home (rural) between January – May 2024. Using simple random sampling, 500 participants (294 pregnant women and 206 mothers of children under five) were selected from facility attendance lists. Quantitative data was collected through structured interviews using a digital questionnaire administered via the ONA platform. Descriptive analysis was performed using SPSS version 26 to identify patterns in healthcare-seeking preferences and perceived effectiveness of integrated health strategies. Results The mean age of pregnant participants was 24.83 years (SD = 4.74), and the average household income showed substantial disparity (Mean = 335.03 NLE; SD = 668.49). Regarding predisposing factors, the preferred strategies included prenatal education (25.91%) and community outreach for early antenatal care (24.12%). Enabling factors were most influenced by transportation support (24.6%) and access to affordable care (24.21%). Illness-level strategies prioritized by participants included strengthening maternal health surveillance systems (27.55%) and prenatal screening services (23.08%). Education level, income, and parity were key determinants of healthcare-seeking behavior. Conclusion Integrated strategies that combine health education, community outreach, logistical and financial support, and health system strengthening are the most effective in influencing maternal and newborn healthcare-seeking behavior. Culturally tailored, equitable, and evidence-informed approaches help improve maternal health service utilization in low-resource settings like Sierra Leone.Item Computer assisted verbal autopsy: comparing large language models to physicians for assigning causes to 6939 deaths in Sierra Leone from 2019–2022(BioMed Central, 2025-12-24) Wen, RichardBACKGROUND: Verbal autopsies (VAs) collect information on deaths in low and middle-income countries occurring outside healthcare facilities to estimate causes of death (CODs) for use in epidemiological or planning studies. Physician coding of VAs focused on the narrative of deaths and past symptoms is current best practice. Large language models (LLM) such as GPT-5 enable possible use of the narrative portion of VAs to assign CODs. However, there are few if any robust comparisons of LLMs to physician coding. METHODS: We analyzed 6,939 VA records from a random sample of deaths in Sierra Leone (2019-2022) to compare five models: three LLMs (GPT-3.5, GPT-4, GPT-5) and two based on symptom algorithms (InterVA-5, InSilicoVA), against physician-assigned CODs. GPT models used narratives, whereas InterVA-5 and InSilicoVA relied on questionnaires. CODs were grouped into 19, 10, and 7 categories for adult, child, and neonatal deaths. We used cause specific mortality fraction (CSMF) accuracy and partial chance corrected concordance (PCCC) to assess population and individual-level agreement respectively, compared to the standard of physician coding. We stratified analyses by age group as CODs vary among neonates, children and adults. RESULTS: Overall, GPT-5 outperformed all models (PCCC = 0.71), followed by GPT-4 (0.61), GPT-3.5 (0.56), InSilicoVA (0.44), and InterVA-5 (0.44). GPT-5 achieved the highest performance for adult (0.68), child (0.71), and neonatal (0.65) deaths. Across ages, performance increased from 1 month to 14 years and declined from 15 to 69 years. GPT-5, GPT-4, GPT-3.5, and InSilicoVA achieved the highest PCCC in 14, 7, 7, and 2 of the 30 CODs, respectively. At the population level, GPT-5 achieved the highest CSMF accuracy (0.9), while all other models had comparable performance (0.74-0.79). CONCLUSIONS: GPT models and InSilicoVA showed greater performance for specific CODs at the individual-level. GPT models demonstrated improvements over InterVA-5 and InSilicoVA models. This study provides foundational evidence for integrating LLM and algorithmic models with physician coding to improve the quality of VA data.